I am using Q2687, Open AT OS version : 6.01.07, Firmware Version: R71. Audio APIs to record (adl_audioStreamListen()) and play (adl_audioStreamPlay()) the audio . it works well there for playing back the recorded audio.
However, I want to understand how I can play a .AMR file (recorded on say a Nokia cellphone) which plays well in QuickTime player on a computer. The same file does not play as is if streamed to OpenAT audio APIs. Similarly if we simply strip off the first 6 bytes header ("#!AMR\n") of the .AMR file, even that does not work. In either way we only hear silence / noise.
Hence the question is: What transformation is required to convert a file recorded as .AMR file from say a cellphone like Nokia, to the AMR (NB) RTP format buffer to play on Q2687 firmware R71?
Can you provide insight into the data structure in which the OpenAT APIs expect the play buffer?