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Separate window function from autocorrelation. 

Signed-off-by: Mans Rullgard <mans@mansr.com>
This commit is contained in:
Justin Ruggles 2011-01-21 00:12:03 +00:00 committed by Mans Rullgard
parent 56f8952b25
commit 77a78e9bdc
6 changed files with 99 additions and 39 deletions
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8
libavcodec/alacenc.c
View File

@ -378,6 +378,7 @@ static void write_compressed_frame(AlacEncodeContext *s)
static av_cold int alac_encode_init(AVCodecContext *avctx)
{
AlacEncodeContext *s = avctx->priv_data;
int ret;
uint8_t *alac_extradata = av_mallocz(ALAC_EXTRADATA_SIZE+1);
avctx->frame_size = DEFAULT_FRAME_SIZE;
@ -455,9 +456,10 @@ static av_cold int alac_encode_init(AVCodecContext *avctx)
avctx->coded_frame->key_frame = 1;
s->avctx = avctx;
ff_lpc_init(&s->lpc_ctx);
ret = ff_lpc_init(&s->lpc_ctx, avctx->frame_size, s->max_prediction_order,
AV_LPC_TYPE_LEVINSON);
return 0;
return ret;
}
static int alac_encode_frame(AVCodecContext *avctx, uint8_t *frame,
@ -513,6 +515,8 @@ verbatim:
static av_cold int alac_encode_close(AVCodecContext *avctx)
{
AlacEncodeContext *s = avctx->priv_data;
ff_lpc_end(&s->lpc_ctx);
av_freep(&avctx->extradata);
avctx->extradata_size = 0;
av_freep(&avctx->coded_frame);

10
libavcodec/flacenc.c
View File

@ -211,13 +211,11 @@ static av_cold int flac_encode_init(AVCodecContext *avctx)
int freq = avctx->sample_rate;
int channels = avctx->channels;
FlacEncodeContext *s = avctx->priv_data;
int i, level;
int i, level, ret;
uint8_t *streaminfo;
s->avctx = avctx;
ff_lpc_init(&s->lpc_ctx);
if (avctx->sample_fmt != AV_SAMPLE_FMT_S16)
return -1;
@ -438,9 +436,12 @@ static av_cold int flac_encode_init(AVCodecContext *avctx)
if (!avctx->coded_frame)
return AVERROR(ENOMEM);
ret = ff_lpc_init(&s->lpc_ctx, avctx->frame_size,
s->options.max_prediction_order, AV_LPC_TYPE_LEVINSON);
dprint_compression_options(s);
return 0;
return ret;
}
@ -1316,6 +1317,7 @@ static av_cold int flac_encode_close(AVCodecContext *avctx)
if (avctx->priv_data) {
FlacEncodeContext *s = avctx->priv_data;
av_freep(&s->md5ctx);
ff_lpc_end(&s->lpc_ctx);
}
av_freep(&avctx->extradata);
avctx->extradata_size = 0;

