I have recompiled ffmpeg and vlc with samr support.
When I try to encode a movie file with samr audio codec, I can't seem to specify the correct audio bitrate.
(Please ignore the mmsh access method, I don't know whether it works, I don't think it is related, I'm testing some mms streaming)
command line:
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vlc inputfile --sout '#transcode{width=128,height=96,vcodec=H263,acodec=samr,vb=28,ab=5.25,fps=12.5,samplerate=8000,channels=1}:standard{access=mmsh,dst=:1234/test.3gp}' -vvvv
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[00000299] stream_out_standard private debug: mux opened
[00000299] main private debug: using sout stream module "stream_out_standard"
[00000296] main private debug: set config option: sout-transcode-width to 128
[00000296] main private debug: set config option: sout-transcode-height to 96
[00000296] main private debug: set config option: sout-transcode-vcodec to H263
[00000296] main private debug: set config option: sout-transcode-acodec to samr
[00000296] main private debug: set config option: sout-transcode-vb to 28
[00000296] main private debug: set config option: sout-transcode-ab to 5.25
[00000296] main private debug: set config option: sout-transcode-fps to 12.5
[00000296] main private debug: set config option: sout-transcode-samplerate to 8000
[00000296] main private debug: set config option: sout-transcode-channels to 1
[00000296] stream_out_transcode private debug: codec audio=samr 8000Hz 1 channels 5Kb/s
[00000296] stream_out_transcode private debug: codec video=H263 128x96 scaling: 1.000000 28kb/s
[00000296] main private debug: set config option: sout-transcode-ab to 5.25
...
[00000296] stream_out_transcode private debug: codec audio=samr 8000Hz 1 channels 5Kb/s
it seems vlc cuts off the bitrate at the decimal point...
This produces the following ffmpeg error message and no audio in the stream:
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[00000345] ffmpeg encoder warning: bitrate not supported: use one of 4.75k, 5.15k, 5.9k, 6.7k, 7.4k, 7.95k, 10.2k or 12.2k
(libamr_nb@0x8456a0)