Re: ivtv-utils/test/ps-analyzer.cpp: error in extracting SCR?
Hi, Just for completeness, attached is the patch against the subversion repository at ivtvdriver.org. Regards, Lars. Am 04.02.2010 08:25, schrieb Hans Verkuil: On Thursday 04 February 2010 04:16:03 Andy Walls wrote: On Thu, 2010-02-04 at 01:18 +0100, Lars Hanisch wrote: Hi, I'm writing some code repacking the program stream that ivtv delivers into a transport stream (BTW: is there existing code for this?). Buy a CX23418 based board. That chip's firmware can produce a TS. I think Compro and LeadTek cards are available in Europe and are supported by the cx18 driver. Since many players needs the PCR I would like to use the SCR of the PS and place it in the adaption field of the TS (if wikipedia [1] and my interpretation of it is correct it should be the same). I stumbled upon the ps-analyzer.cpp in the test-directory of the ivtv-utils (1.4.0). From line 190 to 198 the SCR and SCR extension are extracted from the PS-header. But referring to [2] the SCR extension has 9 bits, the highest 2 bits in the fifth byte after the sync bytes and the lower 7 bits in the sixth byte. The last bit is a marker bit (always 1). So instead of scr_ext = (hdr[4] 0x1) 8; scr_ext |= hdr[5]; I think it should be scr_ext = (unsigned)(hdr[4] 0x3) 7; scr_ext |= (hdr[5] 0xfe) 1; Given the non-authoritative MPEG-2 documents I have, yes, you appear to be correct on this. Please keep in mind that ps-analyzer.cpp is simply a debug tool from an ivtv developer perspective. You base prodcution software off of it at your own risk. :) And the bitrate is coded in the next 22 bits, so it should be mux_rate = (unsigned)(hdr[6]) 14; mux_rate |= (unsigned)(hdr[7]) 6; mux_rate |= (unsigned)(hdr[8] 0xfc) 2; Am I correct? Yes, you are correct. I miscounted the bits when I wrote this originally. Thanks for reporting this! Regards, Hans I did not check this one, but I would not be surprised if ps-analyzer had this wrong too. Regards, Andy Regards, Lars. [1] http://en.wikipedia.org/wiki/Presentation_time_stamp [2] http://en.wikipedia.org/wiki/MPEG_program_stream -- -- To unsubscribe from this list: send the line unsubscribe linux-media in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Index: test/ps-analyzer.cpp === --- test/ps-analyzer.cpp(Revision 4152) +++ test/ps-analyzer.cpp(Arbeitskopie) @@ -194,11 +194,11 @@ scr |= (u64)(hdr[2] 3) 13; scr |= (u64)hdr[3] 5; scr |= (u64)(hdr[4] 0xf8) 3; - scr_ext = (hdr[4] 0x1) 8; - scr_ext |= hdr[5]; - mux_rate = (hdr[6] 0x7f) 15; - mux_rate |= hdr[7] 7; - mux_rate |= (hdr[8] 0xfe) 1; + scr_ext = (unsigned)(hdr[4] 0x3) 7; + scr_ext |= (hdr[5] 0xfe) 1; + mux_rate = (unsigned)(hdr[6]) 14; + mux_rate |= (unsigned)(hdr[7]) 6; + mux_rate |= (unsigned)(hdr[8] 0xfc) 2; if (g_verbose) printf(%lld: pack scr=%lld scr_ext=%3u scr=%lld ns mux_rate=%u\n, pos, scr, scr_ext, scr2ns(scr, scr_ext), mux_rate);
Re: ivtv-utils/test/ps-analyzer.cpp: error in extracting SCR?
