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796 lines
25 KiB
796 lines
25 KiB
/* |
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* Audio and Video frame extraction |
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* Copyright (c) 2003 Fabrice Bellard. |
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* Copyright (c) 2003 Michael Niedermayer. |
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* |
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* This library 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 of the License, or (at your option) any later version. |
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* |
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* This library 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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* |
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* You should have received a copy of the GNU Lesser General Public |
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* License along with this library; if not, write to the Free Software |
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
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*/ |
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#include "avcodec.h" |
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#include "mpegvideo.h" |
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#include "mpegaudio.h" |
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|
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AVCodecParser *av_first_parser = NULL; |
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|
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void av_register_codec_parser(AVCodecParser *parser) |
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{ |
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parser->next = av_first_parser; |
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av_first_parser = parser; |
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} |
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|
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AVCodecParserContext *av_parser_init(int codec_id) |
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{ |
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AVCodecParserContext *s; |
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AVCodecParser *parser; |
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int ret; |
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|
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if(codec_id == CODEC_ID_NONE) |
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return NULL; |
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|
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for(parser = av_first_parser; parser != NULL; parser = parser->next) { |
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if (parser->codec_ids[0] == codec_id || |
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parser->codec_ids[1] == codec_id || |
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parser->codec_ids[2] == codec_id || |
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parser->codec_ids[3] == codec_id || |
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parser->codec_ids[4] == codec_id) |
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goto found; |
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} |
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return NULL; |
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found: |
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s = av_mallocz(sizeof(AVCodecParserContext)); |
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if (!s) |
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return NULL; |
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s->parser = parser; |
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s->priv_data = av_mallocz(parser->priv_data_size); |
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if (!s->priv_data) { |
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av_free(s); |
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return NULL; |
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} |
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if (parser->parser_init) { |
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ret = parser->parser_init(s); |
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if (ret != 0) { |
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av_free(s->priv_data); |
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av_free(s); |
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return NULL; |
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} |
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} |
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s->fetch_timestamp=1; |
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return s; |
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} |
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|
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/* NOTE: buf_size == 0 is used to signal EOF so that the last frame |
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can be returned if necessary */ |
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int av_parser_parse(AVCodecParserContext *s, |
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AVCodecContext *avctx, |
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uint8_t **poutbuf, int *poutbuf_size, |
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const uint8_t *buf, int buf_size, |
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int64_t pts, int64_t dts) |
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{ |
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int index, i, k; |
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uint8_t dummy_buf[FF_INPUT_BUFFER_PADDING_SIZE]; |
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|
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if (buf_size == 0) { |
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/* padding is always necessary even if EOF, so we add it here */ |
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memset(dummy_buf, 0, sizeof(dummy_buf)); |
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buf = dummy_buf; |
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} else { |
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/* add a new packet descriptor */ |
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k = (s->cur_frame_start_index + 1) & (AV_PARSER_PTS_NB - 1); |
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s->cur_frame_start_index = k; |
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s->cur_frame_offset[k] = s->cur_offset; |
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s->cur_frame_pts[k] = pts; |
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s->cur_frame_dts[k] = dts; |
