Hi, this is a followup on Andrew Harkman's original post about dvbcut not finding the AC3 audio track in some TS files.
I have similar files, recorded from the cable TV Comcast's Universal HD (UHD) channel. I was excited to see the patch in response to Andrew's report, so I tried the SVN version but it didn't work for me. Here're the program and tracks in the TS file I was trying to decode, obtained with the Project-X program (http://sourceforge.net/projects/project-x): --- -> Input File 0: 'J:\rip\recorded\hunt-for-red-october (no pvas).ts' (8,837,374,844 bytes) -> Filetype is TS (generic PES Container) -> demux -> Service ID 0x1 -> PMT 0x31 refers to these usable streams: Video: PID: 0x800 Audio: n/a Teletext: n/a Subpict.: n/a !> PID 0x0 (PAT) (0 #1) -> ignored !> PID 0x31 (PMT) (188 #2) -> ignored ok> PID 0x801 has PES-ID 0xBD (private stream 1) (24440 #131) ok> PID 0x800 has PES-ID 0xE0 (MPEG Video) (117312 #625) --- I included a 30MB sample from the beginning of this file at http://cengique.2y.net/~cengiz/dvbcut-sample/hunt-for-red-october%20-%20sample.ts You can see that the PMT contains the video PID but not the audio. However, Project-X correctly recognizes the "private stream 1" PID as AC3, as does MPlayer. This is where dvbcut fails. So here's my hack to fix it in dvbcut: --- [EMAIL PROTECTED]:~/work/dvbcut/src$ svn diff tsfile.cpp Index: tsfile.cpp =================================================================== --- tsfile.cpp (revision 138) +++ tsfile.cpp (working copy) @@ -28,6 +28,7 @@ tsfile::tsfile(inbuffer &b, int initial_offset) : mpgfile(b, initial_offset) { + int verbose=1; for(unsigned int i=0;i<8192;++i) streamnumber[i]=-1; @@ -65,12 +66,19 @@ continue; if ((sid&0xe0) == 0xc0) { // mpeg audio stream + if(verbose) fprintf(stderr,"Found mpeg audio stream: SID=%x\n", sid); audios.push_back(std::pair<int,int>(sid,pid)); apid[pid]=true; } else if (sid==0xbd) { // private stream 1, possibly AC3 audio stream const uint8_t *payload=(const uint8_t*) p.payload(); const uint16_t plen = p.payload_length(); + if(verbose) fprintf(stderr,"Found private stream 1: SID=%x\n" + "Payload len=%d, \n" + "payload[8]=%x\n" + "payload[9 + payload[8]]=%x\n" + "payload[10 + payload[8]]=%x\n", sid, plen, payload[8], + payload[9 + payload[8]], payload[10 + payload[8]]); if (plen >= 9 && plen >= 11 + payload[8] && payload[9 + payload[8]] == 0x0b @@ -79,6 +87,11 @@ apid[pid]=true; } else if (plen == 184 + && payload[8] == 0x05) { // CG hack to recognize AC3 stream in UHD TS files + audios.push_back(std::pair<int,int>(sid,pid)); + apid[pid]=true; + } + else if (plen == 184 && payload[8] == 0x24 && (payload[45] & 0xf0) == 0x10 && payload[47] == 0x2c) { --- Unfortunately my hack only stems from naively analyzing the few files I had with this problem. I'm not sure if it's acceptable for general use. I looked at how Porject-X does this, but the PES parser is so complicated that I couldn't locate a similar place in the code. The closest I got was in the checkPES and AC3Audio functions in src/net/sourceforge/dvb/projectx/parser/Scan.java. Maybe you can make sense of them. Last but not least, thanks for providing dvbcut. Same with Andrew I depend on this tool to encode files that I was never able to keep audio sync after cutting commercials out. My previous routine for these files was using a Windows approach: cut with Mpg2Cut2, correct timings with Pvastrumento to get usable mpeg and AC3 streams. The audio will still get in and out of sync and pvastrumento is out of development and does not work for all files. Project-X recognizes my files, but as Andrew pointed out, drops GOPs because of missing frames. I discussed with the Project-X admins and apparently this is due to the weird use of B-frames in these files. Here's the forum where we discussed this: http://forum.dvbtechnics.info/showthread.php?p=27583#post27583 Yes, I know, too much information. So I'll stop now. Best, Cengiz Gunay -- [EMAIL PROTECTED] [EMAIL PROTECTED] (MSN) [EMAIL PROTECTED] Lab: +1-404-727-3565 Home/Cell: +1-678-559-8694 http://userwww.service.emory.edu/~cgunay/ IMs: ICQ# 21104923, [EMAIL PROTECTED],yahoo.com,Skype} -- ------------------------------------------------------------------------- This SF.Net email is sponsored by the Moblin Your Move Developer's challenge Build the coolest Linux based applications with Moblin SDK & win great prizes Grand prize is a trip for two to an Open Source event anywhere in the world http://moblin-contest.org/redirect.php?banner_id=100&url=/ _______________________________________________ DVBCUT-user mailing list DVBCUT-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/dvbcut-user
