[Bug]: Media sdk sample(sample_encode) encoding problem with bit rate control doesn't work on the specific yuv file.

[HeXianrui]

Which component impacted?

Encode

Is it regression? Good in old configuration?

None

What happened?

1. Run Media SDK sample, sample_decode, on Linux platform, to generate target.yuv file by decoding the given hevc source. Running Command line: ./sample_decode h265 -gpucopy::on -device /dev/dri/card0 -i ./program_2.hevc -o ./target.yuv -n 300 You can access the input source file program2.hevc here: program_2.hevc ： https://pan.baidu.com/s/1fjsNCfDrsBoTos-_qm6POQ Extraction code：7lym_
2. Run Media SDK sample , sample_encode , on Linux platform, bit rate control doesn't work well on the target.yuv file. The output bit rate is much higher than the set value.
3. Running command: ./sample_encode h265 -gpucopy::on -i ./target.yuv -o ./output.h265 -w 1920 -h 1080 -dstw 1920 -dsth 1080 -b 10000 -f 50 -hw -async 1 -u speed -r 1 -g 100 .
4. The input yuv file only contains 300 frames, but with bit rate set value being 10000, framerate being 50, the output.h265 files is about 28MB which is much higher than the expected.
5. We have tried with cbr , vbr, la and other methods, all failed but except method : "extbrc:on" .The output file with extbrc method on is about 7.4MB, but the output file has a few totally black frames. We have no idea about it.
6. Please help us find a valid bit rate control method without any problem on the given source .

Thank you very much!

What's the usage scenario when you are seeing the problem?

Playback, Video Analytics

What impacted?

intel media sdk version

/opt/intel/mediasdk/bin/vainfo

libva info: VA-API version 1.12.0 libva info: Trying to open /opt/intel/mediasdk/lib64/iHD_drv_video.so libva info: Found init function __vaDriverInit_1_12 libva info: va_openDriver() returns 0 vainfo: VA-API version: 1.12 (libva 2.12.0) vainfo: Driver version: Intel iHD driver for Intel(R) Gen Graphics - 21.2.3 (008fb3b4) vainfo: Supported profile and entrypoints

os version :5.10.0-1044-oem ubuntu1~20.04

Debug Information

No response

Do you want to contribute a patch to fix the issue?

None

[intel-mediadev]

Auto Created VSMGWL-64056 for further analysis.

[bai-isaac]

hi @HeXianrui , we analyzed the bit stream and encoding commands you provided. We found that the complexity of this content is very high, and it is a scene similar to Gaussian white noise. When -b is set to 1m, the maximum quantization parameter 51 has been used during brc encoding. Even if -b is set smaller, the size of the bitstream will not decrease much, which is expected. This is due to the complexity of the content.

[HeXianrui]

hi @HeXianrui , we analyzed the bit stream and encoding commands you provided. We found that the complexity of this content is very high, and it is a scene similar to Gaussian white noise. When -b is set to 1m, the maximum quantization parameter 51 has been used during brc encoding. Even if -b is set smaller, the size of the bitstream will not decrease much, which is expected. This is due to the complexity of the content.

Hi， @bai-isaac , I got it, Thank you! But I still confused about one question. We tryed brc method with extbrc:on in that encode sample, it successfully controls the output bit rate, but with a few totally black frames in the output file. Could you help analyze it? Thank you very much!

[HeXianrui]

hi @HeXianrui , we analyzed the bit stream and encoding commands you provided. We found that the complexity of this content is very high, and it is a scene similar to Gaussian white noise. When -b is set to 1m, the maximum quantization parameter 51 has been used during brc encoding. Even if -b is set smaller, the size of the bitstream will not decrease much, which is expected. This is due to the complexity of the content.

Hi，@bai-issac, one more important thing is that sample works fine with h264 encoder, no bit rate out of control issue.

[bai-isaac]

hi @HeXianrui could you please share h264 encoder command here? Thanks!

[HeXianrui]

hi @HeXianrui could you please share h264 encoder command here? Thanks!

./sample_encode h264 -gpucopy::on -i ./target.yuv -o ./output.h264 -w 1920 -h 1080 -b 10000 -f 50 -hw -async 1 -u speed -r 1 -g 100