text:
What are the best Webcam features for recording whiteboard videos in high quality
I stand in front of a whiteboard or a smartboard and teach online. Want to record my mathematics and science lecture videos (1-1.5 hours each) for YouTube but in the best quality. Many cameras provide 1080 at 60fps but their video quality output when seen by students appears different.
End result should be like this example

Was thinking of Logitech Brio 4K Ultra HD or Obsbot Tiny 2 or Insta Link 360 type of 4K PTZ camera because I work alone, but I am not sure. Am a math genius but zero at Web Cameras :(
Budget is not a problem. Suggestions for features to look in those Webcams are welcome.
Thanks for your advice in advance

This is not an answer, but a long comment.
That is a really bad-quality video. The images on the back look good because he is probably superimposing them. But the video shoot itself looks very bad. The camera has a very small dynamic range.
An additional problem, probably the main one is bad light. He is probably using low-quality fluorescent light and he is not white-balancing the result. And the position is not good either, It just happens to be on the ceiling...
But it makes no sense to keep talking about an example of a random video on the internet. It would be better to improve YOUR setting, so post an example of what you have to see what can be improved.

Video quality output when seen by students appears different

That is a problem on the student's side. Probably they have low bandwidth, or a small screen, or a broken screen. You can not measure that.

Was thinking of an X 4K camera.

Having a 4k or 8k camera will not do anything with bad light, and if the students still are using the same screen.
Besides taking a look at how your setup looks, there is something really simple you can and should do.
Do not shoot at 60FPS.
If your students have low bandwidth, don't send them unnecessary high framerate for a professor talking. If you use 30FPS you are sending half the information, so you can actually double the quality of the compression!
If your camera shoots at 24FPS even better!
But, again, post some screenshots of your setup.

In order to decide on a new camera, you should pay attention to the lens: the focal length, and this depends on the space you have and the distances between you and your board.

Well, that sample video looks great on my 6ft OLED TV :) Trust me, the students mostly have very good Internet speed and the right viewing screens. My post is about Webcam features for video recording.
What I am actually asking is with which cam can I shoot similar quality videos at 1080 60fps?
Which of those allows locking the focus on the whiteboard so that the text does not become blurry when the teacher moves and the camera auto focuses?
My other

Distance between the camera and board is around 1 to 1.5 m

Now, you are asking another question about autofocus, or manual/fixed focus. Then simply look for that spec in the features of the cameras, or look for a small aperture like f/8.


text:
Scaling clip problems in davinci resolve 19
im a davinci resolve newbie and im having this problem : im trying to scale this greenscreen clip but when i make it smaller it just gives a black "outline" to the video, cuz i dont know how to explain it, heres a screenshot of what happens:

source: Stack Exchange

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

sort: votes


text:
FFMPEG burn subtitle to master.m3u8 file
Hey i use ffmpeg to process video into hls stream and generate screenshots using this command
 ffmpeg -y -i /tmp/input.mp4 \
  -vf fps=1/10 thumbnails/thumbnail_%03d.jpg \
  -preset slow -g 48 -sc_threshold 0 \
  -map 0:0 -map 0:1 -map 0:0 -map 0:1 -map 0:0 -map 0:1 -map 0:0 -map 0:1 \
  -s:v:0 640x360 -c:v:0 libx264 -b:v:0 365k -c:a:0 aac -b:a:0 96k \
  -s:v:1 960x540 -c:v:1 libx264 -b:v:1 2000k -c:a:1 aac -b:a:1 128k \
  -s:v:2 1280x720 -c:v:2 libx264 -b:v:2 3000k -c:a:2 aac -b:a:2 192k \
  -s:v:3 1920x1080 -c:v:3 libx264 -b:v:3 5000k -c:a:3 aac -b:a:3 256k \
  -var_stream_map "v:0,a:0 v:1,a:1 v:2,a:2 v:3,a:3" \
  -master_pl_name master.m3u8 \
  -f hls -hls_time 6 -hls_list_size 0 \
  -hls_segment_filename "v%v/fileSequence%d.ts" \
  v%v/prog_index.m3u8

But now i need to attach subtitle to the master m3u8 file How do i do that

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


text:
FFMetrics for streaming video
I have come across this article and FFMetrics repo, and was wondering if it is even possible to grab such quality metrics for streaming such as udp or rdp?


text:
Dropzone Cropping Final Cut Pro
I'm using PremiumVFX Simple Split Screens, when I use some compound clips within a drop zone they are strangely cropped. I can't work out why and other clips seem to work.
I don't think it's the fault of PremiumVFX, there's something different in the clips.

As I'm not a power user I'm not even sure I'm using the right terminology. Does anyone have any ideas?

The difference between the clips seems to be an adjustment layer. I still don't know how to solve it.


text:
Multiple trims to a video using ffmpeg generating video with shorter duration than expected
I have an application that given a video it trims multiple parts of that video using ffmpeg. Each part is cropped, scaled and then concatenated to generate a single video.
To share an example, I have a video of 1 minute and 44 seconds of duration and 60 fps. My goal is to trim 3 parts of the video:

First one between seconds 0 to 44.666
Second one between seconds 44.666 to 74.349
Third one between seconds 74.349 to 103.985

The ffmpeg command I use to achieve that is the following one:
ffmpeg -y -hide_banner -i bg_720_1280.png -i error.mp4 -filter_complex "
[1:v]trim=0.0:44.666,setpts=PTS-STARTPTS,crop=405.0:720.0:437.5:0.0,scale=-2:1280.0[crop_1_0_v];
[1:a]atrim=0.0:44.666,volume=1.0,asetpts=PTS-STARTPTS[crop_1_0_a];
[0:v][crop_1_0_v]overlay=enable='between(t,0,44.666)':x=0.0:y=0.0[crop_1_0_v];
[1:v]trim=44.666:74.349,setpts=PTS-STARTPTS,crop=405.0:720.0:437.5:0.0,scale=-2:1280.0[crop_2_0_v];
[1:a]atrim=44.666:74.349,volume=1.0,asetpts=PTS-STARTPTS[crop_2_0_a];
[0:v][crop_2_0_v]overlay=enable='between(t,0,29.683)':x=0.0:y=0.0[crop_2_0_v];
[1:v]trim=74.349:103.985,setpts=PTS-STARTPTS,crop=405.0:720.0:437.5:0.0,scale=-2:1280.0[crop_3_0_v];
[1:a]atrim=74.349:103.985,volume=1.0,asetpts=PTS-STARTPTS[crop_3_0_a];
[0:v][crop_3_0_v]overlay=enable='between(t,0,29.636)':x=0.0:y=0.0[crop_3_0_v];
[crop_1_0_a][crop_2_0_a][crop_3_0_a]concat=n=3:v=0:a=1[a];
[crop_1_0_v][crop_2_0_v][crop_3_0_v]concat=n=3:v=1:a=0[outv];
[a]amix=1:duration=longest[outa]" -map "[outv]" -map "[outa]" -vcodec libx264 -acodec aac -sws_flags lanczos -pix_fmt yuv420p -crf 17 -preset superfast -r 60 test.mp4

Running this command it generates a video of 11 seconds of duration and I'm unable to understand it. What is wrong with the command? Also I'm open to recommendations of the ffmpeg command in case you find another way more efficient or performant.
I tried to isolate the error using this reduced command:
ffmpeg -y -hide_banner -i error.mp4 -filter_complex "
[0:v]trim=0:45,setpts=PTS-STARTPTS[crop_1_0_v];
[0:v]trim=45:74,setpts=PTS-STARTPTS[crop_2_0_v];
[0:v]trim=74:104,setpts=PTS-STARTPTS[crop_3_0_v];
[crop_1_0_v][crop_2_0_v][crop_3_0_v]concat=n=3:v=1:a=0[outv]" -map "[outv]" -vcodec libx264 -sws_flags lanczos -pix_fmt yuv420p -crf 17 -preset superfast -r 60 test.mp4

But using this command I get a video of 1 minute and 24 seconds instead of 1 minute and 44 seconds.
I'm using the following FFMPEG version:
ffmpeg version 7.0.2 Copyright (c) 2000-2024 the FFmpeg developers
  built with Apple clang version 15.0.0 (clang-1500.3.9.4)
  configuration: --prefix=/usr/local/Cellar/ffmpeg/7.0.2 --enable-shared --enable-pthreads --enable-version3 --cc=clang --host-cflags= --host-ldflags='-Wl,-ld_classic' --enable-ffplay --enable-gnutls --enable-gpl --enable-libaom --enable-libaribb24 --enable-libbluray --enable-libdav1d --enable-libharfbuzz --enable-libjxl --enable-libmp3lame --enable-libopus --enable-librav1e --enable-librist --enable-librubberband --enable-libsnappy --enable-libsrt --enable-libssh --enable-libsvtav1 --enable-libtesseract --enable-libtheora --enable-libvidstab --enable-libvmaf --enable-libvorbis --enable-libvpx --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxml2 --enable-libxvid --enable-lzma --enable-libfontconfig --enable-libfreetype --enable-frei0r --enable-libass --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-libspeex --enable-libsoxr --enable-libzmq --enable-libzimg --disable-libjack --disable-indev=jack --enable-videotoolbox --enable-audiotoolbox
  libavutil      59.  8.100 / 59.  8.100
  libavcodec     61.  3.100 / 61.  3.100
  libavformat    61.  1.100 / 61.  1.100
  libavdevice    61.  1.100 / 61.  1.100
  libavfilter    10.  1.100 / 10.  1.100
  libswscale      8.  1.100 /  8.  1.100
  libswresample   5.  1.100 /  5.  1.100
  libpostproc    58.  1.100 / 58.  1.100

But I got the same issue with static ffmpeg builds
The file bg_720_1280.png is just a transparent image of resolution 720x1280. I think I could achieve the same by using nullsrc filter with that resolution instead of using this background image.


text:
Optimize VHS Capturing with OBS Studio
My setup is: VHS > AV2HDMI > UGreen HDMI capture device.

Is the bit rate overkill?
How about incoming resolution and scaled output, should I go smaller?
It seems to currently output 15MB/min, which seems high?

