kapowaz
1st December 2009, 16:55
I'm attempting to remux a number of Matroska-contained videos under Mac OS X. My objectives are that the produced video files be:
• Playable on Mac OS X through QuickTime, iTunes and Front Row (rather than only VLC)
• Playable on a PlayStation 3 (natively, rather than using a streaming server)
For this reason, I would like to use the MP4 container (even though this has some limitations, particularly regarding subtitles; it's still the most pragmatic choice for me).
I've already made several attempts with one video, which have involved the use of tsMuxerGUI to demux the streams and then convert the audio stream from DTS 5.1 to AAC 5.1 using ffmpeg -i source.dts -ab 1536k -ac 6 output.m4a (1536kbps is the reported bitrate of the audio stream according to tsMuxerGUI); I then remuxed using ffmpeg thus: ffmpeg -i source.264 -i output.m4a -vcodec copy -acodec aac final.m4v. There were a couple of warnings in each stage (which I'll show later), but the end result was a playable MP4 video file which suffered stuttering problems (rather than dropped frames it would seem to quickly flicker between a frame and a few frames immediately previous). The audio also didn't seem to be quite right, with odd channel distribution.
The errors I received from ffmpeg were:
• From the audio conversion: [aac @ 0x188e200]This encoder does not yet enforce the restrictions on LFEs. The output will most likely be an illegal bitstream.
• From the remux: Seems stream 0 codec frame rate differs from container frame rate: 47.95 (48000/1001) -> 23.98 (48000/2002)
It's possible that some part of my toolchain has introduced errors, or that the sample video in this case itself is badly encoded, but I'm not even 100% sure at this point if I'm following the correct process for re-encoding (for example) the audio. Since the overwhelming majority of guides and knowledge on doom9 is geared towards Windows users, I'm at something of a dead end without advice. If there are additional command-line tools I need, I'm happy to try compiling them; my ultimate objective is to come up with a reliable workflow for converting MKV contained content to MP4 that can be scripted/batch processed.
So, what suggestions do people have?
• Playable on Mac OS X through QuickTime, iTunes and Front Row (rather than only VLC)
• Playable on a PlayStation 3 (natively, rather than using a streaming server)
For this reason, I would like to use the MP4 container (even though this has some limitations, particularly regarding subtitles; it's still the most pragmatic choice for me).
I've already made several attempts with one video, which have involved the use of tsMuxerGUI to demux the streams and then convert the audio stream from DTS 5.1 to AAC 5.1 using ffmpeg -i source.dts -ab 1536k -ac 6 output.m4a (1536kbps is the reported bitrate of the audio stream according to tsMuxerGUI); I then remuxed using ffmpeg thus: ffmpeg -i source.264 -i output.m4a -vcodec copy -acodec aac final.m4v. There were a couple of warnings in each stage (which I'll show later), but the end result was a playable MP4 video file which suffered stuttering problems (rather than dropped frames it would seem to quickly flicker between a frame and a few frames immediately previous). The audio also didn't seem to be quite right, with odd channel distribution.
The errors I received from ffmpeg were:
• From the audio conversion: [aac @ 0x188e200]This encoder does not yet enforce the restrictions on LFEs. The output will most likely be an illegal bitstream.
• From the remux: Seems stream 0 codec frame rate differs from container frame rate: 47.95 (48000/1001) -> 23.98 (48000/2002)
It's possible that some part of my toolchain has introduced errors, or that the sample video in this case itself is badly encoded, but I'm not even 100% sure at this point if I'm following the correct process for re-encoding (for example) the audio. Since the overwhelming majority of guides and knowledge on doom9 is geared towards Windows users, I'm at something of a dead end without advice. If there are additional command-line tools I need, I'm happy to try compiling them; my ultimate objective is to come up with a reliable workflow for converting MKV contained content to MP4 that can be scripted/batch processed.
So, what suggestions do people have?