<|im_start|>system
You are a helpful AI assistant.<|im_end|>
<|im_start|>user
How would I change the exposure of a series of images with ffmpeg while compiling into an MP4, please give a command line example.<|im_end|>
<|im_start|>assistant
To change the exposure of a series of images using ffmpeg, you can use the "curves" filter. This filter allows you to adjust the brightness and contrast of an image.

Here is an example command that changes the exposure of a series of images and compiles them into an MP4:
``` 
ffmpeg -i image-%d.png -vf "curves=levels=0:0.5:1" -c:v libx264 -pix_fmt yuv420p output.mp4
``` 
In this command:

- image-%d.png specifies the input images, where %d is a placeholder for the frame number.
- curves=levels=0:0.5:1 specifies the "curves" filter and sets the exposure to 0.5. The levels parameter takes three values: the minimum input level, the middle level, and the maximum input level. In this example, 0:0.5:1 means that the minimum input level is 0, the middle level is 0.5, and the maximum input level is 1.
- libx264 specifies the H.264 video codec to be used for encoding the output video.
- yuv420p specifies the pixel format for the output video.
- output.mp4 is the name of the output file.

Note that this is just one example, and you can adjust the exposure further by changing the values in the "curves" filter.<|im_end|>
<|im_start|>user
Can you rewrite this, but with AV1 encoding and outputting to a .MKV file instead?<|im_end|>
<|im_start|>assistant
Certainly! Here is an example command that changes the exposure of a series of images using ffmpeg, encodes the output using the AV1 video codec, and saves the output as an MKV file:
```
ffmpeg -i image-%d.png -vf "curves=levels=0:0.5:1" -c:v libaom-av1 -pix_fmt yuv420p output.mkv
```
In this command, the -c:v option specifies the video codec to be used for encoding the output video. Instead of libx264, we're using libaom-av1, which is the AV1 codec.

The -pix_fmt option specifies the pixel format for the output video, which is set to yuv420p in this example.

Finally, the output file is named output.mkv, which saves the output as an MKV file instead of an MP4 file.<|im_end|>
<|im_start|>user
Can you provide an explanation for each of the command line arguments in your answer ?<|im_end|>
<|im_start|>assistant
Sure! Here's an explanation for each argument:
- `-r 24` sets the video's framerate to 24 FPS
- `pattern_type glob` sets ffmpeg to look for files with the glob pattern type
- `-i 'input_files_*.jpg'` tells ffmpeg to use files named 'input_files_' with the frame number appended to it.
- `-vf "eq=brightness=0.1:saturation=1"` tells ffmpeg to set the brightness 10% higher and set the saturation higher.
- `-c:v libx264` tells ffmpeg to encode in the H.264 (MP4) file format.
- `-pix_fmt yuv420p` sets the color format to yuv420p
- `-crf 23` sets the video's lossiness during encoding, which should be a number from 0 to 51. 
- finally, `output.mp4` sets the filename of the resulting video.

Many of these values can be customized to fit your needs better.<|im_end|>