/*
  * ADX ADPCM codecs
  * Copyright (c) 2001,2003 BERO
  *
  * This file is part of FFmpeg.
  *
  * FFmpeg is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
  * version 2.1 of the License, or (at your option) any later version.
  *
  * FFmpeg is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Lesser General Public License for more details.
  *
  * You should have received a copy of the GNU Lesser General Public
  * License along with FFmpeg; if not, write to the Free Software
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */

 
 #include "libavutil/intreadwrite.h"

 #include "avcodec.h"
 #include "adx.h"
 
 /**

  * @file

  * SEGA CRI adx codecs.
  *
  * Reference documents:
  * http://ku-www.ss.titech.ac.jp/~yatsushi/adx.html
  * adx2wav & wav2adx http://www.geocities.co.jp/Playtown/2004/
  */
 
 /* 18 bytes <-> 32 samples */
 
 static void adx_encode(unsigned char *adx,const short *wav,PREV *prev)
 {
     int scale;
     int i;
     int s0,s1,s2,d;
     int max=0;
     int min=0;
     int data[32];
 
     s1 = prev->s1;
     s2 = prev->s2;
     for(i=0;i<32;i++) {
         s0 = wav[i];
         d = ((s0<<14) - SCALE1*s1 + SCALE2*s2)/BASEVOL;
         data[i]=d;
         if (max<d) max=d;
         if (min>d) min=d;
         s2 = s1;
         s1 = s0;
     }
     prev->s1 = s1;
     prev->s2 = s2;
 
     /* -8..+7 */
 
     if (max==0 && min==0) {
         memset(adx,0,18);
         return;
     }
 
     if (max/7>-min/8) scale = max/7;
     else scale = -min/8;
 
     if (scale==0) scale=1;
 
     AV_WB16(adx, scale);
 
     for(i=0;i<16;i++) {
         adx[i+2] = ((data[i*2]/scale)<<4) | ((data[i*2+1]/scale)&0xf);
     }
 }
 
 static int adx_encode_header(AVCodecContext *avctx,unsigned char *buf,size_t bufsize)
 {
 #if 0
     struct {
         uint32_t offset; /* 0x80000000 + sample start - 4 */
         unsigned char unknown1[3]; /* 03 12 04 */
         unsigned char channel; /* 1 or 2 */
         uint32_t freq;
         uint32_t size;
         uint32_t unknown2; /* 01 f4 03 00 */
         uint32_t unknown3; /* 00 00 00 00 */
         uint32_t unknown4; /* 00 00 00 00 */
 
     /* if loop
         unknown3 00 15 00 01
         unknown4 00 00 00 01
         long loop_start_sample;
         long loop_start_byte;
         long loop_end_sample;
         long loop_end_byte;
         long
     */
     } adxhdr; /* big endian */
     /* offset-6 "(c)CRI" */
 #endif
     AV_WB32(buf+0x00,0x80000000|0x20);
     AV_WB32(buf+0x04,0x03120400|avctx->channels);
     AV_WB32(buf+0x08,avctx->sample_rate);
     AV_WB32(buf+0x0c,0); /* FIXME: set after */
     AV_WB32(buf+0x10,0x01040300);
     AV_WB32(buf+0x14,0x00000000);
     AV_WB32(buf+0x18,0x00000000);
     memcpy(buf+0x1c,"\0\0(c)CRI",8);
     return 0x20+4;
 }
 

 static av_cold int adx_encode_init(AVCodecContext *avctx)

 {
     if (avctx->channels > 2)
         return -1; /* only stereo or mono =) */
     avctx->frame_size = 32;
 
     avctx->coded_frame= avcodec_alloc_frame();
     avctx->coded_frame->key_frame= 1;
 
 //    avctx->bit_rate = avctx->sample_rate*avctx->channels*18*8/32;
 
     av_log(avctx, AV_LOG_DEBUG, "adx encode init\n");
 
     return 0;
 }
 

 static av_cold int adx_encode_close(AVCodecContext *avctx)

 {
     av_freep(&avctx->coded_frame);
 
     return 0;
 }
 
 static int adx_encode_frame(AVCodecContext *avctx,
                 uint8_t *frame, int buf_size, void *data)
 {
     ADXContext *c = avctx->priv_data;
     const short *samples = data;
     unsigned char *dst = frame;
     int rest = avctx->frame_size;
 
 /*
     input data size =
     ffmpeg.c: do_audio_out()
     frame_bytes = enc->frame_size * 2 * enc->channels;
 */
 
 //    printf("sz=%d ",buf_size); fflush(stdout);
     if (!c->header_parsed) {
         int hdrsize = adx_encode_header(avctx,dst,buf_size);
         dst+=hdrsize;
         c->header_parsed = 1;
     }
 
     if (avctx->channels==1) {
         while(rest>=32) {
             adx_encode(dst,samples,c->prev);
             dst+=18;
             samples+=32;
             rest-=32;
         }
     } else {
         while(rest>=32*2) {
             short tmpbuf[32*2];
             int i;
 
             for(i=0;i<32;i++) {
                 tmpbuf[i] = samples[i*2];
                 tmpbuf[i+32] = samples[i*2+1];
             }
 
             adx_encode(dst,tmpbuf,c->prev);
             adx_encode(dst+18,tmpbuf+32,c->prev+1);
             dst+=18*2;
             samples+=32*2;
             rest-=32*2;
         }
     }
     return dst-frame;
 }
 

 AVCodec ff_adpcm_adx_encoder = {

     "adpcm_adx",

     AVMEDIA_TYPE_AUDIO,

     CODEC_ID_ADPCM_ADX,
     sizeof(ADXContext),
     adx_encode_init,
     adx_encode_frame,
     adx_encode_close,
     NULL,

     .sample_fmts = (const enum AVSampleFormat[]){AV_SAMPLE_FMT_S16,AV_SAMPLE_FMT_NONE},

     .long_name = NULL_IF_CONFIG_SMALL("SEGA CRI ADX ADPCM"),

 };