[FFmpeg-user] For Sansa Clip Jam,    FFmpeg is busted but avconv is OK.

batguano999 batguano999 at zoho.com
Thu Dec 24 20:22:21 CET 2015

 > Kind of hard to provide suggestions...
avconv isn't so good after all.
Only avconv m4a files <= 40 seconds duration will play in Sansa Clip Jam.
With mp4creator muxer it will play files <= 30 minutes.

The problems with m4a files are caused because the shaved chimps at Sansa can't design a decoder.
Their literature quotes "AAC (Apple iTunes AAC-LC (.M4A) Audio)".
And the FFmpeg files show...
Format profile    : Apple audio with iTunes info
Codec ID           : M4A 
Format profile    : LC

With previous models it was possible to use RockBox as a workaround.

As demonstrated in the trac report, many other encoders/muxers produce files that play OK with the Sansa.
Seems that avformat is doing something different.
Trying to make perfect files to use with perfect decoders.
Those other old encoders/muxers probably make cheap and cheerful files to use with a wide range of decoders.

does adding "-skip_iods 0" as an output option make a difference? 

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