text:
Can I use my phone's sensor to record movements for DSLR stabilization in post?
So I heard about this SteadXP which attaches to your camera to record movements for stabilization in post production.
Is there any app for Android that can do the same thing?

Would love something like this, anyone know of such an app?

Microsoft Hyperlapse app for Android might be a good example of it but it only processes its own video.


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Panasonic G7 - Low cost zoom lens for video
I'm about to buy the Panasonic Lumix G7 (body) and I would really like some advice about the best lens I can get for it at less than 400$ if possible. I want it for shooting video, and the lens should be a zoom lens.
Thanks.

Welcome Joca Pinto :) For which area of application? Please add a bit more context in order to get a solid answer. Thanks.

@poor Already edited!

A common zoom range of Panasonic MFT lenses is 14-42(45)mm. As an owner of such a lens I found out it's quite a compromise for city videos. 14mm is wide, but often times not wide enough for buildings. 42mm is tele, but not enough for detail shots.
Here are some with a more practical zoom range:

Panasonic Lumix G Vario HD 14-140mm f/4.0-5.8 ASPH./MEGA O.I.S.
Panasonic Lumix G Vario 14-140mm f/3.5-5.6 ASPH. POWER O.I.S.
Panasonic LUMIX G VARIO 35-100mm f/4.0-5.6 ASPH. MEGA O.I.S.

I don't want to get more specific into prices, because they may change fast or be different in other countries.

source: Stack Exchange

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/3.0/

sort: votes


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How to compress videos for a website?
I want to start a website in which there are some videos. When I searched Google regarding this video website I came to know that for the proper working of the videos we should compress the videos. When I searched further I came to know about bitrate, codec etc etc which I didn't understand.
How to compress the videos for website? How YouTube compresses videos? What are the technologies do we need to know to compress a video? What kind of people do I need to hire to compress videos?

You need to provide more information. Are you hosting the site yourself? What browsers, devices, and players are you required to support? Why not just upload to a video service like YouTube and embed that?

I recommend not to host the video files on your web server, but to upload them to YouTube and only embed the YouTube link on your web page. You can even define that your videos won't show up on searches, but are only served when using the link (from your website).
The reason is that these videos add significant load to your web server and bandwidth. And if something goes wrong (like providing the wrong codec), then your users won't see any video at all.
But if you really want to do it, you can even take YouTube as measurement. Upload an HD video and then download the various videos that YouTube has generated from that source.
I use this tool, but there may be others for different browsers:

Downloader as Firefox plugin

You will see that YouTube offers a combination of different resolutions and different codecs. There is quite a complex logic behind which files to serve to which browsers. For ex. a small resolution will be served to mobile phones, but a bigger one to desktops depending on their screen resolution. Older browsers may need one codec, whereas modern ones accept others. YouTube does all that logic for you. But if you want to host the videos by yourself, you have to implement that logic as well.
You need then a tool like ffmpeg to convert your videos to these different formats and resolutions. Or, if you are lazy, just use the videos that you downloaded from YouTube, since they have the formats that you want.
Finally, you have to embed these videos on your web page. Here's the HTML video tag that you have to use. It's the new HTML5 standard, so older browsers don't support it.
As you have seen, these steps may mean a lot of work. That's why uploading to YouTube and embedding that link to your web page is the better choice.
Sorry that I didn't cover these steps in detail. This is just an overview.

all_licenses: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/3.0/


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Optimisation for cropping
I use final cut pro and I have to do a large amount of cropping and ken burns transition.
The picture cropped is always a corner forth of the video. So far to do it I use the shortcut Shift+C and then I have to manually select if I want to use crop or ken burns and use mouse to select the size for the new frame. I helps for cropping when you resize it to a forth it magnetizes to exact forth, when you do the same with ken burns it does not and this makes video to appear 'jumpy' if not done with enough precision.
Is there anything I can do to automate this process, perhaps a way to set shortcuts to change the selection size to preset size or similar?
Thank you


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scaling a stroke mask in after effects?
I have an imported illustrator image that I'm trying to create a stroke mask over so I can animate it's reveal (like someone writing it). Unfortunately, when I try to use the pen tool on the layer it keeps changing the cursor to the "add point" which then makes the next click a brand new path. It's basically impossible to make any kind of path this way.
So, I made an adjustment layer and drew the mask on top of that. But when I copy and paste the mask onto the illustrator layer it's scaled waaaay up. I can't find a way to scale the mask down. When I click on the mask it doesn't give me the box around it, only the actual stroke points (which just move that one point).
Is there not a way to scale a path?

To scale a mask as if you were using the group select tool in Illustrator either alt-click the mask, or hit cmd/ctrlT.  It's truly perplexing how all the Adobe apps have different tools and shortcuts for the same tasks.

If you want to just create an animated writing effect, I use this script:
http://aescripts.com/quickdraw/
It works better for complex shapes than the built in write-on effect in AE.
Alternatively, this script allows you to scale paths:
http://aescripts.com/shapes-and-masks/
Have a look at the video from about 4m30s in:
https://youtu.be/3SSsgdeMSmw?t=4m31s
But I think what you need is the first one from the sounds of it...


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Video editing software like iMovie, for Windows?
Although skeptical at first, I took a liking to iMovie and began to rely on it heavily to edit many music videos. What I liked about iMovie was it's easy to use feel when it came to placing a clip exactly where you need it to be within the audio of a song. I have a Windows computer now, and cannot use the new iMovie anymore. Looking for something as similar as possible.
I'm looking for software that could work similarly on Windows, and the key main I really only need are:

Image stabilization
Color Correction
Speed/Duration settings
Easy to use adjustment of placement of a clip

Any suggestions? Thank you so much!

I've not used it, but Microsoft makes Microsoft Movie Maker. It might meet your needs.
There are also some open source video editors you might have luck with:
ShotCut - http://www.shotcut.org - kind of new, might be buggy
Blender - http://www.blender.org - it's a 3D modelling app with video editing capabilities
Lightworks - http://www.lwks.com - there's a "buy" button, but there's also a free version, as I understand it.
If you don't mind using Linux, you can also try out OpenShot and Kdenlive.

Also: Wax http://www.debugmode.com/wax/ and Lightworks - a professional app with a free version http://www.lwks.com/

Lightworks and shortcut are your best bet.

For future readers: Movie Maker is discontinued and its replacement is exclusively available on Windows 10. Blender worked well for me, though the user interface has a steep learning curve. I have not tried the other options and have a bias toward open source software. A good 30 minute tutorial for combining, cutting and fading clips is here.

As someone else mentioned, Windows Movie Maker is a free option that would fit most of your needs. However, if you don't mind paying a little bit for your software, I'd recommend Adobe Premiere Elements. It's a super-simplified version of Adobe Premiere Pro that should be able to do everything you're asking for.

Movie maker does not have stabilization or colour grading. So it isn't really an option.

In addition to the other answers, I use Hitfilm 3 Express, which is free here.
It's actually very easy to use and isn't export limited like the free version of Lightworks.  Plus if you decide at some point you want the more advanced features of the Pro version you can buy them piecemeal in packs for like $10-$25 rather than shelling out $300 for the full upgrade.
I'd been holding out for the windows version of openshot for a few years but managed to get Hitfilm 3 Express for free during a promo and it was decent.  3 is pretty great software though, I might not even switch to openshot when it comes out...and I put money into their kickstarter so I could get it.

Unfortunately, there are only two version of iMovie: one for Mac OS X (iMac/Macbook) and one for iOS (iPhone/iPad). If you are a Windows user, you'd better to download an alternative to iMovie for Windows to replace iMovie.
There are numerous of tools that claim to completely do what iMovie does. For more information, visit here: iMovie for Windows.
Or
Windows Movie Maker is another tool to edit video in Windows. visit here .
If you are not satisfied with the both above, you can also try VirtualDub, Pinnacle Studio, Shotcut, etc.
Hope it will help you more or less.

all_licenses: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/


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Video file size for web use
What is the best video size for let's say a 5 minute video. I want to host my own videos. So, I want to understand more.
What is an acceptable size?

Why not have a look at youtube's specs for a ballpark? Then test it on your server on a variety of devices and locations. http://bit.ly/1NNxDhX

@stib Why not converting this into an answer?

possible duplicate of How to compress videos for a website?

First off, why host your own videos? YouTube, Vimeo and many others have awesome embed tools, and unless you have a couple of GB to waste on your host, they're very practical.
But to your question, 1080x720 is perfectly fine, and creates a reasonable file size. 1920x1080 is pushing it a little, and 4K is just overkill.
I'm a web developer too, and when I have to host videos for a live background, featured video, etc, 1080x720 is my go to resolution, and I host things of larger size on YouTube since they'll take something like a 4K video, and give viewers the option of a resolution as low as 360p.

I would analyze how YouTube encodes videos, as described in this answer. It also helps you to understand the logic behind it.

Someone removed our close votes, but I don't understand why downvoted your answer then... Anyway,  removed my comment and upvoted the answer! :)


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FFMpeg crop filter doesn't change orientation
I am trying to crop a portrait video of 1280x720 to 568x320 so that the video will be displayed in landscape view (16:9). I am using the following command
ffmpeg -i VID_1438833296.mp4 -vf crop=568:320:0:0 -c:a copy out.mp4

The video gets cropped properly but when I view it in quick time or Android device it still displays in the portrait mode instead of landscape mode.
The quicktime inspector shows Format size as 568x320 (Landscape) but current size is 350x621 (Portrait):

Please include the complete console output from your command and properly format the command and console output.

What's happening here is two things:
1)your video is portrait but stored as a landscape matrix and ffmpeg is applying autorotate so that all players natively display it in what ffmpeg thinks is the correct orientation.
2) the video has a PAL DV aspect ratio of ~1.09, so after the autorotation and aspect ratio correction, 568 x 320 is autorotated to 320 x 568 with 1.09 scaler being applied to both W and H.
Try this, instead:
ffmpeg -i VID_1438833296.mp4 -noautorotate -vf setsar=1,crop=568:320:0:0 -metadata:s:v:0 rotate=0 -c:a copy out.mp4


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ffmpeg - resize and crop
I want to know how to use the scale filter to take an image that is 2154x1136 and scale it down exactly 89.04% such that the image sits in a 1920x1080 frame, with full image left and right and black letterboxing top and bottom.  Using
vf scale=1920:-1

gets me close.   But the resulting file is 1920x1013 and I need to add black pixels top and bottom to fill it out to 1920x1080.
I have other issues including how to feed ffmpeg a dpx sequence and get back an Avid-ready MXF while applying a shot specific cdl file and a show specific display lut, but I need to walk before I can run so a bit of help with this first puzzle is what I'm asking for now.
Thank you in advance.