Generally speaking, existing video files seem to play ok. Just wondering if there could be something else I could be looking at. So far, seems ok, but I'm not sure.
My OBS settings:


text:
Get blur effect inside a drawn box using ass format
I have created an backdrop with rounded corners using [drawing command]. Example of dialog for backdrop.
Dialogue: 0,00:00:38.60,00:00:42.10,Default,,0,0,0,,{\p1\1a&HD8&\c&HE27FA4&\pos(341.07421875,517.5)\an4}  {\p1}m 15 0 b 1202.8515625 .... {\p0}

Now I want to make the backdrop blur. (Text backdrop by ass formatting)
I have tried to use \blur or \be, but they are for other purpose. Below is reference from the doc link to doc
Enable or disable a subtle softening-effect for the edges of the text

Is there any other way to achieve the blurred backdrop. I am ready even to mix ffmpeg commands like boxblur and ass file. I mean separately paint the backdrops and then apply ass subtitles file. Here is an experiment to explain the idea.
[0:v]split=3[base][blur1_in][blur2_in];

[blur1_in]crop=w=100:h=100:x=20:y=40[region1];
[region1]boxblur=luma_radius=10:luma_power=1[blurred_region1];
[base][blurred_region1]overlay=x=20:y=40:enable='between(t,0,5)'[tmp1];

[blur2_in]crop=w=30:h=30:x=20:y=40[region2];
[region2]boxblur=luma_radius=5:luma_power=1[blurred_region2];
[tmp1][blurred_region2]overlay=x=20:y=40:enable='between(t,5,10)'[tmp2];

[tmp2]ass=../logs/ass.ass:fontsdir=../fonts/Audiowide-Regular.ttf[final_video]

The problem in this case is that the corners are not rounded. Could anyone explain to me what is the easiest way to get backdrop with rounded corners an blurred inside


text:
Remove moving text from a video Davinci Resolve
I am new to Davinci resolve and am following this video to remove text from my video:

I followed this cut to cut and at frame 429, I get a proper static image to which I apply paint clone and time track it. Then I create a planar transform and merge it to the output. The node graph looks like this:
[![enter image description here][1]][1]
[1]: https://i.sstatic.net/jtJH31sF.png
This approach is working fine. The issue is that the video is made of slides and each slide has a transition sliding in effect. When the frame which has the text slides, it is having a little glitch and showing the text for some time.


text:
How to Upload a 180-Degree Panoramic Video to YouTube with Limited Panning
I'm trying to upload a 180-degree panoramic video to YouTube so that viewers can pan left and right within a 180-degree range, but not all the way around (not a full 360-degree view). I also want to limit vertical panning, as looking up and down isn't necessary for my content (at least not very much).
Most of what I find online are tutorials for VR and fully 360-degree spherical videos.
Here's what I've tried so far:

Using VSDC Free Video Editor:
I exported the video with the following settings:

Embed 3D video information: Selected "Video is not stereoscopic."
Embed 360 video information: Chose "Equirectangular."

However, when I upload the video to YouTube, it allows viewers to pan a full 360 degrees, which isn't what I want.

Injecting Metadata with Spatial Media Metadata Injector:
I attempted to use the command-line tool to inject metadata that would limit the field of view to 180 degrees. Unfortunately, the arguments to set the FOV don't seem to exist.  The GUI for it is very limited.

My goal: I want YouTube to recognize my video as a 180-degree panoramic video, allowing viewers to pan only within the intended range horizontally and restrict unnecessary vertical panning.
Questions:

How can I properly configure my video and metadata so that YouTube limits the panning to 180 degrees horizontally?
Is there a way to adjust the metadata or use a different tool to achieve this effect?
Has anyone successfully uploaded a monoscopic 180-degree video to YouTube with these panning limitations?

Any guidance or suggestions would be greatly appreciated!


text:
Get rectangular with rounded corners in ffmpeg
I want to get rectangular with rounded corners using ffmpeg commands. I assume it should be done by geq command, but I couldn't make it and couldn't find any examples.  Since I'm going to use this rectangular for blur effect I don't want other tools to be involved. Here is the command I currently have
[0:v]split=3[base][blur1_in][blur2_in];

[blur1_in]crop=w=100:h=100:x=20:y=40[region1];
[region1]boxblur=luma_radius=10:luma_power=1[blurred_region1];
[base][blurred_region1]overlay=x=20:y=40:enable='between(t,0,5)'[tmp1];

[blur2_in]crop=w=30:h=30:x=20:y=40[region2];
[region2]boxblur=luma_radius=5:luma_power=1[blurred_region2];
[tmp1][blurred_region2]overlay=x=20:y=40:enable='between(t,5,10)'[tmp2];

[tmp2]ass=../logs/ass.ass:fontsdir=../fonts/Audiowide-Regular.ttf[final_video]

Now I need to add rounded corners to this boxes.


text:
Frame duration issues when trimming videos in MATLAB/ffmpeg?
I have two videos (A.MOV and B.MOV), that are supposed to be perfectly synced. However, Video A (3708 frames), has 5 more frames than Video B (3703 frames). When I look at the timestamps of these frames, the extra A frames are at the very end of the video. In addition, the last frame in each video is a "padded" frame, with a duration much longer (around 10 times) than that of the other frames.
I need my videos to be perfectly synced, with the same frame number. Since the extra frames are at the end of the video, I want to trim off the extra frames in A, as well as trim the "padded" long frame off of each video.
I currently am running the below MATLAB code to do so,
I have two videos (A.MOV and B.MOV), that are supposed to be perfectly synced. However, Video A (3708 frames), has 5 more frames than Video B (3703 frames). When I look at the timestamps of these frames, the extra A frames are at the very end of the video. In addition, the last frame in each video is a "padded" frame, with a duration much longer (around 10 times) than that of the other frames.

I need my videos to be perfectly synced, with the same frame number. Since the extra frames are at the end of the video, I want to trim off the extra frames in A, as well as trim the "padded" long frame off of each video.

I currently am running the below MATLAB code to do so,

% Specify the input and output file names
inputVideoFile = 'A.MOV';
intermediateVideoFile = 'A_trim_temp.mp4'; % Temporary file
finalOutputFile = 'A_trim_mat.mp4'; % Final output file
% Create VideoReader object
videoReader = VideoReader(inputVideoFile);
% Get the total number of frames and other properties
numFrames = videoReader.NumFrames;
frameRate = videoReader.FrameRate;
videoHeight = videoReader.Height;
videoWidth = videoReader.Width;
% Create VideoWriter object
videoWriter = VideoWriter(intermediateVideoFile, 'MPEG-4');
videoWriter.FrameRate = frameRate;
open(videoWriter);
% Read and write frames except the last 5
for i = 1:(numFrames - 5)
    frame = read(videoReader, i);
    writeVideo(videoWriter, frame);
end
% Close the VideoWriter object
close(videoWriter);
% Handle audio extraction and trimming
% This requires an external tool like FFmpeg, as MATLAB does not handle audio directly
% Command to extract audio
audioExtractCommand = sprintf('ffmpeg -i "%s" -q:a 0 -map a audio_original.wav', inputVideoFile);
[status, cmdout] = system(audioExtractCommand);
if status ~= 0
    error('Error extracting audio: %s', cmdout);
end
% Command to trim audio (matching the length of the trimmed video)
audioTrimCommand = sprintf('ffmpeg -i audio_original.wav -ss 0 -t %f -c copy audio_trimmed.wav', (numFrames - 5) / frameRate);
[status, cmdout] = system(audioTrimCommand);
if status ~= 0
    error('Error trimming audio: %s', cmdout);
end
% Command to merge trimmed audio with the video
audioMergeCommand = sprintf('ffmpeg -i "%s" -i audio_trimmed.wav -c:v copy -c:a aac -strict experimental "%s"', intermediateVideoFile, finalOutputFile);
[status, cmdout] = system(audioMergeCommand);
if status ~= 0
    error('Error merging audio and video: %s', cmdout);
end
% Clean up temporary audio files
delete('audio_original.wav');
delete('audio_trimmed.wav');
delete(intermediateVideoFile); % Delete the intermediate file

When I run the above code for Video B, I change for i = 1:(numFrames - 5) to for i = 1:(numFrames - 1) to remove the padded last frame.
When I run this for both videos, they both return the same frame number (yay!). The timestamps of every frame between A_trim_mat and B_trim_mat match, except for the timestamp of the last frame ( A_trim_mat = 30.8910, B_trim_mat = 30.8890), and perhaps most concerningly, the frame duration between the last two frames of each video is negative (A_trim_mat = -0.0063, B_trim_mat = -0.0083). The duration for all other frames is constant at 0.0083 for both videos.
Any suggestions for how to remedy this are much appreciated. Ideally, I want the timestamps for every frame to match between A and B, and I want the frame duration for each frame to match between A and B.


text:
Generating B-frames before I-frame with ffmpeg (like XAVC)
Several files generated in XAVC have 2 B-frames before the I-frame and I've been trying to transcode those files using ffmpeg to match the structure at a lower resolution/bitrate, but I've been unable to do so. I was hoping that -force_key_frames source would do that, but it always makes the first frame a key frame, so is there a way to match the pict_type and have 2 B-frames before the I-frame while transcoding with ffmpeg?

How are you determining the order of the frames in the source?

This command outputs the frames and then also stepping through the ffmpeg code with a debugger:
ffprobe -show_entries frame=pts,pkt_pos,pict_type -of csv=p=0 -I test.mp4


text:
Adjusting time for audio of HLS stream
Is it possible to adjust a value in the initialization section provided by EXT-X-MAP to adjust the timing of the audio during playback? For example, I'd like to shift the audio forward or backward by 1 second, so can I do that by adjusting a value in the initialization section rather than re-encoding all of the audio data?


text:
How do tools like CapCut and Veed.io add subtitles so quickly?
I've tested video editors like CapCut and Veedio, and I'm amazed at how fast they can add subtitles to a video. I'm curious about how they achieve such impressive performance.
I’m considering two possibilities:

They render a single canvas that combines the video and the subtitles, so the output is the same as what you see in the editor.

They create a separate subtitle track and attach it to the video later using something like FFmpeg.