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|
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/* fill first PTS/DTS */ |
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if (s->fetch_timestamp){ |
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s->fetch_timestamp=0; |
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s->last_pts = pts; |
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s->last_dts = dts; |
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s->cur_frame_pts[k] = |
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s->cur_frame_dts[k] = AV_NOPTS_VALUE; |
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} |
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} |
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|
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/* WARNING: the returned index can be negative */ |
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index = s->parser->parser_parse(s, avctx, poutbuf, poutbuf_size, buf, buf_size); |
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//av_log(NULL, AV_LOG_DEBUG, "parser: in:%lld, %lld, out:%lld, %lld, in:%d out:%d id:%d\n", pts, dts, s->last_pts, s->last_dts, buf_size, *poutbuf_size, avctx->codec_id); |
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/* update the file pointer */ |
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if (*poutbuf_size) { |
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/* fill the data for the current frame */ |
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s->frame_offset = s->last_frame_offset; |
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s->pts = s->last_pts; |
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s->dts = s->last_dts; |
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|
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/* offset of the next frame */ |
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s->last_frame_offset = s->cur_offset + index; |
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/* find the packet in which the new frame starts. It |
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is tricky because of MPEG video start codes |
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which can begin in one packet and finish in |
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another packet. In the worst case, an MPEG |
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video start code could be in 4 different |
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packets. */ |
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k = s->cur_frame_start_index; |
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for(i = 0; i < AV_PARSER_PTS_NB; i++) { |
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if (s->last_frame_offset >= s->cur_frame_offset[k]) |
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break; |
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k = (k - 1) & (AV_PARSER_PTS_NB - 1); |
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} |
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|
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s->last_pts = s->cur_frame_pts[k]; |
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s->last_dts = s->cur_frame_dts[k]; |
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|
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/* some parsers tell us the packet size even before seeing the first byte of the next packet, |
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so the next pts/dts is in the next chunk */ |
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if(index == buf_size){ |
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s->fetch_timestamp=1; |
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} |
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} |
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if (index < 0) |
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index = 0; |
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s->cur_offset += index; |
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return index; |
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} |
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|
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void av_parser_close(AVCodecParserContext *s) |
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{ |
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if (s->parser->parser_close) |
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s->parser->parser_close(s); |
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av_free(s->priv_data); |
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av_free(s); |
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} |
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|
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/*****************************************************/ |
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|
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//#define END_NOT_FOUND (-100) |
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|
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#define PICTURE_START_CODE 0x00000100 |
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#define SEQ_START_CODE 0x000001b3 |
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#define EXT_START_CODE 0x000001b5 |
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#define SLICE_MIN_START_CODE 0x00000101 |
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#define SLICE_MAX_START_CODE 0x000001af |
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typedef struct ParseContext1{ |
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ParseContext pc; |
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/* XXX/FIXME PC1 vs. PC */ |
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/* MPEG2 specific */ |
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int frame_rate; |
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int progressive_sequence; |
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int width, height; |
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|
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/* XXX: suppress that, needed by MPEG4 */ |
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MpegEncContext *enc; |
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int first_picture; |
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} ParseContext1; |
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|
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/** |
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* combines the (truncated) bitstream to a complete frame |
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* @returns -1 if no complete frame could be created |
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*/ |
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int ff_combine_frame(ParseContext *pc, int next, uint8_t **buf, int *buf_size) |
