1/* 2 * DNxHD/VC-3 parser 3 * Copyright (c) 2008 Baptiste Coudurier <baptiste.coudurier@free.fr> 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/** 23 * @file 24 * DNxHD/VC-3 parser 25 */ 26 27#include "parser.h" 28 29#define DNXHD_HEADER_PREFIX 0x0000028001 30 31static int dnxhd_find_frame_end(ParseContext *pc, 32 const uint8_t *buf, int buf_size) 33{ 34 uint64_t state = pc->state64; 35 int pic_found = pc->frame_start_found; 36 int i = 0; 37 38 if (!pic_found) { 39 for (i = 0; i < buf_size; i++) { 40 state = (state<<8) | buf[i]; 41 if ((state & 0xffffffffffLL) == DNXHD_HEADER_PREFIX) { 42 i++; 43 pic_found = 1; 44 break; 45 } 46 } 47 } 48 49 if (pic_found) { 50 if (!buf_size) /* EOF considered as end of frame */ 51 return 0; 52 for (; i < buf_size; i++) { 53 state = (state<<8) | buf[i]; 54 if ((state & 0xffffffffffLL) == DNXHD_HEADER_PREFIX) { 55 pc->frame_start_found = 0; 56 pc->state64 = -1; 57 return i-4; 58 } 59 } 60 } 61 pc->frame_start_found = pic_found; 62 pc->state64 = state; 63 return END_NOT_FOUND; 64} 65 66static int dnxhd_parse(AVCodecParserContext *s, 67 AVCodecContext *avctx, 68 const uint8_t **poutbuf, int *poutbuf_size, 69 const uint8_t *buf, int buf_size) 70{ 71 ParseContext *pc = s->priv_data; 72 int next; 73 74 if (s->flags & PARSER_FLAG_COMPLETE_FRAMES) { 75 next = buf_size; 76 } else { 77 next = dnxhd_find_frame_end(pc, buf, buf_size); 78 if (ff_combine_frame(pc, next, &buf, &buf_size) < 0) { 79 *poutbuf = NULL; 80 *poutbuf_size = 0; 81 return buf_size; 82 } 83 } 84 *poutbuf = buf; 85 *poutbuf_size = buf_size; 86 return next; 87} 88 89AVCodecParser dnxhd_parser = { 90 { CODEC_ID_DNXHD }, 91 sizeof(ParseContext), 92 NULL, 93 dnxhd_parse, 94 ff_parse_close, 95}; 96