Do you think they use a different method to achieve such fast video rendering with subtitles?


text:
HEIC/HEIF to PNG using NVIDIA hevc_cuvid
OS: Ubuntu
I want to convert heic/heif to png using GPU(not software decoding), mostly to avoid patent issues. While hevc_cuvid + ffmpeg works for h265 video. Since heic/heif are on the same platform hevc, How to convert them to png using "hardware decoding"


text:
ffmpeg trying to fix video with out of sync PTS
I'm working with a mp4 video originally from a livestream, that plays the first three minutes normally then only plays audio. I've had some luck using the setpts filter as I end up with video that lasts 68 minutes of the 73 minutes of audio. However, this results in a desync between video and audio that starts early in the video, and builds throughout. The original video has some duplicate frames as a result of frame drops when originally streamed but I don't see these duplicate frames in the output video from ffmpeg. I'm unsure if the setpts filter is dropping these frames or some other issue is apparent. I'm not experienced with using ffmpeg/trying to fix videos so let me know if there is any more detail I can provide..
input video general info
ffmpeg version 2024-08-18-git-7e5410eadb-essentials_build-www.gyan.dev Copyright (c) 2000-2024 the FFmpeg developers
  built with gcc 13.2.0 (Rev5, Built by MSYS2 project)
  configuration: --enable-gpl --enable-version3 --enable-static --disable-w32threads --disable-autodetect --enable-fontconfig --enable-iconv --enable-gnutls --enable-libxml2 --enable-gmp --enable-bzlib --enable-lzma --enable-zlib --enable-libsrt --enable-libssh --enable-libzmq --enable-avisynth --enable-sdl2 --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxvid --enable-libaom --enable-libopenjpeg --enable-libvpx --enable-mediafoundation --enable-libass --enable-libfreetype --enable-libfribidi --enable-libharfbuzz --enable-libvidstab --enable-libvmaf --enable-libzimg --enable-amf --enable-cuda-llvm --enable-cuvid --enable-dxva2 --enable-d3d11va --enable-d3d12va --enable-ffnvcodec --enable-libvpl --enable-nvdec --enable-nvenc --enable-vaapi --enable-libgme --enable-libopenmpt --enable-libopencore-amrwb --enable-libmp3lame --enable-libtheora --enable-libvo-amrwbenc --enable-libgsm --enable-libopencore-amrnb --enable-libopus --enable-libspeex --enable-libvorbis --enable-librubberband
  libavutil      59. 34.100 / 59. 34.100
  libavcodec     61. 11.100 / 61. 11.100
  libavformat    61.  5.101 / 61.  5.101
  libavdevice    61.  2.100 / 61.  2.100
  libavfilter    10.  2.102 / 10.  2.102
  libswscale      8.  2.100 /  8.  2.100
  libswresample   5.  2.100 /  5.  2.100
  libpostproc    58.  2.100 / 58.  2.100
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'input.mp4':
  Metadata:
    major_brand     : isom
    minor_version   : 512
    compatible_brands: isomiso2avc1mp41
    encoder         : Lavf58.26.101
  Duration: 01:13:34.85, start: 0.000000, bitrate: 1042 kb/s
  Stream #0:0[0x1](und): Video: h264 (Baseline) (avc1 / 0x31637661), yuv420p(progressive), 1280x720, 20969 kb/s, 623.94 fps, 29.97 tbr, 90k tbn (default)
      Metadata:
        handler_name    : VideoHandler
        vendor_id       : [0][0][0][0]
  Stream #0:1[0x2](und): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, mono, fltp, 97 kb/s (default)
      Metadata:
        handler_name    : SoundHandler
        vendor_id       : [0][0][0][0]
At least one output file must be specified

Frame logs to the input and output videos if helpful.


text:
How can I fix poor video quality from VLC which occurred after upgrading from Debian Bullseye to Bookworm?
I'm getting very poor quality from VLC after upgrading from Debian 11 to 12, like it drops some frames and tries to recover from that every 10 seconds or so. Mplayer works like a charm by the way. How can I investigate the case?
VLC media player 3.0.21 Vetinari (revision 3.0.21-0-gdd8bfdbabe8)
VLC version 3.0.21 Vetinari (3.0.21-0-gdd8bfdbabe8)
Compiled by marillat on deb-multimedia.org (Jun 12 2024 05:33:04)
Compiler: gcc version 12.2.0 (Debian 12.2.0-14)


text:
Convert mxf and dnxhd to smaller format
I have various HDDs worth of MXF and DNXHD that are huge files done for networks.
I'm in the need of making a personal showreel from some frames of each video, but have no storage to store 10 TB of data just for 500MB of real usable data.
Can I convert them to mp4 h264 or h265 full hd short gop or intra I for editing ?
What ffmpeg options you suggest to use?
Was trying with adobe media encoder but the only option that cames to my mind is the keyframe distance, should I set it to 1 or 4 or 8 as alternative to ffmpeg?


text:
Cast from VLC on windows to DLNA renderer
I am using VLC 3.0.20 under windows and want to cast my audio (music) to a DLNA renderer on my network.  I can do this using MS Windows Media Player (works fine), but I want to use VLC
In VLC under PlayBack>Renderer I only see < LOCAL > and "scanning".  Why will my DLNA renderer not appear?
I found under Tools>Playlist>Service Discovery there is an option to add "services discovery modules" but I can't find what goes in there, or anything about this, in cases that's important.


text:
.TS file missing codec information
I have a bunch of videos recorded in a .ts format. Some of the videos can be played by VLC.
However I have quite a number of files that cant be played. They show the same size as the working files, but cant be played.
Upon checking the corrupted files doenst have any codec information like codec, bitrate and such.
I tried repairing the corrupted files from renaming the extension to using Wondershare Repairit, Untruc and VLC. All doesnt seem to work.
I seek some advice from you video gurus, is there a way to rescue my corrupted files.
Thanks a lot.


text:
Noob question. How does transcoding help with editing? Won't it lower the quality of the final release?
Lets say I have a GH5 and I shoot in AVC/H264. I transcode it to Prores 442 for easier editing load. And I export to H264 mp4 again for web use, and prores 422 mov for master. wouldn't the footage degrade after all this?

If your original video codec is H264/AVC the compression was already there when you received the footage: So the transcode will only serve as a better encoding/compatibility/optimizing with the software your working with. The example you gave of course will degrade your footage because the treatment is making 2 "encoding downgrades" trips when you could just make 1 through working directly with the H264 files; You'll need to conform that sequence with the original H264/AVC files for getting better results on the final master, even though if you don't care about preserving the best quality for archival processes this may be innecesary or not important for you.
The main use of a transcode is optimizing the workflow between editor -- color grading suite + software codec compatibility and read speeds. Generally speaking the transcoder downgrades the 4K - 8K .arx file from an ARRI/RED/DJI cam into something like .mxf in HD for the editor to work on his laptop, this .mxf contains metadata for the color suite conform editor to reconnect with the original media files that are in 4K-8K and export VFX shots into something like .EXR - PRORES4444 with full resolution [Always mantaining the best quality files (CODEC - SIZE - COLORSPACE)] this back and forth mantains a Quality Control check verifying that the best quality files are always updated and without any problem between the trips. Then the final master is always exported from that timeline that the color grading technician has, and will be archived "for the future" to have the best quality preserving copy, or at least hoping to preserve it through time.


text:
Davinci trims beginning and end of my video
I've edited a video in DaVinci Resolve 19.0.2 and I'm trying to render it but right after I click the Render button, it switches the Render mode from "Entire Timeline" to "In/Out Range" and also trims several seconds at the beginning and the end of the video. Nothing seems to be able to fix this.
I've tried copy-pasting the timeline contents into a new project and got the same problem. This is driving me insane. What is wrong with DaVinci here?


text:
I have downloaded 1 .mpd file with videos(1269)(.mp4) and audio(1897)(.mp4) data downloaded, How to play them or combine for offline use
Downloaded some data (VIDEO FILE FROM WITHIN A PC SOFTWARE)
SINGLE .mpd file
videos(1269 files)(.mp4) different folder
audios(1897 files)(.mp4)  different folder
HOW TO VIEW/CONVERT/COMBINE THESE AS VIDEO. Pardon me if I made a mistake, this is the first time that I'm Posting on this website.

DESCRIPTION:
Name    Extension   Path    Size MiB
F:\010_USE-ME\MPD
d4ad5c7d-f89b-4f50-b438-a0ba79c8b163.png    png F:\010_USE-ME\MPD\  0.09
F:\010_USE-ME\MPD\6663321c8423ab0012b7b997
master_480.mpd  mpd F:\010_USE-ME\MPD\6663321c8423ab0012b7b997\ 0.08
F:\010_USE-ME\MPD\6663321c8423ab0012b7b997\dash\
F:\010_USE-ME\MPD\6663321c8423ab0012b7b997\dash\480
1.mp4   mp4 F:\010_USE-ME\MPD\6663321c8423ab0012b7b997\dash\480\    0.17
2.mp4   mp4 F:\010_USE-ME\MPD\6663321c8423ab0012b7b997\dash\480\    0.17
upto videos(1269 files)(.mp4)
F:\010_USE-ME\MPD\6663321c8423ab0012b7b997\dash\audio
1.mp4   mp4 F:\010_USE-ME\MPD\6663321c8423ab0012b7b997\dash\audio\  0.05
2.mp4   mp4 F:\010_USE-ME\MPD\6663321c8423ab0012b7b997\dash\audio\  0.05
3.mp4   mp4
audios(1897 files)(.mp4)


text:
Galaxy A14G - Camera video feedback different than captured photo
I'm working on a web app that uses WebRTC to capture video from a cellphone camera. I've noticed a color accuracy issue on A14G devices. In low-light conditions, the camera's video preview appears significantly duller than the actual captured images. For instance, a photo with four distinct green, blue, red, and light pink dots shows vibrant colors, while the video feed portrays them as muted, especially the light pink which appears completely gray.
This problem persists with automatic settings enabled. However, manually adjusting the ISO improves the video preview. I've tested other phones with identical settings (ISO, shutter, white balance, etc.), but only the A14G exhibits this color inaccuracy. Has anyone else experienced this issue, and if so, how did you resolve it?


text:
How does Azure's Content-Aware Encoding work?
I was reading Azure's Content-Aware Encoding post here: https://learn.microsoft.com/en-us/azure/media-services/latest/encode-content-aware-concept
It says:

In ideal conditions, you want to be aware of the type of content you
are encoding. Using this information you can tune the encoding ladder
to match the complexity and motion in your source video. This means
that at each display size (resolution) in the ladder, there should be
a bitrate beyond which any increase in quality is not perceptive – the
encoder operates at this optimal bitrate value.

