| /* |
| * VC-1 and WMV3 parser |
| * Copyright (c) 2006-2007 Konstantin Shishkov |
| * Partly based on vc9.c (c) 2005 Anonymous, Alex Beregszaszi, Michael Niedermayer |
| * |
| * This file is part of FFmpeg. |
| * |
| * FFmpeg is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU Lesser General Public |
| * License as published by the Free Software Foundation; either |
| * version 2.1 of the License, or (at your option) any later version. |
| * |
| * FFmpeg is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| * Lesser General Public License for more details. |
| * |
| * You should have received a copy of the GNU Lesser General Public |
| * License along with FFmpeg; if not, write to the Free Software |
| * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
| */ |
| |
| /** |
| * @file |
| * VC-1 and WMV3 parser |
| */ |
| |
| #include "parser.h" |
| #include "vc1.h" |
| #include "get_bits.h" |
| |
| typedef struct { |
| ParseContext pc; |
| VC1Context v; |
| } VC1ParseContext; |
| |
| static void vc1_extract_headers(AVCodecParserContext *s, AVCodecContext *avctx, |
| const uint8_t *buf, int buf_size) |
| { |
| VC1ParseContext *vpc = s->priv_data; |
| GetBitContext gb; |
| const uint8_t *start, *end, *next; |
| uint8_t *buf2 = av_mallocz(buf_size + FF_INPUT_BUFFER_PADDING_SIZE); |
| |
| vpc->v.s.avctx = avctx; |
| vpc->v.parse_only = 1; |
| next = buf; |
| s->repeat_pict = 0; |
| |
| for(start = buf, end = buf + buf_size; next < end; start = next){ |
| int buf2_size, size; |
| |
| next = find_next_marker(start + 4, end); |
| size = next - start - 4; |
| buf2_size = vc1_unescape_buffer(start + 4, size, buf2); |
| init_get_bits(&gb, buf2, buf2_size * 8); |
| if(size <= 0) continue; |
| switch(AV_RB32(start)){ |
| case VC1_CODE_SEQHDR: |
| ff_vc1_decode_sequence_header(avctx, &vpc->v, &gb); |
| break; |
| case VC1_CODE_ENTRYPOINT: |
| ff_vc1_decode_entry_point(avctx, &vpc->v, &gb); |
| break; |
| case VC1_CODE_FRAME: |
| if(vpc->v.profile < PROFILE_ADVANCED) |
| ff_vc1_parse_frame_header (&vpc->v, &gb); |
| else |
| ff_vc1_parse_frame_header_adv(&vpc->v, &gb); |
| |
| /* keep AV_PICTURE_TYPE_BI internal to VC1 */ |
| if (vpc->v.s.pict_type == AV_PICTURE_TYPE_BI) |
| s->pict_type = AV_PICTURE_TYPE_B; |
| else |
| s->pict_type = vpc->v.s.pict_type; |
| |
| if (avctx->ticks_per_frame > 1){ |
| // process pulldown flags |
| s->repeat_pict = 1; |
| // Pulldown flags are only valid when 'broadcast' has been set. |
| // So ticks_per_frame will be 2 |
| if (vpc->v.rff){ |
| // repeat field |
| s->repeat_pict = 2; |
| }else if (vpc->v.rptfrm){ |
| // repeat frames |
| s->repeat_pict = vpc->v.rptfrm * 2 + 1; |
| } |
| } |
| |
| break; |
| } |
| } |
| |
| av_free(buf2); |
| } |
| |
| /** |
| * Find the end of the current frame in the bitstream. |
| * @return the position of the first byte of the next frame, or -1 |
| */ |
| static int vc1_find_frame_end(ParseContext *pc, const uint8_t *buf, |
| int buf_size) { |
| int pic_found, i; |
| uint32_t state; |
| |
| pic_found= pc->frame_start_found; |
| state= pc->state; |
| |
| i=0; |
| if(!pic_found){ |
| for(i=0; i<buf_size; i++){ |
| state= (state<<8) | buf[i]; |
| if(state == VC1_CODE_FRAME || state == VC1_CODE_FIELD){ |
| i++; |
| pic_found=1; |
| break; |
| } |
| } |
| } |
| |
| if(pic_found){ |
| /* EOF considered as end of frame */ |
| if (buf_size == 0) |
| return 0; |
| for(; i<buf_size; i++){ |
| state= (state<<8) | buf[i]; |
| if(IS_MARKER(state) && state != VC1_CODE_FIELD && state != VC1_CODE_SLICE){ |
| pc->frame_start_found=0; |
| pc->state=-1; |
| return i-3; |
| } |
| } |
| } |
| pc->frame_start_found= pic_found; |
| pc->state= state; |
| return END_NOT_FOUND; |
| } |
| |
| static int vc1_parse(AVCodecParserContext *s, |
| AVCodecContext *avctx, |
| const uint8_t **poutbuf, int *poutbuf_size, |
| const uint8_t *buf, int buf_size) |
| { |
| VC1ParseContext *vpc = s->priv_data; |
| int next; |
| |
| if(s->flags & PARSER_FLAG_COMPLETE_FRAMES){ |
| next= buf_size; |
| }else{ |
| next= vc1_find_frame_end(&vpc->pc, buf, buf_size); |
| |
| if (ff_combine_frame(&vpc->pc, next, &buf, &buf_size) < 0) { |
| *poutbuf = NULL; |
| *poutbuf_size = 0; |
| return buf_size; |
| } |
| } |
| |
| vc1_extract_headers(s, avctx, buf, buf_size); |
| |
| *poutbuf = buf; |
| *poutbuf_size = buf_size; |
| return next; |
| } |
| |
| static int vc1_split(AVCodecContext *avctx, |
| const uint8_t *buf, int buf_size) |
| { |
| int i; |
| uint32_t state= -1; |
| int charged=0; |
| |
| for(i=0; i<buf_size; i++){ |
| state= (state<<8) | buf[i]; |
| if(IS_MARKER(state)){ |
| if(state == VC1_CODE_SEQHDR || state == VC1_CODE_ENTRYPOINT){ |
| charged=1; |
| }else if(charged){ |
| return i-3; |
| } |
| } |
| } |
| return 0; |
| } |
| |
| static int vc1_parse_init(AVCodecParserContext *s) |
| { |
| VC1ParseContext *vpc = s->priv_data; |
| vpc->v.s.slice_context_count = 1; |
| return ff_vc1_init_common(&vpc->v); |
| } |
| |
| AVCodecParser ff_vc1_parser = { |
| .codec_ids = { AV_CODEC_ID_VC1 }, |
| .priv_data_size = sizeof(VC1ParseContext), |
| .parser_init = vc1_parse_init, |
| .parser_parse = vc1_parse, |
| .parser_close = ff_parse_close, |
| .split = vc1_split, |
| }; |