Demuxer with .mkv file gives bit rate of 0

[xavier630]

Hey team,

I'm using the DemuxerWithStreamInfo and finding that the streams with video encoding for various mkv files always have a bit rate of 0.

This doesn't happen for .mov or .mp4 files, they return actual bit rates.

If I run ffmpeg or ffprobe commands on the .mkv files that I have, I get non-zero numbers for the bit rates. That is, these commands give actual bit rates:
ffprobe -v error -show_format -show_streams file.mkv | grep bit_rate
ffmpeg -i file.mkv 2>&1 | grep "bitrate"

Is this expected? If demuxing .mkv files works fine for others, perhaps we could add a .mkv example to the demuxer examples in the library to show the right way to handle .mkv files?

[operutka]

Hi. This crate is just a wrapper over the FFmpeg libs. If you get 0 bitrate in audio/video codec parameters from the demuxer, it means that the underlying FFmpeg libs return codec parameters with this value. I suggest discussing this with FFmpeg developers.

I'm not sure what exactly the ffprobe and ffmpeg apps do to display the bitrate. They may do additional bitrate estimation if there's 0 bitrate in the codec parameters.