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
  25 /*
  26  * YAMAHA ADPCM
  27  *
  28  * References
  29  * [1] YAMAHA, YAMAHA ADPCM ACM Driver Version 1.0.0.0, 2005
  30  * [2] BlendWorks, YM2608 ADPCM,
  31  *     http://web.archive.org/web/20050208190547/www.memb.jp/~dearna/ma/ym2608/adpcm.html
  32  * [3] Naoyuki Sawa, ADPCM no shikumi #1,
  33  *     http://www.piece-me.org/piece-lab/adpcm/adpcm1.html
  34  * [4] ffmpeg source code, libavcodec/adpcm.c
  35  */
  36
  37 /* ADPCM data block layout
  38  *
  39  * when the block header exists. (for example, encoding by YAMAHA ADPCM ACM Driver)
  40  *    blockAlign = (frequency / 60 + 4) * channels.
  41  *
  42  *    block
  43  *       <Mono> (channels = 1)
  44  *          int16_t   first value (Little endian)
  45  *          uint16_t  first predictor (Little endian)
  46  *          uint8_t   ADPCM data (1st data: 0-3 bit, 2nd data: 4-7 bit)
  47  *          ....
  48  *
  49  *       <Stereo> (channels = 2)
  50  *          int16_t   Left channel first value (Little endian)
  51  *          uint16_t  Left channel first predictor (Little endian)
  52  *          int16_t   Right channel first value (Little endian)
  53  *          uint16_t  Right channel first predictor (Little endian)
  54  *          uint8_t   ADPCM data (Left channel: 0-3 bit, Right channel: 4-7 bit)
  55  *          ....
  56  *
  57  * when the block header does not exist. (for example, encoding by ffmpeg)
  58  *    blockAlign = 8000
  59  *
  60  *    block
  61  *       <Mono> (channels = 1)
  62  *          uint8_t   ADPCM data (1st data: 0-3 bit, 2nd data: 4-7 bit)
  63  *          ....
  64  *
  65  *       <Stereo> (channels = 2)
  66  *          uint8_t   ADPCM data (Left channel: 0-3 bit, Right channel: 4-7 bit)
  67  *          ....
  68  */
  69
  70 static const int32_t amplification_table[] ICONST_ATTR = {
  71     230, 230, 230, 230, 307, 409, 512, 614, 230, 230, 230, 230, 307, 409, 512, 614
  72 };
  73
  74 static bool has_block_header = false;
  75
  76 static struct adpcm_data cur_data;
  77 static int blocksperchunk;
  78
  79 static struct pcm_format *fmt;
  80
  81 static bool set_format(struct pcm_format *format)
  82 {
  83     fmt = format;
  84
  85     if (fmt->bitspersample != 4)
  86     {
  87         DEBUGF("CODEC_ERROR: yamaha adpcm must be 4 bitspersample: %d\n",
  88                              fmt->bitspersample);
  89         return false;
  90     }
  91
  92     /* check exists block header */
  93     if (fmt->blockalign == ((ci->id3->frequency / 60) + 4) * fmt->channels)
  94     {
  95         has_block_header = true;
  96
  97         /* chunksize = about 1/30 [sec] data */
  98         fmt->chunksize = fmt->blockalign;
  99         blocksperchunk = 1;
 100     }
 101     else
 102     {
 103         uint32_t max_chunk_count;
 104
 105         has_block_header = false;
 106
 107         /* blockalign = 2 * channels samples */
 108         fmt->blockalign = fmt->channels;
 109         fmt->samplesperblock = 2;
 110
 111         /* chunksize = about 1/32[sec] data */
 112         blocksperchunk = ci->id3->frequency >> 6;
 113         fmt->chunksize = blocksperchunk * fmt->blockalign;
 114
 115         max_chunk_count = (uint64_t)ci->id3->length * ci->id3->frequency
 116                                       / (2000LL * fmt->chunksize / fmt->channels);
 117
 118         /* initialize seek table */
 119         init_seek_table(max_chunk_count);
 120         /* add first data */
 121         add_adpcm_data(&cur_data);
