3 * Copyright (c) 2006-2007 Konstantin Shishkov
4 * Partly based on vc9.c (c) 2005 Anonymous, Alex Beregszaszi, Michael Niedermayer
6 * This file is part of FFmpeg.
8 * FFmpeg is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU Lesser General Public
10 * License as published by the Free Software Foundation; either
11 * version 2.1 of the License, or (at your option) any later version.
13 * FFmpeg is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 * Lesser General Public License for more details.
18 * You should have received a copy of the GNU Lesser General Public
19 * License along with FFmpeg; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
24 * @file libavcodec/vc1_parser.c
25 * VC-1 and WMV3 parser
37 static void vc1_extract_headers(AVCodecParserContext *s, AVCodecContext *avctx,
38 const uint8_t *buf, int buf_size)
40 VC1ParseContext *vpc = s->priv_data;
42 const uint8_t *start, *end, *next;
43 uint8_t *buf2 = av_mallocz(buf_size + FF_INPUT_BUFFER_PADDING_SIZE);
45 vpc->v.s.avctx = avctx;
46 vpc->v.parse_only = 1;
49 for(start = buf, end = buf + buf_size; next < end; start = next){
52 next = find_next_marker(start + 4, end);
53 size = next - start - 4;
54 buf2_size = vc1_unescape_buffer(start + 4, size, buf2);
55 init_get_bits(&gb, buf2, buf2_size * 8);
56 if(size <= 0) continue;
57 switch(AV_RB32(start)){
59 vc1_decode_sequence_header(avctx, &vpc->v, &gb);
61 case VC1_CODE_ENTRYPOINT:
62 vc1_decode_entry_point(avctx, &vpc->v, &gb);
65 if(vpc->v.profile < PROFILE_ADVANCED)
66 vc1_parse_frame_header (&vpc->v, &gb);
68 vc1_parse_frame_header_adv(&vpc->v, &gb);
70 /* keep FF_BI_TYPE internal to VC1 */
71 if (vpc->v.s.pict_type == FF_BI_TYPE)
72 s->pict_type = FF_B_TYPE;
74 s->pict_type = vpc->v.s.pict_type;
84 * finds the end of the current frame in the bitstream.
85 * @return the position of the first byte of the next frame, or -1
87 static int vc1_find_frame_end(ParseContext *pc, const uint8_t *buf,
92 pic_found= pc->frame_start_found;
97 for(i=0; i<buf_size; i++){
98 state= (state<<8) | buf[i];
99 if(state == VC1_CODE_FRAME || state == VC1_CODE_FIELD){
108 /* EOF considered as end of frame */
111 for(; i<buf_size; i++){
112 state= (state<<8) | buf[i];
113 if(IS_MARKER(state) && state != VC1_CODE_FIELD && state != VC1_CODE_SLICE){
114 pc->frame_start_found=0;
120 pc->frame_start_found= pic_found;
122 return END_NOT_FOUND;
125 static int vc1_parse(AVCodecParserContext *s,
126 AVCodecContext *avctx,
127 const uint8_t **poutbuf, int *poutbuf_size,
128 const uint8_t *buf, int buf_size)
130 VC1ParseContext *vpc = s->priv_data;
133 if(s->flags & PARSER_FLAG_COMPLETE_FRAMES){
136 next= vc1_find_frame_end(&vpc->pc, buf, buf_size);
138 if (ff_combine_frame(&vpc->pc, next, &buf, &buf_size) < 0) {
145 vc1_extract_headers(s, avctx, buf, buf_size);
148 *poutbuf_size = buf_size;
152 static int vc1_split(AVCodecContext *avctx,
153 const uint8_t *buf, int buf_size)
159 for(i=0; i<buf_size; i++){
160 state= (state<<8) | buf[i];
161 if(IS_MARKER(state)){
162 if(state == VC1_CODE_SEQHDR || state == VC1_CODE_ENTRYPOINT){
172 AVCodecParser vc1_parser = {
174 sizeof(VC1ParseContext),