FFmpeg/libavcodec/adx.c
Kostya Shishkov 4783cf0d09 Do not try to decode more data than output buffer may hold
Originally committed as revision 10560 to svn://svn.ffmpeg.org/ffmpeg/trunk
2007-09-24 03:32:24 +00:00

400 lines
9.3 KiB
C

/*
* 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 "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
/* 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;
AV_WB16(adx, 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 = AV_RB16(in);
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;
s2 = s1;
s1 = av_clip_int16(s0);
*out++=s1;
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;
s2 = s1;
s1 = av_clip_int16(s0);
*out++=s1;
}
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 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 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 int is_adx(const unsigned char *buf,size_t bufsize)
{
int offset;
if (buf[0]!=0x80) return 0;
offset = (AV_RB32(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 = AV_RB32(buf+8);
size = AV_RB32(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;
}
/* 18 bytes of data are expanded into 32*2 bytes of audio,
so guard against buffer overflows */
if(rest/18 > *data_size/64)
rest = (*data_size/64) * 18;
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 adpcm_adx_encoder = {
"adpcm_adx",
CODEC_TYPE_AUDIO,
CODEC_ID_ADPCM_ADX,
sizeof(ADXContext),
adx_encode_init,
adx_encode_frame,
adx_encode_close,
NULL,
};
#endif //CONFIG_ENCODERS
AVCodec adpcm_adx_decoder = {
"adpcm_adx",
CODEC_TYPE_AUDIO,
CODEC_ID_ADPCM_ADX,
sizeof(ADXContext),
adx_decode_init,
NULL,
NULL,
adx_decode_frame,
};