57
libavcodec/lpc.c
View File

@ -28,7 +28,7 @@
/**
* Apply Welch window function to audio block
*/
static void apply_welch_window(const int32_t *data, int len, double *w_data)
static void apply_welch_window_c(const int32_t *data, int len, double *w_data)
{
int i, n2;
double w;
@ -54,24 +54,16 @@ static void apply_welch_window(const int32_t *data, int len, double *w_data)
* Calculate autocorrelation data from audio samples
* A Welch window function is applied before calculation.
*/
static void lpc_compute_autocorr_c(const int32_t *data, int len, int lag,
static void lpc_compute_autocorr_c(const double *data, int len, int lag,
double *autoc)
{
int i, j;
double tmp[len + lag + 1];
double *data1= tmp + lag;
apply_welch_window(data, len, data1);
for(j=0; j<lag; j++)
data1[j-lag]= 0.0;
data1[len] = 0.0;
for(j=0; j<lag; j+=2){
double sum0 = 1.0, sum1 = 1.0;
for(i=j; i<len; i++){
sum0 += data1[i] * data1[i-j];
sum1 += data1[i] * data1[i-j-1];
sum0 += data[i] * data[i-j];
sum1 += data[i] * data[i-j-1];
}
autoc[j ] = sum0;
autoc[j+1] = sum1;
@ -80,8 +72,8 @@ static void lpc_compute_autocorr_c(const int32_t *data, int len, int lag,
if(j==lag){
double sum = 1.0;
for(i=j-1; i<len; i+=2){
sum += data1[i ] * data1[i-j ]
+ data1[i+1] * data1[i-j+1];
sum += data[i ] * data[i-j ]
+ data[i+1] * data[i-j+1];
}
autoc[j] = sum;
}
@ -177,8 +169,19 @@ int ff_lpc_calc_coefs(LPCContext *s,
assert(max_order >= MIN_LPC_ORDER && max_order <= MAX_LPC_ORDER &&
lpc_type > AV_LPC_TYPE_FIXED);
/* reinit LPC context if parameters have changed */
if (blocksize != s->blocksize || max_order != s->max_order ||
lpc_type != s->lpc_type) {
ff_lpc_end(s);
ff_lpc_init(s, blocksize, max_order, lpc_type);
}
if (lpc_type == AV_LPC_TYPE_LEVINSON) {
s->lpc_compute_autocorr(samples, blocksize, max_order, autoc);
double *windowed_samples = s->windowed_samples + max_order;
s->lpc_apply_welch_window(samples, blocksize, windowed_samples);
s->lpc_compute_autocorr(windowed_samples, blocksize, max_order, autoc);
compute_lpc_coefs(autoc, max_order, &lpc[0][0], MAX_LPC_ORDER, 0, 1);
@ -236,10 +239,32 @@ int ff_lpc_calc_coefs(LPCContext *s,
return opt_order;
}
av_cold void ff_lpc_init(LPCContext *s)
av_cold int ff_lpc_init(LPCContext *s, int blocksize, int max_order,
enum AVLPCType lpc_type)
{
s->blocksize = blocksize;
s->max_order = max_order;
s->lpc_type = lpc_type;
if (lpc_type == AV_LPC_TYPE_LEVINSON) {
s->windowed_samples = av_mallocz((blocksize + max_order + 2) *
sizeof(*s->windowed_samples));
if (!s->windowed_samples)
return AVERROR(ENOMEM);
} else {
s->windowed_samples = NULL;
}
s->lpc_apply_welch_window = apply_welch_window_c;
s->lpc_compute_autocorr = lpc_compute_autocorr_c;
if (HAVE_MMX)
ff_lpc_init_x86(s);
return 0;
}
av_cold void ff_lpc_end(LPCContext *s)
{
av_freep(&s->windowed_samples);
}

31
libavcodec/lpc.h
View File

@ -37,16 +37,35 @@
typedef struct LPCContext {
int blocksize;
int max_order;
enum AVLPCType lpc_type;
double *windowed_samples;
/**
* Apply a Welch window to an array of input samples.
* The output samples have the same scale as the input, but are in double
* sample format.
* @param data input samples
* @param len number of input samples
* @param w_data output samples
*/
void (*lpc_apply_welch_window)(const int32_t *data, int len,
double *w_data);
/**
* Perform autocorrelation on input samples with delay of 0 to lag.
* @param data input samples.
* no alignment needed.
* constraints: no alignment needed, but must have have at
* least lag*sizeof(double) valid bytes preceeding it, and
* size must be at least (len+1)*sizeof(double) if data is
* 16-byte aligned or (len+2)*sizeof(double) if data is
* unaligned.
* @param len number of input samples to process
* @param lag maximum delay to calculate
* @param autoc output autocorrelation coefficients.
* constraints: array size must be at least lag+1.
*/
void (*lpc_compute_autocorr)(const int32_t *data, int len, int lag,
void (*lpc_compute_autocorr)(const double *data, int len, int lag,
double *autoc);
} LPCContext;
@ -64,9 +83,15 @@ int ff_lpc_calc_coefs(LPCContext *s,
/**
* Initialize LPCContext.
*/
void ff_lpc_init(LPCContext *s);
int ff_lpc_init(LPCContext *s, int blocksize, int max_order,
enum AVLPCType lpc_type);
void ff_lpc_init_x86(LPCContext *s);
/**
* Uninitialize LPCContext.
*/
void ff_lpc_end(LPCContext *s);
#ifdef LPC_USE_DOUBLE
#define LPC_TYPE double
#else