How does it compute the video complexity in a fast pass? What exactly do they measure that can represent the video complexity, in an efficient way?


text:
.srt subtitles added to mkv with ffmpeg are not displayed
I try to add .srt subtitles to the mkv file and it doesn't work.
I use the following very simple command:
$ ffmpeg -y -i original.mkv -i sub_original.srt -map 0 -map 1 -c copy ~/temp.mkv
ffmpeg version n4.2 Copyright (c) 2000-2019 the FFmpeg developers
  built with gcc 9.1.0 (GCC)
  configuration: --prefix=/usr --disable-debug --disable-static --disable-stripping --enable-fontconfig --enable-gmp --enable-gnutls --enable-gpl --enable-ladspa --enable-libaom --enable-libass --enable-libbluray --enable-libdav1d --enable-libdrm --enable-libfreetype --enable-libfribidi --enable-libgsm --enable-libiec61883 --enable-libjack --enable-libmodplug --enable-libmp3lame --enable-libopencore_amrnb --enable-libopencore_amrwb --enable-libopenjpeg --enable-libopus --enable-libpulse --enable-libsoxr --enable-libspeex --enable-libssh --enable-libtheora --enable-libv4l2 --enable-libvidstab --enable-libvorbis --enable-libvpx --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxcb --enable-libxml2 --enable-libxvid --enable-nvdec --enable-nvenc --enable-omx --enable-shared --enable-version3
  libavutil      56. 31.100 / 56. 31.100
  libavcodec     58. 54.100 / 58. 54.100
  libavformat    58. 29.100 / 58. 29.100
  libavdevice    58.  8.100 / 58.  8.100
  libavfilter     7. 57.100 /  7. 57.100
  libswscale      5.  5.100 /  5.  5.100
  libswresample   3.  5.100 /  3.  5.100
  libpostproc    55.  5.100 / 55.  5.100
Input #0, matroska,webm, from 'original.mkv':
  Metadata:
    encoder         : libebml v1.3.0 + libmatroska v1.4.1
    creation_time   : 2019-09-14T13:50:43.000000Z
  Duration: 00:58:52.45, start: 0.000000, bitrate: 8212 kb/s
    Stream #0:0(eng): Video: h264 (High), yuv420p(progressive), 1920x1080 [SAR 1:1 DAR 16:9], 23.98 fps, 23.98 tbr, 1k tbn, 47.95 tbc (default)
    Stream #0:1(rus): Audio: ac3, 48000 Hz, 5.1(side), fltp, 448 kb/s (default)
    Metadata:
      title           : Dub
    Stream #0:2(eng): Audio: ac3, 48000 Hz, 5.1(side), fltp, 640 kb/s
    Stream #0:3(rus): Subtitle: subrip (default) (forced)
    Metadata:
      title           : Forced
    Stream #0:4(rus): Subtitle: subrip
    Stream #0:5(eng): Subtitle: subrip
    Stream #0:6(ger): Subtitle: subrip
    Stream #0:7(fre): Subtitle: subrip
    Stream #0:8(ita): Subtitle: subrip
    Stream #0:9(spa): Subtitle: subrip
    Stream #0:10(dut): Subtitle: subrip
    Stream #0:11(por): Subtitle: subrip
    Stream #0:12(tur): Subtitle: subrip
    Stream #0:13(gre): Subtitle: subrip
    Stream #0:14: Video: mjpeg (Baseline), yuvj420p(pc, bt470bg/unknown/unknown), 854x1280 [SAR 72:72 DAR 427:640], 90k tbr, 90k tbn, 90k tbc (attached pic)
    Metadata:
      filename        : Cover_Unbelievable.jpg
      mimetype        : image/jpeg
Input #1, srt, from 'sub_original.srt':
  Duration: N/A, bitrate: N/A
    Stream #1:0: Subtitle: subrip
Output #0, matroska, to 'temp.mkv':
  Metadata:
    encoder         : Lavf58.29.100
    Stream #0:0(eng): Video: h264 (High) (H264 / 0x34363248), yuv420p(progressive), 1920x1080 [SAR 1:1 DAR 16:9], q=2-31, 23.98 fps, 23.98 tbr, 1k tbn, 1k tbc (default)
    Stream #0:1(rus): Audio: ac3 ([0] [0][0] / 0x2000), 48000 Hz, 5.1(side), fltp, 448 kb/s (default)
    Metadata:
      title           : Dub
    Stream #0:2(eng): Audio: ac3 ([0] [0][0] / 0x2000), 48000 Hz, 5.1(side), fltp, 640 kb/s
    Stream #0:3(rus): Subtitle: subrip (default) (forced)
    Metadata:
      title           : Forced
    Stream #0:4(rus): Subtitle: subrip
    Stream #0:5(eng): Subtitle: subrip
    Stream #0:6(ger): Subtitle: subrip
    Stream #0:7(fre): Subtitle: subrip
    Stream #0:8(ita): Subtitle: subrip
    Stream #0:9(spa): Subtitle: subrip
    Stream #0:10(dut): Subtitle: subrip
    Stream #0:11(por): Subtitle: subrip
    Stream #0:12(tur): Subtitle: subrip
    Stream #0:13(gre): Subtitle: subrip
    Stream #0:14: Video: mjpeg (Baseline) (MJPG / 0x47504A4D), yuvj420p(pc, bt470bg/unknown/unknown), 854x1280 [SAR 72:72 DAR 427:640], q=2-31, 90k tbr, 1k tbn, 90k tbc (attached pic)
    Metadata:
      filename        : Cover_Unbelievable.jpg
      mimetype        : image/jpeg
    Stream #0:15: Subtitle: subrip
Stream mapping:
  Stream #0:0 -> #0:0 (copy)
  Stream #0:1 -> #0:1 (copy)
  Stream #0:2 -> #0:2 (copy)
  Stream #0:3 -> #0:3 (copy)
  Stream #0:4 -> #0:4 (copy)
  Stream #0:5 -> #0:5 (copy)
  Stream #0:6 -> #0:6 (copy)
  Stream #0:7 -> #0:7 (copy)
  Stream #0:8 -> #0:8 (copy)
  Stream #0:9 -> #0:9 (copy)
  Stream #0:10 -> #0:10 (copy)
  Stream #0:11 -> #0:11 (copy)
  Stream #0:12 -> #0:12 (copy)
  Stream #0:13 -> #0:13 (copy)
  Stream #0:14 -> #0:14 (copy)
  Stream #1:0 -> #0:15 (copy)
Press [q] to stop, [?] for help
[matroska @ 0x564c2717f840] Starting new cluster due to timestamp
[matroska @ 0x564c2717f840] Starting new cluster due to timestamp37 bitrate=8282.2kbits/s speed= 387x
frame=84685 fps=9337 q=-1.0 Lq=-1.0 size= 3542743kB time=00:58:52.41 bitrate=8215.9kbits/s speed= 389x
video:3070859kB audio:469153kB subtitle:265kB other streams:0kB global headers:0kB muxing overhead: 0.069655%

At first glance it seems to work - if I open new file with VLC I can see new subtitle stream, but the subtitles themselves are not visible!
I get the followng warnings/errors in the console:

[matroska @ 0x557924efe840] Starting new cluster due to timestamp
[matroska @ 0x557924efe840] Starting new cluster due to timestamp

So I suppose it's the root of the problem, but I don't know what to do with it. Some other videos work fine with the same command, some don't.

https://pastiebin.com/5dae2a8e2a1cb

But I'm 100% sure that everything is fine with this file. Because in order to figure my problem out I used subtitle file from the original file. If I map it directly even multiple times everything works fine without any errors but once I try to map the file using input file it doesn't work.

ffmpeg -y -i /path_to_original.mkv -map 0:v -map 0:a -map 0:s -map 0:s:0 -c copy ~/path_to_result.mkv
this command works perfectly - here I map the first subtitle stream twice and it works, but once I try to map it using the external file it stops working.

Show full log from command.

https://pastiebin.com/5dae2cb7038c5

Possibly #6037 mkv muxing broken and #7064 External subtitle files cause wrong interleaving. Workaround may be to try -max_interleave_delta 0.

Thank you so so so so so much! You've totally saved me, it works!!! Just one more question - it's a universal solution, right? I can add this option for all other similar subtitle injections?

@llogan by the way would you post your comment as an answer so I can accept it?

Possibly #6037 mkv muxing broken and #7064 External subtitle files cause wrong interleaving. Workaround may be to try -max_interleave_delta. Experiment to see which values work for you.


text:
FFMPEG transcription from .webm to HNxHD
I'm a n00bie with video production.
I installed ffmpeg. It's recognized.
So I tried my first conversion.

ffmpeg -i earth.webm earth.DNxHD

and, then, after searching:

ffmpeg -i earth.webm -f DNxHD earth.DNxHD

In both cases I get the following error:

Error initializing output stream 0:0 -- Error while opening encoder
for output stream #0:0 - maybe incorrect parameters such as bit_rate,
rate, width or height
Conversion failed!

