vpx_rac.c (1835B)
1 /* 2 * VP5/6/8 decoder 3 * Copyright (c) 2010 Fiona Glaser <fiona@x264.com> 4 * 5 * This file is part of FFmpeg. 6 * 7 * FFmpeg is free software; you can redistribute it and/or 8 * modify it under the terms of the GNU Lesser General Public 9 * License as published by the Free Software Foundation; either 10 * version 2.1 of the License, or (at your option) any later version. 11 * 12 * FFmpeg is distributed in the hope that it will be useful, 13 * but WITHOUT ANY WARRANTY; without even the implied warranty of 14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 15 * Lesser General Public License for more details. 16 * 17 * You should have received a copy of the GNU Lesser General Public 18 * License along with FFmpeg; if not, write to the Free Software 19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 20 */ 21 22 #include <stdint.h> 23 #include "libavutil/error.h" 24 #include "bytestream.h" 25 #include "vpx_rac.h" 26 27 const uint8_t ff_vpx_norm_shift[256]= { 28 8,7,6,6,5,5,5,5,4,4,4,4,4,4,4,4, 29 3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3, 30 2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2, 31 2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2, 32 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1, 33 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1, 34 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1, 35 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1, 36 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 37 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 38 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 39 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 40 }; 41 42 int ff_vpx_init_range_decoder(VPXRangeCoder *c, const uint8_t *buf, int buf_size) 43 { 44 c->high = 255; 45 c->bits = -16; 46 c->buffer = buf; 47 c->end = buf + buf_size; 48 c->end_reached = 0; 49 if (buf_size < 1) 50 return AVERROR_INVALIDDATA; 51 c->code_word = bytestream_get_be24(&c->buffer); 52 return 0; 53 }