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Bug 595161 - [mpegtsdemux] Internal dataflow problem with some streams.
[mpegtsdemux] Internal dataflow problem with some streams.
Product: GStreamer
Classification: Platform
Component: gst-plugins-bad
Other Linux
: Normal normal
: 0.10.17
Assigned To: GStreamer Maintainers
GStreamer Maintainers
Depends on:
Reported: 2009-09-14 12:42 UTC by Krzysztof Adamski
Modified: 2009-10-29 19:45 UTC
See Also:
GNOME target: ---
GNOME version: ---

mpegtsdemux: Don't send new-segment with start time == -1 (4.88 KB, patch)
2009-10-27 22:10 UTC, Jan Schmidt
committed Details | Review

Description Krzysztof Adamski 2009-09-14 12:42:08 UTC
I'm having problems with playing some mpeg streams from dvb card. From time to time (1/10 of times) when i start watching some channel, it is stuck at the first frame (sometimes audio is playing, though). Here's error message:

(gst-launch-0.10:1975): GStreamer-CRITICAL **: gst_event_new_new_segment_full: assertion `start != -1' failed

(gst-launch-0.10:1975): GStreamer-CRITICAL **: gst_pad_push_event: assertion `event != NULL' failed
WARNING: from element /GstPipeline:pipeline0/GstXvImageSink:xvimagesink0: Internal data flow problem.
Additional debug info:
gstbasesink.c(3283): gst_base_sink_chain_unlocked (): /GstPipeline:pipeline0/GstXvImageSink:xvimagesink0:
Received buffer without a new-segment. Assuming timestamps start from 0.
Pipeline is PREROLLED ...
Setting pipeline to PLAYING ...
New clock: GstSystemClock

I did record some very short samples of this TS files and they can be played without problems on mplayer and VLC but not with gstreamer.

Steps to reproduce:
- Take one of my failing samples from
- Play it with gstreamer using one of following pipelines:
  * gst-launch playbin uri=file:///fail/sample.9.ts
  * gst-launch filesrc location=/fail/sample.9.ts ! mpegtsdemux ! mpeg2dec ! ffmpegcolorspace ! xvimagesink
Actual Results:
The file is not played. It stops at the first frame.

Expected Results:
File being played without problems.

Build Date & Platform:
The problem seams to occur in all versions of mpegtsdemux in gstreamer-plugin-bad. I'm testing this on Ubuntu system (both with it's default packages and my own packages build from newest versions).

Additional Information:
- There are couple failing samples here:
- You can compare them with working samples from:
- debug log attached
Comment 1 Krzysztof Adamski 2009-09-14 12:46:14 UTC
Debug log was to big to attach it here. It's on:
Comment 2 Krzysztof Adamski 2009-09-15 09:26:03 UTC
I have compared two streams (failing one and good one) and it seams they differ in that failing stream does not provide PTS:
DEBUG          mpegpesfilter gstpesfilter.c:298:gst_pes_filter_parse: header_data_length: 0, flags 0x00

which means it's value is set to -1:
DEBUG            mpegtsdemux gstmpegtsdemux.c:1024:gst_mpegts_demux_data_cb:<mpegtsdemux0> setting PTS to (18446744073709551615) time: 99:99:99.999999999 on buffer 0xb6502df0 first buffer: 1 base_time: 0:00:00.000000000

Since no base PCR or last PCR is set:
DEBUG            mpegtsdemux gstmpegtsdemux.c:769:gst_mpegts_demux_send_new_segment:<mpegtsdemux0> no base PCR, using last PCR 18446744073709551615
DEBUG            mpegtsdemux gstmpegtsdemux.c:776:gst_mpegts_demux_send_new_segment:<mpegtsdemux0> no last PCR, using PTS 18446744073709551615

Time is set to -1:
DEBUG            mpegtsdemux gstmpegtsdemux.c:785:gst_mpegts_demux_send_new_segment:<mpegtsdemux0> segment PTS to (18446744073709551615) time: 18446744073709551615

and it is then passed to gst_event_new_new_segment, which causes assertion fail:
GStreamer-CRITICAL **: gst_event_new_new_segment_full: assertion `start != -1' failed

The problem is, I don't know what should be done in such case since I'm not MPEG expert so I can't fix it myself.
Comment 3 Sebastian Dröge (slomo) 2009-09-15 10:02:30 UTC
sample.9.ts works fine for me with latest GIT of gst-plugins-bad. Can you confirm that it's fixed for you too?
Comment 4 Sebastian Dröge (slomo) 2009-09-15 10:04:30 UTC
For the other files (I tested 16 and 20) it still hangs at the first frame and prints the assertion failures.
Comment 5 Krzysztof Adamski 2009-09-15 10:41:03 UTC
Strange. Nothing changed after updating gst-plugins-bad to git version. sample.9.ts still hangs at the first frame.
Comment 6 Jan Schmidt 2009-10-27 22:10:26 UTC
Created attachment 146379 [details] [review]
mpegtsdemux: Don't send new-segment with start time == -1

When sending new-segment to a stream, ensure that there is either a valid
PCR, or else wait until there's a PTS on the stream (dropping packets if
needed) in order to avoid generating an invlaid new-segments event.
Comment 7 Jan Schmidt 2009-10-27 22:10:53 UTC
This patch makes it work for me...
Comment 8 Thiago Sousa Santos 2009-10-27 22:26:10 UTC
Works for me too.
Comment 9 Krzysztof Adamski 2009-10-28 15:38:40 UTC
It fixes the problem for me. Thank you.
Comment 10 Edward Hervey 2009-10-29 15:37:00 UTC
Please let maintainers/developers close bugs. In this case the patch still hasn't been pushed.

Jan, will you do the honors ?
Comment 11 Jan Schmidt 2009-10-29 15:45:41 UTC
I wouldn't mind getting Zaheer's opinion on whether this looks OK...
Comment 12 Zaheer Abbas Merali 2009-10-29 17:35:18 UTC
Comment on attachment 146379 [details] [review]
mpegtsdemux: Don't send new-segment with start time == -1

patch looks good, go ahead and commit
Comment 13 Jan Schmidt 2009-10-29 19:45:32 UTC
commit 91499fd9a78c2175f6be64d655ab8bedfc86fc9e
Author: Jan Schmidt <>
Date:   Tue Oct 27 22:08:42 2009 +0000

    mpegtsdemux: Don't send new-segment with start time == -1
    When sending new-segment to a stream, ensure that there is either a valid
    PCR, or else wait until there's a PTS on the stream (dropping packets if
    needed) in order to avoid generating an invlaid new-segments event.