Use this:
-vf "scale=iw*min(1920/iw\,1080/ih):ih*min(1920/iw\,1080/ih), pad=1920:1080:(1920-iw*min(1920/iw\,1080/ih))/2:(1080-ih*min(1920/iw\,1080/ih))/2"

This code evaluates which ratio to apply for scaling, then scales it and finally applys the requisite amount of padding.


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Trim the part of composition in After Effects along with its key frames
I want to trim a composition b/w the two Composition marker (1) and Composition marker (2):

You see there are many layers with different key frames and I want to trim everything which lies in the selection area. So the rest of the part of the composition (left and right of the two Composition marker (1) and Composition marker (2)) combines and becomes a complete composition.

wait, so you want to make everything after 2 a seperate composition, and before 1 also a seperate composition? why don't you just precomp it, drag it to a new composition and trim it, this way you can retain everything in this comp, but edit the length in the comp with the precomp?

Thanks Alex ! Yeah I can do that. But in that case I need to work on two compositions and things will become messy after that. I was thinking if there is way just to achieve this in this composition itself.

For a better workflow, see this answers: http://video.stackexchange.com/questions/15290/how-to-view-my-project-elements-while-working-in-a-composition/

If you right-click on the work area bar there's something called extract work area and lift(?) work area. They delete everything outside of or inside of the work area, which is kinda what you want to do (you'll have to copy and paste a bit). I don't know if it will simplify your project.

As Alex suggested, precomping is the answer to your question. There is no other way to have two separate compositions within one composition. Precomping is a normal part of the After Effects workflow, and is in fact necessary for many effects to work properly with nested elements.
It need not be messy – just organize your project well and label everything clearly. Learning to navigate between your comps with the Tab key will help you to use this workflow efficiently.

related: http://video.stackexchange.com/a/15291/6685


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Video blurry after dragging it to composition
I am having an issue with a video that I am adding effects to. The video is clear when I import it, but when I drag it on to a composition, it gets blurry.

was the answer sufficient enough for you

Your resolution is on a third
But most importantly, your video is 720 x 480 resolution but on a 1920 x 1080 timeline (so it seems), so you are scaling it to fit (you can't make up for a lack of resolution but upscaling your footage).

To get the right comp size, you can:

Drag your video file onto the little film icon to the immediate left of the 8 bpc selector below your footage tree
Or create a new composition based on the dimensions of your footage

There is no real point in making 480 footage 1080, it will not increase the quality.

good improvements ;)


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Masking messes up in after effects after rendering
I've been masking all day today and everything has worked perfectly up until now. I did my usual mask and then rendered it but upon render everything screwed up. I have tried it multiple times and I've even gone as far as to re-import the clip and mask it all over again. The results were different but only in the pattern of the glitch.
Im busy uploading the clips of the glitch right now so I'll just have to explain it for now. Basically everything looks perfectly fine in the ram preview window but when I render it, it separates the video around and the mask is completely messed up. Can someone please help me with this? It's incredibly frustrating when everything else today has gone smoothly. I'm using After Effects CC
Ram Preview Window:

After Render:

Welcome Ethan :) Hard to say. I'd suggest to check your matte only (create a black solid, copy your masks into the layer, create a white background, render it, import it with the correct frame rate settings).

Thanks but I fixed it by simply freezing everything :)

Great! Can you please elaborate and convert this into an answer?

Having the same issue??
What do you mean you froze everything?? My subject is walking so cannot freeze it?

Once the Rotobrush tool has been selected to use (assuming you used Rotobrush based on the pink outline) a small box in the bottom right of the comp will appear and should say "Freeze." Literally just press that and it'll freeze the mask... fixed my masking render glitch and I hope it does for you too! Best of luck, happy editing.

By "freeze" it's important to note that it really means pre-calculate, not "freeze"-as in stop moving. As you work on rotoBrush, masks are calculated on the fly. When you go to render you need to have the masks pre-calculated or the render engine won't do the mask calculations properly. That's what the freeze button does.


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How to create tutorial videos?
I'd like to know how to create a video tutorial like:

Is there any 'easy to use software' to achieve such effects? I've tried AVS4YOU and other beginner animation software packages, but I don't get it.
I really appreciate any help.

possible duplicate of Simple video animation for teaching purpose

This is not a duplicate question because I'm looking for an easy to use software (for beginners or layman) the link which you referred is a good software but profession

Welcome Sam :) What if there is no easy to use software for what do you want to achieve? The referenced answer could help you anyway, because it contains the following link: https://en.wikipedia.org/wiki/List_of_2D_animation_software Please try to be specific as you can, so no misunderstandings can arise. Anyway, enjoy video.se!

Personally, I don't think those videos look very good. I certainly wouldn't take their message seriously given their poor quality.
But that point aside, many people use either Apple Motion or Adobe After Effects to create motion graphics. Motion offers "behaviors" that make moving objects around a little easier if you aren't familiar with keyframing.

Thanks, I'm checking almost  all the software's and will update here and you as well  very soon with the current update.


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How to loop an animated mask?
I'm trying to make a loop from an animated mask, but each time I introduce my loop expression: loopOut (type="cycle", numKeyframes = 0), After Effects is telling me that:

"Expression is deactivated, because of line 1 and that the layer doesn't allow loop"

I have tried to use the pre-expressions from the application, but it still doesn't work:

What I'm doing wrong or what else can I do to loop the mask?

This expression is not supported for Mask Path Property, because it's a User Defined Property, see the note of the error message.
Workaround

Mask Path animation once

Precompose your layer an with the animated mask (one time) by Selecting the Layer > Right Click > Precompose (and move all attributes in the new composition)
Enable Time Remapping on your new created composition (Right Click on the composition > Time > Time Remapping), this extends the length of the layer to infinity
Add loopOut(type="cycle") expression to the Time Remapping Property by holding Alt and clicking the stop watch left beside the properties name

Time Remapping enabled on the new composition and expresssion applied
Example

Example using 3 keyframes (third is same as first) and using loopOut() only

Another option if you don't want to create a pre-comp:
Make your mask and set the keyframes and apply this expression to the mask path property:
valueAtTime(time % key(numKeys).time)

This is basically an implementation of the loopOut function, but it works for all properties, including custom ones like mask shapes.

How it works: valueAtTime returns the value of the property at a given time, so to loop the property we need a value that goes from 0 and rises until the playhead gets to the last keyframe and then the value loops back to 0.
The expression key(numKeys).time returns the time of the last key (e.g. if there are 3 keys it will be key(3).time). The % operator is the modulus operator, which gives you the remainder when you divide the first term by the second. So if you find the remainder when dividing the current time (time) by the time of the last keyframe it will return a value that starts at 0 and rises in synch with time until the playhead reaches the last keyframe at which point the current time will divide exactly into the time of the last keyframe, so the remainder will go back to 0 then start rising in synch with the playhead, rinse, repeat.
A useful feature of this expression is that you can speed it up and down by multiplying time by another factor, e.g. time * 2 % key(numKeys).time would play back the animation in double speed.

if (numKeys >1 && time > key(numKeys).time){
  t1 = key(1).time;
  t2 = key(numKeys).time;
  span = t2 - t1;
  delta = time - t2;
  t = delta%span;
  valueAtTime(t1 + t)
}else
  value

courtesy of the Master Expressionist Dan Ebberts in this thread:
https://forums.creativecow.net/thread/227/20661#22869


text:
editing 4k and 3840 × 2160 video with a Mac pro1,1
I just got a Panasonic Gh4 camera and recorded some 4k footage with it.
For editing I have a Mac pro1,1 (2007):

Dual-Core Intel Xeon - 2,66 GHz
NVIDIA GeForce 7300 GT - VRAM:32768 MB
15 GB memory

I can´t even see the footage move correctly in order to see what I´ve got and start editing.
I don´t know much about hardware and before I start spending money trying to upgrade my old computer I´d like to know if it is going to work. If I could see it in real time I could then create proxis and work with them. apparently only 512 mbts Cards are compatible with my computer, these are the ones I know about:

Ati radeon HD 4870 512 mbts
Gforce-gt 120 512 mbts
Gforce 8800 gt 512 mbts
and Ati radeon 5770 1 GB (but I´m not sure if this one will work)

My question is: will buying one of these and some more Ram make a difference?
I would truly apreciate some advice on this since I´m completely lost and my budget is very tight...
Thank you very much.

What software are you trying to use? I know, for example, that the latest FCP will not run on the GeForce 8800, though I think you're OK with the 5770. Not sure about the 4870, though. If you're using Premiere or something else, then I'm not sure.

Also, it's no clear that a MacPro 1,1 can run a recent OS, which would preclude you from running a recent version of something like FCPX.


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Remove Greenscreen Reflections?
My work has a green screen that my boss purchased with no knowledge of green screens or how to use or what to do with them.
in Sept. 2014 he gave me the task to create employee introduction / interview videos to explain how some of our procedures work, and I used my knowledge of greenscreens and chroma-keying to do my best. I managed to create a couple of workable videos, where all of the green was easily edited out and the desired effect was achieved without much hassle.
Recently my boss has asked me to create some product spotlight videos utilizing the green screen to place the item on a background of his choice. And here's where the trouble started.

The Setup consists of:

2-flood lights
The screen and a stand for it

I have been using the lights to illuminate the screen and using the ambient light from the warehouse to light the object.
I have the object sitting on a black leather stool while it rotates (desired effect as requested by my boss) sitting about 2-3 feet away from the screen (this is the furthest away I can pull the object away before the screen edges are visible)
The problems arise in editing, when I try to key out the green and add our background in. The black leather and the top of the product reflects so much that the keying eliminates it completely as the color technically matches that of the shadows in the screen its self, and BAM! The item is half transparent.
Modifying the key's parameters do nothing to help and my boss does not want to invest anything except my time and efforts into this.
After researching across the web, I have come to these conclusions:

Lighting is key, but we can not get more/better/more practical
Distance helps, but I can not move it much further because of screen size is too small to go further away and setting up in a warehouse
Reflective surfaces will be a pain anyways so make sure lighting is perfect and i can't get more lights.

I have tried every idea I can think of to reduce reflection in photographs, but because it is not a static shot, there is much I am missing...
What else can I try?

You don't say what you're using to edit these videos, but there may be a better chromakey plugin for your platform than what comes natively.
Also, again depending on your platform, most editors will allow you to crop the key area (garbage matte) so that the green screen doesn't have to cover the entire raster, just enough to back the product you're shooting, so you could put the screen as far away as you like.

Even a typical lamp with a "daylight"-colored bulb in it can act as a lighting source for your product. I'm sure your boss could spring for one light bulb!
If you shoot again with the new lighting, or even without the new lighting, play around with the angle of your product / camera / stool to minimize the reflections.

