[FFmpeg-user] Firefox not playing audio of webm file

[Alex Keeling]

Carl Eugen Hoyos <cehoyos at ag.or.at> wrote:

> Alex Keeling <alex <at> keeling.me> writes:
>
 > I have a webm file created with ffmpeg which plays
> > fine in Chromium, but which Firefox plays silently.
>
> Works fine here with Firefox 23.0
>

Thanks for testing it. I'm dumbfounded.
I wonder what my build of Firefox is missing.


> > You can see the file here: http://0xffffffff.co/test.webm
>
> Generally, you are expected to upload the input file, not
> the output file (although in this case, it makes no
> real difference).
>
> Try -ar 48k
>

This worked for me! Thanks very much Carl. I've uploaded the
file that is working for me here: http://0xffffffff.co/test2.webm

Since I've no longer got a problem, there's probably no one
interested in this, but I'll include the command and output that
worked for me for completeness:

$ ffmpeg -i MVI_9037.AVI -crf 10 -b:v 1M -ar 48k test2.webm
ffmpeg version 0.11.1 Copyright (c) 2000-2012 the FFmpeg developers
  built on Sep  2 2013 14:05:35 with gcc 4.7.1
  configuration: --prefix=/usr --libdir=/usr/lib64 --shlibdir=/usr/lib64
--mandir=/usr/man --disable-debug --enable-shared --disable-static
--enable-pthreads --enable-libtheora --enable-libvorbis --enable-gpl
--enable-version3 --enable-postproc --enable-swscale --enable-x11grab
--enable-avfilter --enable-gnutls --enable-libcdio --arch=x86_64
--enable-libmp3lame --enable-libx264 --enable-libvpx
  libavutil      51. 54.100 / 51. 54.100
  libavcodec     54. 23.100 / 54. 23.100
  libavformat    54.  6.100 / 54.  6.100
  libavdevice    54.  0.100 / 54.  0.100
  libavfilter     2. 77.100 /  2. 77.100
  libswscale      2.  1.100 /  2.  1.100
  libswresample   0. 15.100 /  0. 15.100
  libpostproc    52.  0.100 / 52.  0.100
Guessed Channel Layout for  Input Stream #0.1 : mono
Input #0, avi, from 'MVI_9037.AVI':
  Metadata:
    creation_time   : 2013-05-05 15:25:02
    encoder         : CanonMVI02
  Duration: 00:00:47.43, start: 0.000000, bitrate: 14650 kb/s
    Stream #0:0: Video: mjpeg (MJPG / 0x47504A4D), yuvj422p, 640x480, 30
tbr, 30 tbn, 30 tbc
    Stream #0:1: Audio: pcm_u8 ([1][0][0][0] / 0x0001), 11024 Hz, mono, u8,
88 kb/s
[buffer @ 0x124a340] w:640 h:480 pixfmt:yuvj422p tb:33333/1000000 sar:0/1
sws_param:flags=2
[buffersink @ 0x12408a0] No opaque field provided
[format @ 0x122fb40] auto-inserting filter 'auto-inserted scaler 0' between
the filter 'src' and the filter 'format'
[scale @ 0x1241780] w:640 h:480 fmt:yuvj422p sar:0/1 -> w:640 h:480
fmt:yuv420p sar:0/1 flags:0x4
[aformat @ 0x1291e80] auto-inserting filter 'auto-inserted resampler 0'
between the filter 'src' and the filter 'aformat'
[aresample @ 0x12ab2e0] chl:mono fmt:u8 r:11024Hz -> chl:mono fmt:flt
r:48000Hz
[libvpx @ 0x12568a0] v1.1.0
Output #0, webm, to 'test2.webm':
  Metadata:
    creation_time   : 2013-05-05 15:25:02
    encoder         : Lavf54.6.100
    Stream #0:0: Video: vp8, yuv420p, 640x480, q=-1--1, 1000 kb/s, 1k tbn,
30 tbc
    Stream #0:1: Audio: vorbis, 48000 Hz, mono, flt
Stream mapping:
  Stream #0:0 -> #0:0 (mjpeg -> libvpx)
  Stream #0:1 -> #0:1 (pcm_u8 -> libvorbis)
Press [q] to stop, [?] for help
[libvorbis @ 0x1257200] Que input is backward in time
frame= 1423 fps= 21 q=0.0 Lsize=    6176kB time=00:00:47.39
bitrate=1067.3kbits/s
video:5824kB audio:319kB global headers:3kB muxing overhead 0.480166%

As well, I've put the input file up in case someone has a
burning desire to look at this more closely:
http://0xffffffff.co/MVI_9037.AVI

Thank you Carl.

Alex Keeling