[FFmpeg-devel] [PATCH] lavf/qtpalette: Ignore greyscale bit in 1-bit video

[Mats Peterson]

The QuickTime File Format Specification states the following:

"Depth: A 16-bit integer that indicates the pixel depth of the
compressed image. Values of 1, 2, 4, 8 ,16, 24, and 32 indicate the
depth of color images. The value 32 should be used only if the image
contains an alpha channel. Values of 34, 36, and 40 indicate 2-, 4-, and
8-bit grayscale, respectively, for grayscale images."

There is no mention of value 33, i.e. 1-bit video (0x01) with the
greyscale bit (0x20) set. I therefore suggest that we ignore the
greyscale bit when processing 1-bit video. Another reason to do this is
that the sample file below will be displayed properly with blue colors
in QuickTime in Windows or Mac *in spite of* the greyscale bit being
set.

Sample file:
https://drive.google.com/open?id=0B3_pEBoLs0faTThSek1EeXQ0ZHM

Mats

-- 
Mats Peterson
http://matsp888.no-ip.org/~mats/
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