On Sun, 2010-02-07 at 21:36 +0100, Lars Hanisch wrote: Hi, Just for completeness, attached is the patch against the subversion repository at ivtvdriver.org. Thanks! Regards, Andy Regards, Lars. Am 04.02.2010 08:25, schrieb Hans Verkuil: On Thursday 04 February 2010 04:16:03 Andy Walls wrote: On Thu, 2010-02-04 at 01:18 +0100, Lars Hanisch wrote: Hi, I'm writing some code repacking the program stream that ivtv delivers into a transport stream (BTW: is there existing code for this?). Buy a CX23418 based board. That chip's firmware can produce a TS. I think Compro and LeadTek cards are available in Europe and are supported by the cx18 driver. Since many players needs the PCR I would like to use the SCR of the PS and place it in the adaption field of the TS (if wikipedia [1] and my interpretation of it is correct it should be the same). I stumbled upon the ps-analyzer.cpp in the test-directory of the ivtv-utils (1.4.0). From line 190 to 198 the SCR and SCR extension are extracted from the PS-header. But referring to [2] the SCR extension has 9 bits, the highest 2 bits in the fifth byte after the sync bytes and the lower 7 bits in the sixth byte. The last bit is a marker bit (always 1). So instead of scr_ext = (hdr[4] 0x1) 8; scr_ext |= hdr[5]; I think it should be scr_ext = (unsigned)(hdr[4] 0x3) 7; scr_ext |= (hdr[5] 0xfe) 1; Given the non-authoritative MPEG-2 documents I have, yes, you appear to be correct on this. Please keep in mind that ps-analyzer.cpp is simply a debug tool from an ivtv developer perspective. You base prodcution software off of it at your own risk. :) And the bitrate is coded in the next 22 bits, so it should be mux_rate = (unsigned)(hdr[6]) 14; mux_rate |= (unsigned)(hdr[7]) 6; mux_rate |= (unsigned)(hdr[8] 0xfc) 2; Am I correct? Yes, you are correct. I miscounted the bits when I wrote this originally. Thanks for reporting this! Regards, Hans I did not check this one, but I would not be surprised if ps-analyzer had this wrong too. Regards, Andy Regards, Lars. [1] http://en.wikipedia.org/wiki/Presentation_time_stamp [2] http://en.wikipedia.org/wiki/MPEG_program_stream -- -- To unsubscribe from this list: send the line unsubscribe linux-media in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line unsubscribe linux-media in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: ivtv-utils/test/ps-analyzer.cpp: error in extracting SCR?
Am 04.02.2010 08:25, schrieb Hans Verkuil: On Thursday 04 February 2010 04:16:03 Andy Walls wrote: On Thu, 2010-02-04 at 01:18 +0100, Lars Hanisch wrote: Hi, I'm writing some code repacking the program stream that ivtv delivers into a transport stream (BTW: is there existing code for this?). Buy a CX23418 based board. That chip's firmware can produce a TS. I think Compro and LeadTek cards are available in Europe and are supported by the cx18 driver. My PVR150 and 350 are still ok and I hope I have DVB-S-access in one or two years... But I will keep that in mind in case I need a new card. Since many players needs the PCR I would like to use the SCR of the PS and place it in the adaption field of the TS (if wikipedia [1] and my interpretation of it is correct it should be the same). I stumbled upon the ps-analyzer.cpp in the test-directory of the ivtv-utils (1.4.0). From line 190 to 198 the SCR and SCR extension are extracted from the PS-header. But referring to [2] the SCR extension has 9 bits, the highest 2 bits in the fifth byte after the sync bytes and the lower 7 bits in the sixth byte. The last bit is a marker bit (always 1). So instead of scr_ext = (hdr[4] 0x1) 8; scr_ext |= hdr[5]; I think it should be scr_ext = (unsigned)(hdr[4] 0x3) 7; scr_ext |= (hdr[5] 0xfe) 1; Given the non-authoritative MPEG-2 documents I have, yes, you appear to be correct on this. Please keep in mind that ps-analyzer.cpp is simply a debug tool from an ivtv developer perspective. You base prodcution software off of it at your own risk. :) Of course I will. :-) I already had coded my part and was looking for references... And the bitrate is coded in the next 22 bits, so it should be mux_rate = (unsigned)(hdr[6]) 14; mux_rate |= (unsigned)(hdr[7]) 6; mux_rate |= (unsigned)(hdr[8] 0xfc) 2; Am I correct? Yes, you are correct. I miscounted the bits when I wrote this originally. Thanks for reporting this! You're welcome! Regards, Lars. Regards, Hans I did not check this one, but I would not be surprised if ps-analyzer had this wrong too. Regards, Andy Regards, Lars. [1] http://en.wikipedia.org/wiki/Presentation_time_stamp [2] http://en.wikipedia.org/wiki/MPEG_program_stream -- -- To unsubscribe from this list: send the line unsubscribe linux-media in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line unsubscribe linux-media in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: ivtv-utils/test/ps-analyzer.cpp: error in extracting SCR?
