[FFmpeg-cvslog] r26046 - trunk/libavcodec/ac3enc.c
jbr
subversion
Fri Dec 17 21:52:28 CET 2010
Author: jbr
Date: Fri Dec 17 21:52:27 2010
New Revision: 26046
Log:
Add support for fixed-point MDCT sizes other than 512.
Modified:
trunk/libavcodec/ac3enc.c
Modified: trunk/libavcodec/ac3enc.c
==============================================================================
--- trunk/libavcodec/ac3enc.c Fri Dec 17 16:02:15 2010 (r26045)
+++ trunk/libavcodec/ac3enc.c Fri Dec 17 21:52:27 2010 (r26046)
@@ -37,9 +37,6 @@
#include "audioconvert.h"
-#define MDCT_NBITS 9
-#define MDCT_SAMPLES (1 << MDCT_NBITS)
-
/** Maximum number of exponent groups. +1 for separate DC exponent. */
#define AC3_MAX_EXP_GROUPS 85
@@ -60,6 +57,11 @@ typedef struct IComplex {
typedef struct AC3MDCTContext {
AVCodecContext *avctx; ///< parent context for av_log()
+ int nbits; ///< log2(transform size)
+ int16_t *costab; ///< FFT cos table
+ int16_t *sintab; ///< FFT sin table
+ int16_t *xcos1; ///< MDCT cos table
+ int16_t *xsin1; ///< MDCT sin table
int16_t *rot_tmp; ///< temp buffer for pre-rotated samples
IComplex *cplx_tmp; ///< temp buffer for complex pre-rotated samples
} AC3MDCTContext;
@@ -145,12 +147,6 @@ typedef struct AC3EncodeContext {
} AC3EncodeContext;
-/** MDCT and FFT tables */
-static int16_t costab[64];
-static int16_t sintab[64];
-static int16_t xcos1[128];
-static int16_t xsin1[128];
-
/**
* LUT for number of exponent groups.
* exponent_group_tab[exponent strategy-1][number of coefficients]
@@ -209,6 +205,11 @@ static void deinterleave_input_samples(A
*/
static av_cold void mdct_end(AC3MDCTContext *mdct)
{
+ mdct->nbits = 0;
+ av_freep(&mdct->costab);
+ av_freep(&mdct->sintab);
+ av_freep(&mdct->xcos1);
+ av_freep(&mdct->xsin1);
av_freep(&mdct->rot_tmp);
av_freep(&mdct->cplx_tmp);
}
@@ -219,7 +220,7 @@ static av_cold void mdct_end(AC3MDCTCont
* Initialize FFT tables.
* @param ln log2(FFT size)
*/
-static av_cold void fft_init(int ln)
+static av_cold int fft_init(AC3MDCTContext *mdct, int ln)
{
int i, n, n2;
float alpha;
@@ -227,11 +228,21 @@ static av_cold void fft_init(int ln)
n = 1 << ln;
n2 = n >> 1;
+ FF_ALLOC_OR_GOTO(mdct->avctx, mdct->costab, n2 * sizeof(*mdct->costab),
+ fft_alloc_fail);
+ FF_ALLOC_OR_GOTO(mdct->avctx, mdct->sintab, n2 * sizeof(*mdct->sintab),
+ fft_alloc_fail);
+
for (i = 0; i < n2; i++) {
alpha = 2.0 * M_PI * i / n;
- costab[i] = FIX15(cos(alpha));
- sintab[i] = FIX15(sin(alpha));
+ mdct->costab[i] = FIX15(cos(alpha));
+ mdct->sintab[i] = FIX15(sin(alpha));
}
+
+ return 0;
+fft_alloc_fail:
+ mdct_end(mdct);
+ return AVERROR(ENOMEM);
}
@@ -241,13 +252,21 @@ static av_cold void fft_init(int ln)
*/
static av_cold int mdct_init(AC3MDCTContext *mdct, int nbits)
{
- int i, n, n4;
+ int i, n, n4, ret;
n = 1 << nbits;
n4 = n >> 2;
- fft_init(nbits - 2);
+ mdct->nbits = nbits;
+
+ ret = fft_init(mdct, nbits - 2);
+ if (ret)
+ return ret;
+ FF_ALLOC_OR_GOTO(mdct->avctx, mdct->xcos1, n4 * sizeof(*mdct->xcos1),
+ mdct_alloc_fail);
+ FF_ALLOC_OR_GOTO(mdct->avctx, mdct->xsin1 , n4 * sizeof(*mdct->xsin1),
+ mdct_alloc_fail);
FF_ALLOC_OR_GOTO(mdct->avctx, mdct->rot_tmp, n * sizeof(*mdct->rot_tmp),
mdct_alloc_fail);
FF_ALLOC_OR_GOTO(mdct->avctx, mdct->cplx_tmp, n4 * sizeof(*mdct->cplx_tmp),
@@ -255,12 +274,13 @@ static av_cold int mdct_init(AC3MDCTCont
for (i = 0; i < n4; i++) {
float alpha = 2.0 * M_PI * (i + 1.0 / 8.0) / n;
