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Diffstat (limited to 'contrib/ffmpeg/libavcodec/parser.c')
| -rw-r--r-- | contrib/ffmpeg/libavcodec/parser.c | 316 |
1 files changed, 316 insertions, 0 deletions
diff --git a/contrib/ffmpeg/libavcodec/parser.c b/contrib/ffmpeg/libavcodec/parser.c new file mode 100644 index 000000000..b0a6a2a1b --- /dev/null +++ b/contrib/ffmpeg/libavcodec/parser.c @@ -0,0 +1,316 @@ +/* + * Audio and Video frame extraction + * Copyright (c) 2003 Fabrice Bellard. + * Copyright (c) 2003 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 + */ + +#include "parser.h" + +AVCodecParser *av_first_parser = NULL; + +AVCodecParser* av_parser_next(AVCodecParser *p){ + if(p) return p->next; + else return av_first_parser; +} + +void av_register_codec_parser(AVCodecParser *parser) +{ + parser->next = av_first_parser; + av_first_parser = parser; +} + +AVCodecParserContext *av_parser_init(int codec_id) +{ + AVCodecParserContext *s; + AVCodecParser *parser; + int ret; + + if(codec_id == CODEC_ID_NONE) + return NULL; + + for(parser = av_first_parser; parser != NULL; parser = parser->next) { + if (parser->codec_ids[0] == codec_id || + parser->codec_ids[1] == codec_id || + parser->codec_ids[2] == codec_id || + parser->codec_ids[3] == codec_id || + parser->codec_ids[4] == codec_id) + goto found; + } + return NULL; + found: + s = av_mallocz(sizeof(AVCodecParserContext)); + if (!s) + return NULL; + s->parser = parser; + s->priv_data = av_mallocz(parser->priv_data_size); + if (!s->priv_data) { + av_free(s); + return NULL; + } + if (parser->parser_init) { + ret = parser->parser_init(s); + if (ret != 0) { + av_free(s->priv_data); + av_free(s); + return NULL; + } + } + s->fetch_timestamp=1; + s->pict_type = FF_I_TYPE; + return s; +} + +/** + * + * @param buf input + * @param buf_size input length, to signal EOF, this should be 0 (so that the last frame can be output) + * @param pts input presentation timestamp + * @param dts input decoding timestamp + * @param poutbuf will contain a pointer to the first byte of the output frame + * @param poutbuf_size will contain the length of the output frame + * @return the number of bytes of the input bitstream used + * + * Example: + * @code + * while(in_len){ + * len = av_parser_parse(myparser, AVCodecContext, &data, &size, + * in_data, in_len, + * pts, dts); + * in_data += len; + * in_len -= len; + * + * if(size) + * decode_frame(data, size); + * } + * @endcode + */ +int av_parser_parse(AVCodecParserContext *s, + AVCodecContext *avctx, + uint8_t **poutbuf, int *poutbuf_size, + const uint8_t *buf, int buf_size, + int64_t pts, int64_t dts) +{ + int index, i, k; + uint8_t dummy_buf[FF_INPUT_BUFFER_PADDING_SIZE]; + + if (buf_size == 0) { + /* padding is always necessary even if EOF, so we add it here */ + memset(dummy_buf, 0, sizeof(dummy_buf)); + buf = dummy_buf; + } else { + /* add a new packet descriptor */ + k = (s->cur_frame_start_index + 1) & (AV_PARSER_PTS_NB - 1); + s->cur_frame_start_index = k; + s->cur_frame_offset[k] = s->cur_offset; + s->cur_frame_pts[k] = pts; + s->cur_frame_dts[k] = dts; + + /* fill first PTS/DTS */ + if (s->fetch_timestamp){ + s->fetch_timestamp=0; + s->last_pts = pts; + s->last_dts = dts; + s->last_offset = 0; + s->cur_frame_pts[k] = + s->cur_frame_dts[k] = AV_NOPTS_VALUE; + } + } + + /* WARNING: the returned index can be negative */ + index = s->parser->parser_parse(s, avctx, (const uint8_t **)poutbuf, poutbuf_size, buf, buf_size); +//av_log(NULL, AV_LOG_DEBUG, "parser: in:%"PRId64", %"PRId64", out:%"PRId64", %"PRId64", in:%d out:%d id:%d\n", pts, dts, s->last_pts, s->last_dts, buf_size, *poutbuf_size, avctx->codec_id); + /* update the file pointer */ + if (*poutbuf_size) { + /* fill the data for the current frame */ + s->frame_offset = s->last_frame_offset; + s->pts = s->last_pts; + s->dts = s->last_dts; + s->offset = s->last_offset; + + /* offset of the next frame */ + s->last_frame_offset = s->cur_offset + index; + /* find the packet in which the new frame starts. It + is tricky because of MPEG video start codes + which can begin in one packet and finish in + another packet. In the worst case, an MPEG + video start code could be in 4 different + packets. */ + k = s->cur_frame_start_index; + for(i = 