I have a couple of suggestions that could be of help:
1) Use a polarizer to reduce reflections. You say your boss won't spring for anything else, but you can pick one up fairly cheaply (like under $20 on amazon). If that's really not an option, you can try using some polarized sunglasses in front of the lens, at least to see if it eliminates the reflections. If so, maybe you can convince him it's worth $20.
2) Use a garbage matte or some sort of mask to remove the chroma keyer effect from the area of the leather that's reflecting. You'll end up with green-tinted leather, but it won't be transparent.
3) Find something black and matte to put on top of the leather so it doesn't reflect in the first place. (It's not clear to me whether the object is reflecting or just the stand it's on - sorry if I'm misunderstanding.)

If you use the garbage matte, and wind up with green-tinted leather, that will look less conspicuous against green backgrounds. (Think gardens, forests, meadows and similar settings.)

"Something black and matte to put on top of the leather...."  A nice black tablecloth would probably look artistic (and not like you're just trying to cover a stool).


text:
Does My Business Model Break Youtube API TOS?
I understand from reading youtube api tos that selling youtube content is prohibited.
But here's how my business works:

I sell a physical product, let's say CDs.
On the cover of the CD is a QR code and a serial number, when you scan the QR code you will download my app.
Inside the app there are a few unlisted youtube videos, but they are locked.
In order to unlock it, you need to put the unique serial number that is on the back of the CD.

Why I make this model is to make sure that the people who watch my video have bought my CD. Now does this model break the youtube api tos or not?
https://developers.google.com/youtube/terms
Thanks

Did you have a particular part of the agreement that worried you?  I didn't see anything in my brief scan of it and it seems to be consistent with the plain english (aka, probably not legally defensible) portion at the start that explained what they were trying to accomplish.

It probably wouldn't hurt to double check with them, but it doesn't seem like it would be an issue.  It sounds like their main concern is they don't want people selling other people's content.  Since you are the rights holder of the videos you are linking to, there should probably be no problem there.
From a practical perspective, Youtube still gets their advertising revenue either way and nobody is having their rights violated, so I'm not sure what they would have against it.

It is probably okay, see section 2 (bolding is mine):

The following commercial uses are permitted provided that You comply with all other terms and conditions of this Agreement:

the sale of an API Client

To get a definitive answer you should consult a professional legal counsel, so that the counseling that you get is backed by professional liability.


text:
Does 4K impact quality when filming in low light? (other parameters being equal)
I'm wondering if filming with a 4K camera, possibly downsizing to Full HD, will give better detail than filming with a Full HD camera (other parameters being equals).
Sub-question (maybe I should make it a different question?):

I have some more experience and better equipement for photography (Canon 6D),
I want my video camera to behave well in low light in moving environments,
I'm often filming moving things/people, I don't want much bokeh/focus loss (I never really remember if that means more or less depth or field).

I currently own a Sony Cybershot RX-100 M2. Very unimpressive body size, but makes excellent 1920x1080x50p videos. I am thinking about an upgrade anyway, max budget for an outstanding camera would be 2000 EUR, but I am not sure if I want to put money in it right now since 4K market is still evolving fast, and so far I cannot really decide because other devices I got info about seem to be very similar or trade-off one advantage for another.
For example compared to Sony RX-100, Sony FDR-AX33 has a smaller sensor. Sony FDR-AX100 only opens at f/2.8 and I use for a wider aperture, so has far as I know RX-100 would have a better low light score than both those cameras. GH4 has more bokeh and seems kind of grainy in low light, ... and yet no camcorder in my budget has more than 30p with 4K.
Suggetions would be welcome, because I cannot really tell what would be a serious upgrade or just wasted money.

There are three key factors in your cameras low light performace:
1. Lens (Aperture)
The lower your f-stop, the more light gets through to the sensor, you will also have a very shallow (narrow) Depth of Field. Often this is a requirement at night, since cutting off most of your light is generally a bad idea. When looking at any camera, see what lenses are available to suit your needs.
2. "Pixel" Size
Each little diode on your sensor collects light, the size of each diode directly effects low-light performance. There are two significant factors in the size of diode: sensor size and resolution. If you have 1920 pixels across your sensor and your sensor is an inch wide each diode will be about 1/1920 of an inch across if you sensor is 3840 pixels across your diode will be about 1/3840 of an inch across, much much smaller, and therefor able to collect less light.
3. Sensitivity
The sensitivity of a sensor can be controlled with ISO. The max ISO is very important for low light capture. Some excellent cameras in other regards have very low max ISO's, and are therefor unable to shoot in low light. Some cameras have very high max ISO's, and are designed for low light. Such cameras are the Canon C-Hundreds series, and the spectacular Sony A7s. The A7s has a relatively low resolution sensor and very high resolution.
The simple answer is yes, 4K will negatively effect low light performance, but most cameras already have a 4k-sized sensor that they simply fail to utilize (the canon 6D suffers equally from small diode size as the A7s for example). In your case, no 4K will have no effect, but if you're going to get a 4K camera for low light, buy the A7s and an external recorder. Out of it you will get 4K raw. For about $3k. It will put your 6D's performance to shame. Some people have lit A7s shots with moonlight/an iphone. Gulp.. did you see that last one, it out did the C300..... :O!
PS:
I first mentioned lenses for a reason. The sony A7s takes Sony E mount lenses. In my opinion they are some of the worst selection of lenses on the market. (Some are good glass, but there are no versatile zooms). Be wary of the lenses, they are half the key to getting your night shot. Also you HD will look amazing with a good lens, they've shot Hollywood features in HD (like Scorsese's Hugo), utilizing the power of $30k lenses.

What gets me a little bit confused is that I'm perfectly satisfied with 6D for still. What I'm looking to upgrade is Sony RX100 for some precise usage that's usually in low light and where I cannot risk losing focus any time.

I remember discarding A7S from my choices after watching some YouTube reviews because ... I don't remember if it was too noisy in low light, or had too much bokeh for my use .. or something like that... Also because it's at very limit of my budget.

But if I understand you well, AX33/100 might possibly be a adecrease in low light quality compare to RX100 ?

@TTT You'll have to do a test to the difference between two cameras like that.

That's what I was afraid of, and probably why I could not really decide yet. (And I read rumors about a Sony RX-100 M4 with 4K and a larger sensor ... so maybe I better wait.)

@TTT THe AX33/100 isn't a good camera, if you're looking at something like that, I'd look into a Panasonic GH4

I have seen results of GH4, and for my use and image style I want RX100 is closer to what I want than GH4. Yet AX33/100 are closer to that, my real worry is if they would result in some "low light downgrade".

@TTT I guess to check that you'll need to shoot with both cameras. Maybe you could buy it from a place that offers return, do the tests, and then make your decision.

@GiantCowFilms the sony a7s doesn't take MFT lenses, it takes full frame Sony E-Mount lenses, and has a crop feature for APS-C style lenses. Correct me if I am mistaken, but you should edit your post.

@Alex I was wondering how they managed to get MFT lenses to work on a full frame. Yes, you are correct, and I'll edit my post.

Yes, if you record a video in 4K, then downsize to 1080p, the image will look much clearer than if you shot the video on a 1080p camera. You can also zoom in up to 200% and still retain the quality in a 1080p time line.
Why it may look better is because most sensors these days use chroma subsampling. On most consumer 1080p video camera products, the camera records in 4:2:0. Meaning that each pixel actually shares it's color value with 3 similar surrounding pixels, but every pixel does get its own luminosity value (Y'). This looses 50% of the  information captured by 4:4:4, in which each pixel gets its own color value and luminosity value, but the size of the clips produced are 50% more. This is more expensive, and data-hogging.
But now in 4k video, every 1080p pixel now gets 4 individual pixels (it's still being recorded in 4:2:0 though), in which color values are still being shared however, when you downscale to 1080p, every pixel now gets its own individual color and luminosity value! This is called 4:4:4, which not to long ago, costed upwards of $10,000.
This video can explain this visually: Youtube: Why Does 4K Look Better on 1080p Monitors
As to your sub-question about low-light performance, I am not sure if an identical spec camera (besides pixel count, of course) would give you better low-light performance or not, because that usually depends on the sensor size, aperture of the lens (assuming we're talking about DSLRs), and max ISO. If you just want a good low-light camera, check out the Sony A7S, as GiantCowFilms pointed out in his answer.

Interesting point, but this didn't cover the impact on low light performance...

Thanks, I have edited my answer to include some information about his sub-question.

Much better :D.

Short answer: no, 4K down-scaled to 1080p is not necessarily going to give you a better result than filming with a FullHD camera.
The SONY A7S is the hands-down best low-light video camera for less than $34,000.  (The Panasonic Varicam S35 and the Alexa can shoot better images, albeit at much higher costs).  Here's a surf video shot entirely by moonlight, which is just nuts: https://vimeo.com/108613669
But beware: often people say they want lowlight capabilities because they really just don't want to be bothered with lighting.  Most times, that means boring, flat-looking video.  Good lighting is what gives images depth and makes scenes pop.  If you blow off lighting, you cannot blame the camera for mediocre results.  Even dark scenes in movies are often very well lit: https://www.royalholloway.ac.uk/mediaarts/documents/pdf/lightingfordarkness.pdf
Not all FullHD cameras are created equal.  Canon's Cinema line (C100, C300, C500) have none of the pixel-skipping nonsense of the EOS5D3.  Their FullHD images are going to look much, much better than those that come from Canon DSLRs.  And of course, there are 4K (and up) cameras that are so excellent that yes, they will beat a FullHD camera all day long, because they are just plain better (and usually much more expensive).
For your pricepoint (2000 Euros), a good 4K camera will give you some nice footage that allows you to pull a decent still from the stream and post it as an image.  A good FullHD camera will likely give you better sensitivity, and thus theoretical better low-light performance.  But chances are those benefits are in the noise compared to all the other things you cannot do for 2000 EUR, such as proper lighting.

Thank you, this gives me some additional information. But I already mentionned that for my "specific" use I NEED kind of flat-looking videos and for that purpose  RX100 looks closer to what I need than A7S (based on YouTube samples). I totally agree with you about the importance of lighting, but since I am shooting some types of live events, I usually have (nearly) no control over it.  So no, you can't blame the camera, but I'm trying to pick that that will adapt the best.

