[Solved] Gstreamer not playing Musepack files

[lexming]

I am trying (and failing) to play audio files in the musepack format using the new >=gstreamer-1.0. This used to work on the older <gstreamer-1.0 thanks to the gst-plugins-musepack. However, that plugin has been deprecated and now the compatibility with musepack files relies on libav through gst-plugins-libav.

These are the packages that I have installed in my system:

media-libs/gstreamer-1.2.4-r2
media-plugins/gst-plugins-libav-1.2.4
media-video/libav-9.13-r1

First, I checked that libav works and can play musepack files using the avplay tool. It works:

Code: Select all

 $ avplay test.mpc 
avplay version 9.13, Copyright (c) 2003-2014 the Libav developers
  built on Jun 23 2014 15:59:54 with gcc 4.7.3 (Gentoo 4.7.3-r1 p1.4, pie-0.5.5)
[mpc8 @ 0x7fc66c005d00] max_analyze_duration reached
Input #0, mpc8, from 'test.mpc':
  Metadata:
    Track           : 1/6
    Year            : Some year
    Artist          : Some artist
    Album           : Some album
    Title           : Some title
    Replaygain_Album_Gain: -9.13 dB
    Replaygain_Track_Gain: -9.13 dB
    Replaygain_Track_Peak: 1.17095732284
    Replaygain_Album_Peak: 1.17095732284
  Duration: 00:03:24.28, start: 0.000000, bitrate: 209 kb/s
    Stream #0.0: Audio: mpc8, 48000 Hz, stereo, s16p
   1.93 A-V:  0.000 s:0.0 aq=  326KB vq=    0KB sq=    0B f=0/0   

Next, gst-plugins-libav seems to do its thing and gstreamer reports the demuxer and decoders of musepack from libav to be available:

Code: Select all

 $ gst-inspect-1.0 | grep mpc
libav:  avdec_mpc7: libav Musepack SV7 decoder
libav:  avdec_mpc8: libav Musepack SV8 decoder
libav:  avdemux_mpc: libav Musepack demuxer
typefindfunctions: application/x-apetag: mp3, ape, mpc, wv
typefindfunctions: audio/x-musepack: mpc, mpp, mp+

However, gstreamer does not play any of the files. Using playbin fails complaining about "missing components":

Code: Select all

 $ GST_DEBUG=3  gst-launch-1.0 playbin uri=file:///home/lexming/test.mpc 
Setting pipeline to PAUSED ...
Pipeline is PREROLLING ...
0:00:00.026272692 20864 0x7fa1740c28a0 WARN            uridecodebin /var/tmp/portage/media-libs/gst-plugins-base-1.2.4-r1/work/gst-plugins-base-1.2.4/gst/playback/gsturidecodebin.c:930:unknown_type_cb:<uridecodebin0> warning: No decoder available for type 'audio/x-musepack, streamversion=(int)8'.
Missing element: Musepack (MPC) decoder

[...]

ERROR: pipeline doesn't want to preroll.
Setting pipeline to NULL ...
0:00:00.026548190 20864 0x7fa1740c28a0 WARN                tagdemux /var/tmp/portage/media-libs/gst-plugins-base-1.2.4-r1/work/gst-plugins-base-1.2.4/gst-libs/gst/tag/gsttagdemux.c:1469:gst_tag_demux_element_loop:<apedemux0> error: Stream stopped, reason not-linked
Freeing pipeline ...

And specifying the components of the gstreamer pipe does not help either. The error message says that the file is not a musepack file, but that can't be correct. I have been using them for quite some time and avplay has no problem in playing them.

Code: Select all

 $ GST_DEBUG=3 gst-launch-1.0 filesrc location=test.mpc ! avdemux_mpc ! avdec_mpc8 ! pulsesink
Setting pipeline to PAUSED ...
Pipeline is PREROLLING ...
0:00:00.021242177 21036      0x242d540 ERROR                  libav :0:: Not a Musepack file
0:00:00.021272825 21036      0x242d540 WARN                   libav /var/tmp/portage/media-plugins/gst-plugins-libav-1.2.4/work/gst-libav-1.2.4/ext/libav/gstavdemux.c:1284:gst_ffmpegdemux_open:<avdemux_mpc0> error: Unhandled error code received
0:00:00.021306520 21036      0x242d540 WARN                   libav /var/tmp/portage/media-plugins/gst-plugins-libav-1.2.4/work/gst-libav-1.2.4/ext/libav/gstavdemux.c:1546:gst_ffmpegdemux_loop:<avdemux_mpc0> error: Internal data stream error.
0:00:00.021313429 21036      0x242d540 WARN                   libav /var/tmp/portage/media-plugins/gst-plugins-libav-1.2.4/work/gst-libav-1.2.4/ext/libav/gstavdemux.c:1546:gst_ffmpegdemux_loop:<avdemux_mpc0> error: streaming stopped, reason error
ERROR: from element /GstPipeline:pipeline0/avdemux_mpc:avdemux_mpc0: GStreamer encountered a general supporting library error.
Additional debug info:
/var/tmp/portage/media-plugins/gst-plugins-libav-1.2.4/work/gst-libav-1.2.4/ext/libav/gstavdemux.c(1284): gst_ffmpegdemux_open (): /GstPipeline:pipeline0/avdemux_mpc:avdemux_mpc0:
Unhandled error code received
ERROR: pipeline doesn't want to preroll.
Setting pipeline to NULL ...
Freeing pipeline ...

Is anybody able to play musepack files with anything >=media-libs/gstreamer-1.0 ? I have no idea what tot try next. I am not even sure if this is a problem of my installation or a bug in media-libs/gstreamer-1.2.4-r2 and/or media-plugins/gst-plugins-libav-1.2.4.

Thank you

[Leio]

Yes, mpc stream version 7 works fine. 8 is having issues. It seems avdemux_mpc doesn't declare support for mpc sv8, only sv7, so avdec_mpc8 can't get any input in the pipeline, so wouldn't be plugged and can't manually do so either.
I don't know if it's just an omission in declaring support and it'd just work if the caps are changed in avdemux_mpc, or it needs some actual more complicated work to make gst-plugins-libav support it.
Make sure there exists an upstream bug for this if you are interested in there being a chance of this being fixed.

[lexming]

I see. Then I'll open a bug upstream.

Thank you for the input Leio!

Update: The upstream bug can be found at https://bugzilla.gnome.org/show_bug.cgi?id=732682

[smithjd15]

I just posted a patch enabling musepack sv8 support for gstreamer-libav at the above bug, if anyone's interested.