[FFmpeg-devel] libavcodec/exr : enable support for mipmap/ripmap tile.

Paul B Mahol onemda at gmail.com
Tue Apr 5 22:31:06 CEST 2016

On 4/5/16, Martin Vignali <martin.vignali at gmail.com> wrote:
> Hello,
> Mipmap and ripmap is two way to store several resolution of the picture
> inside an exr file
> The difference between these two mode, is the number of subres level (lot
> more subres in ripmap, than mipmap).
> These files are mainly design to store maps for 3D render.
> After some tests on official samples, it seems that mipmap and ripmap exr
> file, store the full res tiles before subres tiles.
> So the actual way of decoding tile, works fine with mipmap and ripmap (only
> calc the full res tile count), run decode_block for theses tile.
> So i think the patch in attach works fine for mipmap and ripmap.
> I also ignore now, the tile round mode, because this value, is only, for
> detecting tile count in subres level
> This patch decode fine all Multiresolution tile files of the official
> libray :
> http://download.savannah.nongnu.org/releases/openexr/openexr-images-1.7.0.tar.gz
> except : WavyLinesSphere.exr
> But this file, is in fact not a Multiresolution file (exrheader information
> show that it's a scanline PIZ).
> And i suppose the decoding error, is related, to ticket
> https://trac.ffmpeg.org/ticket/3932
> Comments welcome

Shouldn't there be option use lower resolution tiles?

> Martin
> Jokyo Images

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