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{ |
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#if 0 |
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if(pc->overread){ |
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printf("overread %d, state:%X next:%d index:%d o_index:%d\n", pc->overread, pc->state, next, pc->index, pc->overread_index); |
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printf("%X %X %X %X\n", (*buf)[0], (*buf)[1],(*buf)[2],(*buf)[3]); |
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} |
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#endif |
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|
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/* copy overreaded bytes from last frame into buffer */ |
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for(; pc->overread>0; pc->overread--){ |
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pc->buffer[pc->index++]= pc->buffer[pc->overread_index++]; |
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} |
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|
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/* flush remaining if EOF */ |
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if(!*buf_size && next == END_NOT_FOUND){ |
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next= 0; |
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} |
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pc->last_index= pc->index; |
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|
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/* copy into buffer end return */ |
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if(next == END_NOT_FOUND){ |
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pc->buffer= av_fast_realloc(pc->buffer, &pc->buffer_size, (*buf_size) + pc->index + FF_INPUT_BUFFER_PADDING_SIZE); |
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|
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memcpy(&pc->buffer[pc->index], *buf, *buf_size); |
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pc->index += *buf_size; |
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return -1; |
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} |
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*buf_size= |
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pc->overread_index= pc->index + next; |
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|
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/* append to buffer */ |
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if(pc->index){ |
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pc->buffer= av_fast_realloc(pc->buffer, &pc->buffer_size, next + pc->index + FF_INPUT_BUFFER_PADDING_SIZE); |
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|
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memcpy(&pc->buffer[pc->index], *buf, next + FF_INPUT_BUFFER_PADDING_SIZE ); |
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pc->index = 0; |
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*buf= pc->buffer; |
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} |
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|
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/* store overread bytes */ |
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for(;next < 0; next++){ |
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pc->state = (pc->state<<8) | pc->buffer[pc->last_index + next]; |
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pc->overread++; |
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} |
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#if 0 |
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if(pc->overread){ |
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printf("overread %d, state:%X next:%d index:%d o_index:%d\n", pc->overread, pc->state, next, pc->index, pc->overread_index); |
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printf("%X %X %X %X\n", (*buf)[0], (*buf)[1],(*buf)[2],(*buf)[3]); |
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} |
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#endif |
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return 0; |
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} |
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static int find_start_code(const uint8_t **pbuf_ptr, const uint8_t *buf_end) |
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{ |
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const uint8_t *buf_ptr; |
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unsigned int state=0xFFFFFFFF, v; |
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int val; |
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buf_ptr = *pbuf_ptr; |
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while (buf_ptr < buf_end) { |
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v = *buf_ptr++; |
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if (state == 0x000001) { |
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state = ((state << 8) | v) & 0xffffff; |
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val = state; |
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goto found; |
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} |
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state = ((state << 8) | v) & 0xffffff; |
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} |
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val = -1; |
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found: |
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*pbuf_ptr = buf_ptr; |
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return val; |
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} |
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/* XXX: merge with libavcodec ? */ |
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#define MPEG1_FRAME_RATE_BASE 1001 |
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|
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static const int frame_rate_tab[16] = { |
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0, |
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24000, |
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24024, |
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25025, |
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30000, |
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30030, |
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50050, |
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60000, |
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60060, |
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// Xing's 15fps: (9) |
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15015, |
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// libmpeg3's "Unofficial economy rates": (10-13) |
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5005, |
