how to take lossless screenshots from 2 x265 videos and compare them?

[batemanj]

Hi friends,

I need to compare 2 x265 hevc 10-bit encoded videos. To achieve that I would like to take lossless screenshots from both videos at exact time frame.

I heard diff.pics is the best to compare 2 images. is that right or any other better way?


I tried ffmpeg but can't get the best quality even if I set the max quality option.

Please advise. Thanks!!

[Selur]

Personally I would both open using LWLibavVideoSource in Vapoursynth (or Avisynth), stack them horizontally or interleave them for comparison.
That said most video players and editors allow to open videos and take screenshots. (editors are probably better suited since they normally index the frames and thus allow frame accurate screenshot taking)
imho ffmpeg isn't really the right tool for the job.

[batemanj]

Personally I would both open using LWLibavVideoSource in Vapoursynth (or Avisynth), stack them horizontally or interleave them for comparison.
That said most video players and editors allow to open videos and take screenshots. (editors are probably better suited since they normally index the frames and thus allow frame accurate screenshot taking)
imho ffmpeg isn't really the right tool for the job.

Thanks Selur, I will try Vapoursynth / Avisynth.

Could you please let me know few best editors that allow accurate screenshots?

Thanks again,

[LMotlow]

You guys can't be serious. Screenshots?
Many video editors can copy a frame directly to the Windows clipboard. Then you can open that copy in a photo app. Most people would open a video with Avisynth and make a direct frame copy in VirtualDub. Corel's NLE's used to be able to copy directly to the clipboard, so could Adobe. There is a free clipboard copy plugin for AfterEffects.


Screenshots?

[sophisticles]

I prefer to use ffmpeg/ffplay blend filter:

https://ffmpeg.org/ffmpeg-filters.html#blend_002c-tblend

https://www.youtube.com/watch?v=W7Ff0c_Sxx0

https://stackoverflow.com/questions/25774996/how-to-compare-show-the-difference-betwee...deos-in-ffmpeg


What you do is take your source and encoded video 1 and overlay them so that only the differences remain, output that as a lossless video, do the same with the second video, now you have 2 lossless videos that only display the differences between the source and the encoded videos. This way you can visually check to see which of the 2 is closest to the source.

[JVRaines]

I need to compare 2 x265 hevc 10-bit encoded videos.

For what purpose? To see how different they are from each other? To see how close they are to the unencoded source?

[sekininsha]

I need to compare 2 x265 hevc 10-bit encoded videos.

I usually load in VirtualDub and compare with this script .avs:

Source=LWLibavVideoSource("source.mkv", format="YUV420P8").subtitle("Source", text_color=$FFCC00,align=9,font="Tahoma")
Encode=LWLibavVideoSource("encode.mkv", format="YUV420P8").subtitle("Encode", text_color=$FFCC00,align=9,font="Tahoma")

last=interleave(Source, Encode)
last.ffinfo(framenum=true,frametype=true,cfrtime=f alse,vfrtime=false)

regards