/*
  * 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 <stdint.h>

 #include <string.h>
 

 #include "libavutil/atomic.h"

 #include "libavutil/mem.h"

 #include "parser.h"
 

 static AVCodecParser *av_first_parser = NULL;

 AVCodecParser *av_parser_next(const AVCodecParser *p)

 {
     if (p)
         return p->next;
     else
         return av_first_parser;

 }
 

 void av_register_codec_parser(AVCodecParser *parser)
 {

     do {
         parser->next = av_first_parser;
     } while (parser->next != avpriv_atomic_ptr_cas((void * volatile *)&av_first_parser, parser->next, parser));

 }
 
 AVCodecParserContext *av_parser_init(int codec_id)
 {

     AVCodecParserContext *s = NULL;

     AVCodecParser *parser;
     int ret;

     if (codec_id == AV_CODEC_ID_NONE)

         return NULL;

     for (parser = av_first_parser; parser; 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)

         goto err_out;

     s->parser = parser;

     s->priv_data = av_mallocz(parser->priv_data_size);

     if (!s->priv_data)
         goto err_out;

     s->fetch_timestamp=1;
     s->pict_type = AV_PICTURE_TYPE_I;

     if (parser->parser_init) {
         ret = parser->parser_init(s);

         if (ret != 0)
             goto err_out;

     }

     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;

 
 err_out:
     if (s)
         av_freep(&s->priv_data);
     av_free(s);
     return NULL;

 }
 

 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 disabled since MPEG-TS does not 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;

         }
     }
 }
 

 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);

     /* 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;
 }
 

 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)) {

             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_freep(&s->priv_data);

         av_free(s);

     }

 }
 

 int ff_combine_frame(ParseContext *pc, int next,
                      const uint8_t **buf, int *buf_size)

 {

     if (pc->overread) {

         av_dlog(NULL, "overread %d, state:%X next:%d index:%d o_index:%d\n",

                 pc->overread, pc->state, next, pc->index, pc->overread_index);

         av_dlog(NULL, "%X %X %X %X\n",
                 (*buf)[0], (*buf)[1], (*buf)[2], (*buf)[3]);

     }
 

     /* 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;

         if (next > -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->state64 = pc->state64 << 8 | pc->buffer[pc->last_index + next];

         pc->overread++;
     }
 

     if (pc->overread) {

         av_dlog(NULL, "overread %d, state:%X next:%d index:%d o_index:%d\n",

                 pc->overread, pc->state, next, pc->index, pc->overread_index);

         av_dlog(NULL, "%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);

 }
 

 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;
 }