topic Re: IMX6Q- vpu encoder CBR setting in i.MX Processors

IMX6Q- vpu encoder CBR setting

krishnachandrap — Tue, 18 Apr 2017 06:42:32 GMT

Hi,

I just wanted to know the chip capability of imx6q VPU for CBR mode. I have been setting the CBR of 2.5M bits/sec but the vlc shows the bit rate of 4M bits/sec whenever there is a motion.

imxvpuenc_h264‌ imx vpu‌ imxstreaming‌ imx6qvpuCBR‌ imx6quad

Re: IMX6Q- vpu encoder CBR setting

joanxie — Wed, 19 Apr 2017 08:17:33 GMT

refer to the vpu refence manual, The bitrate should be between 0 and 32767.

Re: IMX6Q- vpu encoder CBR setting

krishnachandrap — Thu, 20 Apr 2017 06:31:50 GMT

Hi Joan Xie,

Our problem is : Even though we have set CBR as 2560 kbps our output stream is showing higher bit rate of 4500 - 5000 kbps as read using vlc player. Our understanding was that our output bit rate would not exceed the CBR set (10% tolerance is acceptable) but this was not observed practically as mentioned above.

Could you please tell us how to restrict encoded output bit rate below the CBR set (+/- 10% tolerance)?

Following are the some of the parameters that we have configured

gopSize : 20
. sliceMode : 1
. sliceSizeMode : 1
. sliceSize : 360
MESearchRange : 1
bitRate : 2560