WMA2 Transcoding

[Nitestick]

I've got a number of video files containered as *.avi using WMA2 audio which is quite useless (M$ don't even support it as a codec on the Xbox 360 lol). I've managed to extract the audio stream from it via mplayer:

$mplayer -dumpaudio /path/to/video -dumpfile /path/to/output

Now no matter what I've attempted I can't seem to transcode this to another codec for better support, all I want to do is maintain the video stream as is, modify the audio to a better supported codec (MP3 or AC3) and re-container it as *.avi. My last attempt was with ffmpeg:

$ ffmpeg -i ~/Videos/encoding/audio_streams/test.wma -acodec mp3 -aq 100 ~/Videos/encoding/audio_streams/test.mp3
ffmpeg version 0.8.3-4:0.8.3-0ubuntu0.12.04.1, Copyright (c) 2000-2012 the Libav developers
built on Jun 12 2012 16:52:09 with gcc 4.6.3
*** THIS PROGRAM IS DEPRECATED ***
This program is only provided for compatibility and will be removed in a future release. Please use avconv instead.
/home/nitestick/Videos/encoding/audio_streams/test.wma: Invalid data found when processing input

I've tried using avconv (not sure if this is indeed any different to ffmpeg), receiving the same error.

Anyone have any suggestions?

 

[horndude]

when you run mplayer on the stripped audio file whats the output?

 

[Nitestick]

$ mplayer ~/Videos/encoding/audio_streams/test.wma
MPlayer2 UNKNOWN (C) 2000-2011 MPlayer Team
mplayer: could not connect to socket
mplayer: No such file or directory
Failed to open LIRC support. You will not be able to use your remote control.

Playing /home/nitestick/Videos/encoding/audio_streams/test.wma.
Failed to recognize file format.

Which leads me to believe it's either corrupt or there's issues with the codec; the audio does seem to work fine when contained in the AVI:

player ~/Videos/01\ -\ On\ the\ idle\ hill\ of\ summer.avi
MPlayer2 UNKNOWN (C) 2000-2011 MPlayer Team
mplayer: could not connect to socket
mplayer: No such file or directory
Failed to open LIRC support. You will not be able to use your remote control.

Playing /home/nitestick/Videos/01 - On the idle hill of summer.avi.
Detected file format: AVI format (libavformat)
[lavf] stream 0: video (msmpeg4), -vid 0
[lavf] stream 1: audio (wmav2), -aid 0
VIDEO: [DIV3] 512x384 24bpp 25.001 fps 0.0 kbps ( 0.0 kbyte/s)
Load subtitles in /home/nitestick/Videos/
Failed to open VDPAU backend libvdpau_nvidia.so: cannot open shared object file: No such file or directory
[vdpau] Error when calling vdp_device_create_x11: 1
[VO_XV] Could not grab port 70.
[ass] auto-open
==========================================================================
Opening video decoder: [ffmpeg] FFmpeg's libavcodec codec family
Asking decoder to use 4 threads if supported.
Selected video codec: [ffdivx] vfm: ffmpeg (FFmpeg DivX ;-) (MSMPEG-4 v3))
==========================================================================
==========================================================================
Opening audio decoder: [ffmpeg] FFmpeg/libavcodec audio decoders
AUDIO: 44100 Hz, 2 ch, s16le, 64.1 kbit/4.54% (ratio: 8010->176400)
Selected audio codec: [ffwmav2] afm: ffmpeg (DivX audio v2 (FFmpeg))
==========================================================================
[AO OSS] audio_setup: Can't open audio device /dev/dsp: No such file or directory
AO: [alsa] 44100Hz 2ch s16le (2 bytes per sample)
Starting playback...
Movie-Aspect is undefined - no prescaling applied.
VO: [xv] 512x384 => 512x384 Planar YV12
A: 15.2 V: 15.2 A-V: 0.000 ct: 0.001 0/ 0 2% 0% 0.2% 0 0

 

[horndude]

ya it lost something when you did a dumpfile via mplayer it looks like

looks like the audio is variable bit rate 2 channel 16 bit CD quality audio track using the wma2 codec

try avidemux and strip the audio out and see what you get

 

[Nitestick]

Tried avidemux, worked a charm. Thanks for the advice . I've heard of it before but never used it, it's absolutely perfect for the task of transcoding a single stream or recontaining a video. Next step; script it to clean up videos on my server that aren't compatible with Xbox.

 

[horndude]

no problem

just be careful, I usually just as a matter of habit anymore always change variable bit rate audio to constant rate, it eliminates any muxing or synching errors

for some reason some encoders won't synch or mux right variable bit rate audio

 

[Nitestick]

I've religiously used CBR audio on my rips for the last 5+ years, I've always found that to be a problem.