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I was trying to make seeking of Netstream faster setting NetStream.bufferTime=0.1, but it seems it's ignoring it.

I was trying to find an answer in video conversion process. Setting avconv -g 25, but this helped a only a bit.

If i'll increase amount of keyframes, will that improve seeking time?

I want to make video start instantly, how to achieve this via flash player?

tckmn
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Somebody
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1 Answers1

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having more keyFrame in your video won't change the seeking performance. It only affects the precision of the seeking.

Seeking performance issue might be due to your streaming server. Have you tried to read your stream with a different player (vlc), to check if it's more a player problem than a server one ?

UPDATE :

take a look at this module for nginx : http://nginx.org/en/docs/http/ngx_http_mp4_module.html. Even if i never tried it, it should do the job...

Greg M.
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  • Nope haven't, only used stream via flash player in the webpage. – Somebody Apr 05 '13 at 11:44
  • Nginx is saying that it's transfering about 5-6 mb of metadata. – Somebody Apr 05 '13 at 11:45
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    Did you try to seek at 0 and note the delay. And then, seek far in the file and note the delay. If your server implements seeking, you should have the same delay. If not, the file is downloaded at each request and the player waits for the good keyframe to start playing... – Greg M. Apr 05 '13 at 14:12
  • i'm using nginx mp4 module. – Somebody Apr 06 '13 at 14:07
  • The delay is much lesser when rewinding to the end of movie and much greater when it's closer to the start. – Somebody Apr 06 '13 at 14:08
  • "player waits for the good keyframe to start playing" That's what i was seeking for. Could you tell a bit more about it? What do you mean by "good" keyframe? How to increase good keyframes amount? :) – Somebody Apr 06 '13 at 14:10
  • Videos are made of frames and keyframes. To sayt it simply, keyframes are full image frame and the other frames encode only the delta part between 2 frames (really simple view ^^). But a keyframe is much bigger than the other one. Decoders needs to start from a key frame to compute the following frames. Increasing key frame frequency must be done at the encoding. – Greg M. Apr 06 '13 at 14:48
  • "The delay is much lesser when rewinding...". Are you sure that seeking to the end is faster than playing from 0 ? – Greg M. Apr 06 '13 at 14:55
  • Yes i'm sure about rewinding. About this - "Increasing key frame frequency must be done at the encoding", how to implement that via libav avconv conversion tool? I could not found in their docs. 5-6 seconds rewinding at the start This is closer to the end: 481 ms, 415 ms – Somebody Apr 06 '13 at 17:05
  • you can have a look here using ffmpeg http://stackoverflow.com/questions/14117757/how-to-control-key-frame-generation-of-ffmpeg but i don't believe that it is your problem. Did you try with another player ? try vlc to check if it's a problem of your flash player. – Greg M. Apr 06 '13 at 17:28