Bug 720216 – matroskamux: mkvalidate errors in transcoded webm file

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Bug 720216 - matroskamux: mkvalidate errors in transcoded webm file


Summary:	matroskamux: mkvalidate errors in transcoded webm file


Status:	RESOLVED OBSOLETE

Product:	GStreamer
Classification:	Platform
Component:	gst-plugins-good
Version:	unspecified
Hardware:	Other Linux

Importance:	Normal minor
Target Milestone:	git master
Assigned To:	GStreamer Maintainers
QA Contact:	GStreamer Maintainers

URL:
Whiteboard:

Depends on:
Blocks:

Reported:	2013-12-10 22:00 UTC by Guillaume Desmottes
Modified:	2018-11-03 14:50 UTC

See Also:
GNOME target:	---
GNOME version:	---

Description Guillaume Desmottes 2013-12-10 22:00:19 UTC

Looks like there are things very wrong with this file:
http://agot.be/~lachambre/bug/20131205-1_bb_pl.webm

It has been created using:
gst-launch-1.0 rtspsrc location="rtsp://193.191.129.52/Archive/20131205-1_bb_pl.wmv" protocols=0x00000004 ! decodebin name=demux ! queue ! videoconvert ! vp8enc ! webmmux name=mux ! filesink location=20131205-1_bb_pl.webm demux. ! queue ! audioconvert ! audioresample ! vorbisenc ! mux.

This has been done on a Debian stable system using wheezy-backports packages:
libgstreamer1.0-0:amd64               1.0.8-1~bpo70+1
libgstreamer-plugins-base1.0-0:amd64  1.0.8-1~bpo70+1
gstreamer1.0-plugins-good:amd64       1.0.8-1~bpo70+1
gstreamer1.0-plugins-ugly:amd64       1.0.8-1~bpo70+1
gstreamer1.0-plugins-bad:amd64        1.0.8-1~bpo70+1
gstreamer1.0-libav:amd64              1.0.8-1~bpo70+1

I tried to transcode it to MP4 on my own system (F19 with GStreamer master) and hit a lot of those errors:
qtmux gstqtmux.c:2232:gst_qt_mux_add_buffer: decreasing DTS value 0:00:00.023158730 < 0:00:00.070158730

I used "gst-launch-1.0 filesrc location=20131205-1_bb_pl.webm ! decodebin name=demux ! queue ! videoconvert ! videoparse ! x264enc ! mp4mux name=mux ! filesink location=out.mp4 demux. ! queue ! audioconvert ! audioresample ! audioparse ! faac ! mux."

After some debugging on #gstreamer it seems that there are issues in the source webm file.

Comment 1 Guillaume Desmottes 2013-12-13 16:34:42 UTC

Here is the output of mkvalidator on the transcoded webm file:

WRN201: Unknown 'SegmentUID' for read profile 'webm' in Info at 192
WRN201: Unknown 'Tag' for read profile 'webm' in Tags at 226764534
ERR200: Missing element 'Targets' in Tag at 226764546
ERR200: Missing element 'SimpleTag' in Tag at 226764546
WRN0C2: The timecode of the Cluster at 4702 is not incrementing (may be intentional)
ERR0B1: Block at 4441 track #1 is not a keyframe
........file created with GStreamer plugin version 1.0.8 / GStreamer Matroska muxer

Comment 2 Sebastian Dröge (slomo) 2014-05-26 12:47:36 UTC

Yes, might make sense to make the muxer a bit more webm compliant

Comment 3 GStreamer system administrator 2018-11-03 14:50:35 UTC

-- GitLab Migration Automatic Message --

This bug has been migrated to freedesktop.org's GitLab instance and has been closed from further activity.

You can subscribe and participate further through the new bug through this link to our GitLab instance: https://gitlab.freedesktop.org/gstreamer/gst-plugins-good/issues/99.