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10010, |
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12012, |
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15015, |
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// random, just to avoid segfault !never encode these |
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25025, |
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25025, |
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}; |
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static void mpegvideo_extract_headers(AVCodecParserContext *s, |
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AVCodecContext *avctx, |
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const uint8_t *buf, int buf_size) |
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{ |
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ParseContext1 *pc = s->priv_data; |
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const uint8_t *buf_end; |
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int32_t start_code; |
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int frame_rate_index, ext_type, bytes_left; |
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int frame_rate_ext_n, frame_rate_ext_d; |
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int picture_structure, top_field_first, repeat_first_field, progressive_frame; |
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int horiz_size_ext, vert_size_ext, bit_rate_ext; |
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s->repeat_pict = 0; |
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buf_end = buf + buf_size; |
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while (buf < buf_end) { |
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start_code = find_start_code(&buf, buf_end); |
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bytes_left = buf_end - buf; |
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switch(start_code) { |
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case PICTURE_START_CODE: |
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if (bytes_left >= 2) { |
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s->pict_type = (buf[1] >> 3) & 7; |
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} |
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break; |
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case SEQ_START_CODE: |
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if (bytes_left >= 7) { |
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pc->width = (buf[0] << 4) | (buf[1] >> 4); |
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pc->height = ((buf[1] & 0x0f) << 8) | buf[2]; |
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avcodec_set_dimensions(avctx, pc->width, pc->height); |
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frame_rate_index = buf[3] & 0xf; |
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pc->frame_rate = avctx->frame_rate = frame_rate_tab[frame_rate_index]; |
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avctx->frame_rate_base = MPEG1_FRAME_RATE_BASE; |
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avctx->bit_rate = ((buf[4]<<10) | (buf[5]<<2) | (buf[6]>>6))*400; |
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avctx->codec_id = CODEC_ID_MPEG1VIDEO; |
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avctx->sub_id = 1; |
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} |
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break; |
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case EXT_START_CODE: |
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if (bytes_left >= 1) { |
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ext_type = (buf[0] >> 4); |
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switch(ext_type) { |
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case 0x1: /* sequence extension */ |
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if (bytes_left >= 6) { |
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horiz_size_ext = ((buf[1] & 1) << 1) | (buf[2] >> 7); |
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vert_size_ext = (buf[2] >> 5) & 3; |
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bit_rate_ext = ((buf[2] & 0x1F)<<7) | (buf[3]>>1); |
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frame_rate_ext_n = (buf[5] >> 5) & 3; |
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frame_rate_ext_d = (buf[5] & 0x1f); |
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pc->progressive_sequence = buf[1] & (1 << 3); |
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avctx->has_b_frames= buf[5] >> 7; |
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|
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pc->width |=(horiz_size_ext << 12); |
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pc->height |=( vert_size_ext << 12); |
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avctx->bit_rate += (bit_rate_ext << 18) * 400; |
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avcodec_set_dimensions(avctx, pc->width, pc->height); |
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avctx->frame_rate = pc->frame_rate * (frame_rate_ext_n + 1); |
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avctx->frame_rate_base = MPEG1_FRAME_RATE_BASE * (frame_rate_ext_d + 1); |
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avctx->codec_id = CODEC_ID_MPEG2VIDEO; |
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avctx->sub_id = 2; /* forces MPEG2 */ |
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} |
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break; |
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case 0x8: /* picture coding extension */ |
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if (bytes_left >= 5) { |
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picture_structure = buf[2]&3; |
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top_field_first = buf[3] & (1 << 7); |
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repeat_first_field = buf[3] & (1 << 1); |
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progressive_frame = buf[4] & (1 << 7); |
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|
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/* check if we must repeat the frame */ |
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if (repeat_first_field) { |
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if (pc->progressive_sequence) { |
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if (top_field_first) |
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s->repeat_pict = 4; |
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else |
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s->repeat_pict = 2; |
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} else if (progressive_frame) { |
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s->repeat_pict = 1; |
