PeerStreamer

/*

 * ADX ADPCM codecs

 * Copyright (c) 2001,2003 BERO

 *

 * This library 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 of the License, or (at your option) any later version.

 *

 * This library 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 this library; if not, write to the Free Software

 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

 */

#include "avcodec.h"

/**

 * @file adx.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/

 */

typedef struct {

    int s1,s2;

} PREV;

typedef struct {

    PREV prev[2];

    int header_parsed;

    unsigned char dec_temp[18*2];

    unsigned short enc_temp[32*2];

    int in_temp;

} ADXContext;

//#define    BASEVOL    0x11e0

#define    BASEVOL   0x4000

#define    SCALE1    0x7298

#define    SCALE2    0x3350

#define    CLIP(s)    if (s>32767) s=32767; else if (s<-32768) s=-32768

/* 18 bytes <-> 32 samples */

#ifdef CONFIG_ENCODERS

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;

    adx[0] = scale>>8;

    adx[1] = scale;

    for(i=0;i<16;i++) {

        adx[i+2] = ((data[i*2]/scale)<<4) | ((data[i*2+1]/scale)&0xf);

    }

}

#endif //CONFIG_ENCODERS

static void adx_decode(short *out,const unsigned char *in,PREV *prev)

{

    int scale = ((in[0]<<8)|(in[1]));

    int i;

    int s0,s1,s2,d;

//    printf("%x ",scale);

    in+=2;

    s1 = prev->s1;

    s2 = prev->s2;

    for(i=0;i<16;i++) {

        d = in[i];

        // d>>=4; if (d&8) d-=16;

        d = ((signed char)d >> 4);

        s0 = (BASEVOL*d*scale + SCALE1*s1 - SCALE2*s2)>>14;

        CLIP(s0);

        *out++=s0;

        s2 = s1;

        s1 = s0;

        d = in[i];

        //d&=15; if (d&8) d-=16;

        d = ((signed char)(d<<4) >> 4);

        s0 = (BASEVOL*d*scale + SCALE1*s1 - SCALE2*s2)>>14;

        CLIP(s0);

        *out++=s0;

        s2 = s1;

        s1 = s0;

    }

    prev->s1 = s1;

    prev->s2 = s2;

}

static void adx_decode_stereo(short *out,const unsigned char *in,PREV *prev)

{

    short tmp[32*2];

    int i;

    adx_decode(tmp   ,in   ,prev);

    adx_decode(tmp+32,in+18,prev+1);

    for(i=0;i<32;i++) {

        out[i*2]   = tmp[i];

        out[i*2+1] = tmp[i+32];

    }

}

#ifdef CONFIG_ENCODERS

static void write_long(unsigned char *p,uint32_t v)

{

    p[0] = v>>24;

    p[1] = v>>16;

    p[2] = v>>8;

    p[3] = v;

}

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

    write_long(buf+0x00,0x80000000|0x20);

    write_long(buf+0x04,0x03120400|avctx->channels);

    write_long(buf+0x08,avctx->sample_rate);

    write_long(buf+0x0c,0); /* FIXME: set after */

    write_long(buf+0x10,0x01040300);

    write_long(buf+0x14,0x00000000);

    write_long(buf+0x18,0x00000000);

    memcpy(buf+0x1c,"\0\0(c)CRI",8);

    return 0x20+4;

}

static int adx_decode_init(AVCodecContext *avctx);

static 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");

    adx_decode_init(avctx);

    return 0;

}

static 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;

}

#endif //CONFIG_ENCODERS

static uint32_t read_long(const unsigned char *p)

{

    return (p[0]<<24)|(p[1]<<16)|(p[2]<<8)|p[3];

}

int is_adx(const unsigned char *buf,size_t bufsize)

{

    int    offset;

    if (buf[0]!=0x80) return 0;

    offset = (read_long(buf)^0x80000000)+4;

    if (bufsize<offset || memcmp(buf+offset-6,"(c)CRI",6)) return 0;

    return offset;

