/*
  * DCA parser
  * Copyright (C) 2004 Gildas Bazin
  * Copyright (C) 2004 Benjamin Zores
  * Copyright (C) 2006 Benjamin Larsson
  * Copyright (C) 2007 Konstantin Shishkov
  *
  * 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 "dca.h"

 #include "dca_core.h"

 #include "dca_exss.h"

 #include "dca_lbr.h"

 #include "dca_syncwords.h"

 #include "get_bits.h"

 #include "parser.h"

 
 typedef struct DCAParseContext {
     ParseContext pc;
     uint32_t lastmarker;

     int size;
     int framesize;

     unsigned int startpos;

     DCAExssParser exss;
     unsigned int sr_code;

 } DCAParseContext;
 

 #define IS_CORE_MARKER(state) \
     (((state & 0xFFFFFFFFF0FF) == (((uint64_t)DCA_SYNCWORD_CORE_14B_LE << 16) | 0xF007)) || \
      ((state & 0xFFFFFFFFFFF0) == (((uint64_t)DCA_SYNCWORD_CORE_14B_BE << 16) | 0x07F0)) || \
      ((state & 0xFFFFFFFF00FC) == (((uint64_t)DCA_SYNCWORD_CORE_LE     << 16) | 0x00FC)) || \
      ((state & 0xFFFFFFFFFC00) == (((uint64_t)DCA_SYNCWORD_CORE_BE     << 16) | 0xFC00)))
 
 #define IS_EXSS_MARKER(state)   ((state & 0xFFFFFFFF) == DCA_SYNCWORD_SUBSTREAM)
 

 #define IS_MARKER(state)        (IS_CORE_MARKER(state) || IS_EXSS_MARKER(state))

 #define CORE_MARKER(state)      ((state >> 16) & 0xFFFFFFFF)
 #define EXSS_MARKER(state)      (state & 0xFFFFFFFF)

 #define STATE_LE(state)     (((state & 0xFF00FF00) >> 8) | ((state & 0x00FF00FF) << 8))
 #define STATE_14(state)     (((state & 0x3FFF0000) >> 8) | ((state & 0x00003FFF) >> 6))
 
 #define CORE_FRAMESIZE(state)   (((state >> 4) & 0x3FFF) + 1)
 #define EXSS_FRAMESIZE(state)   ((state & 0x2000000000) ? \
                                  ((state >>  5) & 0xFFFFF) + 1 : \
                                  ((state >> 13) & 0x0FFFF) + 1)
 

 /**

  * Find the end of the current frame in the bitstream.

  * @return the position of the first byte of the next frame, or -1
  */

 static int dca_find_frame_end(DCAParseContext *pc1, const uint8_t *buf,

                               int buf_size)
 {

     int start_found, size, i;

     uint64_t state;

     ParseContext *pc = &pc1->pc;
 
     start_found = pc->frame_start_found;

     state       = pc->state64;

     size        = pc1->size;

 
     i = 0;
     if (!start_found) {

         for (; i < buf_size; i++) {
             size++;

             state = (state << 8) | buf[i];

 
             if (IS_MARKER(state) &&
                 (!pc1->lastmarker ||
                   pc1->lastmarker == CORE_MARKER(state) ||
                   pc1->lastmarker == DCA_SYNCWORD_SUBSTREAM)) {
                 if (!pc1->lastmarker)
                     pc1->startpos = IS_EXSS_MARKER(state) ? size - 4 : size - 6;
 
                 if (IS_EXSS_MARKER(state))
                     pc1->lastmarker = EXSS_MARKER(state);
                 else
                     pc1->lastmarker = CORE_MARKER(state);
 
                 start_found = 1;
                 size        = 0;
 
                 i++;
                 break;

             }
         }
     }

     if (start_found) {
         for (; i < buf_size; i++) {

             size++;

             state = (state << 8) | buf[i];

 
             if (start_found == 1) {
                 switch (pc1->lastmarker) {
                 case DCA_SYNCWORD_CORE_BE:
                     if (size == 2) {
                         pc1->framesize = CORE_FRAMESIZE(state);
                         start_found    = 2;
                     }
                     break;
                 case DCA_SYNCWORD_CORE_LE:
                     if (size == 2) {
                         pc1->framesize = CORE_FRAMESIZE(STATE_LE(state));

