Bob Ingraham wrote: > Hello, > > I've been using the Linux DVB API to grab DBV-S MPEG2 video packets using a TechniSat S2 card. > > But something seems odd about DMX_SET_PES_FILTER. > > It returns a TS packets for my pid just fine, but by MPEG2 frames have no PES headers! The raw compressed MPEG2 frames just immediately follow the TS/adapation-field headers directly. > > When I wrote my TS packet decoder, I was expecting to have to decode PES headers after the TS header. But instead I found the raw compressed frames. > > They decode fine (with ffmpeg's libavcodec mpeg2 decoder,) and they look fine when rendered using SDL. > > But besides my own program, I can't get vlc or mplayer to decode this stream. Both vlc and mplayer sense a TS stream, but then they never render anything because, I suspect, that they can't find PES headers. > > So, two questions: > > 1. Am I crazy or is DMX_SET_PES_FILTER returning a non-standard TS stream? > > 2. Is there a way to receive a compliant MPEG-TS (or MPEG2-PS,) stream? > > 3. Should I use DMX_SET_FILTER instead? > > 4. If so, what goes in the filter/mask members of the dmx_filter_t struct? > > > Thanks, > Bob > > PS: I use the following to filter on my video stream pid (0x1344): > > struct dmx_pes_filter_params f; > > memset(&f, 0, sizeof(f)); > f.pid = (uint16_t) pid; > f.input = DMX_IN_FRONTEND; > f.output = DMX_OUT_TS_TAP; > f.pes_type = DMX_PES_OTHER; > f.flags = DMX_IMMEDIATE_START; > > Hello, I use exactly the same parameters and I get a raw mpeg2-TS stream (ie packet of 188 bytes with the TS headers as defined in the mpeg2-ts norm) If you want your stream to be read with VLC you need also the PAT and the PMT pids. If you want the sound you'll need also the PCR pid. I don't know how to get the PES headers Hope this information will help you Regards -- Brice -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
