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optimize compute_antialias() and add a floating point based alternative (2x faster)

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Originally committed as revision 2679 to svn://svn.ffmpeg.org/ffmpeg/trunk
pull/126/head
Michael Niedermayer 21 years ago
parent ec7d0d2e9e
commit a1e257b231
2 changed files with 109 additions and 12 deletions
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  1. 15
      libavcodec/avcodec.h
  2. 106
      libavcodec/mpegaudiodec.c

15
libavcodec/avcodec.h
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@ -960,6 +960,8 @@ typedef struct AVCodecContext {
/**
* qscale factor between p and i frames.
* if > 0 then the last p frame quantizer will be used (q= lastp_q*factor+offset)
* if < 0 then normal ratecontrol will be done (q= -normal_q*factor+offset)
* - encoding: set by user.
* - decoding: unused
*/
@ -967,8 +969,6 @@ typedef struct AVCodecContext {
/**
* qscale offset between p and i frames.
* if > 0 then the last p frame quantizer will be used (q= lastp_q*factor+offset)
* if < 0 then normal ratecontrol will be done (q= -normal_q*factor+offset)
* - encoding: set by user.
* - decoding: unused
*/
@ -1490,6 +1490,17 @@ typedef struct AVCodecContext {
* - decoding: unused.
*/
int error_rate;
/**
* MP3 antialias algorithm, see FF_AA_* below.
* - encoding: unused
* - decoding: set by user
*/
int antialias_algo;
#define FF_AA_AUTO 0
#define FF_AA_FASTINT 1 //not implemented yet
#define FF_AA_INT 2
#define FF_AA_FLOAT 3
} AVCodecContext;

