[FFmpeg-devel] [PATCH] Remove extensions from MPEG-PS muxers.

Reimar Döffinger Reimar.Doeffinger at gmx.de
Sun Nov 17 17:18:19 CET 2013


On Sun, Nov 17, 2013 at 05:10:14PM +0100, Michael Niedermayer wrote:
> On Sun, Nov 17, 2013 at 04:30:34PM +0100, Reimar Döffinger wrote:
> > On Sun, Nov 17, 2013 at 04:18:27PM +0100, Michael Niedermayer wrote:
> > > On Sun, Nov 17, 2013 at 01:25:32PM +0100, Reimar Döffinger wrote:
> > > > diff --git a/libavformat/mpegenc.c b/libavformat/mpegenc.c
> > > > index 0a9d69b..3c6cef2 100644
> > > > --- a/libavformat/mpegenc.c
> > > > +++ b/libavformat/mpegenc.c
> > > > @@ -1173,7 +1173,6 @@ AVOutputFormat ff_mpeg1system_muxer = {
> > > >      .name              = "mpeg",
> > > >      .long_name         = NULL_IF_CONFIG_SMALL("MPEG-1 Systems / MPEG program stream"),
> > > >      .mime_type         = "video/mpeg",
> > > > -    .extensions        = "mpg,mpeg",
> > > >      .priv_data_size    = sizeof(MpegMuxContext),
> > > >      .audio_codec       = AV_CODEC_ID_MP2,
> > > >      .video_codec       = AV_CODEC_ID_MPEG1VIDEO,
> > > > @@ -1204,7 +1203,6 @@ AVOutputFormat ff_mpeg2vob_muxer = {
> > > >      .name              = "vob",
> > > >      .long_name         = NULL_IF_CONFIG_SMALL("MPEG-2 PS (VOB)"),
> > > >      .mime_type         = "video/mpeg",
> > > > -    .extensions        = "vob",
> > > >      .priv_data_size    = sizeof(MpegMuxContext),
> > > >      .audio_codec       = AV_CODEC_ID_MP2,
> > > >      .video_codec       = AV_CODEC_ID_MPEG2VIDEO,
> > > 
> > > breaks fate and any script that encodes mpeg ps, dvds, .vob, .mpg
> > 
> > As far as I can tell rather "fixes any script that encodes dvds".
> > Going by the description I concluded this muxer isn't suitable for
> > creating vobs for DVDs, which is why I propose removing the extension,
> > considering it _preferable_ to break those scripts to having them
> > continue produce bad files, even though it might have worked...
> > I was thinking about moving the extensions, but that would then
> 
> > for _some_ people probably break scripts silently and without
> > warning.
> 
> any bugfix could break a script that depended on the bug.
> Do we have any evidence that such a script exists ?
> our docs mention .vob primarely in relation to dvds
> 
> 
> > What else could/should be done?
> 
> i honestly dont know but
> 
> ffmpeg myfile this.vob
> and
> make fate
> should not fail
> 
> and IMHO "ffmpeg myfile this.vob" failing because we once had a
> unintended and undocumented issue with vob that someone might have had
> a script based upon seems especially in the long term bad

I don't disagree, but didn't feel confident making that call.
Do you have any opinion on the .mpg/.mpeg case?
To be honest I was wondering why we map it to MPEG-PS, do you know?
It seems to me that nowadays MPEG-TS is probably more flexible and more
common, but I'm very far from an expert on that...


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