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} |
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} |
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|
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/* the packet only represents half a frame |
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XXX,FIXME maybe find a different solution */ |
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if(picture_structure != 3) |
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s->repeat_pict = -1; |
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} |
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break; |
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} |
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} |
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break; |
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case -1: |
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goto the_end; |
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default: |
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/* we stop parsing when we encounter a slice. It ensures |
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that this function takes a negligible amount of time */ |
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if (start_code >= SLICE_MIN_START_CODE && |
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start_code <= SLICE_MAX_START_CODE) |
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goto the_end; |
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break; |
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} |
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} |
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the_end: ; |
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} |
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|
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static int mpegvideo_parse(AVCodecParserContext *s, |
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AVCodecContext *avctx, |
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uint8_t **poutbuf, int *poutbuf_size, |
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const uint8_t *buf, int buf_size) |
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{ |
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ParseContext1 *pc1 = s->priv_data; |
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ParseContext *pc= &pc1->pc; |
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int next; |
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|
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next= ff_mpeg1_find_frame_end(pc, buf, buf_size); |
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|
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if (ff_combine_frame(pc, next, (uint8_t **)&buf, &buf_size) < 0) { |
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*poutbuf = NULL; |
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*poutbuf_size = 0; |
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return buf_size; |
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} |
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/* we have a full frame : we just parse the first few MPEG headers |
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to have the full timing information. The time take by this |
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function should be negligible for uncorrupted streams */ |
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mpegvideo_extract_headers(s, avctx, buf, buf_size); |
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#if 0 |
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printf("pict_type=%d frame_rate=%0.3f repeat_pict=%d\n", |
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s->pict_type, (double)avctx->frame_rate / avctx->frame_rate_base, s->repeat_pict); |
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#endif |
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|
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*poutbuf = (uint8_t *)buf; |
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*poutbuf_size = buf_size; |
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return next; |
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} |
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|
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void ff_parse_close(AVCodecParserContext *s) |
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{ |
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ParseContext *pc = s->priv_data; |
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|
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av_free(pc->buffer); |
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} |
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|
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static void parse1_close(AVCodecParserContext *s) |
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{ |
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ParseContext1 *pc1 = s->priv_data; |
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|
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av_free(pc1->pc.buffer); |
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av_free(pc1->enc); |
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} |
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|
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/*************************/ |
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|
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/* used by parser */ |
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/* XXX: make it use less memory */ |
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static int av_mpeg4_decode_header(AVCodecParserContext *s1, |
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AVCodecContext *avctx, |
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const uint8_t *buf, int buf_size) |
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{ |
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ParseContext1 *pc = s1->priv_data; |
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MpegEncContext *s = pc->enc; |
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GetBitContext gb1, *gb = &gb1; |
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int ret; |
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|
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s->avctx = avctx; |
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s->current_picture_ptr = &s->current_picture; |
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|
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if (avctx->extradata_size && pc->first_picture){ |
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init_get_bits(gb, avctx->extradata, avctx->extradata_size*8); |
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ret = ff_mpeg4_decode_picture_header(s, gb); |
