libavcodec/adxenc.c

   1 /*
   2  * ADX ADPCM codecs
   3  * Copyright (c) 2001,2003 BERO
   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 #include "avcodec.h"
  22 #include "adx.h"
  23
  24 /**
  25  * @file adx.c
  26  * SEGA CRI adx codecs.
  27  *
  28  * Reference documents:
  29  * http://ku-www.ss.titech.ac.jp/~yatsushi/adx.html
  30  * adx2wav & wav2adx http://www.geocities.co.jp/Playtown/2004/
  31  */
  32
  33 /* 18 bytes <-> 32 samples */
  34
  35 static void adx_encode(unsigned char *adx,const short *wav,PREV *prev)
  36 {
  37     int scale;
  38     int i;
  39     int s0,s1,s2,d;
  40     int max=0;
  41     int min=0;
  42     int data[32];
  43
  44     s1 = prev->s1;
  45     s2 = prev->s2;
  46     for(i=0;i<32;i++) {
  47         s0 = wav[i];
  48         d = ((s0<<14) - SCALE1*s1 + SCALE2*s2)/BASEVOL;
  49         data[i]=d;
  50         if (max<d) max=d;
  51         if (min>d) min=d;
  52         s2 = s1;
  53         s1 = s0;
  54     }
  55     prev->s1 = s1;
  56     prev->s2 = s2;
  57
  58     /* -8..+7 */
  59
  60     if (max==0 && min==0) {
  61         memset(adx,0,18);
  62         return;
  63     }
  64
  65     if (max/7>-min/8) scale = max/7;
  66     else scale = -min/8;
  67
  68     if (scale==0) scale=1;
  69
  70     AV_WB16(adx, scale);
  71
  72     for(i=0;i<16;i++) {
  73         adx[i+2] = ((data[i*2]/scale)<<4) | ((data[i*2+1]/scale)&0xf);
  74     }
  75 }
  76
  77 static int adx_encode_header(AVCodecContext *avctx,unsigned char *buf,size_t bufsize)
  78 {
  79 #if 0
  80     struct {
  81         uint32_t offset; /* 0x80000000 + sample start - 4 */
  82         unsigned char unknown1[3]; /* 03 12 04 */
  83         unsigned char channel; /* 1 or 2 */
  84         uint32_t freq;
  85         uint32_t size;
  86         uint32_t unknown2; /* 01 f4 03 00 */
  87         uint32_t unknown3; /* 00 00 00 00 */
  88         uint32_t unknown4; /* 00 00 00 00 */
  89
  90     /* if loop
  91         unknown3 00 15 00 01
  92         unknown4 00 00 00 01
  93         long loop_start_sample;
  94         long loop_start_byte;
  95         long loop_end_sample;
  96         long loop_end_byte;
  97         long
  98     */
  99     } adxhdr; /* big endian */
 100     /* offset-6 "(c)CRI" */
 101 #endif
 102     AV_WB32(buf+0x00,0x80000000|0x20);
 103     AV_WB32(buf+0x04,0x03120400|avctx->channels);
 104     AV_WB32(buf+0x08,avctx->sample_rate);
 105     AV_WB32(buf+0x0c,0); /* FIXME: set after */
 106     AV_WB32(buf+0x10,0x01040300);
 107     AV_WB32(buf+0x14,0x00000000);
 108     AV_WB32(buf+0x18,0x00000000);
 109     memcpy(buf+0x1c,"\0\0(c)CRI",8);
 110     return 0x20+4;
 111 }
 112
 113 static av_cold int adx_encode_init(AVCodecContext *avctx)
 114 {
 115     if (avctx->channels > 2)
 116         return -1; /* only stereo or mono =) */
 117     avctx->frame_size = 32;
 118
 119     avctx->coded_frame= avcodec_alloc_frame();
 120     avctx->coded_frame->key_frame= 1;
 121
 122 //    avctx->bit_rate = avctx->sample_rate*avctx->channels*18*8/32;
 123
 124     av_log(avctx, AV_LOG_DEBUG, "adx encode init\n");
 125
 126     return 0;
 127 }
 128
 129 static av_cold int adx_encode_close(AVCodecContext *avctx)
 130 {
 131     av_freep(&avctx->coded_frame);
 132
 133     return 0;
 134 }
 135
 136 static int adx_encode_frame(AVCodecContext *avctx,
 137                 uint8_t *frame, int buf_size, void *data)
 138 {
 139     ADXContext *c = avctx->priv_data;
 140     const short *samples = data;
 141     unsigned char *dst = frame;
 142     int rest = avctx->frame_size;
 143
 144 /*
 145     input data size =
 146     ffmpeg.c: do_audio_out()
 147     frame_bytes = enc->frame_size * 2 * enc->channels;
 148 */
 149
 150 //    printf("sz=%d ",buf_size); fflush(stdout);
 151     if (!c->header_parsed) {
 152         int hdrsize = adx_encode_header(avctx,dst,buf_size);
 153         dst+=hdrsize;
 154         c->header_parsed = 1;
 155     }
 156
 157     if (avctx->channels==1) {
 158         while(rest>=32) {
 159             adx_encode(dst,samples,c->prev);
 160             dst+=18;
 161             samples+=32;
 162             rest-=32;
 163         }
 164     } else {
 165         while(rest>=32*2) {
 166             short tmpbuf[32*2];
 167             int i;
 168
 169             for(i=0;i<32;i++) {
 170                 tmpbuf[i] = samples[i*2];
 171                 tmpbuf[i+32] = samples[i*2+1];
 172             }
 173
 174             adx_encode(dst,tmpbuf,c->prev);
 175             adx_encode(dst+18,tmpbuf+32,c->prev+1);
 176             dst+=18*2;
 177             samples+=32*2;
 178             rest-=32*2;
 179         }
 180     }
 181     return dst-frame;
 182 }
 183
 184 AVCodec adpcm_adx_encoder = {
 185     "adpcm_adx",
 186     CODEC_TYPE_AUDIO,
 187     CODEC_ID_ADPCM_ADX,
 188     sizeof(ADXContext),
 189     adx_encode_init,
 190     adx_encode_frame,
 191     adx_encode_close,
 192     NULL,
 193     .long_name = NULL_IF_CONFIG_SMALL("SEGA CRI ADX"),
 194 };