What I gather from that is that the default settings did not work and ffmeg wants me to include those values.
And that's the problem. What values should be selected for these unknown files? (I grabbed them from the web - they're copyright free - and want to use them in Da Vinci Resolve (hence the need for DNxHD)
Included is the error msg
C:\Users\GLM\Downloads\test>ffmpeg -i earth.webm -f DNxHD earth.DNxHD
ffmpeg version 4.1.3 Copyright (c) 2000-2019 the FFmpeg developers
  built with gcc 8.3.1 (GCC) 20190414
  configuration: --enable-gpl --enable-version3 --enable-sdl2 --enable-fontconfig --enable-gnutls --enable-iconv --enable-libass --enable-libbluray --enable-libfreetype --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-libopus --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libtheora --enable-libtwolame --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxml2 --enable-libzimg --enable-lzma --enable-zlib --enable-gmp --enable-libvidstab --enable-libvorbis --enable-libvo-amrwbenc --enable-libmysofa --enable-libspeex --enable-libxvid --enable-libaom --enable-libmfx --enable-amf --enable-ffnvcodec --enable-cuvid --enable-d3d11va --enable-nvenc --enable-nvdec --enable-dxva2 --enable-avisynth
  libavutil      56. 22.100 / 56. 22.100
  libavcodec     58. 35.100 / 58. 35.100
  libavformat    58. 20.100 / 58. 20.100
  libavdevice    58.  5.100 / 58.  5.100
  libavfilter     7. 40.101 /  7. 40.101
  libswscale      5.  3.100 /  5.  3.100
  libswresample   3.  3.100 /  3.  3.100
  libpostproc    55.  3.100 / 55.  3.100
Input #0, matroska,webm, from 'Earth.webm':
  Metadata:
    encoder         : Lavf57.8.100
  Duration: 00:00:45.55, start: 0.000000, bitrate: 358 kb/s
    Stream #0:0(eng): Video: vp8, yuv420p(progressive), 426x240, SAR 255:254 DAR 3621:2032, 24 fps, 24 tbr, 1k tbn, 1k tbc (default)
    Stream #0:1(eng): Audio: vorbis, 48000 Hz, stereo, fltp (default)
File 'earth.DNxHD' already exists. Overwrite ? [y/N] y
Stream mapping:
  Stream #0:0 -> #0:0 (vp8 (native) -> dnxhd (native))
Press [q] to stop, [?] for help
[dnxhd @ 000001d544fc7800] video parameters incompatible with DNxHD. Valid DNxHD profiles:
[dnxhd @ 000001d544fc7800] Frame size: 1920x1080p; bitrate: 175Mbps; pixel format: yuv422p10
[dnxhd @ 000001d544fc7800] Frame size: 1920x1080p; bitrate: 185Mbps; pixel format: yuv422p10
[dnxhd @ 000001d544fc7800] Frame size: 1920x1080p; bitrate: 365Mbps; pixel format: yuv422p10
[dnxhd @ 000001d544fc7800] Frame size: 1920x1080p; bitrate: 440Mbps; pixel format: yuv422p10
[dnxhd @ 000001d544fc7800] Frame size: 1920x1080p; bitrate: 115Mbps; pixel format: yuv422p
[dnxhd @ 000001d544fc7800] Frame size: 1920x1080p; bitrate: 120Mbps; pixel format: yuv422p
[dnxhd @ 000001d544fc7800] Frame size: 1920x1080p; bitrate: 145Mbps; pixel format: yuv422p
[dnxhd @ 000001d544fc7800] Frame size: 1920x1080p; bitrate: 240Mbps; pixel format: yuv422p
[dnxhd @ 000001d544fc7800] Frame size: 1920x1080p; bitrate: 290Mbps; pixel format: yuv422p
[dnxhd @ 000001d544fc7800] Frame size: 1920x1080p; bitrate: 175Mbps; pixel format: yuv422p
[dnxhd @ 000001d544fc7800] Frame size: 1920x1080p; bitrate: 185Mbps; pixel format: yuv422p
[dnxhd @ 000001d544fc7800] Frame size: 1920x1080p; bitrate: 220Mbps; pixel format: yuv422p
[dnxhd @ 000001d544fc7800] Frame size: 1920x1080p; bitrate: 365Mbps; pixel format: yuv422p
[dnxhd @ 000001d544fc7800] Frame size: 1920x1080p; bitrate: 440Mbps; pixel format: yuv422p
[dnxhd @ 000001d544fc7800] Frame size: 1920x1080i; bitrate: 185Mbps; pixel format: yuv422p10
[dnxhd @ 000001d544fc7800] Frame size: 1920x1080i; bitrate: 220Mbps; pixel format: yuv422p10
[dnxhd @ 000001d544fc7800] Frame size: 1920x1080i; bitrate: 120Mbps; pixel format: yuv422p
[dnxhd @ 000001d544fc7800] Frame size: 1920x1080i; bitrate: 145Mbps; pixel format: yuv422p
[dnxhd @ 000001d544fc7800] Frame size: 1920x1080i; bitrate: 185Mbps; pixel format: yuv422p
[dnxhd @ 000001d544fc7800] Frame size: 1920x1080i; bitrate: 220Mbps; pixel format: yuv422p
[dnxhd @ 000001d544fc7800] Frame size: 1440x1080i; bitrate: 120Mbps; pixel format: yuv422p
[dnxhd @ 000001d544fc7800] Frame size: 1440x1080i; bitrate: 145Mbps; pixel format: yuv422p
[dnxhd @ 000001d544fc7800] Frame size: 1280x720p; bitrate: 90Mbps; pixel format: yuv422p10
[dnxhd @ 000001d544fc7800] Frame size: 1280x720p; bitrate: 180Mbps; pixel format: yuv422p10
[dnxhd @ 000001d544fc7800] Frame size: 1280x720p; bitrate: 220Mbps; pixel format: yuv422p10
[dnxhd @ 000001d544fc7800] Frame size: 1280x720p; bitrate: 90Mbps; pixel format: yuv422p
[dnxhd @ 000001d544fc7800] Frame size: 1280x720p; bitrate: 110Mbps; pixel format: yuv422p
[dnxhd @ 000001d544fc7800] Frame size: 1280x720p; bitrate: 180Mbps; pixel format: yuv422p
[dnxhd @ 000001d544fc7800] Frame size: 1280x720p; bitrate: 220Mbps; pixel format: yuv422p
[dnxhd @ 000001d544fc7800] Frame size: 1280x720p; bitrate: 60Mbps; pixel format: yuv422p
[dnxhd @ 000001d544fc7800] Frame size: 1280x720p; bitrate: 75Mbps; pixel format: yuv422p
[dnxhd @ 000001d544fc7800] Frame size: 1280x720p; bitrate: 120Mbps; pixel format: yuv422p
[dnxhd @ 000001d544fc7800] Frame size: 1280x720p; bitrate: 145Mbps; pixel format: yuv422p
[dnxhd @ 000001d544fc7800] Frame size: 1920x1080p; bitrate: 36Mbps; pixel format: yuv422p
[dnxhd @ 000001d544fc7800] Frame size: 1920x1080p; bitrate: 45Mbps; pixel format: yuv422p
[dnxhd @ 000001d544fc7800] Frame size: 1920x1080p; bitrate: 75Mbps; pixel format: yuv422p
[dnxhd @ 000001d544fc7800] Frame size: 1920x1080p; bitrate: 90Mbps; pixel format: yuv422p
[dnxhd @ 000001d544fc7800] Frame size: 1920x1080p; bitrate: 350Mbps; pixel format: yuv444p10, gbrp10
[dnxhd @ 000001d544fc7800] Frame size: 1920x1080p; bitrate: 390Mbps; pixel format: yuv444p10, gbrp10
[dnxhd @ 000001d544fc7800] Frame size: 1920x1080p; bitrate: 440Mbps; pixel format: yuv444p10, gbrp10
[dnxhd @ 000001d544fc7800] Frame size: 1920x1080p; bitrate: 730Mbps; pixel format: yuv444p10, gbrp10
[dnxhd @ 000001d544fc7800] Frame size: 1920x1080p; bitrate: 880Mbps; pixel format: yuv444p10, gbrp10
[dnxhd @ 000001d544fc7800] Frame size: 960x720p; bitrate: 42Mbps; pixel format: yuv422p
[dnxhd @ 000001d544fc7800] Frame size: 960x720p; bitrate: 60Mbps; pixel format: yuv422p
[dnxhd @ 000001d544fc7800] Frame size: 960x720p; bitrate: 75Mbps; pixel format: yuv422p
[dnxhd @ 000001d544fc7800] Frame size: 960x720p; bitrate: 115Mbps; pixel format: yuv422p
[dnxhd @ 000001d544fc7800] Frame size: 1440x1080p; bitrate: 63Mbps; pixel format: yuv422p
[dnxhd @ 000001d544fc7800] Frame size: 1440x1080p; bitrate: 84Mbps; pixel format: yuv422p
[dnxhd @ 000001d544fc7800] Frame size: 1440x1080p; bitrate: 100Mbps; pixel format: yuv422p
[dnxhd @ 000001d544fc7800] Frame size: 1440x1080p; bitrate: 110Mbps; pixel format: yuv422p
[dnxhd @ 000001d544fc7800] Frame size: 1440x1080i; bitrate: 80Mbps; pixel format: yuv422p
[dnxhd @ 000001d544fc7800] Frame size: 1440x1080i; bitrate: 90Mbps; pixel format: yuv422p
[dnxhd @ 000001d544fc7800] Frame size: 1440x1080i; bitrate: 100Mbps; pixel format: yuv422p
[dnxhd @ 000001d544fc7800] Frame size: 1440x1080i; bitrate: 110Mbps; pixel format: yuv422p
[dnxhd @ 000001d544fd9800] ff_frame_thread_encoder_init failed
Error initializing output stream 0:0 -- Error while opening encoder for output stream #0:0 - maybe incorrect parameters such as bit_rate, rate, width or height
Conversion failed!

The DNxHD codec has multiple profiles, and the DNxHD profile supports only a limited set of parameters. The DNxHR profiles does not have these restrictions.
Use
ffmpeg -i earth.webm -profile:v dnxhr_hq -f DNxHD earth.DNxHD

This will not keep the audio. If you need that, use
ffmpeg -i earth.webm -c:v dnxhd -profile:v dnxhr_hq earth.mov

Thank you! I'll try it out tonight, when I get home.

Thanks. It worked great. Da Vinci isn't importing these files. But that's yet another thing I have to research.


text:
How good is a DSLR video?

Possible Duplicate:
What are the minimum camera characteristics required to record a movie for cinema?

Can one send Nikon D 3200 or Canon 550 D video to any major film festival (after Reverse Telecine conversion)? Can this video be projected on a large screen...large enough to be displayed in front of 200-300 people? I am aware about the quality of canon 5d...please let me know about the video quality of cameras mentioned (canon 550d or Nikon D 3200).
Please also let me know if it's wiser to invest in a Nikon AF-S DX Nikkor 55-300 mm f/4.5-5.6G ED VR Lens; (considering i am concerned only about the video)? The 55-200 mm lens is much cheaper and i am not very sure (have not handled these lenses before) if 55-300 provides any considerable magnification over the 55-200 one. Please advise which one is significantly better considering the cost as well.

This question is not very well posed as it concerns some subjective questions. You could do a vimeo/youtube search with keywords like Nikon d3200 and Canon 550D. If you choose the Canon 550D you could look into the custom firmware Magic Lantern to improve the video capabilities. Concerning the lenses: it is not clear either on what you exactly want to know. The 55-300 has around 50% more magnification, but I am not sure what you want with that data. Please split up your question and clarify.