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} |
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|
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init_get_bits(gb, buf, 8 * buf_size); |
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ret = ff_mpeg4_decode_picture_header(s, gb); |
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if (s->width) { |
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avcodec_set_dimensions(avctx, s->width, s->height); |
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} |
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pc->first_picture = 0; |
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return ret; |
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} |
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|
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static int mpeg4video_parse_init(AVCodecParserContext *s) |
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{ |
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ParseContext1 *pc = s->priv_data; |
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|
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pc->enc = av_mallocz(sizeof(MpegEncContext)); |
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if (!pc->enc) |
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return -1; |
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pc->first_picture = 1; |
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return 0; |
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} |
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|
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static int mpeg4video_parse(AVCodecParserContext *s, |
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AVCodecContext *avctx, |
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uint8_t **poutbuf, int *poutbuf_size, |
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const uint8_t *buf, int buf_size) |
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{ |
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ParseContext *pc = s->priv_data; |
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int next; |
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|
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next= ff_mpeg4_find_frame_end(pc, buf, buf_size); |
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|
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if (ff_combine_frame(pc, next, (uint8_t **)&buf, &buf_size) < 0) { |
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*poutbuf = NULL; |
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*poutbuf_size = 0; |
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return buf_size; |
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} |
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av_mpeg4_decode_header(s, avctx, buf, buf_size); |
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|
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*poutbuf = (uint8_t *)buf; |
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*poutbuf_size = buf_size; |
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return next; |
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} |
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|
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/*************************/ |
|
|
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typedef struct MpegAudioParseContext { |
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uint8_t inbuf[MPA_MAX_CODED_FRAME_SIZE]; /* input buffer */ |
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uint8_t *inbuf_ptr; |
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int frame_size; |
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int free_format_frame_size; |
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int free_format_next_header; |
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uint32_t header; |
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int header_count; |
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} MpegAudioParseContext; |
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|
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#define MPA_HEADER_SIZE 4 |
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|
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/* header + layer + bitrate + freq + lsf/mpeg25 */ |
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#undef SAME_HEADER_MASK /* mpegaudio.h defines different version */ |
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#define SAME_HEADER_MASK \ |
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(0xffe00000 | (3 << 17) | (3 << 10) | (3 << 19)) |
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|
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static int mpegaudio_parse_init(AVCodecParserContext *s1) |
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{ |
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MpegAudioParseContext *s = s1->priv_data; |
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s->inbuf_ptr = s->inbuf; |
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return 0; |
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} |
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|
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static int mpegaudio_parse(AVCodecParserContext *s1, |
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AVCodecContext *avctx, |
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uint8_t **poutbuf, int *poutbuf_size, |
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const uint8_t *buf, int buf_size) |
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{ |
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MpegAudioParseContext *s = s1->priv_data; |
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int len, ret, sr; |
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uint32_t header; |
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const uint8_t *buf_ptr; |
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|
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*poutbuf = NULL; |
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*poutbuf_size = 0; |
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buf_ptr = buf; |
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while (buf_size > 0) { |
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len = s->inbuf_ptr - s->inbuf; |
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if (s->frame_size == 0) { |
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/* special case for next header for first frame in free |
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format case (XXX: find a simpler method) */ |
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if (s->free_format_next_header != 0) { |
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s->inbuf[0] = s->free_format_next_header >> 24; |