                         start_found    = 4;

                     }
                     break;
                 case DCA_SYNCWORD_CORE_14B_BE:
                     if (size == 4) {

                         pc1->framesize = CORE_FRAMESIZE(STATE_14(state));

                         start_found    = 4;

                     }
                     break;
                 case DCA_SYNCWORD_CORE_14B_LE:
                     if (size == 4) {

                         pc1->framesize = CORE_FRAMESIZE(STATE_14(STATE_LE(state)));

                         start_found    = 4;

                     }
                     break;
                 case DCA_SYNCWORD_SUBSTREAM:
                     if (size == 6) {
                         pc1->framesize = EXSS_FRAMESIZE(state);

                         start_found    = 4;

                     }
                     break;
                 default:
                     av_assert0(0);
                 }
                 continue;
             }
 

             if (start_found == 2 && IS_EXSS_MARKER(state) &&
                 pc1->framesize <= size + 2) {
                 pc1->framesize  = size + 2;
                 start_found     = 3;
                 continue;
             }

             if (start_found == 3) {
                 if (size == pc1->framesize + 4) {
                     pc1->framesize += EXSS_FRAMESIZE(state);
                     start_found     = 4;

                 }

                 continue;

             }
 
             if (pc1->framesize > size)
                 continue;
 

             if (IS_MARKER(state) &&
                 (pc1->lastmarker == CORE_MARKER(state) ||
                  pc1->lastmarker == DCA_SYNCWORD_SUBSTREAM)) {

                 pc->frame_start_found = 0;

                 pc->state64           = -1;

                 pc1->size             = 0;

                 return IS_EXSS_MARKER(state) ? i - 3 : i - 5;

             }
         }
     }

     pc->frame_start_found = start_found;

     pc->state64           = state;

     pc1->size             = size;

     return END_NOT_FOUND;
 }
 

 static av_cold int dca_parse_init(AVCodecParserContext *s)

 {
     DCAParseContext *pc1 = s->priv_data;
 
     pc1->lastmarker = 0;

     pc1->sr_code = -1;

     return 0;
 }
 

 static int dca_parse_params(DCAParseContext *pc1, const uint8_t *buf,

                             int buf_size, int *duration, int *sample_rate,
                             int *profile)

 {

     DCAExssAsset *asset = &pc1->exss.assets[0];

     GetBitContext gb;

     DCACoreFrameHeader h;
     uint8_t hdr[DCA_CORE_FRAME_HEADER_SIZE + AV_INPUT_BUFFER_PADDING_SIZE] = { 0 };

     int ret, frame_size;

     if (buf_size < DCA_CORE_FRAME_HEADER_SIZE)

         return AVERROR_INVALIDDATA;
 

     if (AV_RB32(buf) == DCA_SYNCWORD_SUBSTREAM) {
         if ((ret = ff_dca_exss_parse(&pc1->exss, buf, buf_size)) < 0)
             return ret;
 
         if (asset->extension_mask & DCA_EXSS_LBR) {
             if ((ret = init_get_bits8(&gb, buf + asset->lbr_offset, asset->lbr_size)) < 0)
                 return ret;
 
             if (get_bits_long(&gb, 32) != DCA_SYNCWORD_LBR)
                 return AVERROR_INVALIDDATA;
 
             switch (get_bits(&gb, 8)) {

             case DCA_LBR_HEADER_DECODER_INIT:

                 pc1->sr_code = get_bits(&gb, 8);

             case DCA_LBR_HEADER_SYNC_ONLY:

                 break;
             default:
                 return AVERROR_INVALIDDATA;
             }
 
             if (pc1->sr_code >= FF_ARRAY_ELEMS(ff_dca_sampling_freqs))
                 return AVERROR_INVALIDDATA;
 
             *sample_rate = ff_dca_sampling_freqs[pc1->sr_code];
             *duration = 1024 << ff_dca_freq_ranges[pc1->sr_code];

