<html> <head> <style> .hmmessage P { margin:0px; padding:0px } body.hmmessage { FONT-SIZE: 10pt; FONT-FAMILY:Tahoma } </style> </head> <body class='hmmessage'> Hi, I'm writing a mixer-type (N-to-1) plugin for GStreamer and using "adder" element as my example how to make one. The problem I am having currently is synchronization of input streams - adder is not even trying to synchronize anything, so if I feed it for example 5 perfectly time-synchronized streams from files it starts processing data before all the pads are negotiated. Below is a debug output of what is happening, sink2 gets negotiated just in time to make it to the mix, but sinks 3 and 4 get their requests only after _collected is already ran and first buffer pushed out. Any suggestions for an easy way to do synchronization? Thanks, Rob $ gst-launch-0.10  -v filesrc location=input1.wav ! wavparse ! adder name=add ! wavenc ! filesink location=out.wav \ filesrc location=input2.wav ! wavparse ! add. \ filesrc location=input3.wav ! wavparse ! add. \ filesrc location=input4.wav ! wavparse ! add. \ filesrc location=input5.wav ! wavparse ! add. - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Setting pipeline to PAUSED ... 0:00:00.040771611 16675  0x8051410 DEBUG                adder gstadder.c:789:gst_adder_request_new_pad:<add> request new pad sink0 0:00:00.040813029 16675 0xb6f005c8 DEBUG                adder gstadder.c:789:gst_adder_request_new_pad:<add> request new pad sink1 0:00:00.040887694 16675 0xb6f005c8 DEBUG                adder gstadder.c:209:gst_adder_sink_getcaps:<add> intersecting peer and template caps 0:00:00.040984569 16675  0x8051410 DEBUG                adder gstadder.c:209:gst_adder_sink_getcaps:<add> intersecting peer and template caps 0:00:00.041024661 16675 0xb6f005c8 DEBUG                adder gstadder.c:677:gst_adder_sink_event: Got newsegment event on pad add:sink1 0:00:00.041060282 16675 0xb6f005c8 DEBUG                adder gstadder.c:677:gst_adder_sink_event: Got tag event on pad add:sink1 0:00:00.041114063 16675 0xb6f005c8 DEBUG                adder gstadder.c:209:gst_adder_sink_getcaps:<add> intersecting peer and template caps 0:00:00.041119231 16675  0x8051410 DEBUG                adder gstadder.c:677:gst_adder_sink_event: Got newsegment event on pad add:sink0 0:00:00.041146960 16675  0x8051410 DEBUG                adder gstadder.c:677:gst_adder_sink_event: Got tag event on pad add:sink0 0:00:00.041225256 16675  0x8051410 DEBUG                adder gstadder.c:209:gst_adder_sink_getcaps:<add> intersecting peer and template caps 0:00:00.041241181 16675 0xb6f005c8 LOG                  adder gstadder.c:241:gst_adder_setcaps:<add> setting caps on pad 0x813f3f8,sink1 to audio/x-raw-int, endianness=(int)1234, channels=(int)1, width=(int)16, depth=(int)16, signed=(boolean)true, rate=(int)48000 0:00:00.041356635 16675  0x8051410 LOG                  adder gstadder.c:241:gst_adder_setcaps:<add> setting caps on pad 0x8136d80,sink0 to audio/x-raw-int, endianness=(int)1234, channels=(int)1, width=(int)16, depth=(int)16, signed=(boolean)true, rate=(int)48000 0:00:00.041392117 16675  0x8051410 DEBUG                adder gstadder.c:261:gst_adder_setcaps:<add> parse_caps sets adder to format int /pipeline0/add.sink0: caps = audio/x-raw-int, endianness=(int)1234, channels=(int)1, width=(int)16, depth=(int)16, signed=(boolean)true, rate=(int)48000 