LCOV - code coverage report
Current view: top level - libavcodec - vima.c (source / functions) Hit Total Coverage
Test: coverage.info Lines: 67 71 94.4 %
Date: 2017-12-14 19:11:59 Functions: 2 2 100.0 %

          Line data    Source code
       1             : /*
       2             :  * LucasArts VIMA decoder
       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             : /**
      23             :  * @file
      24             :  * LucasArts VIMA audio decoder
      25             :  * @author Paul B Mahol
      26             :  */
      27             : 
      28             : #include "libavutil/channel_layout.h"
      29             : 
      30             : #include "adpcm_data.h"
      31             : #include "avcodec.h"
      32             : #include "get_bits.h"
      33             : #include "internal.h"
      34             : 
      35             : static int predict_table_init = 0;
      36             : static uint16_t predict_table[5786 * 2];
      37             : 
      38             : static const uint8_t size_table[] = {
      39             :     4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4,
      40             :     4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4,
      41             :     4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4,
      42             :     5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5,
      43             :     6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6,
      44             :     7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7
      45             : };
      46             : 
      47             : static const int8_t index_table1[] = {
      48             :     -1, 4, -1, 4
      49             : };
      50             : 
      51             : static const int8_t index_table2[] = {
      52             :     -1, -1, 2, 6, -1, -1, 2, 6
      53             : };
      54             : 
      55             : static const int8_t index_table3[] = {
      56             :     -1, -1, -1, -1, 1, 2, 4, 6, -1, -1, -1, -1, 1, 2, 4, 6
      57             : };
      58             : 
      59             : static const int8_t index_table4[] = {
      60             :     -1, -1, -1, -1, -1, -1, -1, -1, 1,  1,  1,  2,  2,  4,  5,  6,
      61             :     -1, -1, -1, -1, -1, -1, -1, -1, 1,  1,  1,  2,  2,  4,  5,  6
      62             : };
      63             : 
      64             : static const int8_t index_table5[] = {
      65             :     -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
      66             :      1,  1,  1,  1,  1,  2,  2,  2,  2,  4,  4,  4,  5,  5,  6,  6,
      67             :     -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
      68             :      1,  1,  1,  1,  1,  2,  2,  2,  2,  4,  4,  4,  5,  5,  6,  6
      69             : };
      70             : 
      71             : static const int8_t index_table6[] = {
      72             :     -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
      73             :     -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
      74             :      1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  2,  2,  2,  2,  2,  2,
      75             :      2,  2,  4,  4,  4,  4,  4,  4,  5,  5,  5,  5,  6,  6,  6,  6,
      76             :     -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
      77             :     -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
      78             :      1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  2,  2,  2,  2,  2,  2,
      79             :      2,  2,  4,  4,  4,  4,  4,  4,  5,  5,  5,  5,  6,  6,  6,  6
      80             : };
      81             : 
      82             : static const int8_t *const step_index_tables[] = {
      83             :     index_table1, index_table2, index_table3,
      84             :     index_table4, index_table5, index_table6
      85             : };
      86             : 
      87           3 : static av_cold int decode_init(AVCodecContext *avctx)
      88             : {
      89             :     int start_pos;
      90             : 
      91           3 :     avctx->sample_fmt = AV_SAMPLE_FMT_S16;
      92             : 
      93           3 :     if (predict_table_init)
      94           1 :         return 0;
      95             : 
      96         130 :     for (start_pos = 0; start_pos < 64; start_pos++) {
      97             :         unsigned int dest_pos, table_pos;
      98             : 
      99       11648 :         for (table_pos = 0, dest_pos = start_pos;
     100             :              table_pos < FF_ARRAY_ELEMS(ff_adpcm_step_table);
     101       11392 :              table_pos++, dest_pos += 64) {
     102       11392 :             int put = 0, count, table_value;
     103             : 
     104       11392 :             table_value = ff_adpcm_step_table[table_pos];
     105       79744 :             for (count = 32; count != 0; count >>= 1) {
     106       68352 :                 if (start_pos & count)
     107       34176 :                     put += table_value;
     108       68352 :                 table_value >>= 1;
     109             :             }
     110       11392 :             predict_table[dest_pos] = put;
     111             :         }
     112             :     }
     113           2 :     predict_table_init = 1;
     114             : 
     115           2 :     return 0;
