ref: e3e335f13bd2243f0446576cf46dbd1669d38c21
dir: /libfaac/blockswitch.c/
/*
* FAAC - Freeware Advanced Audio Coder
* Copyright (C) 2002 Krzysztof Nikiel
*
* 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 2.1 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
* $Id: psychkni.c,v 1.19 2012/03/01 18:34:17 knik Exp $
*/
#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include "blockswitch.h"
#include "coder.h"
#include "fft.h"
#include "util.h"
#include <faac.h>
typedef float psyfloat;
typedef struct
{
/* bandwidth */
int bandS;
int lastband;
/* band volumes */
psyfloat *engPrev[8];
psyfloat *eng[8];
psyfloat *engNext[8];
psyfloat *engNext2[8];
}
psydata_t;
static void Hann(GlobalPsyInfo * gpsyInfo, double *inSamples, int size)
{
int i;
/* Applying Hann window */
if (size == BLOCK_LEN_LONG * 2)
{
for (i = 0; i < size; i++)
inSamples[i] *= gpsyInfo->hannWindow[i];
}
else
{
for (i = 0; i < size; i++)
inSamples[i] *= gpsyInfo->hannWindowS[i];
}
}
#define PRINTSTAT 0
#if PRINTSTAT
static struct {
int tot;
int s;
} frames;
#endif
static void PsyCheckShort(PsyInfo * psyInfo, double quality)
{
enum {PREVS = 2, NEXTS = 2};
psydata_t *psydata = psyInfo->data;
int lastband = psydata->lastband;
int firstband = 2;
int sfb, win;
psyfloat *lasteng;
psyInfo->block_type = ONLY_LONG_WINDOW;
lasteng = NULL;
for (win = 0; win < PREVS + 8 + NEXTS; win++)
{
psyfloat *eng;
if (win < PREVS)
eng = psydata->engPrev[win + 8 - PREVS];
else if (win < (PREVS + 8))
eng = psydata->eng[win - PREVS];
else
eng = psydata->engNext[win - PREVS - 8];
if (lasteng)
{
double toteng = 0.0;
double volchg = 0.0;
for (sfb = firstband; sfb < lastband; sfb++)
{
toteng += (eng[sfb] < lasteng[sfb]) ? eng[sfb] : lasteng[sfb];
volchg += fabs(eng[sfb] - lasteng[sfb]);
}
if ((volchg / toteng * quality) > 3.0)
{
psyInfo->block_type = ONLY_SHORT_WINDOW;
break;
}
}
lasteng = eng;
}
#if PRINTSTAT
frames.tot++;
if (psyInfo->block_type == ONLY_SHORT_WINDOW)
frames.s++;
#endif
}
static void PsyInit(GlobalPsyInfo * gpsyInfo, PsyInfo * psyInfo, unsigned int numChannels,
unsigned int sampleRate, int *cb_width_long, int num_cb_long,
int *cb_width_short, int num_cb_short)
{
unsigned int channel;
int i, j, size;
gpsyInfo->hannWindow =
(double *) AllocMemory(2 * BLOCK_LEN_LONG * sizeof(double));
gpsyInfo->hannWindowS =
(double *) AllocMemory(2 * BLOCK_LEN_SHORT * sizeof(double));
for (i = 0; i < BLOCK_LEN_LONG * 2; i++)
gpsyInfo->hannWindow[i] = 0.5 * (1 - cos(2.0 * M_PI * (i + 0.5) /
(BLOCK_LEN_LONG * 2)));
for (i = 0; i < BLOCK_LEN_SHORT * 2; i++)
gpsyInfo->hannWindowS[i] = 0.5 * (1 - cos(2.0 * M_PI * (i + 0.5) /
(BLOCK_LEN_SHORT * 2)));
gpsyInfo->sampleRate = (double) sampleRate;
for (channel = 0; channel < numChannels; channel++)
{
psydata_t *psydata = AllocMemory(sizeof(psydata_t));
psyInfo[channel].data = psydata;
}
size = BLOCK_LEN_LONG;
for (channel = 0; channel < numChannels; channel++)
{
psyInfo[channel].size = size;
psyInfo[channel].prevSamples =
(double *) AllocMemory(size * sizeof(double));
memset(psyInfo[channel].prevSamples, 0, size * sizeof(double));
}
size = BLOCK_LEN_SHORT;
for (channel = 0; channel < numChannels; channel++)
{
psydata_t *psydata = psyInfo[channel].data;
psyInfo[channel].sizeS = size;
for (j = 0; j < 8; j++)
{
psydata->engPrev[j] =
(psyfloat *) AllocMemory(NSFB_SHORT * sizeof(psyfloat));
memset(psydata->engPrev[j], 0, NSFB_SHORT * sizeof(psyfloat));
psydata->eng[j] =
(psyfloat *) AllocMemory(NSFB_SHORT * sizeof(psyfloat));