A lot of the content in this answer is similar to mine. Additional answers shouldn't repeat existing ones (unless there was an accident). If you don't have enough new info, edit it into an existing answer.


text:
Software advice to create animated sketches
I'm an industrial designer, using 3D CAD software to create my designs and Photoshop, Illustrator and inDesign, to create sketches & graphics, edit images, build presentations.
The problem is that most of these tools are +/- static. It's difficult to create & visualise interactions.
E.g. I would like to take a sketch/screenshot of the product I'm designing; sketch a hand; animate the hand so that it manipulates the product (e.g. push a button) and then animate what happens with the product (lights blinking, etc.); add comments, etc.
My main target is not to make very fancy presentation movies, but more "animated sketches", storyboards.
Which software would you recomend to do this. I've explored the animation function of photoshop and that was ok, but a little too basic (e.g. I could make the hand move from A to B at a constant speed, but I couldn't make it follow a curve in a more dynamic way).

related: http://video.stackexchange.com/questions/15331/simple-video-animation-for-teaching-purpose/15335#15335

You would want to use after effects if you want to animate sketches and graphics in flexible ways.

While After Effects is likely a good option for his needs, could you expand the answer a bit more to explain how and/or why After Effects is an ideal choice.  That would make it much more informative.

If you don't mind learning, Blender is a free open source project that you can use to create 3D animation, special effects, tracking, non linear video editing, compositing, etc... I haven't used After Effects as suggested before, but I'm sure Blender can accomplish the same and it's free.


text:
after effects - circular trim path
I have an animated circle shape layer with trim paths applied to it and the end percent animated from 0% to 100%. But half way through the animation, the circle path seems to close itself. How can i fix this?
if the circle animation is somehow not visible here, here is the link to imgur: https://i.sstatic.net/7zszj.jpg

Related: http://graphicdesign.stackexchange.com/questions/49643/how-to-use-after-effects-trim-path-with-an-illustrator-path/49975#49975 Not sure, but I assume the amimation of your mask path is not correct...

its just a simple circle with trim paths and animated end percent

I assume your mask path is a full circle, try to use an outline as mentioned in the answer above.

i dont think that is relevant to my question. i am not using a mask. it is a shape layer

I can't reproduce your issue on my end, but I can offer an alternative method. Another way to create the circle example you've provided is to use a Radial Wipe effect on the shape layer:
Effect > Transition > Radial Wipe

Just animate transition completion from 0 to 100 percent. If your shape layer is moving, you may also need to pickwhip expression the Wipe Center parameter to your position parameter:
transform.position

I hope this helps you out. Good luck!


text:
How can I set the first frame of a video to an I-frame and the rest to P-frames (preferably with ffmpeg)?
I'd like to try to do some datamoshing like this tutorial.  But I'd like to be able to do it programatically, so instead of vdub and avidemux, I'd like to figure out how to do as many parts of this process as I can with ffmpeg and/or other command-line tools.
The first problem I am having is that when I use the ffdshow codec rev 3556 with VDub it just outputs a broken video.  I feel like I got close to getting what I want, which is frame 0 as an I-frame and all the rest as P-frames with the following command
ffmpeg -i input.mp4 -force_key_frames 00:00:00.000 output.avi

There are a couple of problems with this:

I get B-frames too, which don't work with that type of data-moshing
There's still I-frames every 10 or so frames

I feel like the problem is that I need to use a certain codec to encode the video in and also that -force_key_frames probably just enforces the addition of extra keyframe(I-frames) but doesn't prevent other I-frames from being created.

What you want is a very long GOP or I-frame interval. I believe the ffmpeg option -g nnnn will do that, where nnnn is the length of your video in frames. I don't know how to specify "no B-frames", and this will certainly all be codec-dependent. Give it a try.

The first frame of a video from any codec will always be an I frame.  There is no previous picture for other frame types to use as a reference.
B frames might still work.  The video will start to distort ahead of the cut point, too, if any B frames are trying to reference a future frame that's not there anymore.  Actually, with B frames present, display order differs from decode order, and the h.264 stream is always stored in decode order.
Anyway -x264opts bframes=0:keyint_min=250 would force the minimum GOP size to 250 frames, and disallow use of B frames.  keyint sets the max GOP size.  (By default, x264 does scenecut detection for placing I frames, so if you want I frames at scenecuts, you might do well to leave it as-is.)
Err, is that tutorial using ffmpeg's MPEG4-part2 encoder?  (the same format as divx/xvid).  In that case, nvm.  My instructions were for -c:v libx264.
Look at the output of ffmpeg -h encoder=mpeg4 | less, and search for stuff you want to set.  There will be command line options for most everything.  e.g. -bf 0 to set no B frames.  ffmpeg -codecs for a list of codecs, or even ffmpeg -h full.  Also google / check the manual


text:
is there a way to fix this through video editting?
I recorded a video on my phone using a different camera app and it ended like this:

It feels like the video got split in to two if you can understand what i'm trying to say. Is there a way to remedy this using software?

I think you need to upload a portion of the video in order for people to have a better idea of the problem...

I can't tell for sure from the single frame there and not knowing what the source was, but it appears that you were using an HDR video application.  The result of such an application is that you get frames with two different exposure settings that are designed to be combined to form video with frames that have a higher dynamic range.
If that conclusion is correct, then yes, you should be able to split the video in half, merge the two parts of the frame back together and produce an HDR video from that data.  You will need to control how you merge them back together using a typical HDR technique, which you can find many details about how to do online from photo resources.  The process for video is the same, it just gets bulk applied to all the pairs of frames.
It is worth noting that the overall resolution of the video may have suffered as a result of splitting the frame like that and there won't be any way to get back any lost resolution, but you should at least be able to get it reduced to a single video.
If I'm wrong in those assumptions though and the video frames are not individually correct, then there may be more complex blending that needs to be done and it may be specific to that application.  Does the application have an option to export the video after processing?  Whatever the application was, that seems like a very odd final output unless it is either expecting only basic processing to need to be done or it is expecting that that file is only an intermediate stage.


text:
Can Import A 3D Model into madmapper
I'm looking for a way to projection map onto a low poly 3d model, I would like to use mad mapper, but I can seem to figure out if there is a way to load the 3d model into madmapper rather than sit there an draw the surfaces in the program by hand.
How to load a 3d geometry into it?

Alternatively I'd suggest using blender with blam: https://vimeo.com/56955831

this looks very cool, the only thing is that all the blender stuff would need to be pre-rendered, I'm really looking to do something interactive and have the video feed be live

for interactivity you could use the game engine of blender, see: http://www.z25.org/static/rd/3dcanvas_blender_plab/index.html


text:
How to paint on video?

Is there a specific name for this technique? so I can search for tutorials about it.

Don't know the name if there is one. I'd suggest to load the clip into photoshop, because you've got most control about the brush settings. Alternatively blenders new grease pencil is fun to play with: https://vimeo.com/113610809.

I want to achieve that kind of animation that the 2D objects are "on" the video. Take an animated character on the shoulder of an actor (so it moves with movements of the actor). After Effects can do this (really time consuming in Photoshop), but I don't know what I have to look for.

I understand what you mean, will write some instructions as soon as I can.

The technique is classically called rotoscoping after the original process done using projected film. If you google rotoscoping in after effects you should find lots of samples and tutorials.


text:
After Effects - output formats
Why do I only have these formats in my output?  Where's Windows Media Format?


text:
How to transcode HLS with multiple audio tracks
I am trying to create an HLS playlist with multiple audio streams. I have the following files:

videoHD.mp4
videoSD.mp4
audioEN.mp4
audioFR.mp4
audioIT.mp4

How would I transmux these all together in an ffmpeg command to create an HLS playlist?


text:
Reasons for using DNxHD instead of ProRes?
I often use ProRes or DNxHD codec without any thoughts, because the quality is very similar, even though the code and the compression algorithm certainly is very different.
I would like to know in which real world scenarios it makes more sense to use ProRes or DNxHD technically to achieve the best quality?

If you're using a windows machine then that's a good reason to use DNxHD.

Thanks @stib. Makes sense. Other reasons?

I have used both on my Ninja Blade with my C100, no real difference in quality across drastically different circumstances (night vs day). Pro Res works better on Mac, DNXHD works better on Windows. It all comes down to your OS, and whether you have to share the files with broadcasters (in which case I would use DNX as a lot of editors use Avid).
Other then that, I haven't heard, or seen first hand any differences between the two and I can honestly say that any differences pointed out online are mostly conjecture.

Thanks for your answer Alex +1! The operating system does not matter in my case... In the meantime, as you mentiond, I've also found that DNxHD is frequently used by broadcasters, but I'd like to know when I should use it in terms of quality. I'll accept the answer, if no one comes up with another one. Thanks again!

I'm interested too to be honest, so I actually did some research, the best article I could find that remotely addressed the difference was a non scientific test. Comments are interesting however, but still, nothing convincing. http://www.fallenempiredigital.com/blog/2013/02/28/avid-dnxhd-vs-apple-prores-vs-gopro-cineform-recompression-generation-loss/


text:
Mac Hardcode Subtitles from SRT to MP4 & adjust size and screen position
I've been spending all day trying to achieve everything in my question.
The only solution I've found being to encode the subs onto a green matte and then key out the green in premiere and change the screen position and size.
The tricky part is scale and screen placement issue, I've tried handbrake, subler and ffmpeg, but without success.
Any free software suggestions are welcome. Thanks.

Welcome Stefan :) Please start with the tour: http://video.stackexchange.com/tour to get your first badge ;) Anyway, enjoy video.se!

If you convert the .srt files to .ass, then you can have a lot more control over how the subtitles appear.
To convert use ffmpeg:
ffmpeg -i input.srt output.ass

This will give you an .ass subtitle file. You'll see in the header of that file that there will be details about font, size, placement colour and so on. Here's an example from Wikipedia:

[V4+ Styles]
   Format: Name, Fontname, Fontsize, PrimaryColour, SecondaryColour, OutlineColour, BackColour, Bold, Italic, Underline, StrikeOut, ScaleX, ScaleY, Spacing, Angle, BorderStyle, Outline, Shadow, Alignment, MarginL, MarginR, MarginV, Encoding
Style: Default,
  Arial,28,&H00B4FCFC,&H00B4FCFC,&H00000008,&H80000008,-1,0,0,0,100,100,0.00,0.00,1,1.00,2.00,2,30,30,30,0

The first line lists all the settings, and the second lists the values for each style.
You can edit the header by hand to get the size and placement you want, and then burn it in using ffmpeg again:
ffmpeg -i input.mov -vf ass="output.ass" output.mp4

You may want to add encoding settings etc, but that's basically it.

