Hello,
There seems to be an issue with the quality slider when exporting to a mp4 via FFmpeg in Mplay. I included a hip file, a photo, and 4 videos in the zip file. Each of the videos has the settings in the file name. The issue is that the quality slider seems inconsistent. For example, when you set the quality slider to 100, it actually exports a smaller file with bad quality compared to a value of 99 or 70. If you look at the video files, you will notice the file with quality 100 is 1.4 MB while the video at quality 99 is 5.8 MB. The video at 70 quality is 6.6 MB. I made the video have lots of particles because it exposes how poor the compression is. If you watch the video at 100 quality, by the time it gets to the end it looks quite terrible. I included a photo of the video at 100 quality (the one that looks worse) and the other photo is at 70 quality (looks better). What is going on here?
Thanks

I think quality in ffmpeg is a 2 digit number, so 100 would be truncated to 10 and produce a very low quality video. Try setting the quality to 10 and see if it produces an identical file.

jsmack
I think quality in ffmpeg is a 2 digit number, so 100 would be truncated to 10 and produce a very low quality video. Try setting the quality to 10 and see if it produces an identical file.

wow, thanks! I tried that and they are exactly the same file size. What you said is spot on. So the best quality would actually be 99. This threw me off, I had been using ffmpeg (external) to export (which used the version I installed on my PC manually) because every time I used the built-in ffmpeg I would set the quality to 100 and get bad results. I should probably submit an RFE to limit it to 99 or something.

thanks!

Which codec are you using? The quality slider doesn’t map to FFmpeg quality values. Each codec exposes different quality parameters. In order to simplify this, we convert the quality slider to a set of different commands for each codec.

johnmather
Which codec are you using? The quality slider doesn’t map to FFmpeg quality values. Each codec exposes different quality parameters. In order to simplify this, we convert the quality slider to a set of different commands for each codec.

h264 nvenc. I am pretty sure I got the same results for av1 nvenc too. Oh, that last part makes sense. I was looking in the ffmpeg documentation to try to figure out what the "quality" slider was doing. It would also be nice if you could see the command that mplay was using.