0:00:00.041513368 16675 0xb6f00830 DEBUG                adder gstadder.c:789:gst_adder_request_new_pad:<add> request new pad sink2 0:00:00.041574133 16675 0xb6f00830 DEBUG                adder gstadder.c:209:gst_adder_sink_getcaps:<add> intersecting peer and template caps 0:00:00.041699994 16675 0xb6f00830 DEBUG                adder gstadder.c:677:gst_adder_sink_event: Got newsegment event on pad add:sink2 0:00:00.041725069 16675 0xb6f00830 DEBUG                adder gstadder.c:677:gst_adder_sink_event: Got tag event on pad add:sink2 0:00:00.041740155 16675 0xb6f005c8 DEBUG                adder gstadder.c:261:gst_adder_setcaps:<add> parse_caps sets adder to format int /pipeline0/add.sink1: caps = audio/x-raw-int, endianness=(int)1234, channels=(int)1, width=(int)16, depth=(int)16, signed=(boolean)true, rate=(int)48000 0:00:00.041858054 16675 0xb6f005c8 LOG                  adder gstadder.c:877:gst_adder_collected:<add> starting to cycle through channels, 4096 bytes available (bps = 2) 0:00:00.041884875 16675 0xb6f005c8 LOG                  adder gstadder.c:907:gst_adder_collected:<add> channel 0x811e530: making output buffer of 4096 bytes 0:00:00.041904222 16675 0xb6f005c8 LOG                  adder gstadder.c:921:gst_adder_collected:<add> channel 0x811e530: copying 4096 bytes from data 0x8145a00 0:00:00.041921264 16675 0xb6f005c8 LOG                  adder gstadder.c:934:gst_adder_collected:<add> channel 0x813d308: mixing 4096 bytes from data 0x8140c00 0:00:00.041946478 16675 0xb6f005c8 LOG                  adder gstadder.c:934:gst_adder_collected:<add> channel 0xb6f00b88: mixing 4096 bytes from data 0x813d800 0:00:00.041982518 16675 0xb6f005c8 LOG                  adder gstadder.c:999:gst_adder_collected:<add> pushing outbuf, timestamp 0:00:00.000000000 /pipeline0/wavenc0.sink: caps = audio/x-raw-int, endianness=(int)1234, channels=(int)1, width=(int)16, depth=(int)16, signed=(boolean)true, rate=(int)48000 /pipeline0/filesink0.sink: caps = audio/x-wav 0:00:00.042310372 16675 0xb6f00930 DEBUG                adder gstadder.c:789:gst_adder_request_new_pad:<add> request new pad sink3 0:00:00.042369391 16675 0xb6f00930 DEBUG                adder gstadder.c:209:gst_adder_sink_getcaps:<add> intersecting peer and template caps 0:00:00.042495043 16675 0xb6f00930 DEBUG                adder gstadder.c:677:gst_adder_sink_event: Got newsegment event on pad add:sink3 0:00:00.042518790 16675 0xb6f00930 DEBUG                adder gstadder.c:677:gst_adder_sink_event: Got tag event on pad add:sink3 Pipeline is PREROLLING ... 0:00:00.042897491 16675 0xb6f03200 DEBUG                adder gstadder.c:789:gst_adder_request_new_pad:<add> request new pad sink4 0:00:00.042961609 16675 0xb6f03200 DEBUG                adder gstadder.c:209:gst_adder_sink_getcaps:<add> intersecting peer and template caps 0:00:00.043095084 16675 0xb6f03200 DEBUG                adder gstadder.c:677:gst_adder_sink_event: Got newsegment event on pad add:sink4 0:00:00.043120926 16675 0xb6f03200 DEBUG                adder gstadder.c:677:gst_adder_sink_event: Got tag event on pad add:sink4 <hr />Stay up to date on your PC, the Web, and your mobile phone with Windows Live. <a href='http://clk.atdmt.com/MRT/go/msnnkwxp1020093185mrt/direct/01/' target='_new'>See Now</a></body> </html>