Efficient re-encoding of MPEG-2 cartoon animation

Question

I have some cartoon animation stored in MPEG-2 video that I would like to convert to MPEG-4/h264.

The MPEG-2 video compression is rather bad, with both "small" JPEG artefacts around details in the picture and larger JPEG blocks that change slightly hue for each frame.

The compressed file gets rather large, because I guess ffmpeg tries to preserve as much of the original as possible, which also means presering all the wrongdoings of the MPEG-2 compression.

Since the animation originally consisted of large flat color surfaces that would have been a video compressor's dream, is there a smart way to say:

"Take large color surfaces that are almost the same color, and make them a single color as to compress them extremely efficiently?"

In other words, to both optimise file size and video quality by removing the damage done by MPEG-2.

The ffmpeg option -tune animation saved a little file size, but not much. Also, decreasing general video quality just introduces "new" compression damages on top of the old ones.

Answer 1

Postprocessing

Genrally, crap in = crap out, but you could possibly make it look "better" with one of the many FFmpeg postprocessing filters: fspp, pp, pp7, spp, uspp.

_{original image with typical artifacts}

_{postprocessed image}

Example command

ffmpeg -i input.mpg -vf "pp=hb/vb/dr/fq|8" -c:v libx264 -crf 23 -preset medium \
-tune animation -c:a copy output.mkv

• Adjust -crf and -preset according to your needs as explained in FFmpeg Wiki: H.264 Video Encoding Guide.

• The audio is stream copied in this example.

• Postprocessing may be slow.

Use your player instead

Some players, such as VLC (Video → Post processing), may contain postprocessing features, so it could be a better choice to simply use that instead of re-encoding.

Or use ffplay to play or preview the filtering:

ffplay -vf "pp=hb/vb/dr/fq|8" -i input.mpg

Also see

• FFmpeg Wiki: Postprocessing