DMX_OUT_TSDEMUX_TAP: record two streams from same mux, resend

[Resending patch with proper signed-off-by and updated description, but otherwise unchanged]

Hi there,

Currently (in linux-2.6.24, but linux-dvb hg looks similar), the dmx_output_t in the dmx_pes_filter_params decides two things: whether output is sent to demux0 or dvr0 (in dmxdev.c:dvb_dmxdev_ts_callback), *and* whether to depacketise TS (in dmxdev.c:dvb_dmxdev_filter_start). As it stands, those two things can't be set independently: output destined for demux0 is depacketised, output for dvr0 isn't.

This is what you want for capturing multiple audio streams from the same multiplex simultaneously: open demux0 several times and send depacketised output there. And capturing a single video stream is fine
too: open dvr0. But for capturing multiple video streams, it's surely not what you want: you want multi-open (so demux0, not dvr0), but you want the TS nature preserved (because that's what you want on output, as you're going to re-multiplex it with the audio).

At least one existing solution -- GStreamer -- sends all its streams simultaneously via dvr0 and demuxes again in userland, but it seems a bit of a shame to pick out all the PIDs in kernel, stick them back together in kernel, and send them to userland only to get unpicked again, when the alternative is such a small API addition.

The attached patch adds a new value for dmx_output_t:
DMX_OUT_TSDEMUX_TAP, which sends TS to the demux0 device. With this patch and a dvb-usb-dib0700 (and UK Freeview from Sandy Heath), I can successfully capture an audio/video PID pair into a TS file that mplayer can play back.

Peter

@@ -39,9 +39,10 @@ typedef enum
 	DMX_OUT_DECODER, /* Streaming directly to decoder. */
 	DMX_OUT_TAP,     /* Output going to a memory buffer */
 			 /* (to be retrieved via the read command).*/
-	DMX_OUT_TS_TAP   /* Output multiplexed into a new TS  */
+	DMX_OUT_TS_TAP,  /* Output multiplexed into a new TS  */
 			 /* (to be retrieved by reading from the */
 			 /* logical DVR device).                 */
+	DMX_OUT_TSDEMUX_TAP /* Like TS_TAP but retrieved from the DMX device */
 } dmx_output_t;
 
 

@@ -374,7 +374,8 @@ static int dvb_dmxdev_ts_callback(const 
 		return 0;
 	}
 
-	if (dmxdevfilter->params.pes.output == DMX_OUT_TAP)
+	if (dmxdevfilter->params.pes.output == DMX_OUT_TAP
+	    || dmxdevfilter->params.pes.output == DMX_OUT_TSDEMUX_TAP)
 		buffer = &dmxdevfilter->buffer;
 	else
 		buffer = &dmxdevfilter->dev->dvr_buffer;

@@ -618,7 +619,7 @@ static int dvb_dmxdev_filter_start(struc
 		else
 			ts_type = 0;
 
-		if (otype == DMX_OUT_TS_TAP)
+		if (otype == DMX_OUT_TS_TAP || otype == DMX_OUT_TSDEMUX_TAP)
 			ts_type |= TS_PACKET;
 
 		if (otype == DMX_OUT_TAP)

_______________________________________________
linux-dvb mailing list
[email protected]
http://www.linuxtv.org/cgi-bin/mailman/listinfo/linux-dvb

Applied, thanks.

Sorry for being late. I was travelling last week.

Cheers,
Mauro

_______________________________________________
linux-dvb mailing list
[email protected]
http://www.linuxtv.org/cgi-bin/mailman/listinfo/linux-dvb