<html> <head> <meta content="text/html; charset=UTF-8" http-equiv="Content-Type"> </head> <body bgcolor="#FFFFFF" text="#000000"> Dear who may it concerns, I'm Hyunwoo Park. We are working on gstreamer and found some problem on gstreamer base sink element. We set a "render_delay" on our video and audio sink element through gst_base_sink_set_render_delay function. But, the setting values are not working correctly on the base sink element. As an example, fallowing test command shows that the "render_delay" value not working correctly. I have used no “render_delay” on a first fakesink and a second of “render_delay” on a second fakesink. <blockquote type="cite"><tt>GST_DEBUG_NO_COLOR=1 GST_DEBUG=basesink:5 gst-launch-0.10 videotestsrc pattern=4 ! video/x-raw-yuv, width=1, height=1, framerate=1/5 ! tee name=t t.src0 ! queue ! fakesink sync=true dump=true t.src1 ! queue ! fakesink sync=true render-delay=1000000000 dump=true > render-delay.log 2>&</tt> </blockquote> I executed above command on gstreamer 0.10.32. Followings are some part of debug log on gstreamer 0.10.32. <blockquote type="cite"><tt>0:00:04.579000000 776 0x191938 DEBUG basesink gstbasesink.c:3519:gst_base_sink_chain_unlocked:<fakesink1> got times start: 0:00:10.000000000, end: 0:00:15.000000000 0:00:04.579000000 776 0x191938 DEBUG basesink gstbasesink.c:1928:gst_base_sink_get_sync_times:<fakesink1> got times start: 0:00:10.000000000, stop: 0:00:15.000000000, do_sync 1 0:00:04.579000000 776 0x191938 DEBUG basesink gstbasesink.c:2460:gst_base_sink_do_sync:<fakesink1> possibly waiting for clock to reach 0:00:10.000000000, adjusted 0:00:09.000000000 0:00:04.579000000 776 0x191938 LOG basesink gstbasesink.c:2105:gst_base_sink_wait_clock:<fakesink1> time 0:00:09.000000000, base_time 0:22:55.857000002 0:00:06.580000000 776 0x2ca005e8 DEBUG basesink gstbasesink.c:2467:gst_base_sink_do_sync:<fakesink0> clock returned 0, jitter -0:00:04.999000000 0:00:06.580000000 776 0x2ca005e8 DEBUG basesink gstbasesink.c:2755:gst_base_sink_is_too_late:<fakesink0> object was scheduled in time 0:00:06.580000000 776 0x2ca005e8 DEBUG basesink gstbasesink.c:2860:gst_base_sink_render_object:<fakesink0> rendering object 0x4fed8 0:00:06.580000000 776 0x2ca005e8 DEBUG basesink gstbasesink.c:980:gst_base_sink_set_last_buffer_unlocked:<fakesink0> setting last buffer to 0x4fed8 00000000 (0x1918f0): 51 5a 00 f0 QZ.. 0:00:06.580000000 776 0x2ca005e8 DEBUG basesink gstbasesink.c:2974:gst_base_sink_render_object:<fakesink0> object unref after render 0x4fed8 0:00:06.580000000 776 0x2ca005e8 DEBUG basesink gstbasesink.c:3519:gst_base_sink_chain_unlocked:<fakesink0> got times start: 0:00:10.000000000, end: 0:00:15.000000000 0:00:06.580000000 776 0x2ca005e8 DEBUG basesink gstbasesink.c:1928:gst_base_sink_get_sync_times:<fakesink0> got times start: 0:00:10.000000000, stop: 0:00:15.000000000, do_sync 1 0:00:06.580000000 776 0x2ca005e8 DEBUG basesink gstbasesink.c:2460:gst_base_sink_do_sync:<fakesink0> possibly waiting for clock to reach 0:00:10.000000000, adjusted 