FLV_SAMPLERATE_SPECIAL  111 libavformat/flvenc.c                 flags |= FLV_SAMPLERATE_SPECIAL;
FLV_SAMPLERATE_SPECIAL  150 libavformat/flvenc.c         flags = FLV_CODECID_PCM_MULAW | FLV_SAMPLERATE_SPECIAL | FLV_SAMPLESSIZE_16BIT;
FLV_SAMPLERATE_SPECIAL  153 libavformat/flvenc.c         flags = FLV_CODECID_PCM_ALAW  | FLV_SAMPLERATE_SPECIAL | FLV_SAMPLESSIZE_16BIT;