diff options
Diffstat (limited to 'ffmpeg1/libavcodec/h263_parser.c')
| -rw-r--r-- | ffmpeg1/libavcodec/h263_parser.c | 95 |
1 files changed, 95 insertions, 0 deletions
diff --git a/ffmpeg1/libavcodec/h263_parser.c b/ffmpeg1/libavcodec/h263_parser.c new file mode 100644 index 0000000..2e7d493 --- /dev/null +++ b/ffmpeg1/libavcodec/h263_parser.c @@ -0,0 +1,95 @@ +/* + * H.263 parser + * Copyright (c) 2002-2004 Michael Niedermayer <michaelni@gmx.at> + * + * 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 + * H.263 parser + */ + +#include "parser.h" +#include "h263_parser.h" + +int ff_h263_find_frame_end(ParseContext *pc, const uint8_t *buf, int buf_size){ + int vop_found, i; + uint32_t state; + + vop_found= pc->frame_start_found; + state= pc->state; + + i=0; + if(!vop_found){ + for(i=0; i<buf_size; i++){ + state= (state<<8) | buf[i]; + if(state>>(32-22) == 0x20){ + i++; + vop_found=1; + break; + } + } + } + + if(vop_found){ + for(; i<buf_size; i++){ + state= (state<<8) | buf[i]; + if(state>>(32-22) == 0x20){ + pc->frame_start_found=0; + pc->state=-1; + return i-3; + } + } + } + pc->frame_start_found= vop_found; + pc->state= state; + + return END_NOT_FOUND; +} + +static int h263_parse(AVCodecParserContext *s, + AVCodecContext *avctx, + const uint8_t **poutbuf, int *poutbuf_size, + const uint8_t *buf, int buf_size) +{ + ParseContext *pc = s->priv_data; + int next; + + if (s->flags & PARSER_FLAG_COMPLETE_FRAMES) { + next = buf_size; + } else { + next= ff_h263_find_frame_end(pc, buf, buf_size); + + if (ff_combine_frame(pc, next, &buf, &buf_size) < 0) { + *poutbuf = NULL; + *poutbuf_size = 0; + return buf_size; + } + } + + *poutbuf = buf; + *poutbuf_size = buf_size; + return next; +} + +AVCodecParser ff_h263_parser = { + .codec_ids = { AV_CODEC_ID_H263 }, + .priv_data_size = sizeof(ParseContext), + .parser_parse = h263_parse, + .parser_close = ff_parse_close, +}; |
