Lossless conversion from an image to a video

[Phuc-Hong-Tran]

I'm trying to convert an image to a video using the following settings:

  recorder.videoCodec = avcodec.AV_CODEC_ID_FFV1
  recorder.pixelFormat = AV_PIX_FMT_RGB24;
  recorder.videoCodecName = "libx264rgb";
  recorder.videoQuality = 0.0;
  recorder.format = "avi"
  recorder.frameRate = 1.0
  recorder.videoBitrate = 2000000

The result came out is blurry and have different colours compare to the original image. The original image is a JPEG with RGB colour format, its size is about 67KB. May anyone suggest why this is the case? Thanks in advance

[saudet]

Try to increase the quality

[Phuc-Hong-Tran]

@saudet what attribute(s) can I change to increase the quality, is it the videoQuality?

[Phuc-Hong-Tran]

Okay, so I just did a comparison between running ffmpeg though javacv and running ffpmeg straight from the command line, the output of the ffmpeg though javacv is worse compared to ffpmeg straight from the command line even though both use the same settings, is there any reason why this is the case?

[saudet]

You could check the output files with ffprobe to spot the differences

[saudet]

Also, we can easily accomplish this with the ffmpeg program:
http://bytedeco.org/javacpp-presets/ffmpeg/apidocs/org/bytedeco/ffmpeg/ffmpeg.html

[Phuc-Hong-Tran]

You could check the output files with ffprobe to spot the differences

Well I just check the sizes of those files and I can see the one from ffpmeg command line is 10 times bigger than the other one

[Phuc-Hong-Tran]

Also, we can easily accomplish this with the ffmpeg program:
http://bytedeco.org/javacpp-presets/ffmpeg/apidocs/org/bytedeco/ffmpeg/ffmpeg.html

Why can't we achieve the same with ffmpegframerecorder, I thought it is a wrapper around ffmpeg already?

[littlejohnyang]

You just need to do:
recorder.videoCodec = avcodec.AV_CODEC_ID_FFV1
recorder.videoQuality = 0.0;
recorder.frameRate = 30.0
If you read the source code, videoCodecName might be overwriting your videoCodec setting. You'll need gpl dependencies if using libx264. recorder.format is no longer used I think.

[Phuc-Hong-Tran]

Yeah I tried that already but it didn't fix the issue, look like it has been the issue with the FrameRecorder for a while already

[littlejohnyang]

I just manage to use FrameRecorder to record the desktop screen in FFV1 with the above setting though. I also have preset as ultrafast as video option. So it's definitely working. Not sure why it didn't work for you.
Have you tried to use ffmpeg directly and does it end up with the same result?
And one of the question is that you are converting a lossy compressed JPEG into a lossless format (maybe PNG). It sounds like it'll be blurry in some way.

[LouisCAD]

Which JavaCV version are you on?
I had a huge quality issue with 1.5.10 that was using ffmpeg 6.1, then, I tried manually with up to date 7.1.1 ffmpeg, and for the exact same command, the problem was gone.

Then, I upgraded JavaCV to 1.5.11, which is on ffmpeg 7.1, and the issue isn't there either.
Somehow, the main branch is on 7.1.1, but there's no release yet, but once there is, it might fix your issue?

[Phuc-Hong-Tran]

@LouisCAD, I was using 1.5.11