Audio/Video not in sync on M10/frieza

[Michael Zanetti]

Watching a video (either with the media player or the browser) shows a lag between audio and video. It's out of sync for some hundred milliseconds, just enough to be very annoying while watching the video.

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Jim Hodapp (jhodapp)]

@Michael: Can you please provide the more detailed debug info by doing the following from the frieza shell:

1. stop media-hub
2. GST_DEBUG=*:4 CORE_UBUNTU_MEDIA_SERVICE_VIDEO_SINK_NAME=mirsink CORE_UBUNTU_MEDIA_SERVICE_AUDIO_SINK_NAME=pulsesink src/core/media/media-hub-server
3. Then try playing the video and attach the entire output from #2 to this bug report. I want to see if GStreamer is aware of A/V getting out of sink and if it's providing any useful messages as to why.

[Matthias Apitz (gubu)]

I watched the same video
http://www.tagesschau.de/multimedia/sendung/ts-13759.html in

1) with mplayer as local *.mp4 file (downloaded with youtube_dl) on my
   FreeBSD netbook, result: fine;

2) with my BQ E4.5 (OWA-10.1) in webbrowser via HTTP data mobile,
   result: fine

3) in my FreeBSD netbook in chrome browser via HTTP data mobile (BQ E4.5 as
   AP to Internet), result: fine

4) in the M10 with webbrowser via HTTP Wifi, result: off-sync;

5) in the M10 as local *.mp4 file, result: off-sync

[Pat McGowan (pat-mcgowan)]

The video is just behind the audio on every video I played

[Oliver Grawert (ogra)]

a working hack i found is:

pactl set-port-latency-offset droid_card.primary output-speaker -600000

from the terminal-app after boot, this gets me lip-synced video playback in all apps

[Jim Hodapp (jhodapp)]

We could try to set this same property from media-hub since it sets up the use of pulsesink in the GStreamer pipeline [1]. This would at least take care of the mediaplayer-app video playback. We might be able to accomplish something similar for the Oxide media pipeline but can't comment on that part as I'm not familiar enough with it.

https://gstreamer.freedesktop.org/data/doc/gstreamer/head/gst-plugins-good-plugins/html/gst-plugins-good-plugins-pulsesink.html#GstPulseSink--stream-properties

[Oliver Grawert (ogra)]

i guess it is rather a device specific thing (you really dont want -600000 on a device where audio is already in sync) and shoulld go into some device specific pulse config.

after all it is only a workaround though ... there must be something in the drivers (video or audio) itself that makes it a requirement at all.

[Jim Hodapp (jhodapp)]

Yeah I had that thought as well, but I thought it's worth an experiment though on all devices to see if it can be applied generally. Do you happen to know what the default value is for pulse at the moment?

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Jim Hodapp (jhodapp)]

@nandkishorbairagi007: did you commit a fix that we're not aware of? If so please link a source branch to this bug report.

[Oliver Grawert (ogra)]

Just FTR on all devices I have here pact list cards shows a default of 0 usec. For all outputs.

[Matthias Apitz (gubu)]

FWIW, I found some nice test streams in YT, like this:

https://www.youtube.com/watch?v=ucZl6vQ_8Uo

which make any test more objective.

I watched this in my BQ E4.5 with the browser app and in my FreeBSD netbook
with FF: when the jumping ball hits the dash in ground zero, the 'plonk'
sounds exactly with the hit.

With the M10 the dash is already at 4-5 tens of a second ahead when
the 'plonk' sounds, definitely off-sync.

This is regardless of having applied the command proposed by Oli, at
least with my device. Maybe the issue is more complex and not only
software related.

[Halo (carlos1259714)]

Have an Aquaris M10 Ubuntu Edition, same bug as well.

I tried to open terminal and type "pactl set-port-latency-offset droid_card.primary output-speaker -600000", but I'm getting this output:

"Home directory not accessible: Permission denied
Connection error: connection denied
pa_context_connect() failed: connection denied"

I tried with sudo su first and marking as read/write with "sudo mount -o remount,rw /". Have developer mode activated too.

[Ben Sanderson (bennysthe1)]

So after I ran sudo mount -o remount,rw / and added pactl set-port-latency-offset droid_card.primary output-speaker -600000 I have synced video and audio. Ubuntu store still downloads and installs apps although it seems bit slower to download. The updates in system settings seems to work fine too. I have heard about the updates not working so is it possible to update with apt-get? it seems to work fine???

[Jim Hodapp (jhodapp)]

@Ben: most things continue to work fine via apt-get but I strongly advise you to not use it and to stick with the normal system settings updater. Most packages would install cleanly via apt-get but some very important system ones will not and you'll probably break your system trying to do so. So unless you are on a development phone that you don't care if you have to reflash from time to time, just stay with the normal update procedure.

[John McAleely (john.mcaleely)]

@bensmythe1 - this ask ubuntu answer covers the consequences of using apt-get:

http://askubuntu.com/questions/600065/consequences-of-using-apt-get-in-ubuntu-touch/775550#775550

Short version: dont. So I'd restore your device to ro, and then let updates take their course.

[Alessandro Spagnoletta (a-spagnoletta)]

Have an Aquaris M10 FHD Ubuntu Edition, same bug.

I noticed that the audio is <1s ahead the video when playing .mkv .mp4 video with Media Player or youtube video with the default browser. Instead, when playing .avi video with Media Player, the lag is definitely much worse (the audio is several seconds ahead).

[Thomas Voß (thomas-voss)]

Based on ogra's observation and given that both oxide and media-hub are affected, pulse and its configuration are quite likely the issue here. I'm marking pulseaudio as affected. We should aim for fixing the issue centrally in pulse.

[Pat McGowan (pat-mcgowan)]

I can confirm that the command in comment #5 works to fix the video in comment #12

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Leonardo Donelli (learts92)]

Guys, if you can, keep up updated on this. I bought the M10 basically only just to support Ubuntu Touch, knowing well that it wouldn't have (yet) a lof of things Android has, but thinking that "at least I will be able to watch videos on it, which is the primary use I have of a tablet anyway".

Because of this bug, I can't really do that..

[Dave H (dhandhelen-s)]

Hi, just updated my BQ M10 to OTA-12 and the problem is not resolved. I think the media player sound is in sync for the video camera mp4 and youtube mp4 streaming, the problem is with .avi files. With avi files the sound is totally out of sync and stops altogether after a short time, hope this helps.

Regards

Dave H

[Alfonso Sanchez-Beato (alfonsosanchezbeato)]

@gubu, thanks for the link to the sync video, it is great to see the delay between audio and video. To rule out gstreamer of the equation, I have tried to transcode the video by doing:

gst-launch-1.0 filesrc location=Videos/sync-test.mp4 ! decodebin name=demux demux. ! queue ! audioconvert ! lamemp3enc ! mux. qtmux name=mux ! filesink location=recode.mp4 demux. ! queue ! videoconvert ! x264enc ! mux.

The resulting file has correct synchronization, so all points to pulseaudio or android drivers to be the culprit here.

[Alfonso Sanchez-Beato (alfonsosanchezbeato)]

Interesting finding (thanks @Jim for the suggestion): I changed the output device to headphones using the jack, same issue. Then I switched to bluetooth headphones, using A2DP profile, and video and audio came into sync. However, that only lasted a couple of minutes, after that suddenly I got the delay again while watching a youtube video. There is definitely something wrong with pulseaudio sinks.

[Alfonso Sanchez-Beato (alfonsosanchezbeato)]

Device tarballs for testing the fix:

http://people.canonical.com/~abeato/lp1574729/