 122     }
 123
 124     return true;
 125 }
 126
 127 static int16_t create_pcmdata(int ch, uint8_t nibble)
 128 {
 129     int32_t tmp_pcmdata = cur_data.pcmdata[ch];
 130     int32_t step        = cur_data.step[ch];
 131     int32_t delta       = step >> 3;
 132
 133     if (nibble & 4) delta += step;
 134     if (nibble & 2) delta += (step >> 1);
 135     if (nibble & 1) delta += (step >> 2);
 136
 137     if (nibble & 0x08)
 138         tmp_pcmdata -= delta;
 139     else
 140         tmp_pcmdata += delta;
 141
 142     CLIP(tmp_pcmdata, -32768, 32767);
 143     cur_data.pcmdata[ch] = tmp_pcmdata;
 144
 145     step = (step * amplification_table[nibble & 0x07]) >> 8;
 146     CLIP(step, 127, 24576);
 147     cur_data.step[ch] = step;
 148
 149     return cur_data.pcmdata[ch];
 150 }
 151
 152 static int decode(const uint8_t *inbuf, size_t inbufsize,
 153                   int32_t *outbuf, int *outbufcount)
 154 {
 155     int ch;
 156     size_t nsamples = 0;
 157
 158     /* read block header */
 159     if (has_block_header)
 160     {
 161         for (ch = 0; ch < fmt->channels; ch++)
 162         {
 163             cur_data.pcmdata[ch] = inbuf[0] | (SE(inbuf[1]) << 8);
 164             cur_data.step[ch]    = inbuf[2] | (inbuf[3] << 8);
 165
 166             inbuf += 4;
 167             inbufsize -= 4;
 168         }
 169     }
 170
 171     /* read block data */
 172     ch = fmt->channels - 1;
 173     while (inbufsize)
 174     {
 175         *outbuf++ = create_pcmdata(0,  *inbuf     ) << 13;
 176         *outbuf++ = create_pcmdata(ch, *inbuf >> 4) << 13;
 177         nsamples += 2;
 178
 179         inbuf++;
 180         inbufsize--;
 181     }
 182
 183     if (fmt->channels == 2)
 184         nsamples >>= 1;
 185     *outbufcount = nsamples;
 186
 187     if (!has_block_header)
 188         add_adpcm_data(&cur_data);
 189
 190     return CODEC_OK;
 191 }
 192
 193 static int decode_for_seek(const uint8_t *inbuf, size_t inbufsize)
 194 {
 195     int ch = fmt->channels - 1;
 196
 197     while (inbufsize)
 198     {
 199         create_pcmdata(0,  *inbuf     );
 200         create_pcmdata(ch, *inbuf >> 4);
 201
 202         inbuf++;
 203         inbufsize--;
 204     }
 205
 206     add_adpcm_data(&cur_data);
 207
 208     return CODEC_OK;
 209 }
 210
 211 static struct pcm_pos *get_seek_pos(long seek_time,
 212                                     uint8_t *(*read_buffer)(size_t *realsize))
 213 {
 214     static struct pcm_pos newpos;
 215     uint32_t new_count= 0;
 216
 217     if (seek_time > 0)
 218         new_count = ((uint64_t)seek_time * ci->id3->frequency
 219                                   / (1000LL * fmt->samplesperblock)) / blocksperchunk;
 220
 221     if (!has_block_header)
 222     {
 223         new_count = seek(new_count, &cur_data, read_buffer, &decode_for_seek);
 224     }
 225     newpos.pos     = new_count * fmt->chunksize;
 226     newpos.samples = new_count * blocksperchunk * fmt->samplesperblock;
 227     return &newpos;
 228 }
 229
 230 static struct pcm_codec codec = {
 231                                     set_format,
 232                                     get_seek_pos,
 233                                     decode,
 234                                 };
 235
 236 const struct pcm_codec *get_yamaha_adpcm_codec(void)
 237 {
 238     /* initialize first step, pcm data */
 239     cur_data.pcmdata[0] = 0;
 240     cur_data.pcmdata[1] = 0;
 241     cur_data.step[0]    = 127;
 242     cur_data.step[1]    = 127;
 243
 244     return &codec;
 245 }