Hi Johannes Johannes Stezenbach wrote: >>So my conclusion is that either CanalDigitals signal has severe jumps in >>PTS (especially for NRK1 and NRK2), or the receiver PCs builds a >>lag/buffer that eventually gets dropped (50-70 decoded frames). Assuming >>the latter, then where can the data get lost ? Is it on the Hauppauge >>(TT) receivers or in the driver/kernel or in the dvbstream app. ? > > > - at 4Mbit/s two seconds give you one MByte. Is there a 1MB buffer > somewhere that could slowly run full and then get dropped > completely to recover? (maybe the bitrate of the paytv channels > is higer than for FTA?) Checking with NRK1 (1W 12321,H,27800,512,640) I see a 6.5-7.5Mbps measuring saved TS to file. Fiddling (only a little) with the numbers, its approx 2Mb that gets dropped - too close to not look suspeciously. > - do and verify a recording on a receiver PC with one Nova card first > - PTS discontinuities are allowed in the MPEG standard; is there > actually something missing? Difficult to say - for me - the decoded stream just suddently jumps 2-2.8 secs in PTS. I'll try to extract something viewable in MPEG format. As it is now, my output is MPEG-4. Have to rewrite some code for further inspection. > is the discontinuity_indicator set? Hmm, assume that is a flag in the mpeg-2 ts stream. I'll try to see if I can extract it from my demuxer. I'm not an expert here, but maybe I can find something on Google. > does the PTS jump happen only for video and not for audio? Hmm, I use LAME to decode and it says bitstream problem: resyncing... 11:09:58.135-mp4live-3: WARNING : PTS jumped 2.160 seconds from 2811187798 to 2811382198 (54.00 frames) The 'bitstream problem: resyncing..' message is from LAME. I suspect the audio PTS jumps too, but I'll have to rewrite my code a bit to be sure. I'll check. > - how does your libmpeg2 based decoder app sync to the dvbstream > transmitter to ensure buffers never over/underrun? Ehh ! Come again ! Not sure what you mean ! I demux the DVB MPEG-2 TS stream continously on a fast enough system, then feed the video packets to libmpeg2 and the audio packets to LAME. Which buffers should/could get over/underrun ? Kind regards --PMM > > Johannes > > _______________________________________________ > > linux-dvb@xxxxxxxxxxx > http://www.linuxtv.org/cgi-bin/mailman/listinfo/linux-dvb -- +----------------------------------------------------------+ | Kabel-TV over Internettet -- http://www.streamtv.dk/ | +----------------------------------------------------------+