This worked liked a charm! Thanks.


text:
Syntax error when compiling vlc media player
I try to compile vlc, but I always get this syntax error:
Unterminated quoted string

make: *** [.a52] error 2

contribs:make failed

cd a52dec && CC="arm-linux-androideabi-gcc --sysroot=/home/timliu/test/android-ndk-r10e/platforms/android-9/arch-arm" CXX="arm-linux-androideabi-g++ --sysroot=/home/timliu/test/android-ndk-r10e/platforms/android-9/arch-arm" LD="arm-linux-androideabi-ld" AR="arm-linux-androideabi-ar" CCAS="arm-linux-androideabi-gcc --sysroot=/home/timliu/test/android-ndk-r10e/platforms/android-9/arch-arm -c" RANLIB="arm-linux-androideabi-ranlib" STRIP="arm-linux-androideabi-strip" PATH="/home/timliu/net/android/vlc/contrib/arm-linux-androideabi/bin:/home/timliu/net/android/vlc/extras/tools/build/bin:/home/timliu/net/android/vlc/extras/tools/build/bin:/home/timliu/test/android-ndk-r10e/toolchains/arm-linux-androideabi-4.8/prebuilt/linux-x86/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:/usr/lib/jvm/java-1.7.0-openjdk-i386/bin"
:/home/timliu/net/android/vlc/contrib/contrib-android-arm-linux-androideabi/../arm-linux-androideabi/bin" CPPFLAGS=" -g -mfpu=vfpv3-d16 -mcpu=cortex-a8 -mthumb -mfloat-abi=softfp -I/home/timliu/test/android-ndk-r10e/sources/cxx-stl/gnu-libstdc++/4.8/include -I/home/timliu/test/android-ndk-r10e/sources/cxx-stl/gnu-libstdc++/4.8/libs/armeabi-v7a/include -I/home/timliu/net/android/vlc/contrib/arm-linux-androideabi/include" CFLAGS=" -g -mfpu=vfpv3-d16 -mcpu=cortex-a8 -mthumb -mfloat-abi=softfp -I/home/timliu/test/android-ndk-r10e/sources/cxx-stl/gnu-libstdc++/4.8/include -I/home/timliu/test/android-ndk-r10e/sources/cxx-stl/gnu-libstdc++/4.8/libs/armeabi-v7a/include -I/home/timliu/net/android/vlc/contrib/arm-linux-androideabi/include -g" CXXFLAGS=" -g -mfpu=vfpv3-d16 -mcpu=cortex-a8 -mthumb -mfloat-abi=softfp -I/home/timliu/test/android-ndk-r10e/sources/cxx-stl/gnu-libstdc++/4.8/include -I/home/timliu/test/android-ndk-r10e/sources/cxx-stl/gnu-libstdc++/4.8/libs/armeabi-v7a/include -I/home/timliu/net/android/vlc/contrib/arm-linux-androideabi/include -g" LDFLAGS=" -L/home/timliu/test/android-ndk-r10e/sources/cxx-stl/gnu-libstdc++/4.8/libs/armeabi-v7a -lgnustl_static -L/home/timliu/net/android/vlc/contrib/arm-linux-androideabi/lib" ./configure --prefix="/home/timliu/net/android/vlc/contrib/arm-linux-androideabi" --datarootdir="/home/timliu/net/android/vlc/contrib/arm-linux-androideabi/share" --includedir="/home/timliu/net/android/vlc/contrib/arm-linux-androideabi/include" --libdir="/home/timliu/net/android/vlc/contrib/arm-linux-androideabi/lib" --build="i686-linux-gnu" --host="arm-linux-androideabi" --target="arm-linux-androideabi" --program-prefix="" --enable-static --disable-shared --disable-dependency-tracking --with-pic
contribs: make failed

My specifications:

OS: (Ubuntu 14.04 32bit) linux ubuntu 3.13.0-32 generic 2014 i686
NDK: android-ndk-r10e
JDK: adt-bundle-linux-x86-20140702 32bit
java-version: "1.7.0-79" |
OpenJDK runtime Environment (IcedTea 2.5.5) (7u79-2.5.5-Oubuntu0.14.04.2)
vlc:
git clone git://git.videolan.org/vlc-ports/android.git

I'm voting to close this question as off-topic because it's about compiling vlc (a programming issue).

Agreed. It should be on the vlc forum instead

If this question is closed. Then we should also close all the "how to compile ffmpeg" spam.

@Volodya Could you please write a meta post for this?

I have solved this problem. An error happens due to environment variables.
I added :/usr/lib/jvm/java-1.7.0-openjdk-i386 to etc/profile
export JAHA_HOME=/usr/lib/jvm/java-1.7.0-openjdk-i386

Now , I can compile libvlc, but new problem arises:
libvlc:compileReleaseJava FAILED
*what went wrong:
Execution failed for task 'libvlc:compileReleaseJAVA'.
> Cannot find System Java Compiler. Ensure that you have installed a JDK (not just a JRE) and config used your JAVA_HOME system variable to point to the according dirctory.


text:
Converting files to Avid-friendly DNxHD MXF
Please forgive the noob question, I'm new here. I've looked for an answer on this forum but not found one so far. I've also tried the BMXlib forum.
I'm trying to convert small video files that have been digitally generated as DNxHD QuickTime MOV's (via FFmpeg, and not sourced from a camera) into DNxHD MXF files that I can import into Avid Media Composer using the Media Tool. I'm on MC 8.3.1.
These are video-only files, there's no audio.
I'm using FFmpeg to generate a raw .dnx file:
ffmpeg -i [input-file] -vcodec dnxhd -f rawvideo -b:v 185M -flags +ildct -y [intermediate-file]

and then using raw2bmx to wrap that as an MXF:
raw2bmx -t avid -o [output-file-prefix] -f 25 --vc3_1080p_1238 [intermediate-file]

There are no errors that I can see in the resultant outputs. The resultant file is an MXF file which the Media Tool will recognise. The file size seems right (just a few K more than the original file). The duration and video format are correctly recognised, so it appears to be fine.
However, when I try to play back the clip, it won't play. In the source window I get a long and apparently incomplete error message:
HagridBase: Err: 0 | -1979514218 | lk_interruptobject.cpp | 1152 | Error Code: kLPKerr_CodecFatalDecodeError Msg: "Card2:Decode:Pip1DecodeError", Err: 0 | -1979514218 | lk_interruptobject.cpp | 1157 | Error Code: kLPKerr_CodecFatalDecodeError Msg: "Ca

Has anyone got any suggestions where I might be going wrong? I'm new to BMX so I may be making a simple mistake.

Console Output
When using FFmpeg to convert from the MOV to the raw .dnx, this is the console output:
~~~
Reached BMX.B.
secondParameters:
-i "C:\Users\animator\Documents\Renumbers\900-0002_stage1_GHRs.mov" -vcodec dnxhd -f rawvideo -b:v 185M -flags +ildct -y "C:\Users\animator\Documents\Renumbers\900-0002_stage2_GHRs.dnx"
ffmpeg version N-70520-g9d7e42e Copyright (c) 2000-2015 the FFmpeg developers
  built with gcc 4.9.2 (GCC)
  configuration: --enable-gpl --enable-version3 --disable-w32threads --enable-avisynth --enable-bzlib --enable-fontconfig --enable-frei0r --enable-gnutls --enable-iconv --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libfreetype --enable-libgme --enable-libgsm --enable-libilbc --enable-libmodplug --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-libopus --enable-librtmp --enable-libschroedinger --enable-libsoxr --enable-libspeex --enable-libtheora --enable-libtwolame --enable-libvidstab --enable-libvo-aacenc --enable-libvo-amrwbenc --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxavs --enable-libxvid --enable-lzma --enable-decklink --enable-zlib
  libavutil      54. 20.100 / 54. 20.100
  libavcodec     56. 26.100 / 56. 26.100
  libavformat    56. 25.101 / 56. 25.101
  libavdevice    56.  4.100 / 56.  4.100
  libavfilter     5. 12.100 /  5. 12.100
  libswscale      3.  1.101 /  3.  1.101
  libswresample   1.  1.100 /  1.  1.100
  libpostproc    53.  3.100 / 53.  3.100
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'C:\Users\animator\Documents\Renumbers\900-0002_stage1_GHRs.mov':
  Metadata:
    major_brand     : qt
    minor_version   : 512
    compatible_brands: qt
    encoder         : Lavf56.25.101
  Duration: 00:00:10.00, start: 0.000000, bitrate: 183502 kb/s
    Stream #0:0(eng): Video: dnxhd (AVdn / 0x6E645641), yuv422p(tv), 1920x1080, 183500 kb/s, 25 fps, 25 tbr, 12800 tbn, 12800 tbc (default)
    Metadata:
      handler_name    : DataHandler
      encoder         : Lavc56.26.100 dnxhd
Output #0, rawvideo, to 'C:\Users\animator\Documents\Renumbers\900-0002_stage2_GHRs.dnx':
  Metadata:
    major_brand     : qt
    minor_version   : 512
    compatible_brands: qt
    encoder         : Lavf56.25.101
    Stream #0:0(eng): Video: dnxhd, yuv422p, 1920x1080, q=2-1024, 185000 kb/s, 25 fps, 25 tbn, 25 tbc (default)
    Metadata:
      handler_name    : DataHandler
      encoder         : Lavc56.26.100 dnxhd
Stream mapping:
  Stream #0:0 -> #0:0 (dnxhd (native) -> dnxhd (native))
Press [q] to stop, [?] for help
frame=   47 fps=0.0 q=1.0 size=   42112kB time=00:00:01.88 bitrate=183500.8kbits/s
frame=   96 fps= 94 q=1.0 size=   86016kB time=00:00:03.84 bitrate=183500.8kbits/s
frame=  130 fps= 86 q=1.0 size=  116480kB time=00:00:05.20 bitrate=183500.8kbits/s
frame=  180 fps= 89 q=1.0 size=  161280kB time=00:00:07.20 bitrate=183500.8kbits/s
frame=  229 fps= 90 q=1.0 size=  205184kB time=00:00:09.16 bitrate=183500.8kbits/s
frame=  250 fps= 91 q=1.0 Lsize=  224000kB time=00:00:10.00 bitrate=183500.8kbits/s
video:224000kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.000000%
~~~

When I run raw2bmx, I'm not seeing any console output so I can't see anything to paste.

Running FFprobe on the resulting MXF file gives this information:
~~~
[STREAM]
index=0
codec_name=dnxhd
codec_long_name=VC3/DNxHD
profile=unknown
codec_type=video
codec_time_base=1/25
codec_tag_string=[0][0][0][0]
codec_tag=0x0000
width=1920
height=1080
has_b_frames=0
sample_aspect_ratio=1:1
display_aspect_ratio=16:9
pix_fmt=yuv422p
level=-99
color_range=N/A
color_space=unknown
color_transfer=unknown
color_primaries=unknown
chroma_location=unspecified
timecode=N/A
refs=1
id=N/A
r_frame_rate=25/1
avg_frame_rate=25/1
time_base=1/25
start_pts=0
start_time=0.000000
duration_ts=250
duration=10.000000
bit_rate=N/A
max_bit_rate=N/A
bits_per_raw_sample=8
nb_frames=N/A
nb_read_frames=N/A
nb_read_packets=N/A
DISPOSITION:default=0
DISPOSITION:dub=0
DISPOSITION:original=0
DISPOSITION:comment=0
DISPOSITION:lyrics=0
DISPOSITION:karaoke=0
DISPOSITION:forced=0
DISPOSITION:hearing_impaired=0
DISPOSITION:visual_impaired=0
DISPOSITION:clean_effects=0
DISPOSITION:attached_pic=0
TAG:file_package_umid=0x060A2B340101010101010F00130000005580237EF2BE012E060E2B347F7F2A80
[/STREAM]
~~~

Any suggestions would be very welcome.
I can provide more of the console output or possibly a couple of example files if it would help.
Thanks.

