[MPlayer-dev-eng] [PATCH] Add "lpcJ" fourcc to codecs.conf

[Francesco Lavra]

On Fri, 2010-05-28 at 17:19 -0400, compn wrote:
> On Fri, 28 May 2010 21:12:18 +0200, Francesco Lavra wrote:
> >On Fri, 2010-05-07 at 20:47 +0200, Francesco Lavra wrote:
> >> On Sun, 2010-05-02 at 15:34 -0400, compn wrote:
> >> > On Sun, 02 May 2010 16:33:39 +0200, Francesco Lavra wrote:
> >> > >On Sun, 2010-05-02 at 14:08 +0000, Carl Eugen Hoyos wrote:
> >> > >> Francesco Lavra <francescolavra <at> interfree.it> writes:
> >> > >> 
> >> > >> > $subj, "lpcJ" is a valid fourcc for the RealAudio 1.0 codec.
> >> > >> 
> >> > >> Please point us to a sample and I will apply.
> >> > >
> >> > >If/when the just submitted patch series for the FFmpeg RM muxer will be
> >> > >applied, samples can be created with FFmpeg.
> >> > >If I have to wait until then, well, I don't mind :)
> >> > 
> >> > does realplayer handle those 1pcJ files ? is there a difference in the
> >> > codec/bitstream in 14_4 vs 1pcJ ? if not, why not just keep 14_4 and
> >> > abandon 1pcJ (in the encoder patch) ?
> >> > 
> >> > this codecs.conf entry seems fine to me as long as 1pcJ is an actual
> >> > fourcc found in the wild.
> >> 
> >> Realplayer plays those lpcJ files flawlessly.
> >> There is no difference in the bitstream between between 14_4 and lpcJ.
> >> But it would make more sense to drop the 14_4 tag in favor of lpcJ,
> >> since all samples that I found in the wild (including those in
> >> mplayerhq.hu) have lpcJ tag, not 14_4.
> >> The reason why the samples play with the unpatched mplayer is that the
> >> realmedia demuxer does not read the fourcc contained in the samples, and
> >> mplayer fills the codec_tag field based on its own tag lists.
> >> With the changes to the realmedia muxer that I'm proposing on the ffmpeg
> >> list, the format of the created samples is different in that it contains
> >> additional headers, from which the demuxer is able to get the codec tag;
> >> if the codec tag is obtained from the demuxer, mplayer doesn't use its
> >> own tag lists, and that causes it to fail.
> >
> >Ping?
> >Now FFmpeg can create realmedia files that MPlayer cannot play.
> >In my previous mail I wasn't suggesting to drop the 14_4 tag, I just
> >meant that if you wanted only one tag for realaudio 14.4k, then lpcJ is
> >better than 14_4.
> 
> ah, i forgot to apply this.
> 
> comitted, thanks for answering all my noob questions. it just seemed
> odd to me that all wild files work but files created by ffmpeg would
> fail. why isnt ffmpeg generating files like those in the wild ?

I don't know, you should ask who wrote the rm muxer :)
The only changes I made to ffmpeg were to support audio codecs different
from AC-3 in rm files.
Thanks for applying.
Francesco