Re: [Audacity-devel] [Libav-user] Requesting help to port Audacity to recent FFmpeg

[Benjamin D. <bd...@de...>]

Am Samstag, den 24.05.2014, 10:03 +0100 schrieb Gale Andrews:
> | From Benjamin Drung <bd...@de...> 
> | Fri, 23 May 2014 23:23:17 +0200
> | Subject: [Audacity-devel] [Libav-user] Requesting help to port Audacity to recent FFmpeg
> > Hi Michael,
> > 
> > Am Mittwoch, den 21.05.2014, 02:16 +0200 schrieb Michael Niedermayer:
> > > > I like to commit your
> > > > work to the Audacity SVN so that we have both - support for FFmpeg and
> > > > Gstreamer.
> > > 
> > > that sounds great
> > 
> > I committed your code to the Audacity SVN with your name in
> > Signed-off-by, because I failed to find a git-am equivalent to preserve
> > the committer and date. Thanks for your work.
> > 
> > While committing, I made some small indentation adjustments. Audacity
> > uses 3 spaces for indentation and some of your changes used 4 spaces. I
> > merged your debug fprintf removal into the respective commit. I also
> > committed my libav 9 support patch.
> 
> Thanks - just one probably small error compiling release build at 
> SVN r13124 on Windows 7 x64:
> 
> 26>AudacityApp.cpp
> 26>c:\audacitycomm\src\FFmpeg.h(41) : fatal error C1083: Cannot open include file: 'libavutil/frame.h': No such file or directory

Sorry, that was my faulty-late-night commit. I fixed it in (following)
revision 13125.

> Mac produced hundreds of FFmpeg-related errors which I assume 
> are genuine as there is no Mac Nightly. 
> 
> If Paul hasn't commented when I next look in I'll zip up an error 
> report. 

I am interested whether svn head compiles and works on Windows and Mac.

> > > > 2) I can't export audio as mp4. Neither as mp4 export, nor as custom
> > > > FFmpeg export (can't be selected there). FFmpeg has mp4 support enabled:
> > > > 
> > > > $ ffmpeg -formats 2>/dev/null | grep mp4
> > > >  D  mov,mp4,m4a,3gp,3g2,mj2 QuickTime / MOV
> > > >   E mp4             MP4 (MPEG-4 Part 14)
> > > 
> > > hmmm, what do you mean by "mp4" ?
> > > there are alot of audio codecs that can be stored in mp4, for example
> > > aac, mp3, vorbis, also there are multiple ways to encode aac, libfaac
> > > ffmpegs native encoder and a few others ...
> > > 
> > > I tried a few things and found a few bugs (which i fixed) but iam
> > > not convinced i fixed the issue you describe
> > 
> > Sorry. My description was imprecise and incorrectly (m4a instead of
> > mp4). I was talking about File -> Export Audio... -> "M4A (AAC) Files
> > (FFmpeg)". When selecting this format, the exported file has 0 bytes
> > content. Selecting "Custom FFmpeg Export" and then "mp4" format and
> > "aac" codec, the result will be the same (empty exported file). The same
> > applies for the wav format with pcm_s16le codec.
> 
> So is this still to be fixed, or was it fixed by subsequent commits?

This is not fixed, yet. I committed the current state, because the
working ac3, wma, etc. export/import is better than no FFmpeg support at
all and to easy testing the changes on different platforms.

-- 
Benjamin Drung
Debian & Ubuntu Developer