/*
  * 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 = AV_PICTURE_TYPE_I;

     s->key_frame = -1;

     s->convergence_duration = 0;

     s->dts_sync_point       = INT_MIN;
     s->dts_ref_dts_delta    = INT_MIN;
     s->pts_dts_delta        = INT_MIN;

     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 && !s->next_frame_offset)) // first field/frame

             //check is disabled  because 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;

         }
     }
 }
 

 #if LIBAVCODEC_VERSION_MAJOR < 53

 /**
  *
  * @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);
 }

 #endif

 
 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(!(s->flags & PARSER_FLAG_FETCHED_OFFSET)) {
         s->next_frame_offset =
         s->cur_offset        = pos;
         s->flags |= PARSER_FLAG_FETCHED_OFFSET;
     }
 

     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 if (s->cur_offset + buf_size !=
                s->cur_frame_end[s->cur_frame_start_index]) { /* skip remainder packets */

         /* 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 != AV_PICTURE_TYPE_I && (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

  * @return -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)
             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)
             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(pc->overread){

         av_dlog(pc, "overread %d, state:%X next:%d index:%d o_index:%d\n",
                 pc->overread, pc->state, next, pc->index, pc->overread_index);
         av_dlog(pc, "%X %X %X %X\n", (*buf)[0], (*buf)[1],(*buf)[2],(*buf)[3]);

     }
 
     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;
 }