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/*
* 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 libavcodec/adxenc.c
* 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 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 SampleFormat[]){SAMPLE_FMT_S16,SAMPLE_FMT_NONE},
.long_name = NULL_IF_CONFIG_SMALL("SEGA CRI ADX ADPCM"),
};
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