             *profile = FF_PROFILE_DTS_EXPRESS;

             return 0;
         }
 
         if (asset->extension_mask & DCA_EXSS_XLL) {
             int nsamples_log2;
 
             if ((ret = init_get_bits8(&gb, buf + asset->xll_offset, asset->xll_size)) < 0)
                 return ret;
 
             if (get_bits_long(&gb, 32) != DCA_SYNCWORD_XLL)
                 return AVERROR_INVALIDDATA;
 
             if (get_bits(&gb, 4))
                 return AVERROR_INVALIDDATA;
 
             skip_bits(&gb, 8);
             skip_bits_long(&gb, get_bits(&gb, 5) + 1);
             skip_bits(&gb, 4);
             nsamples_log2 = get_bits(&gb, 4) + get_bits(&gb, 4);
             if (nsamples_log2 > 24)
                 return AVERROR_INVALIDDATA;
 
             *sample_rate = asset->max_sample_rate;
             *duration = (1 + (*sample_rate > 96000)) << nsamples_log2;

             *profile = FF_PROFILE_DTS_HD_MA;

             return 0;
         }
 
         return AVERROR_INVALIDDATA;
     }
 

     if ((ret = avpriv_dca_convert_bitstream(buf, DCA_CORE_FRAME_HEADER_SIZE,
                                             hdr, DCA_CORE_FRAME_HEADER_SIZE)) < 0)

         return ret;

     if (avpriv_dca_parse_core_frame_header(&h, hdr, ret) < 0)

         return AVERROR_INVALIDDATA;
 

     *duration = h.npcmblocks * DCA_PCMBLOCK_SAMPLES;

     *sample_rate = avpriv_dca_sample_rates[h.sr_code];

     if (*profile != FF_PROFILE_UNKNOWN)
         return 0;
 
     *profile = FF_PROFILE_DTS;
     if (h.ext_audio_present) {
         switch (h.ext_audio_type) {
         case DCA_EXT_AUDIO_XCH:
         case DCA_EXT_AUDIO_XXCH:
             *profile = FF_PROFILE_DTS_ES;
             break;
         case DCA_EXT_AUDIO_X96:
             *profile = FF_PROFILE_DTS_96_24;
             break;
         }
     }
 
     frame_size = FFALIGN(h.frame_size, 4);
     if (buf_size - 4 < frame_size)
         return 0;
 
     buf      += frame_size;
     buf_size -= frame_size;
     if (AV_RB32(buf) != DCA_SYNCWORD_SUBSTREAM)
         return 0;
     if (ff_dca_exss_parse(&pc1->exss, buf, buf_size) < 0)
         return 0;
 
     if (asset->extension_mask & DCA_EXSS_XLL)
         *profile = FF_PROFILE_DTS_HD_MA;
     else if (asset->extension_mask & (DCA_EXSS_XBR | DCA_EXSS_XXCH | DCA_EXSS_X96))
         *profile = FF_PROFILE_DTS_HD_HRA;

 
     return 0;
 }
 

 static int dca_parse(AVCodecParserContext *s, AVCodecContext *avctx,
                      const uint8_t **poutbuf, int *poutbuf_size,
                      const uint8_t *buf, int buf_size)

 {
     DCAParseContext *pc1 = s->priv_data;
     ParseContext *pc = &pc1->pc;

     int next, duration, sample_rate;

 
     if (s->flags & PARSER_FLAG_COMPLETE_FRAMES) {
         next = buf_size;
     } else {
         next = dca_find_frame_end(pc1, buf, buf_size);
 

         if (ff_combine_frame(pc, next, &buf, &buf_size) < 0) {

             *poutbuf      = NULL;

             *poutbuf_size = 0;
             return buf_size;
         }

 
         /* skip initial padding */
         if (buf_size  > pc1->startpos) {
             buf      += pc1->startpos;
             buf_size -= pc1->startpos;
         }
         pc1->startpos = 0;

     }

 
     /* read the duration and sample rate from the frame header */

     if (!dca_parse_params(pc1, buf, buf_size, &duration, &sample_rate, &avctx->profile)) {

         if (!avctx->sample_rate)
             avctx->sample_rate = sample_rate;
         s->duration = av_rescale(duration, avctx->sample_rate, sample_rate);

     } else
         s->duration = 0;
 

     *poutbuf      = buf;

     *poutbuf_size = buf_size;
     return next;
 }
 

 AVCodecParser ff_dca_parser = {

     .codec_ids      = { AV_CODEC_ID_DTS },

     .priv_data_size = sizeof(DCAParseContext),
     .parser_init    = dca_parse_init,
     .parser_parse   = dca_parse,
     .parser_close   = ff_parse_close,

 };