0; i < AV_PARSER_PTS_NB; i++) { + if (s->last_frame_offset >= s->cur_frame_offset[k]) + break; + k = (k - 1) & (AV_PARSER_PTS_NB - 1); + } + + s->last_pts = s->cur_frame_pts[k]; + s->last_dts = s->cur_frame_dts[k]; + s->last_offset = s->last_frame_offset - s->cur_frame_offset[k]; + + /* some parsers tell us the packet size even before seeing the first byte of the next packet, + so the next pts/dts is in the next chunk */ + if(index == buf_size){ + s->fetch_timestamp=1; + } + } + if (index < 0) + index = 0; + s->cur_offset += index; + return index; +} + +/** + * + * @return 0 if the output buffer is a subset of the input, 1 if it is allocated and must be freed + * @deprecated use AVBitstreamFilter + */ +int av_parser_change(AVCodecParserContext *s, + AVCodecContext *avctx, + uint8_t **poutbuf, int *poutbuf_size, + const uint8_t *buf, int buf_size, int keyframe){ + + if(s && s->parser->split){ + if((avctx->flags & CODEC_FLAG_GLOBAL_HEADER) || (avctx->flags2 & CODEC_FLAG2_LOCAL_HEADER)){ + int i= s->parser->split(avctx, buf, buf_size); + buf += i; + buf_size -= i; + } + } + + /* cast to avoid warning about discarding qualifiers */ + *poutbuf= (uint8_t *) buf; + *poutbuf_size= buf_size; + if(avctx->extradata){ + if( (keyframe && (avctx->flags2 & CODEC_FLAG2_LOCAL_HEADER)) + /*||(s->pict_type != I_TYPE && (s->flags & PARSER_FLAG_DUMP_EXTRADATA_AT_NOKEY))*/ + /*||(? && (s->flags & PARSER_FLAG_DUMP_EXTRADATA_AT_BEGIN)*/){ + int size= buf_size + avctx->extradata_size; + *poutbuf_size= size; + *poutbuf= av_malloc(size + FF_INPUT_BUFFER_PADDING_SIZE); + + memcpy(*poutbuf, avctx->extradata, avctx->extradata_size); + memcpy((*poutbuf) + avctx->extradata_size, buf, buf_size + FF_INPUT_BUFFER_PADDING_SIZE); + return 1; + } + } + + return 0; +} + +void av_parser_close(AVCodecParserContext *s) +{ + if (s->parser->parser_close) + s->parser->parser_close(s); + av_free(s->priv_data); + av_free(s); +} + +/*****************************************************/ + +/** + * combines the (truncated) bitstream to a complete frame + * @returns -1 if no complete frame could be created + */ +int ff_combine_frame(ParseContext *pc, int next, const uint8_t **buf, int *buf_size) +{ +#if 0 + if(pc->overread){ + printf("overread %d, state:%X next:%d index:%d o_index:%d\n", pc->overread, pc->state, next, pc->index, pc->overread_index); + printf("%X %X %X %X\n", (*buf)[0], (*buf)[1],(*buf)[2],(*buf)[3]); + } +#endif + + /* Copy overread bytes from last frame into buffer. */ + for(; pc->overread>0; pc->overread--){ + pc->buffer[pc->index++]= pc->buffer[pc->overread_index++]; + } + + /* flush remaining if EOF */ + if(!*buf_size && next == END_NOT_FOUND){ + next= 0; + } + + pc->last_index= pc->index; + + /* copy into buffer end return */ + if(next == END_NOT_FOUND){ + pc->buffer= av_fast_realloc(pc->buffer, &pc->buffer_size, (*buf_size) + pc->index + FF_INPUT_BUFFER_PADDING_SIZE); + + memcpy(&pc->buffer[pc->index], *buf, *buf_size); + pc->index += *buf_size; + return -1; + } + + *buf_size= + pc->overread_index= pc->index + next; + + /* append to buffer */ + if(pc->index){ + pc->buffer= av_fast_realloc(pc->buffer, &pc->buffer_size, next + pc->index + FF_INPUT_BUFFER_PADDING_SIZE); + + memcpy(&pc->buffer[pc->index], *buf, next + FF_INPUT_BUFFER_PADDING_SIZE ); + pc->index = 0; + *buf= pc->buffer; + } + + /* store overread bytes */ + for(;next < 0; next++){ + pc->state = (pc->state<<8) | pc->buffer[pc->last_index + next]; + pc->overread++; + } + +#if 0 + if(pc->overread){ + printf("overread %d, state:%X next:%d index:%d o_index:%d\n", pc->overread, pc->state, next, pc->index, pc->overread_index); + printf("%X %X %X %X\n", (*buf)[0], (*buf)[1],(*buf)[2],(*buf)[3]); + } +#endif + + return 0; +} + +void ff_parse_close(AVCodecParserContext *s) +{ + ParseContext *pc = s->priv_data; + + av_free(pc->buffer); +} + +void ff_parse1_close(AVCodecParserContext *s) +{ + ParseContext1 *pc1 = s->priv_data; + + av_free(pc1->pc.buffer); + av_free(pc1->enc); +} + +/*************************/ + +int ff_mpeg4video_split(AVCodecContext *avctx, + const uint8_t *buf, int buf_size) +{ + int i; + uint32_t state= -1; + + for(i=0; i<buf_size; i++){ + state= (state<<8) | buf[i]; + if(state == 0x1B3 || state == 0x1B6) + return i-3; + } + return 0; +} |