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


text:
Animation in videos

Possible Duplicate:
Animation in video

I know this is a photography forum but maybe someone can help me with a video related question?
I have a video of a guy doing push ups. On that video I want to be able to draw some lines showing what angles the arms should be at when the guy is down and up. The lines should follow the guy on screen as he doing the exercise to show the viewers the correct way of doing the exercise.
Can anyone suggest any software that i will be able to use to achieve this effect? I have looked at some Final Cut Pro stuff but it is unclear if I can draw primitives (lines, circles etc.) with this package on screen?
Again, sorry if this is the wrong forum to ask. Hopefully someone out there have done something similar to this in the past and can point me in the right direction

@vivek_jonam - please be careful suggesting other sites. It could lead to the question being reposted when it should be migrated.

Yip, like I said I know this was the wrong place to ask...Thanks for pointing me in the right direction though

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


text:
Banding in Premiere preview

Possible Duplicate:
Gradient banding

I have a video imported in Adobe Premier from After effect (16 bits).
Before rendered in the timeline the image looks nice but when rendered I have a important banding (see photo 2 (no banding) and 3 (with banding))
Because it is only on the rendered video in the timeline this must be a codec issue (correct me if I am wrong).
What is the best codec and settings to use in order to have a nice preview and nice final video ?

because I have no reputation I can not add any link nor images.

But I can add it the comment. Here is the original file : http://flic.kr/p/czePj5, a close-up on the nice gradient : http://flic.kr/p/czeQ6q and a close-up on the banded gradient in premier : http://flic.kr/p/czePkW

I checked this answer but the banding is not in the video, the problem lies in the codec / export.

Actually, in looking at the images on a decent monitor at home, it looks like what you have is not banding but compression artifacts. Can you change it to a higher quality setting.


text:
Periodicals/magazines/blogs for cinematography?
I want to stay up-to-date on cinematography techniques -- not just regurgitated press releases on camera technology. What regularly updated resources (not books) should I follow to continually learn the craft of cinematography?
Note: this is a re-post of a question that was closed as off-topic on Photography - Stack Exchange.

For basics in digital cinema the Vimeo School is a great start.
There are tons of blogs for cinematography.
One of the most interesting blogs that covers gear and on the set experiences
is by noted DP, Philip Bloom, a real major force in modern digital cinema:
http://philipbloom.net/blog/
Coen Brothers too:
http://thecoenbrothers.blogspot.com/?zx=2bb8d66a241d6286
For me the best way to find what's up is to see if your favorite
director, studio, camera manufacturer, or whatever has a blog via Google.

American Cinematographer is a magazine and the leading publication on cinematography. At the very least, you should be reading this.
Also, these forums have great communities:

http://www.cinematography.com/One of the oldest communities on the web about cinematography.
http://www.reduser.net/A forum focused on the Red Digital Cinema Camera Company but is very active and a good place to stay up-to-date on cinematography techniques.
http://www.rogerdeakins.com/forum2/A website where 9-time Oscar nominee Roger Deakins answers questions submitted by readers.


text:
How to add text to specific animation frames
I'm not really a video expert, I'm more into Geographical Information Systems (GIS). I've recently been able to make some great time-based animations of Geographical Data using the excellent QGIS with Time Manager plugin, and mencoder. The former outputs a series of static PNG files and the latter converts to a video.
I would like to improve these by adding text to the video, so that over a specific period of time (i.e. specific number of frames) some text is showing. This text should vary by month or week of the video.
I'm wondering if anyone has any good techniques for this. My first thoughts were that I would have to either:

Alter the relevant PNGs programmatically, perhaps using a tool like Image Magick. This would require selecting the correct frames to work on somehow
Do it in video-editing software. I don't know whether there are any that can do something like this. Ideally it would be open-source and able to run on Windows as this is a work project.

Does anyone have any experience with either of these two methods, or some general advice?

I don't know for sure (and don't have it in front of me to check) but doesn't Windows Movie Maker have a basic function like this? I think it's included with Windows.

Quite possibly, but certainly not the locked down, hobbled version of XP that I have here at work. But thanks. Maybe could try at home

If you don't want to mess around with either of the free video editor versions available from Windows, WinXP (Windows Movie Maker) or Win7 (Windows Live Movie Maker) as these may not be flexible enough for your project, then you can try out a pro version with a free demo (good for 30 days) of Sony Vegas Pro 11.
Once you set up your trial version, add your video to the timeline, then use the "media generator/text" (title) features to add the titles you want. There are lots of options on the text generators.
Three links that are of interest.
Free Demo Version of Vegas Pro 11 (make sure you choose the correct version for your computer as in 32 vs. 64 bit):
http://www.sonycreativesoftware.com/download/trials/vegaspro?keycode=64506
Tutorial on how to use the media generator/text on Vegas Pro 11:

Expert advice and overview of Vegas Pro media generator:
http://www.sonycreativesoftware.com/media_generators_in_vegas_pro_software
Likely you can get your whole project done under the 30 day trial period and render a final version ready to post or show. If you don't understand how to render there are tons of tutorials out there, so just for fun I'll add one more link:


text:
Negative SMPTE timecode drop-frame handling?
How are negative timecodes handled with drop-frame:

Is the frame before -00:00:59:29 labelled -00:00:01:02 (symmetric), or
Is the frame after -00:01:00:01 labelled -00:00:59:28 (regular)?

Thanks.

Negative timecodes are not mentioned in SMPTE-12, the relevant standard, so I presume that as with timecodes > 24 hours the behaviour is implementation defined. FFMPEG's timecode flags allow for negative timecodes, you could check their implementation: https://www.ffmpeg.org/doxygen/2.7/timecode_8h_source.html

I know this is a very old Q, but it should be pointed out that a 'negative timecode' makes no sense. The SMPTE frame before 00:00:00:00 is 23:59:59:29. The namespace for drop frame (and non-drop) codes is already well-defined -- no need to postulate negative values. If there are systems or programs that use this notation, they should be rethought.

Taking into account that

frame dropping works on a 10min-regular basis
project offsetting by a multiple of 10min should keep frame dropping at the same positions

I guess the correct way of doing this is on a regular basis.

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/2.5/


text:
Why doesn't an FFT pitch filter fully 'mute' the selected pitch range?
While editing a song, I tried to cut out the bass drum by applying a high-pass FFT filter, i.e. filtering out the low pitch of the bass drum.  This resulted in the drum sound being severely quieted, rather than removed entirely.  I know that higher overtones from the drum would still be present in the audio, but why isn't the lower pitch completely removed?

Really muting sound below a certain frequency only happens when using a so-called 'brickwall' filter. Are you sure you are using such a type of filter?

I believe I was, but I'm not entirely sure how Adobe Audition does it.

Can you see the low tones in a spectrum, or you just perceive that they're still there?  Audition has settings in the FFT filter dialog to make the filter work better.  Did you try adjusting them?

First of all, tell us more about the filter. Is it really a brickwall filter, or are you actually using a low roll-off or low cut-off filter? In the latter case, it is perfectly normal, when using a high cut-off filter, the low frequencies decrease with -6dB per octave below the specified frequency, and are not completely gone. Roll-off is the same, but with less dBs per octave. (either 4,5 or 3, can't really remember.)
If you did use a brickwall filter, there is another possible explaination:
A phenomenon in psycho-accoustics is the hearing of a low note where it is not there, but when the harmonics (= overtones) are there. Every base tone has different overtones. (Really, if multiple overtones are there, there is really not much ambiguity.) The human brain actually processes these overtones and adds the base tone.

Hmm, psycho-acoustics sounds interesting ;) thanks!

In general a filter is not something that completely removes a given set of frequencies.  Rather, it just attenuates them - cutting some percentage of them out.  In extreme cases (kill EQs on DJ mixers come to mind) the attenuation is so much that it may as well be considered getting rid of it entirely.
Wikipedia has a pretty good graph of how a low pass filter cuts out higher frequencies in their article on Low-pass filters.  A low-pass filter can be thought of as a "high-reducing" filter if that makes more sense.
This behavior shows up whether the filters are FFT-based, analog, whatever.

Not entirely correct, you can actually get à real brickwall filter using FFT, as long as the FFT reaches the top frequency of your sample rate. That is, you can have an FFT filter that filters 5000Hz with 0dB and 4999Hz with -96dB. One of the advantages of a Fourier filter.

@Pelle I didn't realize they could actually get that extreme!  Thank you for the clarification :)

Normal filters can't basically, since you always deal with 'filter components'. FFT filters are different, they can get any shape possible within the frequency and the dynamic range, and they can have any phase characteristics you wish. (That is why convolution reverb is based on FFT as well.)

with an FIR filter or FFT-filter (which is kind of the same thing in disguise) you can get an arbitrarily precise and sharp frequency response. See e.g. DSP Guide Chapter 17

all_licenses: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/2.5/


text:
Remove noise in video post production
I have a video, shot with a recent but low-end camcorder (Samsung HMX-Q10) in Full HD 1920x1080/50i.
The problem is that there wasn't enough light (I guess) and the camcorder added some "parasites" to the video on the zones in the shadow (blacks are quite okay, but dark zones are not).
The kind of parasites that you may see on that video (on walls for instance) (this is not a video shot with that camcorder, nor my video).
So, I don't seem to be able to remove them when shooting, whatever the parameters of the cam are. I still need to try with more light, but I'd like to know if it is possible to correct that with a post-production effect on my existing video, especially with Sony Vegas Pro.
Moreover, is there a way to prevent the cam to add those artificial elements to the video ? This looks like some numeric elements added to the video, like the cam tries to correct the lighting. Can't the camcorder write exactly the image it gets from the lens, even if it's too dark ?
Can I achieve this kind of dark image with my cam (or maybe it is darkened in post production ?)

The parasites you talked about is called noise. The setting you can change to get less is called the ISO. It corresponds to the old ASA value we had before the digital age.
We can't see a thing, we can only see light. That's the way the universe is built up. Same with the camera. It sees the light reflected off surfaces. So white objects reflects all light and dark objects no light. And absence of light, as you know, means darkness. Where it is dark it has to "work extra hard" to figure out what's actually there, because there is almost no information there given from the light. Therefore you will get some noise. A better camera will produce less noise.

Turn down the ISO as much as possible without compromising the aperture or "shutter speed" you want.
Remove the noise left in post.

It is also no problem to edit it away in post on your computer! The only compromise is that you will get smoother edges and blurred images the more noise you remove. I once saw a movie shot entirely by moonlight. It was full of noise but they removed everything in post!
There are two plugins you can use:

Neat Video's Noise Removal. I've never tried this, but you can use it with Sony Vegas. They claim to be the best in noise removal.

