H264 Compress problem with OpenCV

[Luo__Yiyun]

System information (version)

- OpenCV => 3.4.3-openvino
- Operating System / Platform => Linux Ubuntu 16.04

- Processor => Intel® Pentium(R) CPU N4200 @ 1.10GHz × 4

- Graphics => Intel® HD Graphics 505 (Broxton)

Detailed description
Hello, I'm using Intel Up-Board Squared to develop a programm which needs to compress video by using INTEL_MFX apiPreference to speed up the process.
I've compiled OpenCV with Intel Media SDK backend, and the compiler didn't give any errors to my code.

 int fourcc = cv::VideoWriter::fourcc('H','2','6','4'); cv::VideoWriter writer("filename.mp4", cv::INTEL_MFX, fourcc, 30, cv::Size(1280,720), true);

What interesting is,  when I run the code, it will show a line with `MFX: unsupported extension: /dev/video0`, but the video could be written in a new file.
The video file which was written is very large. A video about 30 seconds can be 70 MB large. I think that the video has been written without compressing with H264.

I also installed Intel Quick Sync Video for ffmpeg.
 

up-board@upboard-UP-APL01:~$ ffmpeg -codecs | grep 'qsv'ffmpeg version n3.4-dev-2711-g587fada Copyright (c) 2000-2017 the FFmpeg developers
  built with gcc 5.4.0 (Ubuntu 5.4.0-6ubuntu1~16.04.10) 20160609
  configuration: --enab Code Issues 73 Pull requests 33 Wiki Insightsle-libmfx
  libavutil      55. 78.100 / 55. 78.100
  libavcodec     57.107.100 / 57.107.100
  libavformat    57. 83.100 / 57. 83.100
  libavdevice    57. 10.100 / 57. 10.100
  libavfilter     6.107.100 /  6.107.100
  libswscale      4.  8.100 /  4.  8.100
  libswresample   2.  9.100 /  2.  9.100
 DEV.LS h264                 H.264 / AVC / MPEG-4 AVC / MPEG-4 part 10 (decoders: h264 h264_v4l2m2m h264_qsv h264_vdpau h264_cuvid ) (encoders: h264_nvenc h264_qsv h264_v4l2m2m h264_vaapi nvenc nvenc_h264 )
 DEV.L. hevc                 H.265 / HEVC (High Efficiency Video Coding) (decoders: hevc hevc_qsv hevc_cuvid ) (encoders: nvenc_hevc hevc_nvenc hevc_qsv hevc_vaapi )
 DEV.L. mpeg2video           MPEG-2 video (decoders: mpeg2video mpegvideo mpegvideo_vdpau mpeg2_v4l2m2m mpeg2_qsv mpeg2_cuvid ) (encoders: mpeg2video mpeg2_qsv mpeg2_vaapi )
 D.V.L. vc1                  SMPTE VC-1 (decoders: vc1 vc1_vdpau vc1_qsv vc1_v4l2m2m vc1_cuvid )
 DEV.L. vp8                  On2 VP8 (decoders: vp8 vp8_v4l2m2m vp8_cuvid vp8_qsv ) (encoders: vp8_v4l2m2m vp8_vaapi )

I think that it's correctly installed.

Is it possible to set parameters for H.264? Probably has it compressed but with a poor parameter? If it is so, then I want to know how to set the parameters for H.264. Otherwise if it did not compress at all... how can I get it work?

Is there anyone who has experience with Media SDK backend for OpenCV? Hope someone can help me.

Greetings,
Yiyun

[Mark_L_Intel1]

Hi Yiyun,

How did you build OpenCV to enable Media SDK backend? did you referred to the following article:

https://github.com/opencv/opencv/wiki/MediaSDK-encode-decode-backend

Mark

[Luo__Yiyun]

Liu, Mark (Intel) wrote:

Hi Yiyun,

How did you build OpenCV to enable Media SDK backend? did you referred to the following article:

https://github.com/opencv/opencv/wiki/MediaSDK-encode-decode-backend

Mark

Hello Mark,

I used this article (https://github.com/opencv/opencv/wiki/MediaSDK-encode-decode-backend) to build OpenCV to enable Media SDK backend. And in BuildInformation of OpenCV, Intel Media SDK is already 'YES'. By the way, I have solved this problem and written it in OpenCV issue in github: https://github.com/opencv/opencv/issues/13306

Thanks

Yiyun