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s->inbuf[1] = s->free_format_next_header >> 16; |
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s->inbuf[2] = s->free_format_next_header >> 8; |
|
s->inbuf[3] = s->free_format_next_header; |
|
s->inbuf_ptr = s->inbuf + 4; |
|
s->free_format_next_header = 0; |
|
goto got_header; |
|
} |
|
/* no header seen : find one. We need at least MPA_HEADER_SIZE |
|
bytes to parse it */ |
|
len = MPA_HEADER_SIZE - len; |
|
if (len > buf_size) |
|
len = buf_size; |
|
if (len > 0) { |
|
memcpy(s->inbuf_ptr, buf_ptr, len); |
|
buf_ptr += len; |
|
buf_size -= len; |
|
s->inbuf_ptr += len; |
|
} |
|
if ((s->inbuf_ptr - s->inbuf) >= MPA_HEADER_SIZE) { |
|
got_header: |
|
sr= avctx->sample_rate; |
|
header = (s->inbuf[0] << 24) | (s->inbuf[1] << 16) | |
|
(s->inbuf[2] << 8) | s->inbuf[3]; |
|
|
|
ret = mpa_decode_header(avctx, header); |
|
if (ret < 0) { |
|
s->header_count= -2; |
|
/* no sync found : move by one byte (inefficient, but simple!) */ |
|
memmove(s->inbuf, s->inbuf + 1, s->inbuf_ptr - s->inbuf - 1); |
|
s->inbuf_ptr--; |
|
dprintf("skip %x\n", header); |
|
/* reset free format frame size to give a chance |
|
to get a new bitrate */ |
|
s->free_format_frame_size = 0; |
|
} else { |
|
if((header&SAME_HEADER_MASK) != (s->header&SAME_HEADER_MASK) && s->header) |
|
s->header_count= -3; |
|
s->header= header; |
|
s->header_count++; |
|
s->frame_size = ret; |
|
|
|
#if 0 |
|
/* free format: prepare to compute frame size */ |
|
if (decode_header(s, header) == 1) { |
|
s->frame_size = -1; |
|
} |
|
#endif |
|
} |
|
if(s->header_count <= 0) |
|
avctx->sample_rate= sr; //FIXME ugly |
|
} |
|
} else |
|
#if 0 |
|
if (s->frame_size == -1) { |
|
/* free format : find next sync to compute frame size */ |
|
len = MPA_MAX_CODED_FRAME_SIZE - len; |
|
if (len > buf_size) |
|
len = buf_size; |
|
if (len == 0) { |
|
/* frame too long: resync */ |
|
s->frame_size = 0; |
|
memmove(s->inbuf, s->inbuf + 1, s->inbuf_ptr - s->inbuf - 1); |
|
s->inbuf_ptr--; |
|
} else { |
|
uint8_t *p, *pend; |
|
uint32_t header1; |
|
int padding; |
|
|
|
memcpy(s->inbuf_ptr, buf_ptr, len); |
|
/* check for header */ |
|
p = s->inbuf_ptr - 3; |
|
pend = s->inbuf_ptr + len - 4; |
|
while (p <= pend) { |
|
header = (p[0] << 24) | (p[1] << 16) | |
|
(p[2] << 8) | p[3]; |
|
header1 = (s->inbuf[0] << 24) | (s->inbuf[1] << 16) | |
|
(s->inbuf[2] << 8) | s->inbuf[3]; |
|
/* check with high probability that we have a |
|
valid header */ |
|
if ((header & SAME_HEADER_MASK) == |
|
(header1 & SAME_HEADER_MASK)) { |
|
/* header found: update pointers */ |
|
len = (p + 4) - s->inbuf_ptr; |
|
buf_ptr += len; |
|
buf_size -= len; |
|
s->inbuf_ptr = p; |
|
/* compute frame size */ |
|
s->free_format_next_header = header; |
|
s->free_format_frame_size = s->inbuf_ptr - s->inbuf; |
|
padding = (header1 >> 9) & 1; |
|
if (s->layer == 1) |
|
s->free_format_frame_size -= padding * 4; |
|
else |
|
s->free_format_frame_size -= padding; |
|
dprintf("free frame size=%d padding=%d\n", |
|
s->free_format_frame_size, padding); |
|
decode_header(s, header1); |
|
goto next_data; |
|
} |
|
p++; |
|
} |
|
/* not found: simply increase pointers */ |
|
buf_ptr += len; |
|
s->inbuf_ptr += len; |
|
buf_size -= len; |
|
} |
|
} else |
|
#endif |
|
if (len < s->frame_size) { |
|
if (s->frame_size > MPA_MAX_CODED_FRAME_SIZE) |
|
s->frame_size = MPA_MAX_CODED_FRAME_SIZE; |
|
len = s->frame_size - len; |
|
if (len > buf_size) |
|
len = buf_size; |
|
memcpy(s->inbuf_ptr, buf_ptr, len); |
|
buf_ptr += len; |
|
s->inbuf_ptr += len; |
|
buf_size -= len; |
|
} |
|
// next_data: |
|
if (s->frame_size > 0 && |
|
(s->inbuf_ptr - s->inbuf) >= s->frame_size) { |
|
if(s->header_count > 0){ |
|
*poutbuf = s->inbuf; |
|
*poutbuf_size = s->inbuf_ptr - s->inbuf; |
|
} |
|
s->inbuf_ptr = s->inbuf; |
|
s->frame_size = 0; |
|
break; |
|
} |
|
} |
|
return buf_ptr - buf; |
|
} |
|
|
|
#ifdef CONFIG_AC3 |
|
extern int a52_syncinfo (const uint8_t * buf, int * flags, |
|
int * sample_rate, int * bit_rate); |
|
|
|
typedef struct AC3ParseContext { |
|
uint8_t inbuf[4096]; /* input buffer */ |
|
uint8_t *inbuf_ptr; |
|
int frame_size; |
|
int flags; |
|
} AC3ParseContext; |
|
|
|
#define AC3_HEADER_SIZE 7 |
|
#define A52_LFE 16 |
|
|
|
static int ac3_parse_init(AVCodecParserContext *s1) |
|
{ |
|
AC3ParseContext *s = s1->priv_data; |
|
s->inbuf_ptr = s->inbuf; |
|
return 0; |
|
} |
|
|
|
static int ac3_parse(AVCodecParserContext *s1, |
|
AVCodecContext *avctx, |
|
uint8_t **poutbuf, int *poutbuf_size, |
|
const uint8_t *buf, int buf_size) |
|
{ |
|
AC3ParseContext *s = s1->priv_data; |
|
const uint8_t *buf_ptr; |
|
int len, sample_rate, bit_rate; |
|
static const int ac3_channels[8] = { |
|
2, 1, 2, 3, 3, 4, 4, 5 |
|
}; |
|
|
|
*poutbuf = NULL; |
|
*poutbuf_size = 0; |
|
|
|
buf_ptr = buf; |
|
while (buf_size > 0) { |
|
len = s->inbuf_ptr - s->inbuf; |
|
if (s->frame_size == 0) { |
|
/* no header seen : find one. We need at least 7 bytes to parse it */ |
|
len = AC3_HEADER_SIZE - len; |
|
if (len > buf_size) |
|
len = buf_size; |
|
memcpy(s->inbuf_ptr, buf_ptr, len); |
|
buf_ptr += len; |
|
s->inbuf_ptr += len; |
|
buf_size -= len; |
|
if ((s->inbuf_ptr - s->inbuf) == AC3_HEADER_SIZE) { |
|
len = a52_syncinfo(s->inbuf, &s->flags, &sample_rate, &bit_rate); |
|
if (len == 0) { |
|
/* no sync found : move by one byte (inefficient, but simple!) */ |
|
memmove(s->inbuf, s->inbuf + 1, AC3_HEADER_SIZE - 1); |
|
s->inbuf_ptr--; |
|
} else { |
|
s->frame_size = len; |
|
/* update codec info */ |
|
avctx->sample_rate = sample_rate; |
|
/* set channels,except if the user explicitly requests 1 or 2 channels, XXX/FIXME this is a bit ugly */ |
|
if(avctx->channels!=1 && avctx->channels!=2){ |
|
avctx->channels = ac3_channels[s->flags & 7]; |
|
if (s->flags & A52_LFE) |
|
avctx->channels++; |
|
} |
|
avctx->bit_rate = bit_rate; |
|
avctx->frame_size = 6 * 256; |
|
} |
|
} |
|
} else if (len < s->frame_size) { |
|
len = s->frame_size - len; |
|
if (len > buf_size) |
|
len = buf_size; |
|
|
|
memcpy(s->inbuf_ptr, buf_ptr, len); |
|
buf_ptr += len; |
|
s->inbuf_ptr += len; |
|
buf_size -= len; |
|
} else { |
|
*poutbuf = s->inbuf; |
|
*poutbuf_size = s->frame_size; |
|
s->inbuf_ptr = s->inbuf; |
|
s->frame_size = 0; |
|
break; |
|
} |
|
} |
|
return buf_ptr - buf; |
|
} |
|
#endif |
|
|
|
AVCodecParser mpegvideo_parser = { |
|
{ CODEC_ID_MPEG1VIDEO, CODEC_ID_MPEG2VIDEO }, |
|
sizeof(ParseContext1), |
|
NULL, |
|
mpegvideo_parse, |
|
parse1_close, |
|
}; |
|
|
|
AVCodecParser mpeg4video_parser = { |
|
{ CODEC_ID_MPEG4 }, |
|
sizeof(ParseContext1), |
|
mpeg4video_parse_init, |
|
mpeg4video_parse, |
|
parse1_close, |
|
}; |
|
|
|
AVCodecParser mpegaudio_parser = { |
|
{ CODEC_ID_MP2, CODEC_ID_MP3 }, |
|
sizeof(MpegAudioParseContext), |
|
mpegaudio_parse_init, |
|
mpegaudio_parse, |
|
NULL, |
|
}; |
|
|
|
#ifdef CONFIG_AC3 |
|
AVCodecParser ac3_parser = { |
|
{ CODEC_ID_AC3 }, |
|
sizeof(AC3ParseContext), |
|
ac3_parse_init, |
|
ac3_parse, |
|
NULL, |
|
}; |
|
#endif
|
|
|