[FFmpeg-devel] [RFC] avio protocol proxy providing seekability to live streams

[Andrey Utkin]

I was once asked privately for such thing privately; also such feature
was requested recently on maillist:

http://ffmpeg.org/pipermail/ffmpeg-user/2013-May/015522.html (with
reference to http://ffmpeg.org/pipermail/ffserver-user/2012-September/000247.html)

The point is to provide (limited) seek operability on live stream.

I didn't start working on it, but i have some ideas:
- just another avio protocol handler, with name and schema like "proxy";
- AVOption is passed to configure bufferization: should it be last N
seconds, or stream should be saved from the very beginning;
- saving large amount of data will overflow RAM, so dumping to
external file will be needed, but we could start with RAM-only
buffering.

I didn't work with stream seeking in my applications, but the task
seems limited to making up a URLProtocol implementation.
I feel able to implement it by myself.
If you have
- opinion about value of such functionality (is it really needed and
with which parameters),
- experience on topic,
- related work in progress,
comments are appreciated.
--
Andrey Utkin