[MEncoder-users] How to join avi files with x264 streams?

[Josef Wolf]

On Sat, May 08, 2010 at 05:06:44PM +0200, Grozdan wrote:
> On Sat, May 8, 2010 at 4:50 PM, Josef Wolf <jw at raven.inka.de> wrote:
> > On Sat, May 08, 2010 at 03:31:53PM +0200, Grozdan wrote:
> >> On Sat, May 8, 2010 at 3:29 PM, Josef Wolf <jw at raven.inka.de> wrote:
> >> > On Sat, May 08, 2010 at 01:41:05PM +0200, Grozdan wrote:
> >> >> On Sat, May 8, 2010 at 11:48 AM, Josef Wolf <jw at raven.inka.de> wrote:
> >> >> > On Fri, May 07, 2010 at 10:29:31AM -0500, Laine Lee wrote:
> >> >> >> On 5/7/10 1:00 AM, "Josef Wolf" <jw at raven.inka.de> wrote:
> >> >> >> > I have captured my old VHS recordings with mencoder and created x264 avi's
> >> >> >> > using two-pass with those options:
> >> >> >> >
> >> >> >> >   -ovc x264 -x264encopts
> >> >> >> > bitrate=800:pass=2:subq=7:frameref=15:subq=6:frameref=15:me=umh:partitions=all
> >> >> >> > :8x8dct:direct_pred=auto:me_range=64:trellis=2:bframes=5:b_pyramid:weight_b:th
> >> >> >> > reads=auto:nr=1000
> >> >> >> >
> >> >> >> > In the next step, I want to join some of those files. I tried:
> >> >> >> >
> >> >> >> >   mencoder -ovc copy -oac copy -o outfile.avi file1.avi file2.avi
> >> >> >> >
> >> >> >> > But the resulting file has some strange artefacts in the first ten seconds
> >> >> >> > after the join position (that is, in the first ten seconds of file2.avi)
> >> >> >> > which are _not_ present in the original file2.avi.
> >> >> >> >
> >> >> >> > Why does "-ovc copy" do any manipulations on the stream?
> >> >> >> >
> >> >> >> > Any ideas?
> >> >> >>
> >> >> >> Can you use "MP4Box -cat"?
> >> >> >>
> >> >> >> http://gpac.sourceforge.net/doc_mp4box.php
> >> >> >
> >> >> > jw at ubuntu:MP4Box -cat 01.avi -cat 02.avi t.avi
> >> >> > H264/AVC Video format not supported in AVI - please extract to raw format
> >> >> > first
> >> >> > Error appending 01.avi: Feature Not Supported
> >> >> >
> >> >> > Do I have to re-encode into another format first? But then I would loose
> >> >> > quality?
> >> >>
> >> >> No, you have to do exactly as it says above. Extract the video from
> >> >> the avi container. Done like this
> >> >>
> >> >> MP4Box -aviraw video yourfile.avi
> >> >
> >> > Yeah, this seems to work. But now I loose A/V-sync again =:-(
> >> >
> >> > This is what I do:
> >> >
> >> >  MP4Box -aviraw video file1.avi
> >> >  MP4Box -aviraw video file2.avi
> >> >
> >> >  MP4Box -aviraw audio file1.avi
> >> >  MP4Box -aviraw audio file2.avi
> >> >
> >> >  MP4Box -cat file1_video.h264 -cat file2_video.h264 out.h264
> >> >  MP4Box -cat file1_audio.mp3  -cat file2_audio.mp3  out.mp3
> >> >
> >> >  MP4Box -add out.mp3 -add out.h264 out.mpg
> >> >
> >> > What am I doing wrong?
> >>
> >> You need to pass the correct -fps value to MP4Box, which by default uses 25fps
> >
> > Umm, the recordings _are_ 25fps...
> 
> And I'm supposed to know that how?

Oh, sorry ;-)

> There must be some other problem..
> 
> What kind of sync problem? Does it start right away or does it
> gradually build up over time?

At the start is is OK, but after a while it gets out of sync. Then sync
gets better again, then worse again, and so forth.

> If this doesn't work, you can always try it with ffmpeg instead of
> mencoder. Just use multiple -i option, eg
> ffmpeg -i file1.avi -i file2.avi ...
> 
> and copy audio and video with -acodec copy -vcodec copy

So now I tried

  ffmpeg -acodec copy -vcodec copy -i file1.avi -i file2.avi out.avi

but here I get only the first file, the second seems to be ignored.

Seems to be a really hard to join avi files :-(