danieru
4th October 2008, 00:13
Hello,
I'm encoding a 120 minute DVD to x264 video and vorbis audio, with Handbrake. I used a video bitrate of 1800 kbps and vorbis at 160 kbps (I know vorbis uses a quality setting, but handbrake asks for a bitrate so I'm assuming it's equating to quality level 5 or such when it actually calls vorbis). I'm muxing the video and one audio stream and end up with a 1.8GB file.
I was curious how large the separate streams were so I used mkvmerge to dump each single stream to it's own container. I ended up with:
video.mkv - 1.4GB
audio1.mkv - 627MB
video_audio_muxed.mkv - 1.8GB
what?! the final muxed file with both video and audio ends up at 1.8GB! So I'm thinking to myself, this has got to be a bug, there's no way matroska should be taking roughly 3.4GB overhead! I took the separate streams and remuxed to a combined file and still end up with 1.8GB!
As another test, I extracted just 1 chapter from the same movie, and ended up with:
video.mkv - 45.8MB
audio.mkv - 19.9MB
video_audio_muxed.mkv - 65.6MB
...forgiving the MB rounding my file explorer is making, this seems right on, and just what I would expect, but I have no idea where things are going wrong the full-length mux.
Has anyone seen this type of problem before or have any thoughts or insights? I think perhaps Handbrake is messing up the matroska container somehow, but I just don't know enough to discount any other possible causes as well.
I'm encoding a 120 minute DVD to x264 video and vorbis audio, with Handbrake. I used a video bitrate of 1800 kbps and vorbis at 160 kbps (I know vorbis uses a quality setting, but handbrake asks for a bitrate so I'm assuming it's equating to quality level 5 or such when it actually calls vorbis). I'm muxing the video and one audio stream and end up with a 1.8GB file.
I was curious how large the separate streams were so I used mkvmerge to dump each single stream to it's own container. I ended up with:
video.mkv - 1.4GB
audio1.mkv - 627MB
video_audio_muxed.mkv - 1.8GB
what?! the final muxed file with both video and audio ends up at 1.8GB! So I'm thinking to myself, this has got to be a bug, there's no way matroska should be taking roughly 3.4GB overhead! I took the separate streams and remuxed to a combined file and still end up with 1.8GB!
As another test, I extracted just 1 chapter from the same movie, and ended up with:
video.mkv - 45.8MB
audio.mkv - 19.9MB
video_audio_muxed.mkv - 65.6MB
...forgiving the MB rounding my file explorer is making, this seems right on, and just what I would expect, but I have no idea where things are going wrong the full-length mux.
Has anyone seen this type of problem before or have any thoughts or insights? I think perhaps Handbrake is messing up the matroska container somehow, but I just don't know enough to discount any other possible causes as well.