}

/* return data offset or 6 */

static int adx_decode_header(AVCodecContext *avctx,const unsigned char *buf,size_t bufsize)

{

    int offset;

    int channels,freq,size;

    offset = is_adx(buf,bufsize);

    if (offset==0) return 0;

    channels = buf[7];

    freq = read_long(buf+8);

    size = read_long(buf+12);

//    printf("freq=%d ch=%d\n",freq,channels);

    avctx->sample_rate = freq;

    avctx->channels = channels;

    avctx->bit_rate = freq*channels*18*8/32;

//    avctx->frame_size = 18*channels;

    return offset;

}

static int adx_decode_init(AVCodecContext * avctx)

{

    ADXContext *c = avctx->priv_data;

//    printf("adx_decode_init\n"); fflush(stdout);

    c->prev[0].s1 = 0;

    c->prev[0].s2 = 0;

    c->prev[1].s1 = 0;

    c->prev[1].s2 = 0;

    c->header_parsed = 0;

    c->in_temp = 0;

    return 0;

}

#if 0

static void dump(unsigned char *buf,size_t len)

{

    int i;

    for(i=0;i<len;i++) {

        if ((i&15)==0) av_log(NULL, AV_LOG_DEBUG, "%04x  ",i);

        av_log(NULL, AV_LOG_DEBUG, "%02x ",buf[i]);

        if ((i&15)==15) av_log(NULL, AV_LOG_DEBUG, "\n");

    }

    av_log(NULL, AV_LOG_ERROR, "\n");

}

#endif

static int adx_decode_frame(AVCodecContext *avctx,

                void *data, int *data_size,

                uint8_t *buf0, int buf_size)

{

    ADXContext *c = avctx->priv_data;

    short *samples = data;

    const uint8_t *buf = buf0;

    int rest = buf_size;

    if (!c->header_parsed) {

        int hdrsize = adx_decode_header(avctx,buf,rest);

        if (hdrsize==0) return -1;

        c->header_parsed = 1;

        buf  += hdrsize;

        rest -= hdrsize;

    }

    if (c->in_temp) {

        int copysize = 18*avctx->channels - c->in_temp;

        memcpy(c->dec_temp+c->in_temp,buf,copysize);

        rest -= copysize;

        buf  += copysize;

        if (avctx->channels==1) {

            adx_decode(samples,c->dec_temp,c->prev);

            samples += 32;

        } else {

            adx_decode_stereo(samples,c->dec_temp,c->prev);

            samples += 32*2;

        }

    }

    //

    if (avctx->channels==1) {

        while(rest>=18) {

            adx_decode(samples,buf,c->prev);

            rest-=18;

            buf+=18;

            samples+=32;

        }

    } else {

        while(rest>=18*2) {

            adx_decode_stereo(samples,buf,c->prev);

            rest-=18*2;

            buf+=18*2;

            samples+=32*2;

        }

    }

    //

    c->in_temp = rest;

    if (rest) {

        memcpy(c->dec_temp,buf,rest);

        buf+=rest;

    }

    *data_size = (uint8_t*)samples - (uint8_t*)data;

//    printf("%d:%d ",buf-buf0,*data_size); fflush(stdout);

    return buf-buf0;

}

#ifdef CONFIG_ENCODERS

AVCodec adx_adpcm_encoder = {

    "adx_adpcm",

    CODEC_TYPE_AUDIO,

    CODEC_ID_ADPCM_ADX,

    sizeof(ADXContext),

    adx_encode_init,

    adx_encode_frame,

    adx_encode_close,

    NULL,

};

#endif //CONFIG_ENCODERS

AVCodec adx_adpcm_decoder = {

    "adx_adpcm",

    CODEC_TYPE_AUDIO,

    CODEC_ID_ADPCM_ADX,

    sizeof(ADXContext),

    adx_decode_init,

    NULL,

    NULL,

    adx_decode_frame,

};