On 7/31/20, Zong, Wei <wei.z...@intel.com> wrote: > > >> -----Original Message----- >> From: ffmpeg-devel <ffmpeg-devel-boun...@ffmpeg.org> On Behalf Of Paul B >> Mahol >> Sent: Friday, July 31, 2020 3:57 PM >> To: FFmpeg development discussions and patches <ffmpeg-devel@ffmpeg.org> >> Cc: Liu, YinhangX <yinhangx....@intel.com> >> Subject: Re: [FFmpeg-devel] [PATCH] avfilter/vf_xcam: add xcam video >> filter >> >> On 7/31/20, Zong, Wei <wei.z...@intel.com> wrote: >> > Thank you for the comments on this patch, I want to make some >> > explanation on your comments. >> > >> > 1. the purpose of this patch >> > We got some requirements from users who are trying libxcam >> > stitching or developers who showing interests. Many of them want an >> > easy way to construct an end 2 end pipeline of high quality immersive >> > media >> application. >> > The key points are high resolution and low latency, FFMpeg >> > provides high quality video codec framework, if we implement video >> > stitching as a video filter in FFMpeg, they will get benefits. >> > >> > 2. 3rd party dependency >> > The functions exposed by xcam filter only depends on essential >> > build tool-chain. >> > According to hardware configuration, user can get performance >> > improvement by install OCL, GLES or Vulkan. >> > These libraries are not necessary for video stitching, user can build >> > a CPU version without these libraries. >> > Beside these, stitching and DVS function depend on feature match >> > algorithm from OpenCV library to get better quality, I posted demo >> > link in commit message. >> > User can run stitching without install OpenCV, the side effect is the >> > quality will decrease. >> > >> > 3. Immersive media standard >> > Normally the camera manufactures provide video stitching software, >> > they defined private camera calibration parameters, these are very >> > critical to stitching quality. I know MPEG is making proposal on >> > transfer these meta-data in video stream, this will help compose >> > immersive media on cloud or edge server. I think it's a good idea to >> > create such a video filter in FFMpeg pipeline. >> > >> > 4. Why not implement stitching inside FFMpeg video filter >> > The algorithms are complexity and the performance are also >> > important, the stitching function manage computing resource for >> > example thread handling, image data block dispatching. Personally I >> > think we don't need to construct a wheel from the beginning. >> >> Number of supported pixel formats are rather very low. > > Do you mean the pixel format (NV12 & YUV420) that xcam filter supported > is not enough? > xcam filter works as a post processing component between video decoder and > encoder, we suppose the data comes from camera or stored video clips, so it > handles YUV format. > libxcam algorithm optimization highly depends on pixel layout, to support > YUV422 or YUV444 will cost much effort, we do not meet the requirement till > now.
Ok then, I thought library provided support for it already. Supporting only few pixel formats is very limited functionality IMHO. > > >> _______________________________________________ >> ffmpeg-devel mailing list >> ffmpeg-devel@ffmpeg.org >> https://ffmpeg.org/mailman/listinfo/ffmpeg-devel >> >> To unsubscribe, visit link above, or email >> ffmpeg-devel-requ...@ffmpeg.org >> with subject "unsubscribe". > _______________________________________________ > ffmpeg-devel mailing list > ffmpeg-devel@ffmpeg.org > https://ffmpeg.org/mailman/listinfo/ffmpeg-devel > > To unsubscribe, visit link above, or email > ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe". _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-devel To unsubscribe, visit link above, or email ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe".
