apps/codecs/libpcm/yamaha_adpcm.c

   1 /***************************************************************************
   2  *             __________               __   ___.
   3  *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
   4  *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
   5  *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
   6  *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
   7  *                     \/            \/     \/    \/            \/
   8  * $Id$
   9  *
  10  * Copyright (C) 2010 Yoshihisa Uchida
  11  *
  12  * This program is free software; you can redistribute it and/or
  13  * modify it under the terms of the GNU General Public License
  14  * as published by the Free Software Foundation; either version 2
  15  * of the License, or (at your option) any later version.
  16  *
  17  * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
  18  * KIND, either express or implied.
  19  *
  20  ****************************************************************************/
  21 #include "codeclib.h"
  22 #include "pcm_common.h"
  23 #include "adpcm_seek.h"
  24 #include "support_formats.h"
  25
  26 /*
  27  * YAMAHA ADPCM
  28  *
  29  * References
  30  * [1] YAMAHA, YAMAHA ADPCM ACM Driver Version 1.0.0.0, 2005
  31  * [2] BlendWorks, YM2608 ADPCM,
  32  *     http://web.archive.org/web/20050208190547/www.memb.jp/~dearna/ma/ym2608/adpcm.html
  33  * [3] Naoyuki Sawa, ADPCM no shikumi #1,
  34  *     http://www.piece-me.org/piece-lab/adpcm/adpcm1.html
  35  * [4] ffmpeg source code, libavcodec/adpcm.c
  36  */
  37
  38 /* ADPCM data block layout
  39  *
  40  * when the block header exists. (for example, encoding by YAMAHA ADPCM ACM Driver)
  41  *    blockAlign = (frequency / 60 + 4) * channels.
  42  *
  43  *    block
  44  *       <Mono> (channels = 1)
  45  *          int16_t   first value (Little endian)
  46  *          uint16_t  first predictor (Little endian)
  47  *          uint8_t   ADPCM data (1st data: 0-3 bit, 2nd data: 4-7 bit)
  48  *          ....
  49  *
  50  *       <Stereo> (channels = 2)
  51  *          int16_t   Left channel first value (Little endian)
  52  *          uint16_t  Left channel first predictor (Little endian)
  53  *          int16_t   Right channel first value (Little endian)
  54  *          uint16_t  Right channel first predictor (Little endian)
  55  *          uint8_t   ADPCM data (Left channel: 0-3 bit, Right channel: 4-7 bit)
  56  *          ....
  57  *
  58  * when the block header does not exist. (for example, encoding by ffmpeg)
  59  *    blockAlign = 8000
  60  *
  61  *    block
  62  *       <Mono> (channels = 1)
  63  *          uint8_t   ADPCM data (1st data: 0-3 bit, 2nd data: 4-7 bit)
  64  *          ....
  65  *
  66  *       <Stereo> (channels = 2)
  67  *          uint8_t   ADPCM data (Left channel: 0-3 bit, Right channel: 4-7 bit)
  68  *          ....
  69  */
  70
  71 static const int32_t amplification_table[] ICONST_ATTR = {
  72     230, 230, 230, 230, 307, 409, 512, 614, 230, 230, 230, 230, 307, 409, 512, 614
  73 };
  74
  75 static bool has_block_header = false;
  76
  77 static struct adpcm_data cur_data;
  78 static int blocksperchunk;
  79
  80 static struct pcm_format *fmt;
  81
  82 static bool set_format(struct pcm_format *format)
  83 {
  84     fmt = format;
  85
  86     if (fmt->bitspersample != 4)
  87     {
  88         DEBUGF("CODEC_ERROR: yamaha adpcm must be 4 bitspersample: %d\n",
  89                              fmt->bitspersample);
  90         return false;
  91     }
  92
  93     /* check exists block header */
  94     if (fmt->blockalign == ((ci->id3->frequency / 60) + 4) * fmt->channels)
  95     {
  96         has_block_header = true;
  97
  98         /* chunksize = about 1/30 [sec] data */
  99         fmt->chunksize = fmt->blockalign;
 100         blocksperchunk = 1;
 101     }
 102     else
 103     {
 104         uint32_t max_chunk_count;
 105
 106         has_block_header = false;
 107
 108         /* blockalign = 2 * channels samples */
 109         fmt->blockalign = fmt->channels;
