[MPlayer-dev-eng] Question about buffer when doing RTSP audio streaming with Live555 libraries

[Zhaofei Chen]

Hello,

I'm developing something related to real-time audio streaming and I use
MPlayer with Live555 libraries to enable RTSP streaming features. Here is
the problem that I observe:

When a MP3 audio file is streamed, MPlayer starts to play immediately after
receiving RTP packets. However, if other data formats, such as raw PCM
audio data, AMR, WAV files are streamed, MPlayer will starts to play only
after receiving a certain amount of data.

Based on my understanding, there should be a buffer which is used for those
audio formats, except MP3 files, and MPlayer will starts to play after this
buffer is filled with data.

I checked the source code but I'm not sure if this buffer means the stream
cache (default size 2048) since there is a setting of STREAM_NON_CACHEABLE
in stream_live555.c (though it is a hack).

So here are my questions:

1. I would like to ask what could this buffer be and why it acts
differently with MP3 and other audio formats.

2. Is this buffer changeable since my application will suffer from the
delay time caused by this buffer.

Thanks!

Regards,
Zhaofei Chen