DGIndex - unableto create AC3 audio file

[ekarbakar]

I've hesitated in posting this, thinking I must be doing something elementary wrong, but after hours of trying different troubleshooting methods I'm completely stumped. None of the forum topics or FAQ's seem to answer question.

Problem: I capture 1280x720 .ts streams from my Motorola DVR using CAPDVHS. Streams will play with good picture and audio with MediaPlayerClassic. DGIndex reports 2 AC3 tracks and 2 MPEG tracks. Regardless of which tracks I try to demux, I cannot produce an AC3 file. The D2V file is created each time. I'm using XP-SP2, have just tried 1.4-RC6 to no avail. Setting is "Demux All Tracks".

Any ideas on how to troubleshoot this would be most appreciated.

[Guest]

With transport streams, you have to set the audio PID in the stream menu. Did you do that?

[ekarbakar]

Yes. I used STREAM=>DETECT PIDs:RAW, then selected what seemed to be mated pairs (ie. 0x800 MPEG Video, 0x801 Private Stream 1 (AC3 Audio)). It displays the right video in the preview window, but no AC3 file is ever created. What's strange is that at one point a few weeks ago I had this working perfectly. I demuxed several of the same type of .ts streams (Seinfeld to be exact) and it all worked well. Got busy with other activities and came back to it...now its broken. I must have done something crazy to my system. I'm pretty new to video, but an old hacker on PC's, so I believe I've looked at most of the obvious snafu's.
Thanks for any ideas. PJ

[Guest]

Please upload a stream fragment that shows the problem to my FTP server and tell me the filename here. I will figure it out for you.

Did you try Detect PIDs: PAT/PMT? Maybe you're not getting the right audio PID.

[ekarbakar]

I uploaded the .ts file I'm having trouble with to your FTP server.
- File name is: "seinfeld-test3.ts", under new directory "pjones"
- File size is: 21MB
- The Detect PID's=>Raw offered the following streams:
0x800 MPEG Video
0x801 Private Stream 1 (AC3 Audio)

These are what I set as Video and Audio. Audio set to Demux All Audio Tracks. Result is a "d2v" file, but no "ac3" audio file. This is consistent across all my tapings of high-def content.

I'll appreciate any ideas you have.

Thanks,
PJ (ekarbakar)

[Guest]

OK, I know why it is failing and I can make a hack that gets the audio out. The problem is that the current design requires to find the audio in the PAT/PMT to determine the audio type. Strangely, your PAT/PMT lists the video but not the audio. You may want to discuss that with the authors of CAPDVHS.

I will try to develop an alternate method that does not rely on the audio being listed in the PAT/PMT. I will also re-check my PAT/PMT code in case it is failing.

[ekarbakar]

Awesome!
I'll check with them.
Thanks,
PJ

[Guest]

OK, I had a closer look. It's actually a simple bug in my code that gets the audio type. As designed, it is supposed to try the PAT/PMT first and then, if that fails, try the raw info (stream ID). But due to the bug it was not trying the raw info after the PAT/PMT try failed. The fix is easy and I have tested it here at work on 1.3.0. The next release of 1.4.0 will have the fix. Thank you for bringing this to light.

[Guest]

The problem is fixed in DGMPGDec 1.4.0 Final, which is now available at my web site.

[ekarbakar]

It works GREAT! Thanks neuron2, that was a quick turnaround. I appreciate this powerful tool.

PJ