106
libavcodec/mpegaudiodec.c
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@ -66,6 +66,8 @@ typedef int32_t MPA_INT;
#define HEADER_SIZE 4
#define BACKSTEP_SIZE 512
struct GranuleDef;
typedef struct MPADecodeContext {
uint8_t inbuf1[2][MPA_MAX_CODED_FRAME_SIZE + BACKSTEP_SIZE]; /* input buffer */
int inbuf_index;
@ -93,6 +95,7 @@ typedef struct MPADecodeContext {
#ifdef DEBUG
int frame_count;
#endif
void (*compute_antialias)(struct MPADecodeContext *s, struct GranuleDef *g);
} MPADecodeContext;
/* layer 3 "granule" */
@ -127,6 +130,9 @@ typedef struct HuffTable {
#include "mpegaudiodectab.h"
static void compute_antialias_integer(MPADecodeContext *s, GranuleDef *g);
static void compute_antialias_float(MPADecodeContext *s, GranuleDef *g);
/* vlc structure for decoding layer 3 huffman tables */
static VLC huff_vlc[16];
static uint8_t *huff_code_table[16];
@ -144,7 +150,8 @@ static uint32_t *table_4_3_value;
/* intensity stereo coef table */
static int32_t is_table[2][16];
static int32_t is_table_lsf[2][2][16];
static int32_t csa_table[8][2];
static int32_t csa_table[8][4];
static float csa_table_float[8][4];
static int32_t mdct_win[8][36];
/* lower 2 bits: modulo 3, higher bits: shift */
@ -455,6 +462,10 @@ static int decode_init(AVCodecContext * avctx)
}
}
if(avctx->antialias_algo == FF_AA_INT)
s->compute_antialias= compute_antialias_integer;
else
s->compute_antialias= compute_antialias_float;
for(i=0;i<8;i++) {
float ci, cs, ca;
ci = ci_table[i];
@ -462,6 +473,13 @@ static int decode_init(AVCodecContext * avctx)
ca = cs * ci;
csa_table[i][0] = FIX(cs);
csa_table[i][1] = FIX(ca);
csa_table[i][2] = FIX(ca) + FIX(cs);
csa_table[i][3] = FIX(ca) - FIX(cs);
csa_table_float[i][0] = cs;
csa_table_float[i][1] = ca;
csa_table_float[i][2] = ca + cs;
csa_table_float[i][3] = ca - cs;
// printf("%d %d %d %d\n", FIX(cs), FIX(cs-1), FIX(ca), FIX(cs)-FIX(ca));
}
/* compute mdct windows */
@ -1892,11 +1910,11 @@ static void compute_stereo(MPADecodeContext *s,
}
}
static void compute_antialias(MPADecodeContext *s,
static void compute_antialias_integer(MPADecodeContext *s,
GranuleDef *g)
{
int32_t *ptr, *p0, *p1, *csa;
int n, tmp0, tmp1, i, j;
int n, i, j;
/* we antialias only "long" bands */
if (g->block_type == 2) {
@ -1912,17 +1930,85 @@ static void compute_antialias(MPADecodeContext *s,
for(i = n;i > 0;i--) {
p0 = ptr - 1;
p1 = ptr;
csa = &csa_table[0][0];
for(j=0;j<8;j++) {
csa = &csa_table[0][0];
for(j=0;j<4;j++) {
int tmp0 = *p0;
int tmp1 = *p1;
#if 0
*p0 = FRAC_RND(MUL64(tmp0, csa[0]) - MUL64(tmp1, csa[1]));
*p1 = FRAC_RND(MUL64(tmp0, csa[1]) + MUL64(tmp1, csa[0]));
#else
int64_t tmp2= MUL64(tmp0 + tmp1, csa[0]);
*p0 = FRAC_RND(tmp2 - MUL64(tmp1, csa[2]));
*p1 = FRAC_RND(tmp2 + MUL64(tmp0, csa[3]));
#endif
p0--; p1++;
csa += 4;
tmp0 = *p0;
tmp1 = *p1;
#if 0
*p0 = FRAC_RND(MUL64(tmp0, csa[0]) - MUL64(tmp1, csa[1]));
*p1 = FRAC_RND(MUL64(tmp0, csa[1]) + MUL64(tmp1, csa[0]));
p0--;
p1++;
csa += 2;
#else
tmp2= MUL64(tmp0 + tmp1, csa[0]);
*p0 = FRAC_RND(tmp2 - MUL64(tmp1, csa[2]));
*p1 = FRAC_RND(tmp2 + MUL64(tmp0, csa[3]));
#endif
p0--; p1++;
csa += 4;
}
ptr += 18;
ptr += 18;
}
}
static void compute_antialias_float(MPADecodeContext *s,
GranuleDef *g)
{
int32_t *ptr, *p0, *p1;
int n, i, j;
/* we antialias only "long" bands */
if (g->block_type == 2) {
if (!g->switch_point)
return;
/* XXX: check this for 8000Hz case */
n = 1;
} else {
n = SBLIMIT - 1;
}
ptr = g->sb_hybrid + 18;
for(i = n;i > 0;i--) {
float *csa = &csa_table_float[0][0];
p0 = ptr - 1;
p1 = ptr;
for(j=0;j<4;j++) {
float tmp0 = *p0;
float tmp1 = *p1;
#if 1
*p0 = lrintf(tmp0 * csa[0] - tmp1 * csa[1]);
*p1 = lrintf(tmp0 * csa[1] + tmp1 * csa[0]);
#else
float tmp2= (tmp0 + tmp1) * csa[0];
*p0 = lrintf(tmp2 - tmp1 * csa[2]);
*p1 = lrintf(tmp2 + tmp0 * csa[3]);
#endif
p0--; p1++;
csa += 4;
tmp0 = *p0;
tmp1 = *p1;
#if 1
*p0 = lrintf(tmp0 * csa[0] - tmp1 * csa[1]);
*p1 = lrintf(tmp0 * csa[1] + tmp1 * csa[0]);
#else
tmp2= (tmp0 + tmp1) * csa[0];
*p0 = lrintf(tmp2 - tmp1 * csa[2]);
*p1 = lrintf(tmp2 + tmp0 * csa[3]);
#endif
p0--; p1++;
csa += 4;
}
ptr += 18;
}
}
@ -2352,7 +2438,7 @@ static int mp_decode_layer3(MPADecodeContext *s)
#if defined(DEBUG)
sample_dump(0, g->sb_hybrid, 576);
#endif
compute_antialias(s, g);
s->compute_antialias(s, g);
#if defined(DEBUG)
sample_dump(1, g->sb_hybrid, 576);
#endif

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