[FFmpeg-user] How to mitigate stream 1 decoding error?

[Bernard Barton Jr.]

I'm using the following command to convert Apple iTunes .m4a files to .mp3:

ffmpeg -i "$fname" -acodec libmp3lame -ab 256k -vn -y -f mp3 "$dir/$basefile.mp3"


I was getting warnings about frame rates, even though these are audio files, so I added the -vn switch, which eliminated complaints about frame rate.  But I'm still getting the "Missing png signature", and Video:png errors shown below.

How can I eliminate these warnings about about the decoding for stream 1 failing?


[mov,mp4,m4a,3gp,3g2,mj2 @ 0x7fc393832600] stream 0, timescale not set
[png @ 0x7fc393838800] Missing png signature
[mov,mp4,m4a,3gp,3g2,mj2 @ 0x7fc393832600] max_analyze_duration 5000000 reached at 5015510
[mov,mp4,m4a,3gp,3g2,mj2 @ 0x7fc393832600] decoding for stream 1 failed
[mov,mp4,m4a,3gp,3g2,mj2 @ 0x7fc393832600] Could not find codec parameters for stream 1 (Video: png): unspecified size
Consider increasing the value for the 'analyzeduration' and 'probesize' options

-Thanks