0:00:11.000000000 0:00:06.580000000 776 0x2ca005e8 LOG basesink gstbasesink.c:2105:gst_base_sink_wait_clock:<fakesink0> time 0:00:11.000000000, base_time 0:22:55.857000002 0:00:09.580000000 776 0x191938 DEBUG basesink gstbasesink.c:2467:gst_base_sink_do_sync:<fakesink1> clock returned 0, jitter -0:00:04.996000000 0:00:09.580000000 776 0x191938 DEBUG basesink gstbasesink.c:2755:gst_base_sink_is_too_late:<fakesink1> object was scheduled in time 0:00:09.580000000 776 0x191938 DEBUG basesink gstbasesink.c:2860:gst_base_sink_render_object:<fakesink1> rendering object 0x4ff30 0:00:09.580000000 776 0x191938 DEBUG basesink gstbasesink.c:980:gst_base_sink_set_last_buffer_unlocked:<fakesink1> setting last buffer to 0x4ff30 00000000 (0x191928): 51 5a 00 f0 QZ.. 0:00:09.580000000 776 0x191938 DEBUG basesink gstbasesink.c:2974:gst_base_sink_render_object:<fakesink1> object unref after render 0x4ff30 0:00:09.580000000 776 0x191938 DEBUG basesink gstbasesink.c:3519:gst_base_sink_chain_unlocked:<fakesink1> got times start: 0:00:15.000000000, end: 0:00:20.000000000 0:00:09.580000000 776 0x191938 DEBUG basesink gstbasesink.c:1928:gst_base_sink_get_sync_times:<fakesink1> got times start: 0:00:15.000000000, stop: 0:00:20.000000000, do_sync 1 0:00:09.580000000 776 0x191938 DEBUG basesink gstbasesink.c:2460:gst_base_sink_do_sync:<fakesink1> possibly waiting for clock to reach 0:00:15.000000000, adjusted 0:00:14.000000000 0:00:09.580000000 776 0x191938 LOG basesink gstbasesink.c:2105:gst_base_sink_wait_clock:<fakesink1> time 0:00:14.000000000, base_time 0:22:55.857000002 0:00:11.580000000 776 0x2ca005e8 DEBUG basesink gstbasesink.c:2467:gst_base_sink_do_sync:<fakesink0> clock returned 0, jitter -0:00:04.995000000 0:00:11.580000000 776 0x2ca005e8 DEBUG basesink gstbasesink.c:2755:gst_base_sink_is_too_late:<fakesink0> object was scheduled in time 0:00:11.580000000 776 0x2ca005e8 DEBUG basesink gstbasesink.c:2860:gst_base_sink_render_object:<fakesink0> rendering object 0x4ff30 0:00:11.580000000 776 0x2ca005e8 DEBUG basesink gstbasesink.c:980:gst_base_sink_set_last_buffer_unlocked:<fakesink0> setting last buffer to 0x4ff30 00000000 (0x191928): 51 5a 00 f0 QZ.. 0:00:11.580000000 776 0x2ca005e8 DEBUG basesink gstbasesink.c:2974:gst_base_sink_render_object:<fakesink0> object unref after render 0x4ff30</tt> </blockquote> According to the red part of the above log message, a video buffer that has timestamp 10 second rendered at 9 second and 11 second, which supposed to be at 10 second and 11 second. And I found that gst_base_sink_do_sync function subtract render_delay from “stime” was already subtracted from gst_base_sink_adjust_time function. See a relevant patch that cause this problem, <a class="moz-txt-link-freetext" href="http://cgit.freedesktop.org/gstreamer/gstreamer/commit/libs/gst/base/gstbasesink.c?id=54a587143454320ed63ce82b052e07050ed6a584">http://cgit.freedesktop.org/gstreamer/gstreamer/commit/libs/gst/base/gstbasesink.c?id=54a587143454320ed63ce82b052e07050ed6a584</a> Regards. Hyunwoo Park. </body> </html>