diff options
Diffstat (limited to 'ffmpeg/libavcodec/vc1_parser.c')
| -rw-r--r-- | ffmpeg/libavcodec/vc1_parser.c | 201 |
1 files changed, 201 insertions, 0 deletions
diff --git a/ffmpeg/libavcodec/vc1_parser.c b/ffmpeg/libavcodec/vc1_parser.c new file mode 100644 index 0000000..53af61c --- /dev/null +++ b/ffmpeg/libavcodec/vc1_parser.c @@ -0,0 +1,201 @@ +/* + * 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, +}; |