From 9b61d838f643f780b2597442a63e6c5b98ee8821 Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Tue, 24 Feb 2009 01:08:29 +0000 Subject: Pixel Format descriptor, try #1. (yes its intentionally unused, this is intended as a basis for further work, and to prevent repeation of the whole discussion dying and the results being forgotten) Originally committed as revision 17548 to svn://svn.ffmpeg.org/ffmpeg/trunk --- libavcodec/pixdesc.h | 91 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 91 insertions(+) create mode 100644 libavcodec/pixdesc.h (limited to 'libavcodec/pixdesc.h') diff --git a/libavcodec/pixdesc.h b/libavcodec/pixdesc.h new file mode 100644 index 0000000000..883ad5cd8c --- /dev/null +++ b/libavcodec/pixdesc.h @@ -0,0 +1,91 @@ +/* + * Pixel Format descriptor + * Copyright (c) 2009 Michael Niedermayer + * + * This file is part of FFmpeg. + * + * FFmpeg is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2.1 of the License, or (at your option) any later version. + * + * FFmpeg is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with FFmpeg; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA + */ + +#include + +#include "libavutil/intreadwrite.h" + +typedef struct AVComponentDescriptor{ + uint16_t plane :2; ///< which of the 4 planes contains the component + uint16_t step_minus1 :3; ///< number of bytes between 2 horizontally consecutive pixels minus 1 + uint16_t offset_plus1 :3; ///< number of bytes before the component of the first pixel plus 1 + uint16_t shift :3; ///< number of lsb that must be shifted away to get the value + uint16_t depth_minus1 :4; ///< number of bits in the component minus 1 +}AVComponentDescriptor; + +typedef struct AVPixFmtDescriptor{ + uint8_t nb_channels; ///< The number of components each pixel has, (1-4) + + /** + * Amount to shift the luma width right to find the chroma width, this is for + * example 1 for YV12 + * chroma_width = -((-luma_width )>>log2_chroma_w) + * note above is needed to ensure rounding up + */ + uint8_t log2_chroma_w; ///< chroma_width = -((-luma_width )>>log2_chroma_w) + + /** + * Amount to shift the luma height right to find the chroma height, this is for + * example 1 for YV12 + * chroma_height= -((-luma_height)>>log2_chroma_h) + * note above is needed to ensure rounding up + */ + uint8_t log2_chroma_h; + uint8_t flags; + AVComponentDescriptor comp[4]; ///< parameters that describes how pixels are packed +}AVPixFmtDescriptor; + +#define PIX_FMT_BE 1 ///< Big endian +#define PIX_FMT_PAL 2 ///< Pixel format has a palette i data[1], values are indexes in this palette +#define PIX_FMT_BITSTREAM 4 ///< All values of a component are bitwise packed end to end + + +static inline void read_line(uint16_t *dst, const uint8_t *data[4], const int linesize[4], AVPixFmtDescriptor *desc, int x, int y, int c, int w) +{ + AVComponentDescriptor comp= desc->comp[c]; + int plane= comp.plane; + int depth= comp.depth_minus1+1; + int mask = (1<flags; + const uint8_t *p= data[plane]+y*linesize[plane] + x * step + comp.offset_plus1 - 1; + + //FIXME initial x in case of PIX_FMT_BITSTREAM is wrong + + while(w--){ + int val; + if(flags & PIX_FMT_BE) val= AV_RB16(p); + else val= AV_RL16(p); + val = (val>>shift) & mask; + if(flags & PIX_FMT_PAL) + val= data[1][4*val + c]; + if(flags & PIX_FMT_BITSTREAM){ + shift-=depth; + while(shift<0){ + shift+=8; + p++; + } + }else + p+= step; + *dst++= val; + } +} -- cgit v1.2.3