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
  22 #include "libavutil/intreadwrite.h"
  23 #include "avcodec.h"
  24 #include "adx.h"
  25
  26 /**
  27  * @file libavcodec/adxenc.c
  28  * SEGA CRI adx codecs.
  29  *
  30  * Reference documents:
  31  * http://ku-www.ss.titech.ac.jp/~yatsushi/adx.html
  32  * adx2wav & wav2adx http://www.geocities.co.jp/Playtown/2004/
  33  */
  34
  35 /* 18 bytes <-> 32 samples */
  36
  37 static void adx_encode(unsigned char *adx,const short *wav,PREV *prev)
  38 {
  39     int scale;
  40     int i;
  41     int s0,s1,s2,d;
  42     int max=0;
  43     int min=0;
  44     int data[32];
  45
  46     s1 = prev->s1;
  47     s2 = prev->s2;
  48     for(i=0;i<32;i++) {
  49         s0 = wav[i];
  50         d = ((s0<<14) - SCALE1*s1 + SCALE2*s2)/BASEVOL;
  51         data[i]=d;
  52         if (max<d) max=d;
  53         if (min>d) min=d;
  54         s2 = s1;
  55         s1 = s0;
  56     }
  57     prev->s1 = s1;
  58     prev->s2 = s2;
  59
  60     /* -8..+7 */
  61
  62     if (max==0 && min==0) {
  63         memset(adx,0,18);
  64         return;
  65     }
  66
  67     if (max/7>-min/8) scale = max/7;
  68     else scale = -min/8;
  69
  70     if (scale==0) scale=1;
  71
  72     AV_WB16(adx, scale);
  73
  74     for(i=0;i<16;i++) {
  75         adx[i+2] = ((data[i*2]/scale)<<4) | ((data[i*2+1]/scale)&0xf);
  76     }
  77 }
  78
  79 static int adx_encode_header(AVCodecContext *avctx,unsigned char *buf,size_t bufsize)
  80 {
  81 #if 0
  82     struct {
  83         uint32_t offset; /* 0x80000000 + sample start - 4 */
  84         unsigned char unknown1[3]; /* 03 12 04 */
  85         unsigned char channel; /* 1 or 2 */
  86         uint32_t freq;
  87         uint32_t size;
  88         uint32_t unknown2; /* 01 f4 03 00 */
  89         uint32_t unknown3; /* 00 00 00 00 */
  90         uint32_t unknown4; /* 00 00 00 00 */
  91
  92     /* if loop
  93         unknown3 00 15 00 01
  94         unknown4 00 00 00 01
  95         long loop_start_sample;
  96         long loop_start_byte;
  97         long loop_end_sample;
  98         long loop_end_byte;
  99         long
 100     */
 101     } adxhdr; /* big endian */
 102     /* offset-6 "(c)CRI" */
 103 #endif
 104     AV_WB32(buf+0x00,0x80000000|0x20);
 105     AV_WB32(buf+0x04,0x03120400|avctx->channels);
 106     AV_WB32(buf+0x08,avctx->sample_rate);
 107     AV_WB32(buf+0x0c,0); /* FIXME: set after */
 108     AV_WB32(buf+0x10,0x01040300);
 109     AV_WB32(buf+0x14,0x00000000);
 110     AV_WB32(buf+0x18,0x00000000);
 111     memcpy(buf+0x1c,"\0\0(c)CRI",8);
 112     return 0x20+4;
 113 }
 114
 115 static av_cold int adx_encode_init(AVCodecContext *avctx)
 116 {
 117     if (avctx->channels > 2)
 118         return -1; /* only stereo or mono =) */
 119     avctx->frame_size = 32;
 120
 121     avctx->coded_frame= avcodec_alloc_frame();
 122     avctx->coded_frame->key_frame= 1;
 123
 124 //    avctx->bit_rate = avctx->sample_rate*avctx->channels*18*8/32;
 125
 126     av_log(avctx, AV_LOG_DEBUG, "adx encode init\n");
 127
 128     return 0;
 129 }
 130
 131 static av_cold int adx_encode_close(AVCodecContext *avctx)
 132 {
 133     av_freep(&avctx->coded_frame);
 134
 135     return 0;
 136 }
 137
 138 static int adx_encode_frame(AVCodecContext *avctx,
 139                 uint8_t *frame, int buf_size, void *data)
 140 {
 141     ADXContext *c = avctx->priv_data;
 142     const short *samples = data;
 143     unsigned char *dst = frame;
 144     int rest = avctx->frame_size;
 145
 146 /*
 147     input data size =
 148     ffmpeg.c: do_audio_out()
 149     frame_bytes = enc->frame_size * 2 * enc->channels;
 150 */
 151
 152 //    printf("sz=%d ",buf_size); fflush(stdout);
 153     if (!c->header_parsed) {
 154         int hdrsize = adx_encode_header(avctx,dst,buf_size);
 155         dst+=hdrsize;
 156         c->header_parsed = 1;
 157     }
 158
 159     if (avctx->channels==1) {
 160         while(rest>=32) {
 161             adx_encode(dst,samples,c->prev);
 162             dst+=18;
 163             samples+=32;
 164             rest-=32;
 165         }
 166     } else {
 167         while(rest>=32*2) {
 168             short tmpbuf[32*2];
 169             int i;
 170
 171             for(i=0;i<32;i++) {
 172                 tmpbuf[i] = samples[i*2];
 173                 tmpbuf[i+32] = samples[i*2+1];
 174             }
 175
 176             adx_encode(dst,tmpbuf,c->prev);
 177             adx_encode(dst+18,tmpbuf+32,c->prev+1);
 178             dst+=18*2;
 179             samples+=32*2;
 180             rest-=32*2;
 181         }
 182     }
 183     return dst-frame;
 184 }
 185
 186 AVCodec adpcm_adx_encoder = {
 187     "adpcm_adx",
 188     CODEC_TYPE_AUDIO,
 189     CODEC_ID_ADPCM_ADX,
 190     sizeof(ADXContext),
 191     adx_encode_init,
 192     adx_encode_frame,
 193     adx_encode_close,
 194     NULL,
 195     .sample_fmts = (const enum SampleFormat[]){SAMPLE_FMT_S16,SAMPLE_FMT_NONE},
 196     .long_name = NULL_IF_CONFIG_SMALL("SEGA CRI ADX ADPCM"),
 197 };