I have an MKV with a video stream with wrong resolution of 1920x800, but the inside film is 1920x1080 so my main video player, an LG Smart TV, shows a flattened image. I can easily change resolution in container metadata but LG TV ignores this data and read only video stream data.
First question: only way to change video stream resolution data is scale the video?
To scale with ffmpeg I used this command:
ffmpeg -i input.mkv -map 0 -c:a copy -c:s copy -c:v libx264 -preset slow -crf 17 -vf scale=1920:1080,setdar=16/9 output.mkv
Now the mkv is fine, my LG TV read it, looks awesome but..... size went from 3,3Gb to 12Gb!! Overall bit rate of 3,3Gb video is 2.704 Kbps, 12Gb is 9.829 Kbps. I think that 7000Kbps more are useless, in original video there aren't info to raise quality.
Second question: Why this huge size change? What is my mistake?
Best Regards
The
-crfoption is maybe a little bit low. This value can be from 0 - 51 where 23 is normal. 0 is very high quality and 51 is very poor. Try-crf 23.If time is not a factor for you (speed of conversion) try the preset
-preset veryslow.