Workaround for broken(?) m4a files from ffmpeg, was Re: [PATCH] Output AAC as M4A for iTunes with metadata tags

[bat guano]

----------------------------------------

> >
> rtmpdump produces FLV files, which have nowhere to put a value for the
> average bit rate. So this isn't something that rtmpdump could fix.
>
> I think ffmpeg is the right place to handle this. When ffmpeg runs
> (using -acodec copy), it displays a status line of the form
> size= 33270kB time=821.71 bitrate= 331.7kbits/s
> where these values are updated every second or so. So ffmpeg does
> know the average bit rate, but it doesn't store it in the m4a file.
>
> Simon
> >
> >
Hi
I also don't think it's a problem caused by streamed files from RTMPDump.

And it's not just '-acodec copy' that gives no avgBitrate.
FFmpeg doesn't seem to set the avgBitrate when converting other files to m4a.
Using commands like this:-
ffmpeg -i foo -acodec libfaac foo.m4a

Other encoders, such as faac and neroAacEnc, seem to set the avgBitrate OK though.