Okay I am trying to convert a mp4 file into 3gp.
ffmpeg -i input.mp4 -s 176x144 output.3gp
and the error received was :
[libopencore_amrnb @ 0x85531c0] Only 8000Hz sample rate supported
Then, I tried to change the sample rate and my command became
ffmpeg -i input.mp4 -s 176x144 -sample_rate 8000Hz output.3gp
But still I am getting the same error, what am I doing wrong?