[MEncoder-users] How to repackage MP4 files to avi container?

[Grozdan]

On Fri, May 14, 2010 at 11:18 PM, Miroslav Rovis <m.rovis at inet.hr> wrote:
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> Hi!
> There was a useful discussion on joining avi files with x264 streams a
> few days ago.
> And it is true that sync can often best be gotten back with the use of
> MP4Box, as Grozdan explained.
> avimerge often does the work faster, and equally well, but MP4Box can
> fix the sync better through "MP4Box -cat ..." and "MP4Box -splitx
> ..."  etc...
> But MP4 it is not the best of formats, and I thought a plain avi
> container, where there's no subtitles and such, would be the better
> option.
> Starting with file_PART1.avi and file_PART2.avi, upon trials and
> errors few or many, eventually there is the resulting file_ALL.aac and
> file_ALL.h264 that can be muxed into good-synced file_ALL.mp4.
> But I'd rather have a good-synced file_ALL.avi with that content.
> This I can do:
> mencoder  -ovc copy file.h264  -o file_fromMP4.avi
> (fine avi, but only video)
> But this:
> mencoder  -audiofile file.aac  -oac copy -ovc copy file.h264  -o file.avi
> errors out.
> Also this (with the file_fromMP4.avi from the above step):
> mencoder  -audiofile file.aac  -oac copy  -ovc copy file_fromMP4.avi
> - -o file.avi
> errors out. Like this:

I would surely NOT recommend going from mp4 -> avi, especially if
you're putting h264 video in it. There is absolutely no standard way
of storing such video in an avi, nor are there any decent HW players
that'll support it. In essence, since there's no standardized way of
storing such video in avi, many different ways/implementations can
arise which in the end will make it difficult to support.

Avi is only good for intermediate container when dealing with h264
video. Do NOT, I repeat, DO NOT permanently store your h264 videos in
an avi container. If you dislike mp4 then use mkv, as most enthusiasts
prefer it over mp4

You said mp4 is not the best of formats. Do you think avi is one (or
better than mp4)? If so, you surely need to educate yourself on that
topic. Avi is a very basic container and it doesn't even support some
important parts of modern video codecs. This combined with some ugly
hacks added to support modern stuff, makes it even more shitty. Not to
mention its overhead compared to more modern containers like mkv & mp4


>
> success: format: 0  data: 0x0 -
> 0xad82b08
> Seek
> failed
>
>
>
>
> libavformat file format
> detected.
>
>
>
>
> [h264 @ 0x2ca7c30]max_analyze_duration
> reached
> [lavf] Video stream found, -vid
> 0
> VIDEO:  [H264]  704x576  0bpp  25.000 fps    0.0 kbps ( 0.0
> kbyte/s)
> Seek
> failed
>
>
>
>
> libavformat file format
> detected.
>
>
>
>
> [aac @ 0x2cb34a0]max_analyze_duration
> reached
> [lavf] Audio stream found, -aid
> 0
> [V] filefmt:65536  fourcc:0x34363248  size:704x576  fps:25.000
> ftime:=0.0400
> videocodec: framecopy (704x576 0bpp
> fourcc=34363248)
> Audio format 0x4134504d is incompatible with '-oac copy', please try
> '-oac pcm' instead or use '-fafmttag' to override
> it.
>
>
>
>
>
> Afterwards, neither -oac pcm, nor -fafmttag 80 (pretending it was mp3)
> gave anything right...
>
> I would really like to be able to repackage mp4 files when I need to,
> and reencoding them through mkv2avi.py which I found somewhere on the
> net, and which reencodes the audio to mp3, would possibly not be full
> success... Or am I missing something in my understanding of the issue?
> Anyone knows more about this?
>
> Miro
>
>
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