[Scummvm-devel] DXA file format for videos

Eugene Sandulenko sev at scummvm.org
Fri Apr 28 21:57:05 CEST 2006

On Sat, 29 Apr 2006 01:26:34 +0300
Eugene Sandulenko <sev at scummvm.org> wrote:

I reencoded videos with DXA and ZMBV with highest compression level and
here are the results:

> Low quality MPEG2 (we distribute those now)
> BS1: 32M video
> BS2: 27M video

> Adequate quality mpeg2 videos take somewhat more:
> BS1: 68MB video
> BS2: 70MB video

> advmng -S 64 -3
> BS1: 67MB video
> BS2: 136MB video
These are left for reference. BS1 size is for full set now.

> > DXA
> > BS1: 96M video
> > BS2: 186M video
BS1: 94MB video
BS2: 181MB video

> BS1: 100M video
> BS2: 180M video
BS1: 96MB video
BS2: 170MB video

Also I decreased block size from 16x16 to 8x8 and chose smallest file
among the two, i.e. the task similar to AdvanceCOMP utilities. That
gave me following results:

BS1: 93MB video
BS2: 164MB video

A bit better.

So high gain for ZMBV optimized video appeared because initially it
used compression level 4.

So, in the end we have these ratios:

against Low Q MPEG2:
  ZMBV       MNG
BS1: 2.9x    2.1x
BS2: 6x      5x

against High Q MPEG2:
  ZMBV       MNG
BS1: 1.4x    1x
BS2: 2.3x    1.9x

Option yet to try is PNG compression. PNG library itself is not
big, very portable and will be useful in other parts of ScummVM, i.e.
thumbnails. However I don't expect more than 5-10% gain, though I may


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