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  1. /*
  2.  * TAK common code
  3.  * Copyright (c) 2012 Paul B Mahol
  4.  *
  5.  * This file is part of FFmpeg.
  6.  *
  7.  * FFmpeg is free software; you can redistribute it and/or
  8.  * modify it under the terms of the GNU Lesser General Public
  9.  * License as published by the Free Software Foundation; either
  10.  * version 2.1 of the License, or (at your option) any later version.
  11.  *
  12.  * FFmpeg is distributed in the hope that it will be useful,
  13.  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14.  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15.  * Lesser General Public License for more details.
  16.  *
  17.  * You should have received a copy of the GNU Lesser General Public
  18.  * License along with FFmpeg; if not, write to the Free Software
  19.  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  20.  */
  21.  
  22. #include "libavutil/crc.h"
  23. #include "libavutil/intreadwrite.h"
  24. #include "tak.h"
  25.  
  26. static const int64_t tak_channel_layouts[] = {
  27.     0,
  28.     AV_CH_FRONT_LEFT,
  29.     AV_CH_FRONT_RIGHT,
  30.     AV_CH_FRONT_CENTER,
  31.     AV_CH_LOW_FREQUENCY,
  32.     AV_CH_BACK_LEFT,
  33.     AV_CH_BACK_RIGHT,
  34.     AV_CH_FRONT_LEFT_OF_CENTER,
  35.     AV_CH_FRONT_RIGHT_OF_CENTER,
  36.     AV_CH_BACK_CENTER,
  37.     AV_CH_SIDE_LEFT,
  38.     AV_CH_SIDE_RIGHT,
  39.     AV_CH_TOP_CENTER,
  40.     AV_CH_TOP_FRONT_LEFT,
  41.     AV_CH_TOP_FRONT_CENTER,
  42.     AV_CH_TOP_FRONT_RIGHT,
  43.     AV_CH_TOP_BACK_LEFT,
  44.     AV_CH_TOP_BACK_CENTER,
  45.     AV_CH_TOP_BACK_RIGHT,
  46. };
  47.  
  48. static const uint16_t frame_duration_type_quants[] = {
  49.     3, 4, 6, 8, 4096, 8192, 16384, 512, 1024, 2048,
  50. };
  51.  
  52. static int tak_get_nb_samples(int sample_rate, enum TAKFrameSizeType type)
  53. {
  54.     int nb_samples, max_nb_samples;
  55.  
  56.     if (type <= TAK_FST_250ms) {
  57.         nb_samples     = sample_rate * frame_duration_type_quants[type] >>
  58.                          TAK_FRAME_DURATION_QUANT_SHIFT;
  59.         max_nb_samples = 16384;
  60.     } else if (type < FF_ARRAY_ELEMS(frame_duration_type_quants)) {
  61.         nb_samples     = frame_duration_type_quants[type];
  62.         max_nb_samples = sample_rate *
  63.                          frame_duration_type_quants[TAK_FST_250ms] >>
  64.                          TAK_FRAME_DURATION_QUANT_SHIFT;
  65.     } else {
  66.         return AVERROR_INVALIDDATA;
  67.     }
  68.  
  69.     if (nb_samples <= 0 || nb_samples > max_nb_samples)
  70.         return AVERROR_INVALIDDATA;
  71.  
  72.     return nb_samples;
  73. }
  74.  
  75. int ff_tak_check_crc(const uint8_t *buf, unsigned int buf_size)
  76. {
  77.     uint32_t crc, CRC;
  78.  
  79.     if (buf_size < 4)
  80.         return AVERROR_INVALIDDATA;
  81.     buf_size -= 3;
  82.  
  83.     CRC = AV_RB24(buf + buf_size);
  84.     crc = av_crc(av_crc_get_table(AV_CRC_24_IEEE), 0xCE04B7U, buf, buf_size);
  85.     if (CRC != crc)
  86.         return AVERROR_INVALIDDATA;
  87.  
  88.     return 0;
  89. }
  90.  
  91. void avpriv_tak_parse_streaminfo(GetBitContext *gb, TAKStreamInfo *s)
  92. {
  93.     uint64_t channel_mask = 0;
  94.     int frame_type, i;
  95.  
  96.     s->codec = get_bits(gb, TAK_ENCODER_CODEC_BITS);
  97.     skip_bits(gb, TAK_ENCODER_PROFILE_BITS);
  98.  
  99.     frame_type = get_bits(gb, TAK_SIZE_FRAME_DURATION_BITS);
  100.     s->samples = get_bits64(gb, TAK_SIZE_SAMPLES_NUM_BITS);
  101.  
  102.     s->data_type   = get_bits(gb, TAK_FORMAT_DATA_TYPE_BITS);
  103.     s->sample_rate = get_bits(gb, TAK_FORMAT_SAMPLE_RATE_BITS) +
  104.                      TAK_SAMPLE_RATE_MIN;
  105.     s->bps         = get_bits(gb, TAK_FORMAT_BPS_BITS) +
  106.                      TAK_BPS_MIN;
  107.     s->channels    = get_bits(gb, TAK_FORMAT_CHANNEL_BITS) +
  108.                      TAK_CHANNELS_MIN;
  109.  
  110.     if (get_bits1(gb)) {
  111.         skip_bits(gb, TAK_FORMAT_VALID_BITS);
  112.         if (get_bits1(gb)) {
  113.             for (i = 0; i < s->channels; i++) {
  114.                 int value = get_bits(gb, TAK_FORMAT_CH_LAYOUT_BITS);
  115.  
  116.                 if (value < FF_ARRAY_ELEMS(tak_channel_layouts))
  117.                     channel_mask |= tak_channel_layouts[value];
  118.             }
  119.         }
  120.     }
  121.  
  122.     s->ch_layout     = channel_mask;
  123.     s->frame_samples = tak_get_nb_samples(s->sample_rate, frame_type);
  124. }
  125.  
  126. int ff_tak_decode_frame_header(AVCodecContext *avctx, GetBitContext *gb,
  127.                                TAKStreamInfo *ti, int log_level_offset)
  128. {
  129.     if (get_bits(gb, TAK_FRAME_HEADER_SYNC_ID_BITS) != TAK_FRAME_HEADER_SYNC_ID) {
  130.         av_log(avctx, AV_LOG_ERROR + log_level_offset, "missing sync id\n");
  131.         return AVERROR_INVALIDDATA;
  132.     }
  133.  
  134.     ti->flags     = get_bits(gb, TAK_FRAME_HEADER_FLAGS_BITS);
  135.     ti->frame_num = get_bits(gb, TAK_FRAME_HEADER_NO_BITS);
  136.  
  137.     if (ti->flags & TAK_FRAME_FLAG_IS_LAST) {
  138.         ti->last_frame_samples = get_bits(gb, TAK_FRAME_HEADER_SAMPLE_COUNT_BITS) + 1;
  139.         skip_bits(gb, 2);
  140.     } else {
  141.         ti->last_frame_samples = 0;
  142.     }
  143.  
  144.     if (ti->flags & TAK_FRAME_FLAG_HAS_INFO) {
  145.         avpriv_tak_parse_streaminfo(gb, ti);
  146.  
  147.         if (get_bits(gb, 6))
  148.             skip_bits(gb, 25);
  149.         align_get_bits(gb);
  150.     }
  151.  
  152.     if (ti->flags & TAK_FRAME_FLAG_HAS_METADATA)
  153.         return AVERROR_INVALIDDATA;
  154.  
  155.     skip_bits(gb, 24);
  156.  
  157.     return 0;
  158. }
  159.