Please do provide the console output from all the operations. There may well be clues in them.

In the end I have discovered what the problem was here, to an extent, and thanks to a post on the BMXlib forum:
By changing the option in raw2bmx from --vc3_1080p_1238 to simply --vc3, this forced raw2bmx to look at the data to determine what video format it was - and it turns out that in this case, it wasn't vc3_1080p_1238.


text:
Film a 3D video using Genlock cameras or LANC?
I am doing some research in 3D stereo, particularly in 3D videos. I was successful creating 3D photos (using ordinary webcams) and viewing on a 3D laptop and 3D TV, but I've been reading that video recording is not so straightforward.
What would be the cheapest way to build a 3D video camera set-up (Rigs, controllers, etc)? I live in India, so buying an expensive rig from abroad may not be possible at the moment. I'm also confused about using genlock cameras or a LANC controller for the video cameras. I currently don't have any video cameras, so which brands would be best to buy to have them in sync? My ultimate goal would be to film a scene 'live' in 3D (under 20 min).
Any help here would be very much appreciated.

Very closely related

Genlock would allow the capture of frames to be synchronized to a common external timecode.  It is only a feature on pretty high end cameras, so if you are trying to keep costs down, it really isn't an option.  The other question I linked to in the comment goes over a few possible ways to try to get usable sync for multiple cameras, but sadly, there aren't particularly good options for most cases.
There is a 3d kit for certain model GoPros that may be worth considering, but otherwise, you are probably best looking for a camera that supports lens splitting for 3d capture or purpose built consumer targeted cameras if you want things to remain fairly cheap.

Gopro 3 black + has a kit with sync cable for genlock.
There are sony cameras with dual lens dual sensor.
Also there are genloc syncers based on Lan C for regular Hd sony cameras sincing in the microsecond range.


text:
How to stitch images from DIY panorama video rig with 3 canon 60d's?
I want to build a camera rig with 3 canon 60d's to get some kind of panorama video. To verify my idea before building the real rig, I've implemented the setup in Blender  to test all possible cases:

Unfortunately I don't have much experience to stitch the images/videos correctly. How can I achieve that? Which software is suitable for that? How far the images of the cameras should overlap to get the best results? Besides the lens distortion, is there still something to consider?

I to have thought about this idea, I saw it in a video explaining the different types of film sizes. they had a similar rig to this but the cameras faced inwards rather than out which gave them immense widescreens but there was a lot of trial and error back in the days and the cameras were huge
http://filmmakeriq.com/lessons/the-changing-shape-of-cinema-the-history-of-aspect-ratio/

You could try if kolor works for you. It's not free but it's made for your exact needs. Check out the gallery for what they did. Or you can do it manually as Adam explains.

Here's a labor intensive solution.
http://punkoryan.com/2011/02/08/shooting-360-degree-video-with-four-gopro-hd-hero-cameras
Post if you have found another solution.
I have some 3 camera video panoramas from the 1980's I want to stitch.
thnks
chris

Thanks Chris! +1 Welcome to video.se :) In order to have a solid answer here, it would be nice if you could explain more on how to use ptgui, because link only answers are poor practice, see: http://meta.stackexchange.com/questions/8231/are-answers-that-just-contain-links-elsewhere-really-good-answers I'll keep you posted if I've found a suitable solution. Thanks again.

From the ffmpeg docs
ffmpeg -i LEFT -i RIGHT -filter_complex framepack=sbs OUTPUT
framepack only works with 2 inputs, but you could merge 3 with a more complex filtergraph.  sbs means side-by-side.
This doesn't correct for perspective or handle the overlap or anything else needed for it to look good, and the word "panorama" doesn't appear in the ffmpeg docs.  If it's possible to do it properly with ffmpeg, it will require non-standard video filters.  (And by properly, I mean without manually finding how many pixels to crop from the inputs before feeding them to framepack).
Just posting in case people were wondering if ffmpeg did this.  Turns out the answer seems to be no.  It does have filters called "perspective" and "lenscorrection", but nothing for smart-stitching panoramas that I can see.
edit:
 After further questions from poor, I googled for ffmpeg panoramic, and found http://krpano.com/.  It says it can do panoramic video, but I'm not exactly sure WHAT it can do with it.  It doesn't list any video formats as input formats, but maybe it can work with image-per-frame PNGs or JPEGs or something.  Ok, no nvm, http://comments.gmane.org/gmane.comp.misc.ptx/24263 says krpano can play back / "explore" panoramic video.
The other google hits were from people trying to make a panoramic single image from multiple frames of a panning shot.
Hmm, this looks interesting.  Says it uses ffmpeg and pano tools.
http://webuser.hs-furtwangen.de/~dersch/mp/MotionPanoramas.html
Not sure it can actually stitch, though.  Might just correct fisheye->panorama.
Maybe this one:
https://groups.google.com/forum/#!topic/hugin-ptx/NroNAfQTz-8
mentions http://www.video-stitch.com/.  Commercial software with a free version that watermarks videos larger than 1024x768, but does have a download for Linux.  (presumably a statically linked x86 32bit binary.  It might use NVidia CUDA, at least on Windows.)

Thanks for your response. For "exact" measured rigs this can be interesting maybe. Can you elaborate how to lens correct with it? New question on this?

No, I can't sorry.  All I know is that http://www.ffmpeg.org/ffmpeg-all.html#lenscorrection exists, not what it does, how good it is, or what options it has.

Very interesting. I asked a new question on this: http://video.stackexchange.com/questions/14772/correct-lens-distortion-with-ffmpeg In terms of the process it could be useful/of interest to move the outer plates inside pixel wise to match the center plate. Is this also possible with ffmpeg? If yes could you add this to your answer?

To crop the center stream before tacking the left/right streams onto it?  (or crop each of them before attaching them to the center)

ffmpeg alone isn't a good tool for this job, since you don't want to be calculating pixel offsets manual each time you do it.  I posted some stuff I googled.

No, I thought if you know the distortion and have a static inudustry like perfectly measured  rig - you can stitch the images with ffmpeg because the pixel area that intersects is always the same. You are right, it is not possible to do it with my rig but maybe with a 2 camera rig... Move the plates would be key to do all the stuff with ffmpeg.

Ok, IDK anything about actually doing this.  I wouldn't have assumed things would stay aligned to the pixel.  But if you can do it with 2, you can do it with 3.  You just need to chain the filters together in a tree like ((1 2) 3).

I would guess you would need to make a canvas size in your NLE to match the full width of the video ie: 3*1920=5760 with a height of 1080, I would assume this would work as long as your NLE and PC/Mac can handle the throughput of playing 3 videos simultaneously. baring in mind as well, who is going to be able to play this back at this resolution.

Perspective and depth issues as well as lens distortions are going to prevent this from working properly.  It isn't that simple.


text:
Dxtory recording randomly crashing game
Whenever I try to record gameplay with Dxtory (using the h.264 codec) my game will crash after a seemingly random amount of time, although it is usually after at least 30 minutes. Dxtory produces no error logs and there is no recording because I have to end the game's process to close it and this seems to make Dxtory just toss out the entire file... The game in question is Counter Strike: Global Offensive, but I don't know if that makes a difference. I am not sure if the codec is the source of the problem, but I was wondering if someone with a little more knowledge than me has any idea of what is wrong. These are my video settings:

I have done 2 successful recordings with Dxtory so far, but I cannot remember if they were both using the default codec or if the second one was using H.264. Is this the fault of my settings or is it the codec that is malfunctioning?

Does it work if you stop prior to the crash?  Are you able to monitor your system performance (memory and CPU usage) leading up to the crash?

No, I cannot really monitor it because I don't know when it'll happen. BUT, after you asked, I tried just starting a recording and stopping it, and Dxtory gets stuck on FIN (right before the recording ends, but the FPS counter is still the recording color) and the game crashes... I'll be using the default codec until I know how to fix this.

authors: Дмитрий Красотин


text:
Video noise and harsh shadows on green screen caused by feet
We have a recurring shoot where we continue to run into the same two issues. Our set consists of a medical exam table sitting on top of a green screen. The talent sits on the exam table and we record 'Doctor/Patient interviews'.
ISSUE 1: When the talent is on the taller side, their feet hang down past the bottom of the exam table and create really harsh shadows on the green screen, making the footage very difficult to key.
ISSUE 2: The dark area on the front of the exam table, behind the talent's legs, is very noisy.
I believe these two issues are linked and both have to do with lighting. However, I have yet to find a permanent solution to either one of them. I am currently setting a small LED light in front of the camera that helps with the shadows, but it still isn't solving the problem.
Our camera is a Panasonic HMC150 and I use the 'Keylight' effect in After Effects to key the footage. Keying is very difficult around the feet shadows and some of the green reflection shows on the exam table, which in turn, ends up being keyed slightly creating a lot of noise. I use the 'Remove Grain' effect to help remove the noise.
Any advice on a different lighting setup, keying solution, or anything else that could help this situation is greatly appreciated. I've attached images demonstrating the issues.

do you use a waveform monitor when you set up the lights?  that might help.

Yes, I do. It doesn't help much with the shadows though.

To reduce or eliminate the greenish reflection on the front of the table, you can buy some dark gray or black construction paper, or something equally non-reflective, cut it to size, and tape it over the 2 dark rectangles on the front of the table.
I have 3 different solutions for the foot-shadows on the floor.

You could point a semi-dim spotlight directly on that section of the green screen. Make sure to mask it so it doesn't hit the dark rectangles on the front of the table too much.
If the camera is always stationary, you could lower the camera slightly so the talent's feet never extend past the dark rectangle on the front of the table and into the green (as the tip of her left shoe does in the pictures you included). Then you can mask out that part of the shot instead of relying on the Keylight effect.
You could just move the camera about a foot closer to the talent so you crop out the bottom of the table (and the green in front of it). You can also do this by cropping the shot during post production.

(Or, obviously, just get shorter talent.)

Thanks, Brett! I hadn't thought of putting some dark paper over the exam table. That may work. Your first solution for the shadows is what I am going to test first. The second and third solution won't work though because of the exam room environment used as the background. Thanks for the input!