- xcos1[i] = FIX15(-cos(alpha));
- xsin1[i] = FIX15(-sin(alpha));
+ mdct->xcos1[i] = FIX15(-cos(alpha));
+ mdct->xsin1[i] = FIX15(-sin(alpha));
}
return 0;
mdct_alloc_fail:
+ mdct_end(mdct);
return AVERROR(ENOMEM);
}
@@ -293,7 +313,7 @@ mdct_alloc_fail:
* @param z complex input/output samples
* @param ln log2(FFT size)
*/
-static void fft(IComplex *z, int ln)
+static void fft(AC3MDCTContext *mdct, IComplex *z, int ln)
{
int j, l, np, np2;
int nblocks, nloops;
@@ -345,7 +365,7 @@ static void fft(IComplex *z, int ln)
p++;
q++;
for(l = nblocks; l < np2; l += nblocks) {
- CMUL(tmp_re, tmp_im, costab[l], -sintab[l], q->re, q->im);
+ CMUL(tmp_re, tmp_im, mdct->costab[l], -mdct->sintab[l], q->re, q->im);
BF(p->re, p->im, q->re, q->im,
p->re, p->im, tmp_re, tmp_im);
p++;
@@ -367,29 +387,33 @@ static void fft(IComplex *z, int ln)
*/
static void mdct512(AC3MDCTContext *mdct, int32_t *out, int16_t *in)
{
- int i, re, im;
+ int i, re, im, n, n2, n4;
int16_t *rot = mdct->rot_tmp;
IComplex *x = mdct->cplx_tmp;
+ n = 1 << mdct->nbits;
+ n2 = n >> 1;
+ n4 = n >> 2;
+
/* shift to simplify computations */
- for (i = 0; i < MDCT_SAMPLES/4; i++)
- rot[i] = -in[i + 3*MDCT_SAMPLES/4];
- memcpy(&rot[MDCT_SAMPLES/4], &in[0], 3*MDCT_SAMPLES/4*sizeof(*in));
+ for (i = 0; i <n4; i++)
+ rot[i] = -in[i + 3*n4];
+ memcpy(&rot[n4], &in[0], 3*n4*sizeof(*in));
/* pre rotation */
- for (i = 0; i < MDCT_SAMPLES/4; i++) {
- re = ((int)rot[ 2*i] - (int)rot[MDCT_SAMPLES -1-2*i]) >> 1;
- im = -((int)rot[MDCT_SAMPLES/2+2*i] - (int)rot[MDCT_SAMPLES/2-1-2*i]) >> 1;
- CMUL(x[i].re, x[i].im, re, im, -xcos1[i], xsin1[i]);
+ for (i = 0; i < n4; i++) {
+ re = ((int)rot[ 2*i] - (int)rot[ n-1-2*i]) >> 1;
+ im = -((int)rot[n2+2*i] - (int)rot[n2-1-2*i]) >> 1;
+ CMUL(x[i].re, x[i].im, re, im, -mdct->xcos1[i], mdct->xsin1[i]);
}
- fft(x, MDCT_NBITS - 2);
+ fft(mdct, x, mdct->nbits - 2);
/* post rotation */
- for (i = 0; i < MDCT_SAMPLES/4; i++) {
+ for (i = 0; i < n4; i++) {
re = x[i].re;
im = x[i].im;
- CMUL(out[MDCT_SAMPLES/2-1-2*i], out[2*i], re, im, xsin1[i], xcos1[i]);
+ CMUL(out[n2-1-2*i], out[2*i], re, im, mdct->xsin1[i], mdct->xcos1[i]);
}
}
@@ -1824,10 +1848,12 @@ init_fail:
#include "libavutil/lfg.h"
+#define MDCT_NBITS 9
+#define MDCT_SAMPLES (1 << MDCT_NBITS)
#define FN (MDCT_SAMPLES/4)
-static void fft_test(AVLFG *lfg)
+static void fft_test(AC3MDCTContext *mdct, AVLFG *lfg)
{
IComplex in[FN], in1[FN];
int k, n, i;
@@ -1838,7 +1864,7 @@ static void fft_test(AVLFG *lfg)
in[i].im = av_lfg_get(lfg) % 65535 - 32767;
in1[i] = in[i];
}
- fft(in, 7);
+ fft(mdct, in, 7);
/* do it by hand */
for (k = 0; k < FN; k++) {
@@ -1855,7 +1881,7 @@ static void fft_test(AVLFG *lfg)
}
-static void mdct_test(AVLFG *lfg)
+static void mdct_test(AC3MDCTContext *mdct, AVLFG *lfg)
{
int16_t input[MDCT_SAMPLES];
int32_t output[AC3_MAX_COEFS];
@@ -1869,7 +1895,7 @@ static void mdct_test(AVLFG *lfg)
input1[i] = input[i];
}
- mdct512(output, input);
+ mdct512(mdct, output, input);
/* do it by hand */
for (k = 0; k < AC3_MAX_COEFS; k++) {
@@ -1897,12 +1923,14 @@ static void mdct_test(AVLFG *lfg)
int main(void)
{
AVLFG lfg;
+ AC3MDCTContext mdct;
+ mdct.avctx = NULL;
av_log_set_level(AV_LOG_DEBUG);
- mdct_init(9);
+ mdct_init(&mdct, 9);
- fft_test(&lfg);
- mdct_test(&lfg);
+ fft_test(&mdct, &lfg);
+ mdct_test(&mdct, &lfg);
return 0;
}
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