13
libavcodec/ra144enc.c
View File

@ -36,6 +36,7 @@
static av_cold int ra144_encode_init(AVCodecContext * avctx)
{
RA144Context *ractx;
int ret;
if (avctx->sample_fmt != AV_SAMPLE_FMT_S16) {
av_log(avctx, AV_LOG_ERROR, "invalid sample format\n");
@ -52,7 +53,16 @@ static av_cold int ra144_encode_init(AVCodecContext * avctx)
ractx->lpc_coef[0] = ractx->lpc_tables[0];
ractx->lpc_coef[1] = ractx->lpc_tables[1];
ractx->avctx = avctx;
ff_lpc_init(&ractx->lpc_ctx);
ret = ff_lpc_init(&ractx->lpc_ctx, avctx->frame_size, LPC_ORDER,
AV_LPC_TYPE_LEVINSON);
return ret;
}
static av_cold int ra144_encode_close(AVCodecContext *avctx)
{
RA144Context *ractx = avctx->priv_data;
ff_lpc_end(&ractx->lpc_ctx);
return 0;
}
@ -506,5 +516,6 @@ AVCodec ra_144_encoder =
sizeof(RA144Context),
ra144_encode_init,
ra144_encode_frame,
ra144_encode_close,
.long_name = NULL_IF_CONFIG_SMALL("RealAudio 1.0 (14.4K) encoder"),
};

19
libavcodec/x86/lpc_mmx.c
View File

@ -69,21 +69,13 @@ static void apply_welch_window_sse2(const int32_t *data, int len, double *w_data
#undef WELCH
}
static void lpc_compute_autocorr_sse2(const int32_t *data, int len, int lag,
static void lpc_compute_autocorr_sse2(const double *data, int len, int lag,
double *autoc)
{
double tmp[len + lag + 2];
double *data1 = tmp + lag;
int j;
if((x86_reg)data1 & 15)
data1++;
apply_welch_window_sse2(data, len, data1);
for(j=0; j<lag; j++)
data1[j-lag]= 0.0;
data1[len] = 0.0;
if((x86_reg)data & 15)
data++;
for(j=0; j<lag; j+=2){
x86_reg i = -len*sizeof(double);
@ -114,7 +106,7 @@ static void lpc_compute_autocorr_sse2(const int32_t *data, int len, int lag,
"movsd %%xmm1, 8(%1) \n\t"
"movsd %%xmm2, 16(%1) \n\t"
:"+&r"(i)
:"r"(autoc+j), "r"(data1+len), "r"(data1+len-j)
:"r"(autoc+j), "r"(data+len), "r"(data+len-j)
:"memory"
);
} else {
@ -137,7 +129,7 @@ static void lpc_compute_autocorr_sse2(const int32_t *data, int len, int lag,
"movsd %%xmm0, %1 \n\t"
"movsd %%xmm1, %2 \n\t"
:"+&r"(i), "=m"(autoc[j]), "=m"(autoc[j+1])
:"r"(data1+len), "r"(data1+len-j)
:"r"(data+len), "r"(data+len-j)
);
}
}
@ -148,6 +140,7 @@ av_cold void ff_lpc_init_x86(LPCContext *c)
int mm_flags = av_get_cpu_flags();
if (mm_flags & (AV_CPU_FLAG_SSE2|AV_CPU_FLAG_SSE2SLOW)) {
c->lpc_apply_welch_window = apply_welch_window_sse2;
c->lpc_compute_autocorr = lpc_compute_autocorr_sse2;
}
}