[MPlayer-users] Problem with audio in DVB-S2 transport stream

[Mark Zimmerman]

On Sun, Aug 08, 2010 at 02:09:02PM -0600, Mark Zimmerman wrote:
> > Mark Zimmerman <markz <at> frii.net> writes:
> >  
> > > I recorded a transport stream from AMC-1 and I am having problems with the  
> > > audio.
> > > It sounds like I am getting just the rear channels, or something like  
> > > that. The
> > > audio I get seems to me in sync, but most of it is just not there.
> >  
> > The sample you uploaded only contains 2-channel MP2 audio, so I don't think
> > there is much MPlayer can do to improve it.
> >  
> > There is indication, however, that you managed not to record all audio streams
> > for this program - looking at FFmpeg's output:
> >     Stream #0.1[0x2ef](aaa): Audio: mp2, 48000 Hz, 2 channels, s16, 384 kb/s
> >     Stream #0.2[0x2f0](aac): Audio: mp3, 0 channels, s16
> >     Stream #0.3[0x2f1](aae): Audio: mp3, 0 channels, s16
> >     Stream #0.4[0x2f2](aag): Audio: mp3, 0 channels, s16
> >     Stream #0.5[0x1fd0]: Data: [6][0][0][0] / 0x0006
> >     Stream #0.6[0x400]: Data: [241][0][0][0] / 0x00F1
> > 0x2ef was recorded correctly, 2f0, 2f1 and 2f2 are missing (and while they
> > probably don't contain audio, it might not hurt to record 0x1fd0 and 0x400 as
> > well, if they contain teletext, we would be very interested in the sample).
> > You possibly used szap to record, unfortunately, it does not work the way we
> > would all like it to work...
> 
> Yes, I used szap-s2, which will not let you specify multiple audio
> streams. I think I will fix this limitation and try again.
> 
> >  
> > > Command line:
> > >  
> > > mplayer -nocorrect-pts -v sample.ts > mplayer.out
> > >  
> > > The -nocorrect-pts option is needed to keep it from playing at half speed.
> >  
> > That sounds unlikely to me, if it is really true, could you upload a longer
> > sample (this one is too short for A/V sync issues, imo).
> >  

There is a 2 minute (372MB) sample here:

<http://users.frii.com/markzimm/dvb-s2-test/sample-2010-08-08.ts>

with all the audio streams. I also tried to get 0x1fd0 and 0x400 but
I am not sure if I succeeded:

Input #0, mpegts, from 'sample-2010-08-08.ts':
  Duration: 00:01:59.63, start: 14200.413444, bitrate: 26084 kb/s
  Program 1 
    Stream #0.0[0x200]: Video: h264, yuvj420p, 1920x1080 [PAR 1:1 DAR 16:9], 126.58 fps, 59.94 tbr, 90k tbn, 59.94 tbc
    Stream #0.1[0x2ef](aaa): Audio: mp2, 48000 Hz, 2 channels, s16, 384 kb/s
    Stream #0.2[0x2f0](aac): Audio: mp2, 48000 Hz, 2 channels, s16, 384 kb/s
    Stream #0.3[0x2f1](aae): Audio: mp2, 48000 Hz, 2 channels, s16, 384 kb/s
    Stream #0.4[0x2f2](aag): Audio: mp2, 48000 Hz, 2 channels, s16, 384 kb/s
    Stream #0.5[0x1fd0]: Data: [6][0][0][0] / 0x0006
    Stream #0.6[0x400]: Data: [241][0][0][0] / 0x00F1

I can play it without the -nocorrect-pts option. For audio, the clip
begins and ends with sound but there are several commercials in it;
some have sound and some do not.

This idea of multiple audio streams is new to me and I am not sure how
to tell mplayer how to do the right thing. Is it supposed to merge the
streams? Other clips I have recorded sometimes play back with only the
left or right channel, or sometimes just background (crowd noise). So
far it seems random.