I don't think anyone would notice the paper if it's cut to the right size and it's taped flush with the surface it's covering. Also, viewers are focused on the talent, not the details of the special effects!

One more thought, on which I may be wrong: Number 3 might work if you also crop the exam room environment you use as the background. But if #1 works, then never mind!

Number three would work if we could crop the environment, but the environment is locked so that's not possible. And I think you're right about the paper. Thanks, again!

I LOVE coming up with solutions for this kind of question! All those other questions about technical software issues are not my cup of tea. If you have more on-set production questions like this, please post them!

The best bet is probably a combination of more light and using a flatter exposure.  h.264 in particular does very bad with noise levels in shadow as do many CMOS sensors.  If you are near the dark end of what the camera can capture, you are going to get lots of noise.  The obvious solution is to keep things away from the dark end of what you can capture.
This can be done either by tweaking exposure settings (if the dynamic range of the scene is narrow enough) or by adjusting lighting to be more even.  I'd personally go for trying to use a low down and fairly powerful light with a barn door on it to fill the bottom of the table and provide more even lighting underneath as this will also look better in the finished product.
Alternately, as Brett suggested, positioning the actor such that you can mask the area is another option (but would still have a harsh shadow and noise in the dark portions of the video.)  Probably best to prevent the dark areas in the first place.

I don't know if this might be an option or even work but, couldn't you get a dark piece of paper or card and create a linear curve from the bottom under the seat to extend to the floor creating a curve just at the end so it looks like part of the chair.

EXCELLENT IDEA! Don't make the section under the talent's feet green at all! You could even position a small rug there, if the "extension of the chair" didn't look natural.

cheers @BrettFromLA just my practical thinking


text:
Kung Fury VHS effect
I hope everybody seen this amazing trailer of upcoming Swedish masterpiece:

FULL HD TRAILER
So, I wonder, how to achieve this cool video effect. Please, pay attention on the edges:

The image some kinda decomposes into 2 channels.
How to reproduce this?

I have no answer for you, but this movie looks frickin' great!!

@BrettFromLA, yeah, right! They gathered 620k$ on Kickstarter instead of 200r$! It's in post-production now.

@DrMayhem, pls, check screenshot
https://yadi.sk/i/4F-plZn2cjF4y

@DrMayhem, possibly, but I think not effect of lenses, 'cause everything was shot in a single room using chroma-key (check this video https://www.youtube.com/watch?v=Ed3dnF5wZkU).

@BrettFromLA, you can check my research )

Ok, after a research I found the solution.
Watch this tutorial.
At a glance:

Create Adobe After Effects project.
Add "Channel set" effect.
Duplicate layer 3 times.
Adjust each layer to show only one channel (Red/Green/Blue).
Set Blending Mode as Screen.
Add transformation for each layer. Play with rotation/scale.

Voila! Check my example.
Original frame (sorry for low bitrate)

RGB shifted

I think it's cool as hell!

That's brilliant! Nicely researched.

@DrMayhem, thanks! Today I celebrate ) Gonna use it in music video producing.


text:
Centered motion tracking with Mocha AE/Pro and After Effects?
I haven't been able to figure out yet how I get stabilized footage from mocha Pro to After Effects.
I start a new project, import my footage and am able within mocha Pro to get a nice motion tracking and stabilizing it, so it always remains centered in the frame.
How do I get this data to After Effects so the motion tracking is centered as well? If I hit Export Stabilized Tracking Data... and paste it to my footage layer, it isn't as stabilized as what mocha Pro is able to do.
The reason I want it back in After Effects is to increase the canvas size as mocha Pro crops the footage because it moves the footage around.
The idea is to make something like this or this.
Is there a better way doing this than After Effects/mocha?

What are the differences between what you see in Mocha and what you see in AE.  It sounds like you are doing things correctly (the intended output of Mocha is generally a motion track), but without more description of the problem, it is going to be hard to tell where it is failing.

As you can see here the After Effects (third) is much more shaky/unstable than the mocha Pro version (second). The first is the original footage. I stabilized in mocha Pro, hit the export within the stabilize module and pasted it to the footage in After Effects. No other changes have been made. I tried to track his face.

That is very odd indeed.  It looks like the magnitude of the motion effect got doubled somehow, but I have no idea how that could have happened.


text:
Premiere Pro CC 2014 renders incredibly slow / Cineform
I created a movie with Adobe Premiere Pro CC 2014 and I have serious performance issues when it comes to export the movie.
The first 10% renders pretty fast and takes 1 hour. Then it takes for every additional 1% about 4 hours! (never rendered it to finish so far, 14% max so far)
Here are some facts that might help to isolate the problem:
Project:

Length: 24 minutes in total, splitted into several sequences (up to 4 minutes) and arranged on a "main-sequence"
Input: Cineform AVI files, 1080p, 59fps (I converted GoPro 3+ footage (3D!) using GoPro Studio to the Cineform format for further processing)
Desired Output: Same as input, preserving 3D (Render 3D Intermediate)
Effects  used: Warp-Stabilizer (default settings) and Auto-Color (smoothing 1-2 sec) on almost every clip.

Hardware / Software:

i7-3770K @3.5 GHZ (Quadcore)
16 GB RAM
NVIDIA Geforce GTX 970 (also tried with a ATI Radeon R9 290X)
Windows 8.1
SSD for OS and programs, RAID 0 for media files and project, separate drive for rendering output.

Then I tried to render using AME using the same settings. The whole video rendered in about 14 hours what is acceptable in my case. There problem here is that the 3D gets lost, even if I selected "Render 3D Intermediate". The picture for the left eye is the same as the one for the right eye.
This is not happening when I do a direct export. But the direct export get almost stuck at around 10%.
There is almost no difference in choosing Software-Rendering and GPU. Also, the GPU has almost no load.
Premiere Pro uses the CPU for about 45% (total usage 65%) and takes up 5-9 GB of memory (total usage 65%). Disk usage at around 14b/s.
I think there are two problems. One is that AME renders differently (no 3D) and the other is that the direct export takes way too long.
Can someone help me with any of these problems?
Thank you,
Martin
Update 18.11.2014
I did some additional research and found out, that the slow rendering happens with this combination:

Auto-Color using Temporal Smoothing
Render 3D Intermediate

Without rendering the 3D intermediate, Temporal Smoothing is not a problem. And without temporal smoothing, Rendering 3D Intermediate is not a problem.
Might this be a problem in the codec or in Premiere?

It may very well be.  Probably best to bring it to Adobe's support and see what they say.


text:
Logo overlay with Windows Movie Maker
I am currently editing a video with Windows Movie Maker. I am trying to insert an overlay of my logo (which is transparent) on the upper right hand side of my video, but I don't know how to do that. If it is not possible (I heard of some comments saying it's not possible to add a logo in WMM), is there any software which can complete the task?

I'll leave this open in case someone knows of a way to do it with WMM, however for other options, see https://video.stackexchange.com/questions/9922/tools-to-combine-a-video-with-an-animated-logo.

There is no way to do this with WMM, it doesn't support video compositing.  Filelab Video Editor is a free, online program that can do this for you.


text:
How to remove an object (Tooth) in After Effects
I have a 5 second Video clip of our main Character smiling and when he opens his mouth we see that his tooth is gone. We have painted the whole tooth black but there is a shine on it and it doesn't look right. You can see that the hole up to his gum is black and probably should probably be more red.The shot itself is static.
I was wondering how to remove this tooth in after effects. Its the final shot of the film so is important to get right. I have after Effects CS5.5 and Motion.
If necessary we would shoot it again if anyone has any tips. Thanks!
Thanks everyone that replied. Sorry for the delay in getting back. We had a bereavement in the family and everything was left. I think Rotoscoping is the way to go. Will update when i fix the problem.

Could you possibly be working with the MC Bat Commander?

Could you add a screenshot of your issue to the question?

You might want to look at the Roto Brush, and mask tracking. These will make roto a lot easier.

I like that you went the practical route first, ie painting the tooth black.  Any chance you could just pull the tooth?  ;-)

Unfortunately, the only answer is rotoscoping.  You have to remove the tooth from each frame manually.  Rotoscoping tools will help give a closer starting point, but that kind of object removal where both the object and the background behind it are changing and moving is nearly impossible to do without manual effort.
Note, if everything in the mouth behind the teeth is black or basically the same color, then you have a lot more options as Brett outlined in his answer.  I was assuming that there was more detail in the mouth based on your description that would require background painting, but if you can avoid background painting for the mouth, then rotoscoping isn't needed.

I have a couple options you might consider.
1) Create a small picture in Photoshop that looks like the "hole" you want.  Include a transparent (alpha channel) background, so it's really just the black or black+red color that you want, in the shape of his tooth.  Then in After Effects, or even Premiere, place that image in the right place.  Finally, animate it to follow any subtle movements of the actor's face.  (This probably won't work if the actor is talking or if his lip is moving at all.)
2) This one is a bit more dicey, but COULD work. Since you're willing to shoot the shot again, do a test where you cover someone's tooth with BRIGHT GREEN, with the same lighting conditions you'll use. Then use the After Effects chromakey (green screen) feature to see if you can replace that green area with a black or red-black color or image.  Using that technique will create a traveling mask FOR you, so you don't have to mask every frame yourself.  But as I suggested, do a test FIRST.  Since the actor's upper lip will create a shadow on the tooth, it might not work (or might not work very well).

Since they painted it black, they might also be able to try a luminance key with the existing footage (and some major healing tolerance for the bright spot).  What to replace it with is going to be the major issue though unless it is exposed such that the back of the mouth is completely or near completely black.

I came up with another option last night. It involves reshooting, and would cost some money. The idea is to get "dentures" for the actor that have a tooth missing.  The gumline of the "dentures" would be where the actor's real teeth are. The artificial teeth would extend beyond that, and of course one would be missing.  If the actor could position his lips so it looked natural, this would probably give the most believable effect since the tooth would actually be missing.

Great idea for a non-technical solution to a complex technical problem.

@AJHenderson Thanks! I wish there were more questions on this forum that had potentially low-tech solutions like this one.

For such a short clip, just paint over each frame as needed using the brush tool.
This reminds me of "The Hangover", but Ed Helms actually had his implant removed for the film. No effect needed there.
If it helps, everything I've ever seen where they just painted the tooth has been obvious to me. I think the audience is pretty forgiving here. Should be easy to at least remove the shine ("specular highlights" if we're being technical), and anything further that you do is just bonus.


text:
How to make a decent video from a capture by an old Panasonic webcam?
I have about 30 minutes worth of video and audio captured 10+ years ago by an older Panasonic web-cam. The two streams are in separate files:

The video-MP4V-ES-2. 640x480. mplayer says, it is 5 FPS, but mpv claims 25 FPS. The file-utility says: MPEG sequence, v4, video, simple @ L1. I suspect, 5FPS is correct...
The audio-G726-32-1: adpcm_g726, 8000 Hz, mono, s16, 32 kb/s. Not sure, if all of these parameters are correctly detected.

