Problem setting CBR AAC encoding with some assets

[GoogleCodeExporter]

When we create H.264/AAC MP4 files we require the audio to be 96Kbps CBR.

We use this command line:
ffmbc -i P2_DVCProHD_1080p_10sec.mov -f mp4 -vf scale=400:226 -vcodec libx264 
-b 800k -maxrate 800k -bufsize 5097k -r 25 -map_audio_channel 0:1:0:0:1:0 
-map_audio_channel 0:2:0:0:1:1 -ab 96k -ar 48000 -ac 2 -acodec libfaac -y 
web-P2.mp4

We run the output through Mediainfo and it says:
Bit rate mode                    : Constant
Bit rate                         : 96.0 Kbps

However, for a different asset with the same command line it reports:
Bit rate mode                    : Variable
Bit rate                         : 73.5 Kbps

The problem asset is a mov-wrapped AVC-Intra with PCM audio.

I'll drop you an email with links to the assets we used.

Thanks, Darren.

Original issue reported on code.google.com by boncey@gmail.com on 25 Jan 2012 at 3:37

[GoogleCodeExporter]

Hi Baptiste, any input on this please?

Thanks, Darren.

Original comment by boncey@gmail.com on 2 Feb 2012 at 1:48

[GoogleCodeExporter]

I have no idea yet, I'll have a look

Original comment by baptiste...@gmail.com on 2 Feb 2012 at 4:45

[GoogleCodeExporter]

This problem is related to faac. I cannot fix.

Original comment by baptiste...@gmail.com on 1 Nov 2012 at 8:31

• Changed state: Invalid