[Live-devel] Mpeg Audio missing or corrupted in MPEG-2 Transport Stream or seperate sreams

[Eric Pheatt]

On Dec 16, 2007 4:09 PM, Ross Finlayson <finlayson at live555.com> wrote:
> >  > What happens if you specify "-mpegaudio 192" and "-mpeg2" *instead*
> >>  of "-mpegtransport 192"?
> >
> >This produces no audio.
> >
> >>  What happens if you specify "-mpegaudio 192" *only* (and not "-mpeg2"
> >>  or "-mpegtransport 192")?
> >
> >This produces no audio and but the video is the default mpeg4 with
> >default rate.
>
> That's odd.  It seems that the (software) MPEG audio encoder is not
> working properly for you.  I don't know why that would be, though...
>
> >
> >next steps?
>
> 1/ Try streaming MPEG audio, but no video:
>         -mpegaudio 192 -nv

Nothing here either.

> 2/ Try changing the audio output bitrate
>         -mpegaudio 128

Nope nothing either.

> 3/ Try changing the audio sampling frequency
>         -f 44100 -mpegaudio 192

Still nothing.

> 4/ Try combining 2/ and 3/
>         -f 44100 -mpegaudio 128
>
> Unfortunately I'm just grasping at straws at this point...

Still nothing on those.

I had updated WISInput.cpp neat line 208 to look more like gorecord
for audio device selection because the I was getting an "Unable to
find emulated OSS device node" message. But since I am getting pcm
audio I doubt that is the issue.

+     char *c;
+      printf(line, "%d: [%u-%*u]: digital audio\n", &m, &n);
-      //if (sscanf(line, "%d: [%u-%*u]: digital audio\n", &m, &n) !=
2) continue;
+      if ((c = strrchr(line, ':')) == NULL ||
+                        strcmp(c, ": digital audio\n") ||
+                        sscanf(line, "%d: [%u-%*u]:", &m, &n) != 2)
+                continue;

Also with aac I no sound.
With amr  I get no sound but I also get the following from wis-streamer:
RTCPInstance::RTCPInstance error: totSessionBW parameter should not be zero!

And with ulaw all I get is static.

Here is some sound device info from my system:

#ls -ltr /dev/dsp*
crw-rw---- 1 root audio 14, 3 Dec 14 17:38 /dev/dsp

3cat /proc/asound/oss/devices
  0: [0- 0]: mixer
  3: [0- 0]: digital audio
  4: [0- 0]: digital audio

#cat /sys/class/sound/dsp/dev
14:3

#cat /proc/asound/oss/sndstatcat /proc/asound/oss/sndstat
Sound Driver:3.8.1a-980706 (ALSA v1.0.14 emulation code)
Kernel: Linux KUROHG 2.6.23.9 #2 Fri Dec 7 13:43:42 PST 2007 ppc
Config options: 0

Installed drivers:
Type 10: ALSA emulation

Card config:
Plextor PX-TV402

Audio devices:
0:

Synth devices: NOT ENABLED IN CONFIG

Midi devices: NOT ENABLED IN CONFIG

Timers:
7: system timer

Mixers:
0: mixer00


Could this be an endian issue with the audio encoders that are
currently being used?

Im running this on a KuroHG PowerPC
(http://www.nas-central.org/index.php/Category:Kurobox) that I have
used with mythtv as regular recording device but the current mythtv
support does not include mpeg2 video at the moment. Adding mythtv
support for mpeg2 is out of my league, so I had hoped that
wis-streamer would meet my needs.

It appears that the mpegaudio.c in wis-streamer is close to an older
version of ffmpeg based on the comments, do you recall when this was
included?

Thanks for helping track this issue for me down.
-Eric