Red Giant's Magic Bullet DeNoiser. I've used this and am very satisfied with it. Does a really good job. I don't know if this works in Vegas, but it certainly works great in Adobe After Effects and Premiere Pro!

Wow, Neat Video's plugin work really great !

Good to hear! :)

The parasites you are referring to is actually called 'noise'.

Digital noise comes from two main sources. The first being the inherent noise in the camera's sensor. This is exacerbated by heat buildup on the chip from multiple exposures or long exposures, or by having many photosites clustered onto a small chip. This is why dSLRs have less noise than point and shoots. The second source of noise you allude to is from the ISO rating. The ISO setting simply amplifies the signal through the chip, much like turning up the volume on your stereo. With the volume at 3, you can't hear the noise in your stereo, at 10 you hear the hiss through the speakers. This is amplification noise.
  The best advice for avoiding camera noise. Buy a camera with a larger CCD or CMOS chip (think dSLR), and work to dial in your exposures. Underexposed images always end up being noisier than correctly exposed images.
  - Jay Kinghorn.
  RGB Imaging

There is no real way to remove this noise from your image in post. Adobe After Effects may have a Reduce Noise filter (I don't use it so I don't know for sure) but what it could actually achieve would be very limited. I also don't use Sony Vegas so I can't help you there, but I'm going to take a stab in the dark and say it doesn't have a Reduce Noise filter.

Regarding this part of the question:
"Can I achieve this kind of dark image with my cam (or maybe it is darkened in post production ?)"
This looks like post production work and Vegas can do this. There are two things going on
in the video to make it look dark. One is the use of a border or frame that is feathered on the inside edge and totally black at the outside (frame) edge. The other effect is a tweak on the brightness and contrast levels of this clip and possibly some color grading.
In Vegas Pro you can get the border a couple of ways.
1) Vega Pro--> choose Video FX (tab) --> choose 'border' --> select 'soft edge' --> adjust size in pop up to suit your need.
2) Vega Pro--> choose Video FX (tab) --> choose 'cookie cutter' --> select 'circle' --> in pop up change the following: set 'shape' to rectangle', set 'method' to "cut away all but section', set size and feather to your need.
The 2nd method will allow you more control of the soft zone of the border.
And to make the overall scene darker.
1) Vega Pro--> choose Video FX (tab) --> choose 'brightness and contrast' --> adjust brightness and contrast sliders to where you want it.
2) additionally: Vega Pro--> choose Video FX (tab) --> choose 'color correction' or '2nd color correction' to tweak the color grade as a part of the overall look of this clip.


text:
How to help the autofocus feature of an amateur camcorder
I just acquired an amateur camcorder (Samsung HMX-Q10) that has only a few settings available, most of them are automatic.
I tried to shoot a video of me playing a bass guitar cover but it seems that the image is always slightly out of focus. I'm just slightly blurred but with HD image this kind of detail is really noticeable.
Shooting environment : me standing in front of the camcorder (~2-3 meters) with an instrument, in my appartment (walls mostly white), natural winter/cloudy lighting, white /  bright brown background, black clothes, red guitar.
Cam specifications/settings : Full HD 1920x1080/50i, Exposure Value : 0, Shutter 1/50 of a second (there is a "low light mode" that set it to 1/25 but it adds colored artifacts).
I can't notice that the image is blurred on the camcorder small monitoring screen, but when I open the video on the computer it is more obvious (especially because the guitar brand label is blurred), so without proper feedback it is quite hard to manually set the focus.
So what can I do to help the autofocus ?
What can I change in the shooting environment to improve its accuracy ?
I'm thinking, maybe the lighting, the colors (background / clothes), some camcorder settings, another element I forgot ?

I reviewed the specifications for the Samsung HMX-Q10 and have to say there is not a whole lot of information e.g., optics has no mention of "Minimum Focus Distance". So we are pretty much in the dark on the near boundary of the depth of field.
(a little rant on auto-focus)
Most auto focus systems have two modes: Single AF and Full-time AF. Single AF translates into setting the focus once, focusing what ever the sensor picks up first usually in the center of the frame (there are other possible areas depending on the camera, but I'm guessing this Samsung is limited to center weighted focus). Single AF keeps the same focus area during the whole shot. Full-time AF changes focus according to what is changing in the frame. This would be good for tracking a sports event or something moving. Unfortunately the Samsung specs don't mention any of this so I am not sure if this camera has two modes, or one, or if one mode, which one Samsung made the default.
Here is how I would approach shooting your bass playing.
1) mount the camera on a tripod so the camera is steady.
2) Likely 1 meter to 2 meters will be far enough away to be in focus. I recommend that you
   experiment with this to see if 1 meter is better than 2 or if 2 is better than 3 meters.
3) light the set with as much light as you can as this will force the auto-exposure to
   'stop-down' the iris as in a smaller aperture, which translates into more depth of
   field.
4) in front of the camera, dead center, put a chair or something where you will be playing,
   (use some gaffers tape to mark this spot off camera on the floor assuming your not
   going to show your feet) this will force the auto-focus to focus on the space you are
   going to be.
5) set the camera zoom to full wide (the wider you set the lens, the greater the depth
   of field).
6) press the record button, walk to your spot toss the chair or prop that was standing in
   for you and start your action. All the stuff that happened before you started playing
   your bass can be cut out in post production.
Alternately you can have a friend stand in for you on your mark before you start the camera, you could even have them give an intro then decide later to keep it or cut it and go direct to the bass playing. Also, you could have an assistant do all this camera work for you while you stay in place to start the show.
Quick review:
1) tripod to steady the camera,
2) lots of light,
3) set zoom to widest angle,
4) have your spot in focus before you start.


text:
Different luminosity between preview and render on Sony Vegas 13
I currently have a problem with a video I'm editing, when I render it with Sony Vegas 13 (with the Sony AVC/MVC 1080p-30fps "Internet" preset), the resulting video is much darker than the preview (on the same screen), whatever player I use (VLC, Youtube, Windows Media Player).
This is really annoying because I now have to export small chunks of the video to check the resulting luminosity without being able to preview it properly.
I already did dozens of video with the exact same process (same camera, same lighting setup...), except I was using version 12, and I currently can't try to revert back to previous version.
Any idea of what's happening ?
Any suggestion of what I can do to have a preview that matches the rendered video ?
Some context :
The video is a man wearing black standing in front of a green screen. The green screen is keyed to a complete black screen.
In order to be able to see the man's body, I adjust the luminosity and contrast so that the clothes are slightly brighter than the background.
After rendering, everything is darker so the clothes are of the same color as the background and you just see a face with hands floating...
UPDATE
User altarvic suggested that I check the histograms of both videos and to do that I imported back the rendered video in Vegas. And there, the luminosity is correct in preview (the image is exactly what the preview displayed).
So it seems that the luminosity is wrong on players (at least the ones I tried), but not in Vegas.
Could it be a codec issue ? (Vegas using it's own, player using the machine's).
Or the Vegas preview is not displaying properly the video (I checked I have no output effects applied).

Have you compared the source and the result using video scopes? (Histogram/Waveform)?

No, good idea, it'll try that and post the result.

Oh ! Now that's interesting... Importing the rendered video into Vegas, the luminosity is correct (so scopes are very similar). But PLAYING the video in any player, the luminosity is wrong... Codec issue ?

Or possibly a color profile in the meta-information that is being respected by Vegas and not by the players.  Could also be an adjustment being applied by your graphics card that is overridden by Vegas.

Looks like a problem with full range levels 0..255 vs video levels 16..235 (Computer/Studio RGB levels in Vegas). Maybe video players treat video as 0..255, but it is 16..235 Have you applied Levels FX to your video?

Yes, this is a tip I found and that seem to work (it gives me something acceptable when rendering) but it's also applied to the preview (it's brighter) so the rendered video is still different from the preview, quite hard to apply effects quickly then, as I need to render each time I want to try changing a value.

@altarvic that helped me, thanks

I believe I have a solution. Render the video, put it into Vegas again and apply "Sony Levels" with "Computer RGB to Studio RGB". Worked for me.

Better than rendering twice : you can add the plugin "Levels" (they removed the "Sony") to the Video output FX (in the video preview panel).
Keep it disabled until you render (it will mess up your luminosity, but the rendered video will be good).

Vegas 15 has Finally fixed these issues with the new ACES 1.0 support. To render perfect colors for video AND stills you must ensure the following project project properties are as followed.
https://imghost.io/image/GS3sB

You should actually embed the image above in the post.  As it is, nobody knows what the heck that link goes to.


text:
Sony Vegas default chroma key seem to shift blue colors
After a few videos, I think that now I manage pretty well chroma key on a green screen.
But in my last video, my subject handles items that are light blue / cyan, and I started to notice that those items shift color and become an unnatural blue, it looks like contrast has been pushed A LOT after applying the chroma key effect, I never noticed that before (probably because this color is quite greenish).
But this is not how I thought chroma key was working. I thought it was just removing the parts of the video that was matching the selected color (+some margin) and not touch the other parts/colors of the video.
And indeed, testing it with several other tools (Adobe After Effects, Lightworks, and the NewBlueFX chroma key plugin), it does exactly what I expect : remove the background and doesn't touch the colors that doesn't match. Only the default chroma key plugin seem to do that.
Is it a bug in the chroma key plugin (that seem to exist at least on version 12 and 13) ? (but it would be surprising as I guess a lot of people would be affected)
Is it a bug with my installation ? (keeping in mind that uninstalling Vegas 12 and installing Vegas 13 didn't fix it)
Is it some parameter or something I forgot somewhere that would affect the chroma key plugin ?
Update :
Here is small parts of the video, with different effects applied :

The raw image
The best I can do with the NewBlueFX Chroma Key plugin
The best I can do with the default Vegas Chroma Key plugin (pretty ugly...)

Vegas Settings :

NewBlue Settings :

This might be an issue with the Vegas chroma key program removing green from all objects and making it transparent rather than finding only solid green and modifying that.
Someone may know how to fix this in Vegas, but if all else fails you can run your keyed footage through a program like Davinci Resolve Lite (free) and correct the colors.