I'd like to make the best possible video from it, viewable by all (or most) players. The problems:

The audio has some pervasive hum -- that was not there at the time of recording.
What little conversations there are, are in low whisper -- I'd like to have those emphasized.
The video has multiple VOL headers, which ffmpeg reports -- and ignores.
The video is grainy. Worse, what light comes from the window changes because of the moving clouds. And about 5 minutes into it the electric light is turned off -- so whatever video-filtering parameters anyone suggests, might have to be different for different sections.
According to ffmpeg, there is one "timestamp discontinuity" in the video stream.

So far I tried the following audio-filtering: -af "highpass=f=200, lowpass=f=3000, afftdn=nf=-23", which seems to have improved things but only a little: there is still hum. Loud noises (things falling) are loud, which is fine, but the whispering conversations aren't enhanced.
ffmpeg -i video-MP4V-ES-2 -f g726 -i audio-G726-32-1 -af "highpass=f=200, lowpass=f=3000, afftdn=nf=-23" -vf "nlmeans" out.mp4

For video I tried the nlmeans filter without any arguments. The result is nicer, than the original -- especially in the part, where the electric light is still on. But the darker part is still quite grainy.
The resulting video also plays way too fast -- probably, the artifact of the original being at 5 frames-per-second, which FFMpeg didn't account for? This can be overcome while watching -- with mpv -- by lowering the speed repeatedly by pressing [. (Same button is supposed to work with mplayer, but does not...)
When trying to skip forward during playback (with mpv or mplayer), there are odd effects -- going back, for example, does not return you to the same moment, from where you just went forward -- probably, because of that "discontinuity"?
While playing the resulting file with mplayer, every once in a while it turns off the sound and complains:
Too many video packets in the buffer: (2987 in 33554782 bytes).
Maybe badly- or non-interleaved stream/file or the codec failed?
Fix the file or try the -ni option (can cause high memory usage).

How would I overcome these so that the video presents, what the eye would see and the ear would hear being there at the time, and is normally playable -- without losing any details recorded in the originals?

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/


text:
Error decoding timecode using ffprobe
I'm using ffprobe to get timecode from an mxf which has DF timecode but with a non DF frame rate. I'm getting the error Drop frame is only allowed with 30000/1001 or 60000/1001 FPS.
I'm running ffprobe -i "IMX 10bit.mxf" -print_format json -show_streams -show_format and getting the following:
ffprobe version 3.2 Copyright (c) 2007-2016 the FFmpeg developers
  built with gcc 5.4.0 (GCC)
  configuration: --enable-gpl --enable-version3 --disable-w32threads --enable-dxva2 --enable-libmfx --enable-nvenc --enable-avisynth --enable-bzlib --enable-libebur128 --enable-fontconfig --enable-frei0r --enable-gnutls --enable-iconv --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libfreetype --enable-libgme --enable-libgsm --enable-libilbc --enable-libmodplug --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenh264 --enable-libopenjpeg --enable-libopus --enable-librtmp --enable-libschroedinger --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libtheora --enable-libtwolame --enable-libvidstab --enable-libvo-amrwbenc --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxavs --enable-libxvid --enable-libzimg --enable-lzma --enable-decklink --enable-zlib
  libavutil      55. 34.100 / 55. 34.100
  libavcodec     57. 64.100 / 57. 64.100
  libavformat    57. 56.100 / 57. 56.100
  libavdevice    57.  1.100 / 57.  1.100
  libavfilter     6. 65.100 /  6. 65.100
  libswscale      4.  2.100 /  4.  2.100
  libswresample   2.  3.100 /  2.  3.100
  libpostproc    54.  1.100 / 54.  1.100
{
[mxf @ 0000000000da9740] Drop frame is only allowed with 30000/1001 or 60000/1001 FPS
Input #0, mxf, from 'IMX 10bit.mxf':
  Metadata:
    uid             : 2b3801ea-ec5e-4dc1-ab3a-dba9a2b30ce4
    generation_uid  : 2b3801ea-ec5e-4dc2-ab3a-dba9a2b30ce4
    product_uid     : 00000000-0000-0000-0000-000000000000
    modification_date: 2009-11-04T10:39:42.000000Z
    material_package_umid: 0x060A2B340101010501010D43130000005C91020063D700800210F3FFFE154618
  Duration: 00:00:19.52, start: 0.000000, bitrate: 62580 kb/s
    Stream #0:0: Video: mpeg2video (4:2:2), yuv422p(tv, top first), 720x608 [SAR 152:135 DAR 4:3], 50000 kb/s, 25 fps, 25 tbr, 25 tbn, 50 tbc
    Metadata:
      file_package_umid: 0x060A2B340101010501010D43130000005D91020063D700800210F3FFFE154618
    Stream #0:1: Audio: pcm_s24le, 48000 Hz, 4 channels, s32 (24 bit), 4608 kb/s
    Metadata:
      file_package_umid: 0x060A2B340101010501010D43130000005D91020063D700800210F3FFFE154618
    "streams": [
        {
            "index": 0,
            "codec_name": "mpeg2video",
            "codec_long_name": "MPEG-2 video",
            "profile": "4:2:2",
            "codec_type": "video",
            "codec_time_base": "1/25",
            "codec_tag_string": "[0][0][0][0]",
            "codec_tag": "0x0000",
            "width": 720,
            "height": 608,
            "coded_width": 0,
            "coded_height": 0,
            "has_b_frames": 0,
            "sample_aspect_ratio": "152:135",
            "display_aspect_ratio": "4:3",
            "pix_fmt": "yuv422p",
            "level": 5,
            "color_range": "tv",
            "chroma_location": "topleft",
            "field_order": "tt",
            "refs": 1,
            "r_frame_rate": "25/1",
            "avg_frame_rate": "25/1",
            "time_base": "1/25",
            "start_pts": 0,
            "start_time": "0.000000",
            "duration_ts": 488,
            "duration": "19.520000",
            "bit_rate": "50000000",
            "disposition": {
                "default": 0,
                "dub": 0,
                "original": 0,
                "comment": 0,
                "lyrics": 0,
                "karaoke": 0,
                "forced": 0,
                "hearing_impaired": 0,
                "visual_impaired": 0,
                "clean_effects": 0,
                "attached_pic": 0,
                "timed_thumbnails": 0
            },
            "tags": {
                "file_package_umid": "0x060A2B340101010501010D43130000005D91020063D700800210F3FFFE154618"
            }
        },
        {
            "index": 1,
            "codec_name": "pcm_s24le",
            "codec_long_name": "PCM signed 24-bit little-endian",
            "codec_type": "audio",
            "codec_time_base": "1/48000",
            "codec_tag_string": "[0][0][0][0]",
            "codec_tag": "0x0000",
            "sample_fmt": "s32",
            "sample_rate": "48000",
            "channels": 4,
            "bits_per_sample": 24,
            "r_frame_rate": "0/0",
            "avg_frame_rate": "0/0",
            "time_base": "1/48000",
            "start_pts": 0,
            "start_time": "0.000000",
            "duration_ts": 936960,
            "duration": "19.520000",
            "bit_rate": "4608000",
            "bits_per_raw_sample": "24",
            "disposition": {
                "default": 0,
                "dub": 0,
                "original": 0,
                "comment": 0,
                "lyrics": 0,
                "karaoke": 0,
                "forced": 0,
                "hearing_impaired": 0,
                "visual_impaired": 0,
                "clean_effects": 0,
                "attached_pic": 0,
                "timed_thumbnails": 0
            },
            "tags": {
                "file_package_umid": "0x060A2B340101010501010D43130000005D91020063D700800210F3FFFE154618"
            }
        }
    ],
    "format": {
        "filename": "IMX 10bit.mxf",
        "nb_streams": 2,
        "nb_programs": 0,
        "format_name": "mxf",
        "format_long_name": "MXF (Material eXchange Format)",
        "start_time": "0.000000",
        "duration": "19.520000",
        "size": "152695808",
        "bit_rate": "62580249",
        "probe_score": 100,
        "tags": {
            "uid": "2b3801ea-ec5e-4dc1-ab3a-dba9a2b30ce4",
            "generation_uid": "2b3801ea-ec5e-4dc2-ab3a-dba9a2b30ce4",
            "product_uid": "00000000-0000-0000-0000-000000000000",
            "modification_date": "2009-11-04T10:39:42.000000Z",
            "material_package_umid": "0x060A2B340101010501010D43130000005C91020063D700800210F3FFFE154618"
        }
    }
}

Unfortunately, I don't have an answer to your current problem. But consider filling out the SMPTE Time Label survey found at the bottom of this page to share your experiences with time code.

can you run ffprobe -i {filename} -print_format json -show_streams
and then post the result please?

Do it with -show_format as well.

Done. I've looked into the ffmpeg code base and it seems that timecode has its own frame rate specified...maybe this file was converted from an 29.97 to 25 without converting the timecode framerate?

I'm not sure what is going on here, but anyway you don't need DF timecode when you have NDF footage - this appears to be running at 25FPS so the timecode will run in real time anyway. DF is only going to be useful to you when you are running at a non-integer frame rate.


text:
ffmpeg adds unneeded zero samples at beginning of resulting m4a file
Input file original.wav
ffmpeg -i original.wav
...
  Duration: 00:03:36.93, bitrate: 1411 kb/s

Convert wav to m4a with fdk-aac encoder:
ffmpeg -i original.wav -c:a libfdk_aac -vbr 5 ffmpeg.m4a

Check duration of resulting m4a:
ffmpeg -i ffmpeg.m4a
...
  Duration: 00:03:36.98, start: 0.046440, bitrate: 240 kb/s

So, ffmpeg adds ~2000 zero samples at beginning of resulting file. How to disable this?

I try few different codecs and all work fine, problem only with fdk-aac.

ffmpeg versions: 2.2.10 and 2.4.3
fdk-aac version: 0.1.1 and 0.1.3

UPD1: I try fdkaac and vlc (it also use fdk-aac library). Both produce correct file (no zero samples at begin). So problem only with ffmpeg+fdk.

Is ffmpeg adding the padding, or is it the external encoding library? Does it also occur if you use fdkaac? It's a command line encoder frontend for libfdk-aac.

I have seen this also with libfdk_aac and x264 and am not sure what causes it but I have had success using the itsoffset flag like this:
ffmpeg -itsoffset 0.046440 -i original.wav -c:a libfdk_aac -vbr 5 ffmpeg.m4a