libavcodec/parser.c - vendor/opensource/ffmpeg - Git at Google

 /*
  * 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"

 static 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;
     s->key_frame = -1;
     s->convergence_duration = AV_NOPTS_VALUE;
     s->dts_sync_point       = INT_MIN;
     s->dts_ref_dts_delta    = INT_MIN;
     s->pts_dts_delta        = INT_MIN;
 	s->field_frame_flag     = 0;
     return s;
 }

 void ff_fetch_timestamp(AVCodecParserContext *s, int off, int remove){
     int i;

     s->dts= s->pts= AV_NOPTS_VALUE;
     s->pos= -1;
     s->offset= 0;
     for(i = 0; i < AV_PARSER_PTS_NB; i++) {
         if (   s->cur_offset + off >= s->cur_frame_offset[i]
             &&(s->     frame_offset       <  s->cur_frame_offset[i] || !s->frame_offset)
             //check is disabled  becausue mpeg-ts doesnt send complete PES packets
             && /*s->next_frame_offset + off <*/  s->cur_frame_end[i]){
             s->dts= s->cur_frame_dts[i];
             s->pts= s->cur_frame_pts[i];
             s->pos= s->cur_frame_pos[i];
             s->offset = s->next_frame_offset - s->cur_frame_offset[i];
             if(remove)
                 s->cur_frame_offset[i]= INT64_MAX;
             if(s->cur_offset + off < s->cur_frame_end[i])
                 break;
         }
     }
 }

 /**
  *
  * @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
  *
  * @deprecated Use av_parser_parse2() instead.
  */
 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)
 {
     return av_parser_parse2(s, avctx, poutbuf, poutbuf_size, buf, buf_size, pts, dts, AV_NOPTS_VALUE);
 }

 int av_parser_parse2(AVCodecParserContext *s,
                      AVCodecContext *avctx,
                      uint8_t **poutbuf, int *poutbuf_size,
                      const uint8_t *buf, int buf_size,
                      int64_t pts, int64_t dts,
                      int64_t pos)
 {
     int index, i;
     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 */
             i = (s->cur_frame_start_index + 1) & (AV_PARSER_PTS_NB - 1);
             s->cur_frame_start_index = i;
             s->cur_frame_offset[i] = s->cur_offset;
             s->cur_frame_end[i] = s->cur_offset + buf_size;
             s->cur_frame_pts[i] = pts;
             s->cur_frame_dts[i] = dts;
             s->cur_frame_pos[i] = pos;
     }

     if (s->fetch_timestamp){
         s->fetch_timestamp=0;
         s->last_pts = s->pts;
         s->last_dts = s->dts;
         s->last_pos = s->pos;
         ff_fetch_timestamp(s, 0, 0);
     }

     /* 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->next_frame_offset;

         /* offset of the next frame */
         s->next_frame_offset = s->cur_offset + index;
         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 != FF_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){
         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, AVERROR(ENOMEM) if there was a memory allocation error
  */
 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){
         void* new_buffer = av_fast_realloc(pc->buffer, &pc->buffer_size, (*buf_size) + pc->index + FF_INPUT_BUFFER_PADDING_SIZE);

         if(!new_buffer) {
             pc->index = 0;
             return AVERROR(ENOMEM);
         }
         pc->buffer = new_buffer;
         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){
         void* new_buffer = av_fast_realloc(pc->buffer, &pc->buffer_size, next + pc->index + FF_INPUT_BUFFER_PADDING_SIZE);

         if(!new_buffer) {
             pc->overread_index =
             pc->index = 0;
             return AVERROR(ENOMEM);
         }
         pc->buffer = new_buffer;
         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->state64 = (pc->state64<<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_freep(&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;
 }
	/*
	* 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"

	static 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;
	s->key_frame = -1;
	s->convergence_duration = AV_NOPTS_VALUE;
	s->dts_sync_point = INT_MIN;
	s->dts_ref_dts_delta = INT_MIN;
	s->pts_dts_delta = INT_MIN;
	s->field_frame_flag = 0;
	return s;
	}

	void ff_fetch_timestamp(AVCodecParserContext *s, int off, int remove){
	int i;

	s->dts= s->pts= AV_NOPTS_VALUE;
	s->pos= -1;
	s->offset= 0;
	for(i = 0; i < AV_PARSER_PTS_NB; i++) {
	if ( s->cur_offset + off >= s->cur_frame_offset[i]
	&&(s-> frame_offset < s->cur_frame_offset[i] \|\| !s->frame_offset)
	//check is disabled becausue mpeg-ts doesnt send complete PES packets
	&& /s->next_frame_offset + off </ s->cur_frame_end[i]){
	s->dts= s->cur_frame_dts[i];
	s->pts= s->cur_frame_pts[i];
	s->pos= s->cur_frame_pos[i];
	s->offset = s->next_frame_offset - s->cur_frame_offset[i];
	if(remove)
	s->cur_frame_offset[i]= INT64_MAX;
	if(s->cur_offset + off < s->cur_frame_end[i])
	break;
	}
	}
	}

	/**
	*
	* @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
	*
	* @deprecated Use av_parser_parse2() instead.
	*/
	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)
	{
	return av_parser_parse2(s, avctx, poutbuf, poutbuf_size, buf, buf_size, pts, dts, AV_NOPTS_VALUE);
	}

	int av_parser_parse2(AVCodecParserContext *s,
	AVCodecContext *avctx,
	uint8_t *poutbuf, int poutbuf_size,
	const uint8_t *buf, int buf_size,
	int64_t pts, int64_t dts,
	int64_t pos)
	{
	int index, i;
	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 */
	i = (s->cur_frame_start_index + 1) & (AV_PARSER_PTS_NB - 1);
	s->cur_frame_start_index = i;
	s->cur_frame_offset[i] = s->cur_offset;
	s->cur_frame_end[i] = s->cur_offset + buf_size;
	s->cur_frame_pts[i] = pts;
	s->cur_frame_dts[i] = dts;
	s->cur_frame_pos[i] = pos;
	}

	if (s->fetch_timestamp){
	s->fetch_timestamp=0;
	s->last_pts = s->pts;
	s->last_dts = s->dts;
	s->last_pos = s->pos;
	ff_fetch_timestamp(s, 0, 0);
	}

	/* 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->next_frame_offset;

	/* offset of the next frame */
	s->next_frame_offset = s->cur_offset + index;
	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 != FF_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){
	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, AVERROR(ENOMEM) if there was a memory allocation error
	*/
	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){
	void* new_buffer = av_fast_realloc(pc->buffer, &pc->buffer_size, (*buf_size) + pc->index + FF_INPUT_BUFFER_PADDING_SIZE);

	if(!new_buffer) {
	pc->index = 0;
	return AVERROR(ENOMEM);
	}
	pc->buffer = new_buffer;
	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){
	void* new_buffer = av_fast_realloc(pc->buffer, &pc->buffer_size, next + pc->index + FF_INPUT_BUFFER_PADDING_SIZE);

	if(!new_buffer) {
	pc->overread_index =
	pc->index = 0;
	return AVERROR(ENOMEM);
	}
	pc->buffer = new_buffer;
	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->state64 = (pc->state64<<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_freep(&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;
	}