I would guess that it is trying to correct for green highlights in the chromakeyed video and overdoing it.  It's relatively common for green screen footage to have greenish reflections due to light bouncing off the green wall back on to subjects.  The chroma-key effect may be attempting to automatically correct this and catching objects that have no such reflections in the crossfire.  I would expect it to be a setting that can be turned on and off, but I'm not familiar enough with Vegas to take a guess as to what it might be called there.
Possibly something like "bleed prevention" or "reflection correction", but those are just guesses.

I don't think it's that. It already occured to me on one of my first attempts at chroma key, and it only made the green parts transparent, it didn't change the color of the "not keyed" parts.

Can you post a screen shot of the green screen settings you are using that also shows the color change you are experiencing?  That would help a lot with figuring it out.  I tried to find documentation on Sony's site, but it was less than helpful.

I added a screenshot (the image is bigger, I expected the site to open a popup... please use open image as new tab). As you see, the blue color become awful (in my mind it was more purple, but it's still ugly). There is a bit of green reflection but other tools handle it pretty well (it disappears with the keying and the blue is slightly darker but it looks okay, nothing like what Vegas' plugin does).

Ok, I know it won't help you much now after 4,5 years, but i found roundabout for those still looking. Set up color corrector (secondary) with hue rotation 180, then chroma keyer, then color corrector (secondary) with hue rotation 180 again. It's not perfect as you'll have to play around with the slider, but at least you won't have to switch/download other programs.


text:
Tips to make a stopmotion walk
I'm making a game using photographs for the animation. I've asked a friend to walk in place, and taking pictures of each step, using a 6-steps cycle.
It ended "cool", but as the photo session was made in like 20 minutes, it needs to be improved.
I myself added some tips:

Use a better camera (right know I'm using a standard digital camera).
Place the camera on a tripod.
Use a greenscreen to better separate the subject from the background.
Don't use auto, because the lightning can't vary from picture to picture.
Trace a line on the floor to indicate where my friend has to stand.

Do you have any more ideas to help me with this? What I don't really know is how to make the walking to appear as "natural" as possible.
You can play what I've done so far here. (Or just watch a video if you don't have the patience).
You can also see a making-of in this video.
And finally, these are the pictures I'm currently using (don't mind the posterize, that's just a filter for the game):

Given the prevalence of video on cameras, can't you take a video of it?  If you want it to look stop motion just drop frames from the video then.

Thanks for the suggestion of the treadmill. I tried using video but the video gets so blurry with movement, and my friend can't move slow-motion.

To reduce blur in video, use brighter light. The camera will compensate by taking shorter exposures each frame. If you have manual controls, make the aperture as open as it'll go.

I'm not sure you need a better camera for this. since you are downgrading the images to a pretty low quality anyway. The secret to good green screen photography is in the lighting more than in the camera. You need to light the background as evenly as possible, and use a background color that is not present in the subject's clothing. In your example blue would not work due to the shirt, but green might. You can also use a white sheet if you make sure no part of your subject gets blown specular highlights. You need to make sure your subject is not too close to the background, as it may catch reflected light from it. This is particularly important if you go with blue or green background, maybe less with white.
The camera on a tripod is a good idea, but don't expect you'll get images that will be perfectly registered. I expect you will still need to align them, but the job will be easier when the camera was fixed on a tripod.
The camera should be in manual. If you don't want to mess much with the settings just take a few test pictures in auto mode (no on-camera flash, try to use other light sources from the sides, to not create shadows on the background) and once you find one that you like switch to manual and copy the exposure settings.
I think you want to mark a spot on the floor that your subject can use to position himself for the pictures. A line does not seem too useful, since your friend isn't really walking.
My final advice (the one that might be off-topic for this site) is that you grab a good book on animation and learn the animated walk cycle. You just need to have your friend pose in those proven positions that make up natural walks in cartoons. My recommendation is the Preston Blair book, Cartoon Animation.
Good luck with your game.


text:
How do you load a Bolex H-16?
How do you load a Bolex H-16?
A complete answer will include a link to the camera manual, page number for reference in the ASC manual, and a video demonstrating effective loading technique.

The following resources show how to load a Bolex H-16 camera:
Instructional video for loading a Bolex (4 mins, Vimeo.com)
PDF of the manual (see page 13 - "Feeding the film into-the camera by hand")
You can also find instructions on loading this camera in the American Cinematographer Manual.


text:
How to create 3D video from two separate stereo images?
I have two images that form a stereo pair. I'd like to view this in 3D on a Samsung 3D television. I was looking for such a software but did not find anything exactly for this task. My question is: how could I put this togedher? What if I make a video that changes the two images frame-by-frame in 25 fps? Is 3d avi supposed to work that way?

Use Sony Vegas. It can merge the stereo inputs and renders the output file as the format you need.

While this does answer the question, could you expand it a bit with more information about how this is accomplished in Vegas?

For creating a 3d image (from two jpeg images), this piece of software works pretty well:
http://stereo.jpn.org/eng/stphmkr/
Creating a full 3d video is a bit more difficult, so I'm not sure if I can help you there.

I recommended to use the Dashwood Stereo3D Toolbox (link: http://www.dashwood3d.com/stereo3dtoolbox.php).
I use it for convert SBS to TaB and adjust the 3D effect with Final Cut, it works well.

you can try the gopro studio that can create a 3d video using a proprietary codec as output ( hold the 2 video stream synchronized). After that you can use more traditionnal editor that recognize the codec (need to be installed on windows) and make you final video (including most of video modification) and export in several 3d format (anaglyphe, SBS, ...). In fact this is the codec manager that hold the 3D until export.
The main problem (not tested because i use footage from gopro) is that gopro studion need to recognize your 2 video stream as source.


text:
Is there a method (or tool) to convert video from a SWF container to another more portable format (e.g., H.264)
I have a client who has misplaced the original source video, only has an SWF, and would like to use it in a non-flash environment.
Is there any way to do this?
So far, I've tried ffmpeg but it's failed, complaining about the compressed SWF.
[swf @ 0x101807c00] Compressed SWF format not supported
Any help would be appreciated.

This question seems more broadcast and compression specific than AV Production! Inviting experts to a new site proposal Broadcast and Media Technologies which aims to capture more architectural and theoretical views around subjects like this. Join and invite others.

You should get a SWF decompiler (perhaps one of the trails for: Sothink SWF Decompiler   or Decompiler SWF) and use that to find the nested movie file, and extract that.

Sadly, I think this is the only way out of my situation. Will confirm and let you know.

If your lucky, VLC might be able to play it. Then you can use its Convert/Save functionality to get it into a usable format.

No dice… avformat error: av_open_input_stream failed

swfextract from SWF Tools looks like it does what you want: http://wiki.swftools.org/index.php/Swfextract
It'll probably give you an FLV, but you can then use ffmpeg or similar to turn it into a better container format.

Of course having said that without trying it, I'm now struggling to get it to do that. Looks like you could build something to do this on top of it but it doesn't do it on its own.

Sony Vegas can read some SWF files and then you can render to any of its supported formats, including H.264. The free trial is at http://www.sonycreativesoftware.com/download/trials/vegaspro

If you're on a Mac, there's an app called Adapter that is supposed to handle SWFs.
If you're on Windows, you might try Free SWF Convertor.

Also tried Adapter with no luck. I suspect that it's choking on my “compressed” SWF


text:
Is there any relation between a Exposure & Flicker
I am trying to understand if there is any relation between Exposure(Manual/Auto) function of a Camera and Flicker effect that might be visible in a video shot by that camera?
If one has to do flicker removal, does it have any commonality with the Auto exposure parameters like Exposure time, exposure gain? Can those parameters in anyway tuned/changed to remvoe flicker effect?

Can you provide more detail on exactly what is flickering for you, and under what circumstances?  The techniques to control different kinds of flicker (e.g. fluorescent lights, CRTs) depend heavily on what you're experiencing flicker with.

As Itai indicated, there are a couple of possible questions here.  CRT (picture tube) video devices paint images on their screens using an electron "gun" that scans left-to-right and top-to-bottom.  Photos taken with a fast shutter speed will catch a display like this in mid-paint, showing recently-painted lines brightly, with a darker area just below them (about to be refreshed).  Although LCD screens also have a "refresh rate", you don't see the same kind of dimming between pixel painting, so this type of problem is much more subtle (you can still catch a picture in mid-paint, but it's just based on movement in the video).  I used to have a Ricoh SLR with a "video" setting designed specifically to keep the shutter slow enough to avoid this effect when shooting a CRT.  Quaint, huh?
If, on the other hand, you're talking about the "rolling shutter" video effect seen to some extent on most CMOS DSLR's, we're staying clear of video questions here, but you might have some luck with this on avp.stackexchange.com/.


text:
How can I change the default Production file save location in Camtasia Studio?
When producing a video, Camtasia lets you pick the save location for the produced file but I can't find an option to change the location for this. I have set the recording and temp directories through other menus, but Camtasia asks for this location each time I produce and I have to manually change it each time.
The default location is /users/documents/camtasia studio/ but I'd like to dump them into a different directory for ease of access.
Is there any way at all to change this location? If it matters I'm testing Camtasia Studio 8, but I've always had the same problem in Camtasia 7, and will be going back to Camtasia 7 if I don't like 8 enough to purchase it.

I believe this is a bug.  When you specify the folder, make sure you select the post-production option, "Show production results".  If you don't, it won't remember the last folder location.  I'm using 8.0.4 and that worked for me.

In camtasia, if you choose a certain location that it will store it in your used places. Then you can access it easily through the dropdown list. Here is an image:

It isn't possible to change the default output folder though....

Ah, good to know! Not quite as good as setting the default, but a lot easier than fiddling with the directory picker each time

Hm doesn't seem to work in Camtasia 8 actually. The dropdown is there but never populates.

This link appears to say that the production folder is not configurable.

Crap, I'll just make a Junction point to lead that default folder to the location I want it then...

Just wanted to say @BenBrocka, that I installed the trial Camtasia Studio 8, and that it populated the dropdown list, and the last location produced at was the selected one the next time.

Really? Is it on the same drive? Did you type out the path or use the directory picker?

I used the directory picker.

Neither is working here. Always starts in the My Documents/camtasia studio...

Edited my answer to show an image from Camtasia 8.

I have a 1 minute video on how to do this. It took me a while to find it as well so I thought it would be easier to show it this way.

You can create a custom production preset when you are selecting your video settings. I noticed that when I did this it also includes the output save location.