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