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 Libav.
8 * Libav 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 * Libav 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 Libav; 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
28 #include "libavutil/attributes.h"
38 static void vc1_extract_headers(AVCodecParserContext *s, AVCodecContext *avctx,
39 const uint8_t *buf, int buf_size)
41 VC1ParseContext *vpc = s->priv_data;
43 const uint8_t *start, *end, *next;
44 uint8_t *buf2 = av_mallocz(buf_size + FF_INPUT_BUFFER_PADDING_SIZE);
46 vpc->v.s.avctx = avctx;
47 vpc->v.parse_only = 1;
51 for(start = buf, end = buf + buf_size; next < end; start = next){
54 next = find_next_marker(start + 4, end);
55 size = next - start - 4;
56 buf2_size = vc1_unescape_buffer(start + 4, size, buf2);
57 init_get_bits(&gb, buf2, buf2_size * 8);
58 if(size <= 0) continue;
59 switch(AV_RB32(start)){
61 ff_vc1_decode_sequence_header(avctx, &vpc->v, &gb);
63 case VC1_CODE_ENTRYPOINT:
64 ff_vc1_decode_entry_point(avctx, &vpc->v, &gb);
67 if(vpc->v.profile < PROFILE_ADVANCED)
68 ff_vc1_parse_frame_header (&vpc->v, &gb);
70 ff_vc1_parse_frame_header_adv(&vpc->v, &gb);
72 /* keep AV_PICTURE_TYPE_BI internal to VC1 */
73 if (vpc->v.s.pict_type == AV_PICTURE_TYPE_BI)
74 s->pict_type = AV_PICTURE_TYPE_B;
76 s->pict_type = vpc->v.s.pict_type;
78 if (avctx->ticks_per_frame > 1){
79 // process pulldown flags
81 // Pulldown flags are only valid when 'broadcast' has been set.
82 // So ticks_per_frame will be 2
86 }else if (vpc->v.rptfrm){
88 s->repeat_pict = vpc->v.rptfrm * 2 + 1;
92 if (vpc->v.broadcast && vpc->v.interlace && !vpc->v.psf)
93 s->field_order = vpc->v.tff ? AV_FIELD_TT : AV_FIELD_BB;
95 s->field_order = AV_FIELD_PROGRESSIVE;
105 * Find the end of the current frame in the bitstream.
106 * @return the position of the first byte of the next frame, or -1
108 static int vc1_find_frame_end(ParseContext *pc, const uint8_t *buf,
113 pic_found= pc->frame_start_found;
118 for(i=0; i<buf_size; i++){
119 state= (state<<8) | buf[i];
120 if(state == VC1_CODE_FRAME || state == VC1_CODE_FIELD){
129 /* EOF considered as end of frame */
132 for(; i<buf_size; i++){
133 state= (state<<8) | buf[i];
134 if(IS_MARKER(state) && state != VC1_CODE_FIELD && state != VC1_CODE_SLICE){
135 pc->frame_start_found=0;
141 pc->frame_start_found= pic_found;
143 return END_NOT_FOUND;
146 static int vc1_parse(AVCodecParserContext *s,
147 AVCodecContext *avctx,
148 const uint8_t **poutbuf, int *poutbuf_size,
149 const uint8_t *buf, int buf_size)
151 VC1ParseContext *vpc = s->priv_data;
154 if(s->flags & PARSER_FLAG_COMPLETE_FRAMES){
157 next= vc1_find_frame_end(&vpc->pc, buf, buf_size);
159 if (ff_combine_frame(&vpc->pc, next, &buf, &buf_size) < 0) {
166 vc1_extract_headers(s, avctx, buf, buf_size);
169 *poutbuf_size = buf_size;
173 static int vc1_split(AVCodecContext *avctx,
174 const uint8_t *buf, int buf_size)
180 for(i=0; i<buf_size; i++){
181 state= (state<<8) | buf[i];
182 if(IS_MARKER(state)){
183 if(state == VC1_CODE_SEQHDR || state == VC1_CODE_ENTRYPOINT){
193 static av_cold int vc1_parse_init(AVCodecParserContext *s)
195 VC1ParseContext *vpc = s->priv_data;
196 vpc->v.s.slice_context_count = 1;
197 return ff_vc1_init_common(&vpc->v);
200 AVCodecParser ff_vc1_parser = {
201 .codec_ids = { AV_CODEC_ID_VC1 },
202 .priv_data_size = sizeof(VC1ParseContext),
203 .parser_init = vc1_parse_init,
204 .parser_parse = vc1_parse,
205 .parser_close = ff_parse_close,