Doom9's Forum - View Single Post - Bad AC3 sound when converting from PS to TS

Florisel · 10th October 2007, 08:25

Fixed it!
Thanks enormously for DGIndex with the source code. I could step through Audio demuxing process with the debugger and it appeared that MyTheatre adds 4 extra bytes between PES pack header and actual pack data. I do not know what these bytes are as they are not present in the standard. Here is the memory dump of the beginning of three consequitive AC3 PES packs:
0x004CAA4E 00 00 01 bd 07 ec 80 80 05 21 00 01 81 4b 80 02 00 01 .....ì€€.!...K€...
0x004CAA60 0b 77 a1 07 1c 30 43 7f 70 80 01 00 00 7e fb eb 86 0e .w¡..0C.p€...~ûë..

0x004CAA4E 00 00 01 bd 07 ec 80 80 05 21 00 01 ae 4b 80 01 04 21 .....ì€€.!..®K€..!
0x004CAA60 b0 45 15 27 76 e7 bc 69 3b fd 7b ad 02 e1 ac a0 6b ab °E.'vç.i;ý{*.á¬ k«

0x004CAA4E 00 00 01 bd 07 ec 80 80 05 21 00 01 c4 cb 80 01 02 41 .....ì€€.!..ÄË€..A
0x004CAA60 d4 fb ef e0 b9 35 ca 16 f3 d3 37 c9 74 6b 05 8b 42 eb Ôûïà.5Ê.óÓ7Étk..Bë

These bytes look like memory pointer or flags of some kind. Anyway, I have extended the PES pack header length by 4 bytes and the problem was fixed!

Big thanks again for your help.

10th October 2007, 08:25	#12 \| Link
Florisel Registered User Join Date: Aug 2007 Posts: 9	Fixed it! Thanks enormously for DGIndex with the source code. I could step through Audio demuxing process with the debugger and it appeared that MyTheatre adds 4 extra bytes between PES pack header and actual pack data. I do not know what these bytes are as they are not present in the standard. Here is the memory dump of the beginning of three consequitive AC3 PES packs: 0x004CAA4E 00 00 01 bd 07 ec 80 80 05 21 00 01 81 4b 80 02 00 01 .....ì€€.!...K€... 0x004CAA60 0b 77 a1 07 1c 30 43 7f 70 80 01 00 00 7e fb eb 86 0e .w¡..0C.p€...~ûë.. 0x004CAA4E 00 00 01 bd 07 ec 80 80 05 21 00 01 ae 4b 80 01 04 21 .....ì€€.!..®K€..! 0x004CAA60 b0 45 15 27 76 e7 bc 69 3b fd 7b ad 02 e1 ac a0 6b ab °E.'vç.i;ý{*.á¬ k« 0x004CAA4E 00 00 01 bd 07 ec 80 80 05 21 00 01 c4 cb 80 01 02 41 .....ì€€.!..ÄË€..A 0x004CAA60 d4 fb ef e0 b9 35 ca 16 f3 d3 37 c9 74 6b 05 8b 42 eb Ôûïà.5Ê.óÓ7Étk..Bë These bytes look like memory pointer or flags of some kind. Anyway, I have extended the PES pack header length by 4 bytes and the problem was fixed! Big thanks again for your help.