 110         fmt->samplesperblock = 2;
 111
 112         /* chunksize = about 1/32[sec] data */
 113         blocksperchunk = ci->id3->frequency >> 6;
 114         fmt->chunksize = blocksperchunk * fmt->blockalign;
 115
 116         max_chunk_count = (uint64_t)ci->id3->length * ci->id3->frequency
 117                                       / (2000LL * fmt->chunksize / fmt->channels);
 118
 119         /* initialize seek table */
 120         init_seek_table(max_chunk_count);
 121         /* add first data */
 122         add_adpcm_data(&cur_data);
 123     }
 124
 125     return true;
 126 }
 127
 128 static int16_t create_pcmdata(int ch, uint8_t nibble)
 129 {
 130     int32_t tmp_pcmdata = cur_data.pcmdata[ch];
 131     int32_t step        = cur_data.step[ch];
 132     int32_t delta       = step >> 3;
 133
 134     if (nibble & 4) delta += step;
 135     if (nibble & 2) delta += (step >> 1);
 136     if (nibble & 1) delta += (step >> 2);
 137
 138     if (nibble & 0x08)
 139         tmp_pcmdata -= delta;
 140     else
 141         tmp_pcmdata += delta;
 142
 143     CLIP(tmp_pcmdata, -32768, 32767);
 144     cur_data.pcmdata[ch] = tmp_pcmdata;
 145
 146     step = (step * amplification_table[nibble & 0x07]) >> 8;
 147     CLIP(step, 127, 24576);
 148     cur_data.step[ch] = step;
 149
 150     return cur_data.pcmdata[ch];
 151 }
 152
 153 static int decode(const uint8_t *inbuf, size_t inbufsize,
 154                   int32_t *outbuf, int *outbufcount)
 155 {
 156     int ch;
 157     size_t nsamples = 0;
 158
 159     /* read block header */
 160     if (has_block_header)
 161     {
 162         for (ch = 0; ch < fmt->channels; ch++)
 163         {
 164             cur_data.pcmdata[ch] = inbuf[0] | (SE(inbuf[1]) << 8);
 165             cur_data.step[ch]    = inbuf[2] | (inbuf[3] << 8);
 166
 167             inbuf += 4;
 168             inbufsize -= 4;
 169         }
 170     }
 171
 172     /* read block data */
 173     ch = fmt->channels - 1;
 174     while (inbufsize)
 175     {
 176         *outbuf++ = create_pcmdata(0,  *inbuf     ) << 13;
 177         *outbuf++ = create_pcmdata(ch, *inbuf >> 4) << 13;
 178         nsamples += 2;
 179
 180         inbuf++;
 181         inbufsize--;
 182     }
 183
 184     if (fmt->channels == 2)
 185         nsamples >>= 1;
 186     *outbufcount = nsamples;
 187
 188     if (!has_block_header)
 189         add_adpcm_data(&cur_data);
 190
 191     return CODEC_OK;
 192 }
 193
 194 static int decode_for_seek(const uint8_t *inbuf, size_t inbufsize)
 195 {
 196     int ch = fmt->channels - 1;
 197
 198     while (inbufsize)
 199     {
 200         create_pcmdata(0,  *inbuf     );
 201         create_pcmdata(ch, *inbuf >> 4);
 202
 203         inbuf++;
 204         inbufsize--;
 205     }
 206
 207     add_adpcm_data(&cur_data);
 208
 209     return CODEC_OK;
 210 }
 211
 212 static struct pcm_pos *get_seek_pos(long seek_time,
 213                                     uint8_t *(*read_buffer)(size_t *realsize))
 214 {
 215     static struct pcm_pos newpos;
 216     uint32_t new_count= 0;
 217
 218     if (seek_time > 0)
 219         new_count = ((uint64_t)seek_time * ci->id3->frequency
 220                                   / (1000LL * fmt->samplesperblock)) / blocksperchunk;
 221
 222     if (!has_block_header)
 223     {
 224         new_count = seek(new_count, &cur_data, read_buffer, &decode_for_seek);
 225     }
 226     newpos.pos     = new_count * fmt->chunksize;
 227     newpos.samples = new_count * blocksperchunk * fmt->samplesperblock;
 228     return &newpos;
 229 }
 230
 231 static struct pcm_codec codec = {
 232                                     set_format,
 233                                     get_seek_pos,
 234                                     decode,
 235                                 };
 236
 237 const struct pcm_codec *get_yamaha_adpcm_codec(void)
 238 {
 239     /* initialize first step, pcm data */
 240     cur_data.pcmdata[0] = 0;
 241     cur_data.pcmdata[1] = 0;
 242     cur_data.step[0]    = 127;
 243     cur_data.step[1]    = 127;
 244
 245     return &codec;
 246 }