[Asterisk-video] Video bandwidth consumption

[Sergio Garcia Murillo]

Again, you are the one that sets in the encoder how much bandwidth you want.

Also vlc, ffmpeg and the like are vbr encoders for *movies*, so the 
bandwith you set is the media, so expect BIG peaks of bandwidth, 
especially on I Frames, followed by very very small P frames. For 
example that is the reason for the delay of video using standard mp4 
movies and h324m (as you transmit at a fixed bitrate). You can try to 
control a bit the output of the encoder (a bit). I had to do some other 
techniques (like variable fps) in app_transcoder to be able to control 
that bitrate peaks.

You should use a CBR encoder, but it AFAIK there is no one available in 
open source. If you want to control the maximum of the peaks you can 
also try by setting a constant quantizer, but quality is going to be 
veeeery bad (as you will have to set a very low q).

Best regards
Sergio


Salvatore Frandina escribió:
>
> Hi Sergio,
>
> I know that the bitrate depend from information content of source. I 
> use VLC as source that transmits still image CIF picture with 1 fps 
> and format YUV 4:2:0.
>
> At the moment I'm not interested in quality, but only in video 
> bandwidth consumption.
>
> I have taken in account the sixth column IP BW of Wireshark capture 
> file and with Matlab I have extract the Probability Density Function. 
> The mean and max bandwidth values are very high respect how I'm expecting.
>
> I would like to know what can be the total video bandwidth with H263p 
> codec and H264 codec of CIF picture with 1 fps and format YUV 4:2:0?
>
> The values that I have measured are strange for me, but I can't find 
> documentation about video bandwidth as this 
> http://www.voip-info.org/wiki/view/Bandwidth+consumption.
>
>
> Thank
>
> -- 
> _______________________________________
> Salvatore Frandina
> website: http://frandinas.altervista.org
> mail: salvatore.frandina at gmail.com <mailto:salvatore.frandina at gmail.com>
>
> _______________________________________
>

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