GNOME Bugzilla – Bug 628218
[alsa] Sound distortion with stereo upmix
Last modified: 2013-04-30 15:31:50 UTC
Created attachment 168969 [details] custom asoundrc On Gentoo as well as on Ubuntu (all 32 and 64bit versions between 9.04 - 10.04), I'm experiencing some trouble getting gstreamer to play well with my working alsa stereo upmix (custom .asoundrc). I already had a pure alsa setup (without gstreamer and pulseaudio) working flawlessly. Now I've decided to install gstreamer again on Gentoo, which is necessary to get players like guayadeque or banshee to work, but with gstreamer alsasink the upmix only works for 1 or 2 minutes and then the sound gets distorted. It's like the music is played at least twice as fast (though my receiver still thinks its dolby surround and plays this ugly noise). Alsa alone works fine, most lightweight players with pure alsa upmix cause only up to 7% cpu use per core (dual-core system); the same players go up to 36% per core, when I use gstreamer, plus a little more after the sound finally crashes. I've tested this with several alsa and gstreamer versions and on several computers (actually Ubuntu 8.10 had the last working gstreamer version for me). I know that stereo to 5.1 upmix isn't common, but I'd be happy if this could be fixed somehow. Please notify me if further informations are needed.
I am one step further now: I entered a custom device in gstreamer-properties: alsasink device="pcm.Filter_RoutingUpmix" Now it plays already for 12 minutes without distortion, but after the second sound change one core is always at 100% :-( Should I rebuild some package with "debug" option? If so, which? Currently I've got the following gstreamer packages installed: dev-python/gst-python media-libs/gst-plugins-bad media-libs/gst-plugins-base media-libs/gst-plugins-good media-libs/gst-plugins-ugly media-libs/gstreamer media-plugins/gst-plugins-a52dec media-plugins/gst-plugins-alsa media-plugins/gst-plugins-dvb media-plugins/gst-plugins-dvdread media-plugins/gst-plugins-ffmpeg media-plugins/gst-plugins-flac media-plugins/gst-plugins-gconf media-plugins/gst-plugins-lame media-plugins/gst-plugins-mad media-plugins/gst-plugins-meta media-plugins/gst-plugins-mpeg2dec media-plugins/gst-plugins-ogg media-plugins/gst-plugins-pango media-plugins/gst-plugins-resindvd media-plugins/gst-plugins-soup media-plugins/gst-plugins-theora media-plugins/gst-plugins-vorbis media-plugins/gst-plugins-x
Sorry no one ever managed to have a look at this issue until now. Is it still an issue with current (1.x) versions of GStreamer? If yes, what's the best way to reproduce it? Does this also fail: gst-launch-1.0 audiotestsrc ! audio/x-raw,channels=2 ! alsasink device=pcm.Filter_RoutingUpmix ? If yes, could you make a debug log like this: GST_DEBUG=*alsa*:6,*audio*:6 gst-launch-1.0 audiotestsrc ! audio/x-raw,channels=2 ! alsasink device=pcm.Filter_RoutingUpmix 2>dbg.log and hit control-C shortly after the distortion starts.
Closing this bug report as no further information has been provided. Please feel free to reopen this bug if you can provide the information asked for. Thanks!