[Mp4-tech] BitRate

[ramirez alejandro]

  Hi,
  Sandro thanks for your suggestions. You are right:
  The JM-10.1 H.264 software reference encoder takes a little time to stabilize the bitrate.
  I did some experiments with bigger sequence (>100 frames) and I founded that the target bitrate was stabilized. The opposite case (<100 frames) the target bitrate was not respected.
  I would like to know if some one could explain me the why of this problem. 
  Or literature other than JVT-0079.doc about the how works the rate control algorithm of  JM-10.1 H.264 software reference and talks about this problem.
  Thank you very much!
  Alejandro
ee09176 student.estg.ipleiria.pt a écrit :
  Hi Ramirez,
I suggest you to use the latest release JM10.1.
The config used by you seems to be right (but I never tried use rate control).
I heard that the rate control has some problems to stabilize the bitrate, try 
to encode a bigger sequence (>100 frames).
Good luck...
Sandro
On Wednesday 21 December 2023 14:31, ramirez alejandro wrote:
> Dear all,
>
> I am trying to do some experiments using the JM-9.5 H.264 software
> reference for baseline and main profiles for different bit rate values
> (10kbps, 64kbps, 128kbps, 768kbps and 2Mbps) . For that I am coding some
> test sequences (qcif, cif) using the reference encoder.
>
> In special I want to know how can I control the bit rate?
>
> What I did is :
> In the bin’s directory of the software JM, there are two files called
> encoder_baseline.cfg and encoder_main.cfg.
>
> In the section under Rate Control,
>
> I changed the parameters value:
>
> RateControlEnable = 1 # 0 Disable, 1 Enable
> Bitrate = 768000 # Bitrate(bps)
> InitialQP = 24
>
> For the bitrate parameter I tried for 10kbps,64kbps,128kbps,768kbps and
> 2Mbps. In all the cases the Bitrate wasn’t respected. (stats.dat) for
> example: For this bitrate:
> Bitrate = 10000 # Bitrate(bps)
> In the stats.dat I had:
> Freq. for encoded bitstream : 10
> Total Bitrate(kb/s) : 24.29
>
> I will appreciate if some one can give me some examples about the
> configure file (.cfg) or some comments about it.
>
> Thank you very much!
>
>
> Alejandro
>
> Note : I checked JVT-0017.doc and JVT-0079.doc
>
>
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