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Code Issues Releases Activity

adx: remove unneeded post-decode channel interleaving

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instead interleave channels while decoding
This commit is contained in:
Justin Ruggles 2011-11-20 12:46:41 -05:00
parent e2d1eace00
commit 837bbd19eb
2 changed files with 20 additions and 39 deletions
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1
libavcodec/adx.h
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@ -36,6 +36,7 @@ typedef struct {
} ADXChannelState;
typedef struct {
int channels;
ADXChannelState prev[2];
int header_parsed;
unsigned char dec_temp[18*2];

58
libavcodec/adxdec.c
View File

@ -45,8 +45,9 @@ static av_cold int adx_decode_init(AVCodecContext *avctx)
* 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)
static void adx_decode(ADXContext *c, int16_t *out, const uint8_t *in, int ch)
{
ADXChannelState *prev = &c->prev[ch];
int scale = AV_RB16(in);
int i;
int s0, s1, s2, d;
@ -60,33 +61,21 @@ static void adx_decode(int16_t *out, const uint8_t *in, ADXChannelState *prev)
s0 = (BASEVOL * d * scale + SCALE1 * s1 - SCALE2 * s2) >> 14;
s2 = s1;
s1 = av_clip_int16(s0);
*out++ = s1;
*out = s1;
out += c->channels;
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;
out += c->channels;
}
prev->s1 = s1;
prev->s2 = s2;
}
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 ];
out[i*2+1] = tmp[i+32];
}
}
/**
* Decode stream header.
*
@ -98,6 +87,7 @@ static void adx_decode_stereo(int16_t *out,const uint8_t *in,
static int adx_decode_header(AVCodecContext *avctx, const uint8_t *buf,
int bufsize)
{
ADXContext *c = avctx->priv_data;
int offset;
if (buf[0] != 0x80)
@ -106,7 +96,7 @@ static int adx_decode_header(AVCodecContext *avctx, const uint8_t *buf,
if (bufsize < offset || memcmp(buf + offset - 6, "(c)CRI", 6))
return AVERROR_INVALIDDATA;
avctx->channels = buf[7];
c->channels = avctx->channels = buf[7];
if (avctx->channels > 2)
return AVERROR_INVALIDDATA;
avctx->sample_rate = AV_RB32(buf + 8);
@ -149,29 +139,19 @@ static int adx_decode_frame(AVCodecContext *avctx, void *data, int *data_size,
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;
}
adx_decode(c, samples, c->dec_temp, 0);
if (avctx->channels == 2)
adx_decode(c, samples + 1, c->dec_temp + 18, 1);
samples += 32 * c->channels;
}
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 * c->channels) {
adx_decode(c, samples, buf, 0);
if (c->channels == 2)
adx_decode(c, samples + 1, buf + 18, 1);
rest -= 18 * c->channels;
buf += 18 * c->channels;
samples += 32 * c->channels;
}
c->in_temp = rest;