On Thu, 2010-02-04 at 01:18 +0100, Lars Hanisch wrote: Hi, I'm writing some code repacking the program stream that ivtv delivers into a transport stream (BTW: is there existing code for this?). Buy a CX23418 based board. That chip's firmware can produce a TS. I think Compro and LeadTek cards are available in Europe and are supported by the cx18 driver. Since many players needs the PCR I would like to use the SCR of the PS and place it in the adaption field of the TS (if wikipedia [1] and my interpretation of it is correct it should be the same). I stumbled upon the ps-analyzer.cpp in the test-directory of the ivtv-utils (1.4.0). From line 190 to 198 the SCR and SCR extension are extracted from the PS-header. But referring to [2] the SCR extension has 9 bits, the highest 2 bits in the fifth byte after the sync bytes and the lower 7 bits in the sixth byte. The last bit is a marker bit (always 1). So instead of scr_ext = (hdr[4] 0x1) 8; scr_ext |= hdr[5]; I think it should be scr_ext = (unsigned)(hdr[4] 0x3) 7; scr_ext |= (hdr[5] 0xfe) 1; Given the non-authoritative MPEG-2 documents I have, yes, you appear to be correct on this. Please keep in mind that ps-analyzer.cpp is simply a debug tool from an ivtv developer perspective. You base prodcution software off of it at your own risk. :) And the bitrate is coded in the next 22 bits, so it should be mux_rate = (unsigned)(hdr[6]) 14; mux_rate |= (unsigned)(hdr[7]) 6; mux_rate |= (unsigned)(hdr[8] 0xfc) 2; Am I correct? I did not check this one, but I would not be surprised if ps-analyzer had this wrong too. Regards, Andy Regards, Lars. [1] http://en.wikipedia.org/wiki/Presentation_time_stamp [2] http://en.wikipedia.org/wiki/MPEG_program_stream -- -- To unsubscribe from this list: send the line unsubscribe linux-media in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: ivtv-utils/test/ps-analyzer.cpp: error in extracting SCR?
On Thursday 04 February 2010 04:16:03 Andy Walls wrote: On Thu, 2010-02-04 at 01:18 +0100, Lars Hanisch wrote: Hi, I'm writing some code repacking the program stream that ivtv delivers into a transport stream (BTW: is there existing code for this?). Buy a CX23418 based board. That chip's firmware can produce a TS. I think Compro and LeadTek cards are available in Europe and are supported by the cx18 driver. Since many players needs the PCR I would like to use the SCR of the PS and place it in the adaption field of the TS (if wikipedia [1] and my interpretation of it is correct it should be the same). I stumbled upon the ps-analyzer.cpp in the test-directory of the ivtv-utils (1.4.0). From line 190 to 198 the SCR and SCR extension are extracted from the PS-header. But referring to [2] the SCR extension has 9 bits, the highest 2 bits in the fifth byte after the sync bytes and the lower 7 bits in the sixth byte. The last bit is a marker bit (always 1). So instead of scr_ext = (hdr[4] 0x1) 8; scr_ext |= hdr[5]; I think it should be scr_ext = (unsigned)(hdr[4] 0x3) 7; scr_ext |= (hdr[5] 0xfe) 1; Given the non-authoritative MPEG-2 documents I have, yes, you appear to be correct on this. Please keep in mind that ps-analyzer.cpp is simply a debug tool from an ivtv developer perspective. You base prodcution software off of it at your own risk. :) And the bitrate is coded in the next 22 bits, so it should be mux_rate = (unsigned)(hdr[6]) 14; mux_rate |= (unsigned)(hdr[7]) 6; mux_rate |= (unsigned)(hdr[8] 0xfc) 2; Am I correct? Yes, you are correct. I miscounted the bits when I wrote this originally. Thanks for reporting this! Regards, Hans I did not check this one, but I would not be surprised if ps-analyzer had this wrong too. Regards, Andy Regards, Lars. [1] http://en.wikipedia.org/wiki/Presentation_time_stamp [2] http://en.wikipedia.org/wiki/MPEG_program_stream -- -- To unsubscribe from this list: send the line unsubscribe linux-media in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html -- Hans Verkuil - video4linux developer - sponsored by TANDBERG -- To unsubscribe from this list: send the line unsubscribe linux-media in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