     116             : }
     117             : 
     118          16 : static int decode_frame(AVCodecContext *avctx, void *data,
     119             :                         int *got_frame_ptr, AVPacket *pkt)
     120             : {
     121             :     GetBitContext gb;
     122          16 :     AVFrame *frame = data;
     123             :     int16_t pcm_data[2];
     124             :     uint32_t samples;
     125             :     int8_t channel_hint[2];
     126             :     int ret, chan;
     127          16 :     int channels = 1;
     128             : 
     129          16 :     if (pkt->size < 13)
     130           0 :         return AVERROR_INVALIDDATA;
     131             : 
     132          16 :     if ((ret = init_get_bits8(&gb, pkt->data, pkt->size)) < 0)
     133           0 :         return ret;
     134             : 
     135          16 :     samples = get_bits_long(&gb, 32);
     136          16 :     if (samples == 0xffffffff) {
     137          16 :         skip_bits_long(&gb, 32);
     138          16 :         samples = get_bits_long(&gb, 32);
     139             :     }
     140             : 
     141          16 :     if (samples > pkt->size * 2)
     142           0 :         return AVERROR_INVALIDDATA;
     143             : 
     144          16 :     channel_hint[0] = get_sbits(&gb, 8);
     145          16 :     if (channel_hint[0] & 0x80) {
     146          16 :         channel_hint[0] = ~channel_hint[0];
     147          16 :         channels = 2;
     148             :     }
     149          16 :     avctx->channels = channels;
     150          16 :     avctx->channel_layout = (channels == 2) ? AV_CH_LAYOUT_STEREO
     151          16 :                                             : AV_CH_LAYOUT_MONO;
     152          16 :     pcm_data[0] = get_sbits(&gb, 16);
     153          16 :     if (channels > 1) {
     154          16 :         channel_hint[1] = get_sbits(&gb, 8);
     155          16 :         pcm_data[1]     = get_sbits(&gb, 16);
     156             :     }
     157             : 
     158          16 :     frame->nb_samples = samples;
     159          16 :     if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
     160           0 :         return ret;
     161             : 
     162          48 :     for (chan = 0; chan < channels; chan++) {
     163          32 :         uint16_t *dest = (uint16_t *)frame->data[0] + chan;
     164          32 :         int step_index = channel_hint[chan];
     165          32 :         int output = pcm_data[chan];
     166             :         int sample;
     167             : 
     168      191132 :         for (sample = 0; sample < samples; sample++) {
     169             :             int lookup_size, lookup, highbit, lowbits;
     170             : 
     171      191100 :             step_index  = av_clip(step_index, 0, 88);
     172      191100 :             lookup_size = size_table[step_index];
     173      191100 :             lookup      = get_bits(&gb, lookup_size);
     174      191100 :             highbit     = 1 << (lookup_size - 1);
     175      191100 :             lowbits     = highbit - 1;
     176             : 
     177      191100 :             if (lookup & highbit)
     178       93134 :                 lookup ^= highbit;
     179             :             else
     180       97966 :                 highbit = 0;
     181             : 
     182      191100 :             if (lookup == lowbits) {
     183        8197 :                 output = get_sbits(&gb, 16);
     184             :             } else {
     185             :                 int predict_index, diff;
     186             : 
     187      182903 :                 predict_index = (lookup << (7 - lookup_size)) | (step_index << 6);
     188      182903 :                 predict_index = av_clip(predict_index, 0, 5785);
     189      182903 :                 diff          = predict_table[predict_index];
     190      182903 :                 if (lookup)
     191      153682 :                     diff += ff_adpcm_step_table[step_index] >> (lookup_size - 1);
     192      182903 :                 if (highbit)
     193       89050 :                     diff = -diff;
     194             : 
     195      182903 :                 output = av_clip_int16(output + diff);
     196             :             }
     197             : 
     198      191100 :             *dest = output;
     199      191100 :             dest += channels;
     200             : 
     201      191100 :             step_index += step_index_tables[lookup_size - 2][lookup];
     202             :         }
     203             :     }
     204             : 
     205          16 :     *got_frame_ptr = 1;
     206             : 
     207          16 :     return pkt->size;
     208             : }
     209             : 
     210             : AVCodec ff_adpcm_vima_decoder = {
     211             :     .name         = "adpcm_vima",
     212             :     .long_name    = NULL_IF_CONFIG_SMALL("LucasArts VIMA audio"),
     213             :     .type         = AVMEDIA_TYPE_AUDIO,
     214             :     .id           = AV_CODEC_ID_ADPCM_VIMA,
     215             :     .init         = decode_init,
     216             :     .decode       = decode_frame,
     217             :     .capabilities = AV_CODEC_CAP_DR1,
     218             : };

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