When I am trying to using avenc_mp2 to encode a wav file into mp3 file，
I used below command line:
gst-launch-1.0 filesrc location=test_32kHz_mono.wav ! wavparse ! avenc_mp2 ! filesink location=enc.mp3

It will report "streaming stopped, reason not-negotiated (-4)"

And when I add audioconvert after wavparse:
gst-launch-1.0 filesrc location=test_32kHz_mono.wav ! wavparse ! audioconvert ! avenc_mp2 ! filesink location=enc.mp3

It works fine.


I checked avenc_mp2, sink caps support
       audio/x-raw
           channel-mask: 0x0000000000000000
               channels: 1
                   rate: { (int)48000, (int)44100, (int)32000, (int)24000, (int)22050, (int)16000 }
                 layout: interleaved
                 format: S16LE


however wavparse src pad with no channel-mask property.

I'm not sure it is wavparse's issue or avenc_mp2's issue.
should we care channel-mask for wavpars's output