Playback of certain VP9 Videos on VLC for Android Fails

When playing back some VP9 video with VLC for Android the video attempts to start, then freezes. The audio keeps playing but the video stays frozen. Any attempt to seek causes the app to become unresponsive.

I have tried other, lower resolution, VP9 videos and they seem to work. I have attached a screenshot of the file info (the screenshot won't load) from VLC and the log data I collected. At request I can also include one of the files that has an issue, it is 37.2 MB.

System Info

Model	LG Nexus 5
Android	Android 5.1.1
VLC	VLC 1.5.2 (Revision 7361d5b)

MediaInfo

Below is the MediaInfo of the file that won't playback.

General
Unique ID                                : 92721915473681515876237021383282059892 (0x45C19762CA51EE7811FCD75791C2EA74)
Complete name                            :
Format                                   : WebM
Format version                           : Version 4 / Version 2
File size                                : 37.2 MiB
Duration                                 : 3mn 1s
Overall bit rate                         : 1 723 Kbps
Writing application                      : Lavf56.40.101
Writing library                          : Lavf56.40.101

Video
ID                                       : 1
Format                                   : VP9
Codec ID                                 : V_VP9
Duration                                 : 3mn 1s
Width                                    : 1 920 pixels
Height                                   : 1 080 pixels
Display aspect ratio                     : 16:9
Frame rate mode                          : Constant
Frame rate                               : 23.976 fps
Default                                  : Yes
Forced                                   : No

Audio
ID                                       : 2
Format                                   : Opus
Codec ID                                 : A_OPUS
Duration                                 : 3mn 1s
Channel(s)                               : 6 channels
Channel positions                        : Front: L C R, Rear: L R, LFE
Sampling rate                            : 48.0 KHz
Bit depth                                : 32 bits
Compression mode                         : Lossy
Language                                 : English
Default                                  : Yes
Forced                                   : No

Text
ID                                       : 3
Format                                   : D_WEBVTT/SUBTITLES
Codec ID                                 : D_WEBVTT/SUBTITLES
Language                                 : English
Default                                  : Yes
Forced                                   : No

http://streams.videolan.org/issues/15433/TestClip%20webm.webm.webm

File Info

Added attachment:

• Screenshot_2015-09-07-14-57-54.png

Crash Log

Added attachment:

• VLCVP9Crash.txt

Who compiled it?

( 4401): Wrote stack traces to '/data/anr/traces.txt'

can we have that one?

Added attachment:

• traces.txt

I have added traces.txt as an attachment.

It was compiled by jb@kahlan on 2015-08-20.

I forgot to note that VP8 in the same container (WebM), same audio format (Opus 5.1 @ 384 kbps), same resolution (1920 x 1080), and same bit rate (2 Mbps) worked flawlessly.

It's pretty weird, tbh.

I have uploaded the offending test file to OneDrive: http://1drv.ms/1LUlsOi Hope it helps.

I decided to play with VLC some more and see what happens if I wait, and not touch it, when VLC is seeking or opening the file after it has progressed a bit. Turns out it waits about two minutes then just the audio plays. In the log it says it "can't decode one frame" over and over. I have attached the log.

Updated log file with new test results

Added attachment:

• VLC VP9 Log 2.txt

I have just tried the same video again with VLC 1.6.0 built by jb on 2015-10-07 and the same thing happens, playback hangs.

Other VP9 videos I have tried that have been 720p or less work fine.

I'm seeing a similar problem with a 480p video snippet I've selected for an encoding test. I'm still testing ffmpeg/libvpx VP9 encodings with varying options to find out what might cause failed decoded frames on android.

Decoding on a Linux desktop is fine, but vlc on android shows failed decoded frames. It's looking like the player fails to decode certain key frames, even when not seeking within the video.

Google Video Player plays the video without decoding problems, but does not support seeking nor does it play audio (opus).

My ffmpeg used for VP9/mkv encoding is linked against libvpx 1.4.0. My mobe is a Sony Xperia Z3 compact running CM12.1 nightlies.

android build is not using libvpx to decode VP9 (avcodec is used).

Maybe we should add it ?

From all the research I've done recently says avcodec's ffvp9 codec is much faster at decoding than libvpx, which has poor multithreading support.

I tried out the 1080p videos I have in Kodi for Android and they play OK, seeking and decoding speed are issues. I believe they also use avcodec?

Yes, the Desktop version of VLC also use avcodec for VP9.

So, the only difference with android is the version of avcodec used. We'll update it soon but we'll need to test it before doing an android release.

Did you test 1.7.5?

changed the description

I just tried it with 1.7.5 and the picture still freezes. However, it will exit the payback without an ANR. It looks like, based on the log, that it is having trouble decoding the video and is dropping the frame, for every frame.

Log taken from VLC 1.7.5 while decoding the test clip on a Nexus 5.

Added attachment:

• 2016-01-07 VLC Log VP9.txt