The problem of VBR value variation range being too large during imx8mm VPU H264 encoding

[pyh0603]

Hi,all

 we are using imx8mm for H264 encoding, system information is as bellow:
    CPU: MIMX8MM6DVTLZAA
    software version: imx-4.14.98-2.0.0_ga.xml
    vpu:====== VPUENC: 4.4.5 build on Oct 30 2019 12:04:50. ====== 
           wrapper: 3.0.0 (VPUWRAPPER_ARM64_LINUX Build on Sep 24 2021 08:24:44)    vpulib: 1.1.1  firmware: 1.1.1.65535
  
    Issues describe:
    If we use the CBR mode, The output bit rate fluctuates by approximately 20%.
    but in the VBR mode, The output bit rate fluctuates about 30k~30M (1080p/60fps, H264 encoding);
   
    however, we test another solution,  its  output bit rate fluctuates  about 30k~5M (most time is 4M);
    so our quetsion is: is it possible to optimize  MIMX8MM vpu for its VBR mode?  can we make it's output bit rate fluctuates from 30k~30M to 30k~5M in VBR mode(1080p/60fps, H264 encoding)? anyother update? or give us some suggetion, thanks.

Looking forward to your reply

[DR_Akzhol]

Hello there, could you find a solution for that? We have tested VBR with highprofile mode. At DAY we have normal Bitrate 100kb-3Mb, night time camera gives more noise, so the bitrate goes to 15-20Mb (too big files at night)

[Bio_TICFSL]

Hello,

Thanks depend of the video, but with current codecs is not possible to optimize the VBR but there is a VPU manual on your yocto documentation where your can apply the api and check is there optimization.

Regards