The current implementation of the CQP mode encode has a
compressed buffer size restriction of 4Kb. The restriction
doesn't make sense for low-resolution & low-bitrate
video encoding use cases since inter-frames can be encoded
with much less number of bytes.
For eg: most of the P-frames in a video-conferencing session
of 640x480 resolution at 750kbps require only 1Kb bitrate
allocation and currently the hardware PAK unit fill the rest
of the 3Kb (4Kb-1Kb) with zeros. This will jeopardize the
quality & bit-rate allocation of the hybrid CBR encode
models1 where we run the bitrate control algorithm in
software clubbed with a CQP hardware encoder:
The current implementation of the CQP mode encode has a compressed buffer size restriction of 4Kb. The restriction doesn't make sense for low-resolution & low-bitrate video encoding use cases since inter-frames can be encoded with much less number of bytes.
For eg: most of the P-frames in a video-conferencing session of 640x480 resolution at 750kbps require only 1Kb bitrate allocation and currently the hardware PAK unit fill the rest of the 3Kb (4Kb-1Kb) with zeros. This will jeopardize the quality & bit-rate allocation of the hybrid CBR encode models1 where we run the bitrate control algorithm in software clubbed with a CQP hardware encoder: