[FFmpeg-devel] [PATCH] lavc/rawdec: Use AV_PIX_FMT_PAL8 for 1 bpp raw video in AVI

Mats Peterson matsp888 at yahoo.com
Tue Jan 26 16:53:54 CET 2016


On 01/26/2016 04:48 PM, Mats Peterson wrote:
>  From https://en.wikipedia.org/wiki/BMP_file_format#Pixel_format:
>
> "The 1-bit per pixel (1bpp) format supports 2 distinct colors, (for
> example: black and white). The pixel values are stored in each bit, with
> the first (left-most) pixel in the most-significant bit of the first
> byte.[5] Each bit is an index into a table of 2 colors. An unset bit
> will refer to the first color table entry, and a set bit will refer to
> the last (second) color table entry."
>
> I don't know whether this Wikipedia article has a lot of authority
> really, but please note the "for example black and white".
>
> Mats
>

 From 
https://msdn.microsoft.com/en-us/library/windows/desktop/dd318229%28v=vs.85%29.aspx:

"If biCompression equals BI_RGB and the bitmap uses 8 bpp or less, the 
bitmap has a color table immediatelly following the BITMAPINFOHEADER 
structure. The color table consists of an array of RGBQUAD values. The 
size of the array is given by the biClrUsed member. If biClrUsed is 
zero, the array contains the maximum number of colors for the given 
bitdepth; that is, 2^biBitCount colors."

Nothing about "monochrome" here.

Mats

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


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