memset(psydata->eng[j], 0, NSFB_SHORT * sizeof(psyfloat));
psydata->engNext[j] =
(psyfloat *) AllocMemory(NSFB_SHORT * sizeof(psyfloat));
memset(psydata->engNext[j], 0, NSFB_SHORT * sizeof(psyfloat));
psydata->engNext2[j] =
(psyfloat *) AllocMemory(NSFB_SHORT * sizeof(psyfloat));
memset(psydata->engNext2[j], 0, NSFB_SHORT * sizeof(psyfloat));
}
}
}
static void PsyEnd(GlobalPsyInfo * gpsyInfo, PsyInfo * psyInfo, unsigned int numChannels)
{
unsigned int channel;
int j;
if (gpsyInfo->hannWindow)
FreeMemory(gpsyInfo->hannWindow);
if (gpsyInfo->hannWindowS)
FreeMemory(gpsyInfo->hannWindowS);
for (channel = 0; channel < numChannels; channel++)
{
if (psyInfo[channel].prevSamples)
FreeMemory(psyInfo[channel].prevSamples);
}
for (channel = 0; channel < numChannels; channel++)
{
psydata_t *psydata = psyInfo[channel].data;
for (j = 0; j < 8; j++)
{
if (psydata->engPrev[j])
FreeMemory(psydata->engPrev[j]);
if (psydata->eng[j])
FreeMemory(psydata->eng[j]);
if (psydata->engNext[j])
FreeMemory(psydata->engNext[j]);
if (psydata->engNext2[j])
FreeMemory(psydata->engNext2[j]);
}
}
for (channel = 0; channel < numChannels; channel++)
{
if (psyInfo[channel].data)
FreeMemory(psyInfo[channel].data);
}
#if PRINTSTAT
printf("short frames: %.2f %%\n", 100.0*frames.s/frames.tot);
#endif
}
/* Do psychoacoustical analysis */
static void PsyCalculate(ChannelInfo * channelInfo, GlobalPsyInfo * gpsyInfo,
PsyInfo * psyInfo, int *cb_width_long, int
num_cb_long, int *cb_width_short,
int num_cb_short, unsigned int numChannels,
double quality
)
{
unsigned int channel;
// limit switching threshold
if (quality < 40)
quality = 40;
for (channel = 0; channel < numChannels; channel++)
{
if (channelInfo[channel].present)
{
if (channelInfo[channel].cpe &&
channelInfo[channel].ch_is_left)
{ /* CPE */
int leftChan = channel;
int rightChan = channelInfo[channel].paired_ch;
PsyCheckShort(&psyInfo[leftChan], quality);
PsyCheckShort(&psyInfo[rightChan], quality);
}
else if (!channelInfo[channel].cpe &&
channelInfo[channel].lfe)
{ /* LFE */
// Only set block type and it should be OK
psyInfo[channel].block_type = ONLY_LONG_WINDOW;
}
else if (!channelInfo[channel].cpe)
{ /* SCE */
PsyCheckShort(&psyInfo[channel], quality);
}
}
}
}
// imported from filtbank.c
static void mdct( FFT_Tables *fft_tables, double *data, int N )
{
double *xi, *xr;
double tempr, tempi, c, s, cold, cfreq, sfreq; /* temps for pre and post twiddle */
double freq = 2.0 * M_PI / N;
double cosfreq8, sinfreq8;
int i, n;
xi = (double*)AllocMemory((N >> 2)*sizeof(double));
xr = (double*)AllocMemory((N >> 2)*sizeof(double));
/* prepare for recurrence relation in pre-twiddle */
cfreq = cos (freq);
sfreq = sin (freq);
cosfreq8 = cos (freq * 0.125);
sinfreq8 = sin (freq * 0.125);
c = cosfreq8;
s = sinfreq8;
for (i = 0; i < (N >> 2); i++) {
/* calculate real and imaginary parts of g(n) or G(p) */
n = 2 * i;
if (n < (N >> 2))
tempr = data [(N>>2) + (N>>1) - 1 - n] + data [N - (N>>2) + n];
else
tempr = data [(N>>2) + (N>>1) - 1 - n] - data [-(N>>2) + n];
if (n < (N >> 2))
tempi = data [(N>>2) + n] - data [(N>>2) - 1 - n];
else
tempi = data [(N>>2) + n] + data [N + (N>>2) - 1 - n];
/* calculate pre-twiddled FFT input */
xr[i] = tempr * c + tempi * s;
xi[i] = tempi * c - tempr * s;
/* use recurrence to prepare cosine and sine for next value of i */
cold = c;
c = c * cfreq - s * sfreq;
s = s * cfreq + cold * sfreq;
}
/* Perform in-place complex FFT of length N/4 */
switch (N) {
