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adx: cosmetics: general pretty-printing and comment clean-up

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pull/2/head
Justin Ruggles 13 years ago
parent fbc79a9101
commit 8db67610c0
1 changed files with 73 additions and 61 deletions
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  1. 134
      libavcodec/adxdec.c

134
libavcodec/adxdec.c
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@ -38,82 +38,95 @@ static av_cold int adx_decode_init(AVCodecContext *avctx)
return 0;
}
/* 18 bytes <-> 32 samples */
static void adx_decode(int16_t *out,const unsigned char *in,
ADXChannelState *prev)
/**
* Decode 32 samples from 18 bytes.
*
* A 16-bit scalar value is applied to 32 residuals, which then have a
* 2nd-order LPC filter applied to it to form the output signal for a single
* channel.
*/
static void adx_decode(int16_t *out, const uint8_t *in, ADXChannelState *prev)
{
int scale = AV_RB16(in);
int i;
int s0,s1,s2,d;
int s0, s1, s2, d;
in+=2;
in += 2;
s1 = prev->s1;
s2 = prev->s2;
for(i=0;i<16;i++) {
d = in[i];
d = ((signed char)d >> 4);
s0 = (BASEVOL*d*scale + SCALE1*s1 - SCALE2*s2)>>14;
for (i = 0; i < 16; i++) {
d = in[i];
d = (signed char)d >> 4;
s0 = (BASEVOL * d * scale + SCALE1 * s1 - SCALE2 * s2) >> 14;
s2 = s1;
s1 = av_clip_int16(s0);
*out++=s1;
*out++ = s1;
d = in[i];
d = ((signed char)(d<<4) >> 4);
s0 = (BASEVOL*d*scale + SCALE1*s1 - SCALE2*s2)>>14;
d = in[i];
d = (signed char)(d << 4) >> 4;
s0 = (BASEVOL * d * scale + SCALE1 * s1 - SCALE2 * s2) >> 14;
s2 = s1;
s1 = av_clip_int16(s0);
*out++=s1;
*out++ = s1;
}
prev->s1 = s1;
prev->s2 = s2;
}
static void adx_decode_stereo(int16_t *out,const unsigned char *in,
static void adx_decode_stereo(int16_t *out,const uint8_t *in,
ADXChannelState *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];
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];
}
}
/* return data offset or 0 */
static int adx_decode_header(AVCodecContext *avctx,const unsigned char *buf,size_t bufsize)
/**
* Decode stream header.
*
* @param avctx codec context
* @param buf packet data
* @param bufsize packet size
* @return data offset or 0 if header is invalid
*/
static int adx_decode_header(AVCodecContext *avctx, const uint8_t *buf,
int 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;
if (buf[0] != 0x80)
return 0;
offset = (AV_RB32(buf) ^ 0x80000000) + 4;
if (bufsize < offset || memcmp(buf + offset - 6, "(c)CRI", 6))
return 0;
avctx->channels = buf[7];
avctx->sample_rate = AV_RB32(buf+8);
avctx->bit_rate = avctx->sample_rate*avctx->channels*18*8/32;
avctx->sample_rate = AV_RB32(buf + 8);
avctx->bit_rate = avctx->sample_rate * avctx->channels * 18 * 8 / 32;
return offset;
}
static int adx_decode_frame(AVCodecContext *avctx,
void *data, int *data_size,
AVPacket *avpkt)
static int adx_decode_frame(AVCodecContext *avctx, void *data, int *data_size,
AVPacket *avpkt)
{
const uint8_t *buf0 = avpkt->data;
int buf_size = avpkt->size;
ADXContext *c = avctx->priv_data;
int16_t *samples = data;
const uint8_t *buf = buf0;
int rest = buf_size;
int buf_size = avpkt->size;
ADXContext *c = avctx->priv_data;
int16_t *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;
int hdrsize = adx_decode_header(avctx, buf, rest);
if (!hdrsize)
return -1;
c->header_parsed = 1;
buf += hdrsize;
rest -= hdrsize;
@ -121,46 +134,46 @@ static int adx_decode_frame(AVCodecContext *avctx,
/* 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 (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);
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);
if (avctx->channels == 1) {
adx_decode(samples, c->dec_temp, c->prev);
samples += 32;
} else {
adx_decode_stereo(samples,c->dec_temp,c->prev);
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;
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;
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;
memcpy(c->dec_temp, buf, rest);
buf += rest;
}
*data_size = (uint8_t*)samples - (uint8_t*)data;
return buf-buf0;
return buf - buf0;
}
AVCodec ff_adpcm_adx_decoder = {
@ -170,6 +183,5 @@ AVCodec ff_adpcm_adx_decoder = {
.priv_data_size = sizeof(ADXContext),
.init = adx_decode_init,
.decode = adx_decode_frame,
.long_name = NULL_IF_CONFIG_SMALL("SEGA CRI ADX ADPCM"),
.long_name = NULL_IF_CONFIG_SMALL("SEGA CRI ADX ADPCM"),
};

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