00001 /* 00002 * DNxHD/VC-3 parser 00003 * Copyright (c) 2008 Baptiste Coudurier <baptiste.coudurier@free.fr> 00004 * 00005 * This file is part of FFmpeg. 00006 * 00007 * FFmpeg is free software; you can redistribute it and/or 00008 * modify it under the terms of the GNU Lesser General Public 00009 * License as published by the Free Software Foundation; either 00010 * version 2.1 of the License, or (at your option) any later version. 00011 * 00012 * FFmpeg is distributed in the hope that it will be useful, 00013 * but WITHOUT ANY WARRANTY; without even the implied warranty of 00014 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 00015 * Lesser General Public License for more details. 00016 * 00017 * You should have received a copy of the GNU Lesser General Public 00018 * License along with FFmpeg; if not, write to the Free Software 00019 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 00020 */ 00021 00027 #include "parser.h" 00028 00029 #define DNXHD_HEADER_PREFIX 0x0000028001 00030 00031 static int dnxhd_find_frame_end(ParseContext *pc, 00032 const uint8_t *buf, int buf_size) 00033 { 00034 uint64_t state = pc->state64; 00035 int pic_found = pc->frame_start_found; 00036 int i = 0; 00037 00038 if (!pic_found) { 00039 for (i = 0; i < buf_size; i++) { 00040 state = (state<<8) | buf[i]; 00041 if ((state & 0xffffffffffLL) == DNXHD_HEADER_PREFIX) { 00042 i++; 00043 pic_found = 1; 00044 break; 00045 } 00046 } 00047 } 00048 00049 if (pic_found) { 00050 if (!buf_size) /* EOF considered as end of frame */ 00051 return 0; 00052 for (; i < buf_size; i++) { 00053 state = (state<<8) | buf[i]; 00054 if ((state & 0xffffffffffLL) == DNXHD_HEADER_PREFIX) { 00055 pc->frame_start_found = 0; 00056 pc->state64 = -1; 00057 return i-4; 00058 } 00059 } 00060 } 00061 pc->frame_start_found = pic_found; 00062 pc->state64 = state; 00063 return END_NOT_FOUND; 00064 } 00065 00066 static int dnxhd_parse(AVCodecParserContext *s, 00067 AVCodecContext *avctx, 00068 const uint8_t **poutbuf, int *poutbuf_size, 00069 const uint8_t *buf, int buf_size) 00070 { 00071 ParseContext *pc = s->priv_data; 00072 int next; 00073 00074 if (s->flags & PARSER_FLAG_COMPLETE_FRAMES) { 00075 next = buf_size; 00076 } else { 00077 next = dnxhd_find_frame_end(pc, buf, buf_size); 00078 if (ff_combine_frame(pc, next, &buf, &buf_size) < 0) { 00079 *poutbuf = NULL; 00080 *poutbuf_size = 0; 00081 return buf_size; 00082 } 00083 } 00084 *poutbuf = buf; 00085 *poutbuf_size = buf_size; 00086 return next; 00087 } 00088 00089 AVCodecParser dnxhd_parser = { 00090 { CODEC_ID_DNXHD }, 00091 sizeof(ParseContext), 00092 NULL, 00093 dnxhd_parse, 00094 ff_parse_close, 00095 };