case BLOCK_LEN_SHORT * 2:
fft( fft_tables, xr, xi, 6);
break;
case BLOCK_LEN_LONG * 2:
fft( fft_tables, xr, xi, 9);
}
/* prepare for recurrence relations in post-twiddle */
c = cosfreq8;
s = sinfreq8;
/* post-twiddle FFT output and then get output data */
for (i = 0; i < (N >> 2); i++) {
/* get post-twiddled FFT output */
tempr = 2. * (xr[i] * c + xi[i] * s);
tempi = 2. * (xi[i] * c - xr[i] * s);
/* fill in output values */
data [2 * i] = -tempr; /* first half even */
data [(N >> 1) - 1 - 2 * i] = tempi; /* first half odd */
data [(N >> 1) + 2 * i] = -tempi; /* second half even */
data [N - 1 - 2 * i] = tempr; /* second half odd */
/* use recurrence to prepare cosine and sine for next value of i */
cold = c;
c = c * cfreq - s * sfreq;
s = s * cfreq + cold * sfreq;
}
if (xr) FreeMemory(xr);
if (xi) FreeMemory(xi);
}
static void PsyBufferUpdate( FFT_Tables *fft_tables, GlobalPsyInfo * gpsyInfo, PsyInfo * psyInfo,
double *newSamples, unsigned int bandwidth,
int *cb_width_short, int num_cb_short)
{
int win;
double transBuff[2 * BLOCK_LEN_LONG];
double transBuffS[2 * BLOCK_LEN_SHORT];
psydata_t *psydata = psyInfo->data;
psyfloat *tmp;
int sfb;
psydata->bandS = psyInfo->sizeS * bandwidth * 2 / gpsyInfo->sampleRate;
memcpy(transBuff, psyInfo->prevSamples, psyInfo->size * sizeof(double));
memcpy(transBuff + psyInfo->size, newSamples, psyInfo->size * sizeof(double));
for (win = 0; win < 8; win++)
{
int first = 0;
int last = 0;
memcpy(transBuffS, transBuff + (win * BLOCK_LEN_SHORT) + (BLOCK_LEN_LONG - BLOCK_LEN_SHORT) / 2,
2 * psyInfo->sizeS * sizeof(double));
Hann(gpsyInfo, transBuffS, 2 * psyInfo->sizeS);
mdct( fft_tables, transBuffS, 2 * psyInfo->sizeS);
// shift bufs
tmp = psydata->engPrev[win];
psydata->engPrev[win] = psydata->eng[win];
psydata->eng[win] = psydata->engNext[win];
psydata->engNext[win] = psydata->engNext2[win];
psydata->engNext2[win] = tmp;
for (sfb = 0; sfb < num_cb_short; sfb++)
{
double e;
int l;
first = last;
last = first + cb_width_short[sfb];
if (first < 1)
first = 1;
if (first >= psydata->bandS) // band out of range
break;
e = 0.0;
for (l = first; l < last; l++)
e += transBuffS[l] * transBuffS[l];
psydata->engNext2[win][sfb] = e;
}
psydata->lastband = sfb;
for (; sfb < num_cb_short; sfb++)
{
psydata->engNext2[win][sfb] = 0;
}
}
memcpy(psyInfo->prevSamples, newSamples, psyInfo->size * sizeof(double));
}
static void BlockSwitch(CoderInfo * coderInfo, PsyInfo * psyInfo, unsigned int numChannels)
{
unsigned int channel;
int desire = ONLY_LONG_WINDOW;
/* Use the same block type for all channels
If there is 1 channel that wants a short block,
use a short block on all channels.
*/
for (channel = 0; channel < numChannels; channel++)
{
if (psyInfo[channel].block_type == ONLY_SHORT_WINDOW)
desire = ONLY_SHORT_WINDOW;
}
for (channel = 0; channel < numChannels; channel++)
{
int lasttype = coderInfo[channel].block_type;
if (desire == ONLY_SHORT_WINDOW
|| coderInfo[channel].desired_block_type == ONLY_SHORT_WINDOW)
{
if (lasttype == ONLY_LONG_WINDOW || lasttype == SHORT_LONG_WINDOW)
coderInfo[channel].block_type = LONG_SHORT_WINDOW;
else
coderInfo[channel].block_type = ONLY_SHORT_WINDOW;
}
else
{
if (lasttype == ONLY_SHORT_WINDOW || lasttype == LONG_SHORT_WINDOW)
coderInfo[channel].block_type = SHORT_LONG_WINDOW;
else
coderInfo[channel].block_type = ONLY_LONG_WINDOW;
}
coderInfo[channel].desired_block_type = desire;
}
}
psymodel_t psymodel2 =
{
PsyInit,
PsyEnd,
PsyCalculate,
PsyBufferUpdate,
BlockSwitch
};