FFmpeg/libavcodec/rle.c
Michael Niedermayer c581cb4e4f Merge remote-tracking branch 'qatar/master'
* qatar/master:
  Fix even more missing includes after the common.h removal
  build: Factor out rangecoder dependencies to CONFIG_RANGECODER
  build: Factor out error resilience dependencies to CONFIG_ERROR_RESILIENCE
  x86: avcodec: Consistently name all init files
  Add more missing includes after removing the implicit common.h
  Add some more missing includes after removing the implicit common.h
  Don't include common.h from avutil.h
  rtmp: Automatically compute the hash for SWFVerification

Conflicts:
	configure
	doc/APIchanges
	doc/examples/decoding_encoding.c
	libavcodec/Makefile
	libavcodec/assdec.c
	libavcodec/audio_frame_queue.c
	libavcodec/avpacket.c
	libavcodec/dv_profile.c
	libavcodec/dwt.c
	libavcodec/libtheoraenc.c
	libavcodec/rawdec.c
	libavcodec/rv40dsp.c
	libavcodec/tiff.c
	libavcodec/tiffenc.c
	libavcodec/v210dec.h
	libavcodec/vc1dsp.c
	libavcodec/x86/Makefile
	libavfilter/asrc_anullsrc.c
	libavfilter/avfilter.c
	libavfilter/buffer.c
	libavfilter/formats.c
	libavfilter/vf_ass.c
	libavfilter/vf_drawtext.c
	libavfilter/vf_fade.c
	libavfilter/vf_select.c
	libavfilter/video.c
	libavfilter/vsrc_testsrc.c
	libavformat/version.h
	libavutil/audioconvert.c
	libavutil/error.h
	libavutil/version.h

Merged-by: Michael Niedermayer <michaelni@gmx.at>
2012-08-16 16:20:30 +02:00

86 lines
2.9 KiB
C

/*
* RLE encoder
* Copyright (c) 2007 Bobby Bingham
*
* 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 "avcodec.h"
#include "rle.h"
#include "libavutil/common.h"
/**
* Count up to 127 consecutive pixels which are either all the same or
* all differ from the previous and next pixels.
* @param start Pointer to the first pixel
* @param len Maximum number of pixels
* @param bpp Bytes per pixel
* @param same 1 if searching for identical pixel values. 0 for differing
* @return Number of matching consecutive pixels found
*/
static int count_pixels(const uint8_t *start, int len, int bpp, int same)
{
const uint8_t *pos;
int count = 1;
for(pos = start + bpp; count < FFMIN(127, len); pos += bpp, count ++) {
if(same != !memcmp(pos-bpp, pos, bpp)) {
if(!same) {
/* if bpp == 1, then 0 1 1 0 is more efficiently encoded as a single
* raw block of pixels. for larger bpp, RLE is as good or better */
if(bpp == 1 && count + 1 < FFMIN(127, len) && *pos != *(pos+1))
continue;
/* if RLE can encode the next block better than as a raw block,
* back up and leave _all_ the identical pixels for RLE */
count --;
}
break;
}
}
return count;
}
int ff_rle_encode(uint8_t *outbuf, int out_size, const uint8_t *ptr , int bpp, int w,
int add_rep, int xor_rep, int add_raw, int xor_raw)
{
int count, x;
uint8_t *out = outbuf;
for(x = 0; x < w; x += count) {
/* see if we can encode the next set of pixels with RLE */
if((count = count_pixels(ptr, w-x, bpp, 1)) > 1) {
if(out + bpp + 1 > outbuf + out_size) return -1;
*out++ = (count ^ xor_rep) + add_rep;
memcpy(out, ptr, bpp);
out += bpp;
} else {
/* fall back on uncompressed */
count = count_pixels(ptr, w-x, bpp, 0);
if(out + bpp*count >= outbuf + out_size) return -1;
*out++ = (count ^ xor_raw) + add_raw;
memcpy(out, ptr, bpp * count);
out += bpp * count;
}
ptr += count * bpp;
}
return out - outbuf;
}