<div dir="ltr"><p class="MsoNormal" style="margin:0cm 0cm 0.0001pt;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US">Hello,</span></p> <p class="MsoNormal" style="margin:0cm 0cm 0.0001pt;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> </span></p> <p class="MsoNormal" style="margin:0cm 0cm 0.0001pt;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US">I’m currently developing an application to display live TV using GStreamer on a Raspberry Pi 2B.</span></p> <p class="MsoNormal" style="margin:0cm 0cm 0.0001pt;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> </span></p> <p class="MsoNormal" style="margin:0cm 0cm 0.0001pt;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US">Therefore I use two appsrc elements (one for video and one for audio) to connect them to the V4L DVB demux device ‘/dev/dvb/adapter0/demux0’.</span></p> <p class="MsoNormal" style="margin:0cm 0cm 0.0001pt;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US">My pipelines are: </span></p> <p class="MsoNormal" style="margin:0cm 0cm 0.0001pt;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> </span></p> <p class="MsoNormal" style="margin:0cm 0cm 0.0001pt;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US">Video</span></p> <p class="MsoNormal" style="margin:0cm 0cm 0.0001pt;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> V4L DVB demux (DMX_OUT_TAP) -> appsrc ! h264parse ! v4l2h264dec ! queue ! kmssink</span></p> <p class="MsoNormal" style="margin:0cm 0cm 0.0001pt;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US">Audio</span></p> <p class="MsoNormal" style="margin:0cm 0cm 0.0001pt;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> V4L DVB demux (DMX_OUT_TAP) -> appsrc ! mpegaudioparse ! mpg123audiodec ! queue ! alsasink</span></p> <p class="MsoNormal" style="margin:0cm 0cm 0.0001pt;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> </span></p> <p class="MsoNormal" style="margin:0cm 0cm 0.0001pt;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US">I’ve created a thread which feeds the output of the 2 video and audio demux devices into my appsrc elements and they feed them to both pipelines:</span></p> <p class="MsoNormal" style="margin:0cm 0cm 0.0001pt;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> </span></p> <p class="MsoNormal" style="margin:0cm 0cm 0.0001pt;font-size:11pt;font-family:Calibri,sans-serif">uint8_t vbuf[65536];</p> <p class="MsoNormal" style="margin:0cm 0cm 0.0001pt;font-size:11pt;font-family:Calibri,sans-serif">uint8_t abuf[4096];</p> <p class="MsoNormal" style="margin:0cm 0cm 0.0001pt;font-size:11pt;font-family:Calibri,sans-serif"> </p> <p class="MsoNormal" style="margin:0cm 0cm 0.0001pt;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US">// Read data from demux</span></p> <p class="MsoNormal" style="margin:0cm 0cm 0.0001pt;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US">vrc = read(vdfd, vbuf, sizeof(vbuf));</span></p> <p class="MsoNormal" style="margin:0cm 0cm 0.0001pt;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US">arc = read(adfd, abuf, sizeof(abuf));</span></p> <p class="MsoNormal" style="margin:0cm 0cm 0.0001pt;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> </span></p> <p class="MsoNormal" style="margin:0cm 0cm 0.0001pt;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US">// Create a new empty buffer and fill data into it</span></p> <p class="MsoNormal" style="margin:0cm 0cm 0.0001pt;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US">gvbuffer = gst_buffer_new_allocate(NULL, vrc, NULL);</span></p> <p class="MsoNormal" style="margin:0cm 0cm 0.0001pt;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US">gst_buffer_fill(gvbuffer, 0, vbuf, vrc);</span></p> <p class="MsoNormal" style="margin:0cm 0cm 0.0001pt;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US">gabuffer = gst_buffer_new_allocate(NULL, arc, NULL);</span></p> <p class="MsoNormal" style="margin:0cm 0cm 0.0001pt;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US">gst_buffer_fill(gabuffer, 0, abuf, arc);</span></p> <p class="MsoNormal" style="margin:0cm 0cm 0.0001pt;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> </span></p> <p class="MsoNormal" style="margin:0cm 0cm 0.0001pt;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US">// Push the buffer into the appsrc</span></p> <p class="MsoNormal" style="margin:0cm 0cm 0.0001pt;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US">g_signal_emit_by_name (((CustomData *)data)->vappsrc, "push-buffer", gvbuffer, &vrb);</span></p> <p class="MsoNormal" style="margin:0cm 0cm 0.0001pt;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US">g_signal_emit_by_name (((CustomData *)data)->aappsrc, "push-buffer", gabuffer, &arb);</span></p> <p class="MsoNormal" style="margin:0cm 0cm 0.0001pt;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> </span></p> <p class="MsoNormal" style="margin:0cm 0cm 0.0001pt;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US">// Free the buffers now that we are done with it</span></p> <p class="MsoNormal" style="margin:0cm 0cm 0.0001pt;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US">gst_buffer_unref (gvbuffer);</span></p> <p class="MsoNormal" style="margin:0cm 0cm 0.0001pt;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US">gst_buffer_unref (gabuffer);</span></p> <p class="MsoNormal" style="margin:0cm 0cm 0.0001pt;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> </span></p> <p class="MsoNormal" style="margin:0cm 0cm 0.0001pt;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US">This works quite well and I’ve got video and audio.</span></p> <p class="MsoNormal" style="margin:0cm 0cm 0.0001pt;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> </span></p> <p class="MsoNormal" style="margin:0cm 0cm 0.0001pt;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US">The only thing which doesn’t work as expected is that video and audio isn’t synchronous.</span></p> <p class="MsoNormal" style="margin:0cm 0cm 0.0001pt;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> </span></p> <p class="MsoNormal" style="margin:0cm 0cm 0.0001pt;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US">What am I missing here and how to get video and audio synchronous?</span></p> <p class="MsoNormal" style="margin:0cm 0cm 0.0001pt;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> </span></p> <p class="MsoNormal" style="margin:0cm 0cm 0.0001pt;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US">Thanks for any advice.</span></p> <p class="MsoNormal" style="margin:0cm 0cm 0.0001pt;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> </span></p> <p class="MsoNormal" style="margin:0cm 0cm 0.0001pt;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US">Best Regards,</span></p> <p class="MsoNormal" style="margin:0cm 0cm 0.0001pt;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US">Joerg</span></p></div>