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* Copyright (c) 2006-2007 Konstantin Shishkov
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* Partly based on vc9.c (c) 2005 Anonymous, Alex Beregszaszi, Michael Niedermayer
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* This file is part of FFmpeg.
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* FFmpeg is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2.1 of the License, or (at your option) any later version.
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* FFmpeg is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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* You should have received a copy of the GNU Lesser General Public
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* License along with FFmpeg; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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* VC-1 and WMV3 parser
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static void vc1_extract_headers(AVCodecParserContext *s, AVCodecContext *avctx,
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const uint8_t *buf, int buf_size)
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VC1ParseContext *vpc = s->priv_data;
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const uint8_t *start, *end, *next;
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uint8_t *buf2 = av_mallocz(buf_size + FF_INPUT_BUFFER_PADDING_SIZE);
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vpc->v.s.avctx = avctx;
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vpc->v.parse_only = 1;
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for(start = buf, end = buf + buf_size; next < end; start = next){
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next = find_next_marker(start + 4, end);
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size = next - start - 4;
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buf2_size = vc1_unescape_buffer(start + 4, size, buf2);
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init_get_bits(&gb, buf2, buf2_size * 8);
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if(size <= 0) continue;
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switch(AV_RB32(start)){
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vc1_decode_sequence_header(avctx, &vpc->v, &gb);
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case VC1_CODE_ENTRYPOINT:
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vc1_decode_entry_point(avctx, &vpc->v, &gb);
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if(vpc->v.profile < PROFILE_ADVANCED)
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vc1_parse_frame_header (&vpc->v, &gb);
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vc1_parse_frame_header_adv(&vpc->v, &gb);
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/* keep FF_BI_TYPE internal to VC1 */
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if (vpc->v.s.pict_type == FF_BI_TYPE)
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s->pict_type = FF_B_TYPE;
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s->pict_type = vpc->v.s.pict_type;
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* finds the end of the current frame in the bitstream.
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* @return the position of the first byte of the next frame, or -1
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static int vc1_find_frame_end(ParseContext *pc, const uint8_t *buf,
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pic_found= pc->frame_start_found;
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for(i=0; i<buf_size; i++){
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state= (state<<8) | buf[i];
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if(state == VC1_CODE_FRAME || state == VC1_CODE_FIELD){
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/* EOF considered as end of frame */
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for(; i<buf_size; i++){
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state= (state<<8) | buf[i];
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if(IS_MARKER(state) && state != VC1_CODE_FIELD && state != VC1_CODE_SLICE){
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pc->frame_start_found=0;
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pc->frame_start_found= pic_found;
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return END_NOT_FOUND;
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static int vc1_parse(AVCodecParserContext *s,
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AVCodecContext *avctx,
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const uint8_t **poutbuf, int *poutbuf_size,
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const uint8_t *buf, int buf_size)
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VC1ParseContext *vpc = s->priv_data;
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if(s->flags & PARSER_FLAG_COMPLETE_FRAMES){
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next= vc1_find_frame_end(&vpc->pc, buf, buf_size);
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if (ff_combine_frame(&vpc->pc, next, &buf, &buf_size) < 0) {
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vc1_extract_headers(s, avctx, buf, buf_size);
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*poutbuf_size = buf_size;
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static int vc1_split(AVCodecContext *avctx,
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const uint8_t *buf, int buf_size)
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for(i=0; i<buf_size; i++){
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state= (state<<8) | buf[i];
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if(IS_MARKER(state)){
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if(state == VC1_CODE_SEQHDR || state == VC1_CODE_ENTRYPOINT){
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AVCodecParser vc1_parser = {
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sizeof(VC1ParseContext),