no audio on some .tp .ts transport stream files

[zetavu]

I have over the air HD recordings as .tp files (can also be .ts) and some will play in the latest vlc player (either ubuntu or windows) fine, others have no audio. On examining the files, it seems any file where the main audio track is in PID 51 will not have audio, while any file where the first audio track is PID 52 will play audio.

For the files with no audio, I tried to change the audio track but neither track has audio. Also, for those files Audio Device and Audio Channels are grayed out, for good files these are accessible. I checked the tracks in Zoom player and the 51 track has audio (English) while the 52 track is blank (labeled Spanish). The files which do have audio in vlc have audio in both tracks (52 (English) and 53 (Spanish). These are recorded from various tv tuner cards and so far three tv channels I tested do not have audio in vlc, two tv channels do, so it is something about where the audio streams are stored and how vlc chooses those streams. I think vlc may ignore the 51 track entierely, which is why no audio. Is there anyway to change this? If not, can it be fixed? Any suggestions would be appreciated.

[zetavu]

Ok, I have an update on the issue. The transport streams in question are recorded from Chicago HD stations, ch 2 (CBS) and ch 7 (ABC) I use Beyondtv, not sure if that makes a difference. All other shows play audio in VLC, these channels do not. I thought both stored the first audio stream in pid 51, but Ch 7 stores audio in PID 52 like all other working channels.

I looked at the recordings with Mediainfo http://mediainfo.sourceforge.net/en and it saw two things unique about those channels. First, it did not calculate file duration for those channels. Second, audio menu is for those two channels was 1(0x1), while all working channels were 3(0x3) or 4(0x4). I know those two channels are in the ch2-12 for actual HD frequencies, all other channels are above that (UHF range?)

So, any ideas why those channels have recordings with no audio in vlc? Only VLC doesn't play audio, other programs (zoom, WMP,) all play the audio.

[shawnph]

I have the exact same problem. BeyondTV "streamsnips" TP files to get rid of the extra sub-channels. I don't think this is the problem because shows on other channels work. But on a certain local channel, I get no audio in VLC or MediaPlayer. I tried installing an AC/52 codec. No help there. But BeyondTV itself can play these TP files with audio.

I'm a little frustrated over this. I see that BeyondTV is using a Snapstream audio codec. But VLC doesn't seem to have a way to specify a custom codec.

So it's not just you. If you found a solution, it'd be nice to hear what it was.