[Libav-user] http streaming latency depends on frame rate

Aleksey Shubin x.morion.x at gmail.com
Wed Jun 13 01:36:22 CEST 2012

2012/6/10 Andrey Utkin <andrey.krieger.utkin at gmail.com>:

> Latency you address everywhere in the letter is playback start latency, or
> time latency on player side? I assume first.

The second. The player's playback position is behind the actual live
position by the mentioned latency value.

> I just don't know, does iis streaming format have global metadata headers,
> or not. If not, the delay could be introduced by seeking for in-stream
> metadata. Afaiu x264 encodes instream metadata into keyframes, which go once
> per "keyframes interval" video frames. This explains why things are bad on
> low fps. You could try reduce keyframe interval for such cases.

Also don't sure about global metadata headers, but AVOutputFormat for
Smooth Streaming has AVFMT_GLOBALHEADER flag, so seems it has the
global headers.
Anyway my keyframes interval is as small as possible (every frame is keyframe).

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