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
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;
50 for(start = buf, end = buf + buf_size; next < end; start = next){
53 next = find_next_marker(start + 4, end);
54 size = next - start - 4;
55 buf2_size = vc1_unescape_buffer(start + 4, size, buf2);
56 init_get_bits(&gb, buf2, buf2_size * 8);
57 if(size <= 0) continue;
58 switch(AV_RB32(start)){
60 ff_vc1_decode_sequence_header(avctx, &vpc->v, &gb);
62 case VC1_CODE_ENTRYPOINT:
63 ff_vc1_decode_entry_point(avctx, &vpc->v, &gb);
66 if(vpc->v.profile < PROFILE_ADVANCED)
67 ff_vc1_parse_frame_header (&vpc->v, &gb);
69 ff_vc1_parse_frame_header_adv(&vpc->v, &gb);
71 /* keep AV_PICTURE_TYPE_BI internal to VC1 */
72 if (vpc->v.s.pict_type == AV_PICTURE_TYPE_BI)
73 s->pict_type = AV_PICTURE_TYPE_B;
75 s->pict_type = vpc->v.s.pict_type;
77 if (avctx->ticks_per_frame > 1){
78 // process pulldown flags
80 // Pulldown flags are only valid when 'broadcast' has been set.
81 // So ticks_per_frame will be 2
85 }else if (vpc->v.rptfrm){
87 s->repeat_pict = vpc->v.rptfrm * 2 + 1;
99 * Find the end of the current frame in the bitstream.
100 * @return the position of the first byte of the next frame, or -1
102 static int vc1_find_frame_end(ParseContext *pc, const uint8_t *buf,
107 pic_found= pc->frame_start_found;
112 for(i=0; i<buf_size; i++){
113 state= (state<<8) | buf[i];
114 if(state == VC1_CODE_FRAME || state == VC1_CODE_FIELD){
123 /* EOF considered as end of frame */
126 for(; i<buf_size; i++){
127 state= (state<<8) | buf[i];
128 if(IS_MARKER(state) && state != VC1_CODE_FIELD && state != VC1_CODE_SLICE){
129 pc->frame_start_found=0;
135 pc->frame_start_found= pic_found;
137 return END_NOT_FOUND;
140 static int vc1_parse(AVCodecParserContext *s,
141 AVCodecContext *avctx,
142 const uint8_t **poutbuf, int *poutbuf_size,
143 const uint8_t *buf, int buf_size)
145 VC1ParseContext *vpc = s->priv_data;
148 if(s->flags & PARSER_FLAG_COMPLETE_FRAMES){
151 next= vc1_find_frame_end(&vpc->pc, buf, buf_size);
153 if (ff_combine_frame(&vpc->pc, next, &buf, &buf_size) < 0) {
160 vc1_extract_headers(s, avctx, buf, buf_size);
163 *poutbuf_size = buf_size;
167 static int vc1_split(AVCodecContext *avctx,
168 const uint8_t *buf, int buf_size)
174 for(i=0; i<buf_size; i++){
175 state= (state<<8) | buf[i];
176 if(IS_MARKER(state)){
177 if(state == VC1_CODE_SEQHDR || state == VC1_CODE_ENTRYPOINT){
187 static int vc1_parse_init(AVCodecParserContext *s)
189 VC1ParseContext *vpc = s->priv_data;
190 vpc->v.s.slice_context_count = 1;
191 return ff_vc1_init_common(&vpc->v);
194 AVCodecParser ff_vc1_parser = {
195 .codec_ids = { CODEC_ID_VC1 },
196 .priv_data_size = sizeof(VC1ParseContext),
197 .parser_init = vc1_parse_init,
198 .parser_parse = vc1_parse,
199 .parser_close = ff_parse_close,