FFmpeg PCMA Audio
1) PCMA
When PCMA is transmitted in a RTP message, you can clearly see the sign PT = ITU-T G.711 PCMA. It takes up more bandwidth. Audio NAL has no start code as a definition
2) mp3
Ffplay plays mp3 audio
FFmpeg version 4.0.1
Audio Open Interface SDL_OpenAudioDevice
Ffplay-showmode 1 output.mp3
The noise of the effect card is not the same as that of NetEYYun music.
Reason av_log_set_callback (log_callback_help); write a file to the log
