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Code Issues Releases Activity

ac3enc: add SIMD-optimized shifting functions for use with the fixed-point AC3 encoder.

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This commit is contained in:
Justin Ruggles 2011-03-11 16:45:01 -05:00
parent 323e6fead0
commit f1efbca5e9
5 changed files with 120 additions and 37 deletions
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37
libavcodec/ac3dsp.c
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@ -50,10 +50,47 @@ static int ac3_max_msb_abs_int16_c(const int16_t *src, int len)
return v;
}
static void ac3_lshift_int16_c(int16_t *src, unsigned int len,
unsigned int shift)
{
uint32_t *src32 = (uint32_t *)src;
const uint32_t mask = ~(((1 << shift) - 1) << 16);
int i;
len >>= 1;
for (i = 0; i < len; i += 8) {
src32[i ] = (src32[i ] << shift) & mask;
src32[i+1] = (src32[i+1] << shift) & mask;
src32[i+2] = (src32[i+2] << shift) & mask;
src32[i+3] = (src32[i+3] << shift) & mask;
src32[i+4] = (src32[i+4] << shift) & mask;
src32[i+5] = (src32[i+5] << shift) & mask;
src32[i+6] = (src32[i+6] << shift) & mask;
src32[i+7] = (src32[i+7] << shift) & mask;
}
}
static void ac3_rshift_int32_c(int32_t *src, unsigned int len,
unsigned int shift)
{
do {
*src++ >>= shift;
*src++ >>= shift;
*src++ >>= shift;
*src++ >>= shift;
*src++ >>= shift;
*src++ >>= shift;
*src++ >>= shift;
*src++ >>= shift;
len -= 8;
} while (len > 0);
}
av_cold void ff_ac3dsp_init(AC3DSPContext *c)
{
c->ac3_exponent_min = ac3_exponent_min_c;
c->ac3_max_msb_abs_int16 = ac3_max_msb_abs_int16_c;
c->ac3_lshift_int16 = ac3_lshift_int16_c;
c->ac3_rshift_int32 = ac3_rshift_int32_c;
if (HAVE_MMX)
ff_ac3dsp_init_x86(c);

22
libavcodec/ac3dsp.h
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@ -46,6 +46,28 @@ typedef struct AC3DSPContext {
* @return a value with the same MSB as max(abs(src[]))
*/
int (*ac3_max_msb_abs_int16)(const int16_t *src, int len);
/**
* Left-shift each value in an array of int16_t by a specified amount.
* @param src input array
* constraints: align 16
* @param len number of values in the array
* constraints: multiple of 32 greater than 0
* @param shift left shift amount
* constraints: range [0,15]
*/
void (*ac3_lshift_int16)(int16_t *src, unsigned int len, unsigned int shift);
/**
* Right-shift each value in an array of int32_t by a specified amount.
* @param src input array
* constraints: align 16
* @param len number of values in the array
* constraints: multiple of 16 greater than 0
* @param shift right shift amount
* constraints: range [0,31]
*/
void (*ac3_rshift_int32)(int32_t *src, unsigned int len, unsigned int shift);
} AC3DSPContext;
void ff_ac3dsp_init (AC3DSPContext *c);

41
libavcodec/ac3enc_fixed.c
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@ -277,40 +277,6 @@ static int log2_tab(AC3EncodeContext *s, int16_t *src, int len)
}
/**
* Left-shift each value in an array by a specified amount.
* @param tab input array
* @param n number of values in the array
* @param lshift left shift amount
*/
static void lshift_tab(int16_t *tab, int n, unsigned int lshift)
{
int i;
if (lshift > 0) {
for (i = 0; i < n; i++)
tab[i] <<= lshift;
}
}
/**
* Right-shift each value in an array of int32_t by a specified amount.
* @param src input array
* @param len number of values in the array
* @param shift right shift amount
*/
static void ac3_rshift_int32_c(int32_t *src, unsigned int len, unsigned int shift)
{
int i;
if (shift > 0) {
for (i = 0; i < len; i++)
src[i] >>= shift;
}
}
/**
* Normalize the input samples to use the maximum available precision.
* This assumes signed 16-bit input samples.
@ -320,7 +286,8 @@ static void ac3_rshift_int32_c(int32_t *src, unsigned int len, unsigned int shif
static int normalize_samples(AC3EncodeContext *s)
{
int v = 14 - log2_tab(s, s->windowed_samples, AC3_WINDOW_SIZE);
lshift_tab(s->windowed_samples, AC3_WINDOW_SIZE, v);
if (v > 0)
s->ac3dsp.ac3_lshift_int16(s->windowed_samples, AC3_WINDOW_SIZE, v);
/* +6 to right-shift from 31-bit to 25-bit */
return v + 6;
}
@ -336,8 +303,8 @@ static void scale_coefficients(AC3EncodeContext *s)
for (blk = 0; blk < AC3_MAX_BLOCKS; blk++) {
AC3Block *block = &s->blocks[blk];
for (ch = 0; ch < s->channels; ch++) {
ac3_rshift_int32_c(block->mdct_coef[ch], AC3_MAX_COEFS,
block->coeff_shift[ch]);
s->ac3dsp.ac3_rshift_int32(block->mdct_coef[ch], AC3_MAX_COEFS,
block->coeff_shift[ch]);
}
}
}

45
libavcodec/x86/ac3dsp.asm
View File

@ -133,3 +133,48 @@ INIT_XMM
AC3_MAX_MSB_ABS_INT16 sse2, min_max
%define ABS2 ABS2_SSSE3
AC3_MAX_MSB_ABS_INT16 ssse3, or_abs
;-----------------------------------------------------------------------------
; macro used for ff_ac3_lshift_int16() and ff_ac3_rshift_int32()
;-----------------------------------------------------------------------------
%macro AC3_SHIFT 4 ; l/r, 16/32, shift instruction, instruction set
cglobal ac3_%1shift_int%2_%4, 3,3,5, src, len, shift
movd m0, shiftd
.loop:
mova m1, [srcq ]
mova m2, [srcq+mmsize ]
mova m3, [srcq+mmsize*2]
mova m4, [srcq+mmsize*3]
%3 m1, m0
%3 m2, m0
%3 m3, m0
%3 m4, m0
mova [srcq ], m1
mova [srcq+mmsize ], m2
mova [srcq+mmsize*2], m3
mova [srcq+mmsize*3], m4
add srcq, mmsize*4
sub lend, mmsize*32/%2
ja .loop
.end:
REP_RET
%endmacro
;-----------------------------------------------------------------------------
; void ff_ac3_lshift_int16(int16_t *src, unsigned int len, unsigned int shift)
;-----------------------------------------------------------------------------
INIT_MMX
AC3_SHIFT l, 16, psllw, mmx
INIT_XMM
AC3_SHIFT l, 16, psllw, sse2
;-----------------------------------------------------------------------------
; void ff_ac3_rshift_int32(int32_t *src, unsigned int len, unsigned int shift)
;-----------------------------------------------------------------------------
INIT_MMX
AC3_SHIFT r, 32, psrad, mmx
INIT_XMM
AC3_SHIFT r, 32, psrad, sse2

12
libavcodec/x86/ac3dsp_mmx.c
View File

@ -32,6 +32,12 @@ extern int ff_ac3_max_msb_abs_int16_mmxext(const int16_t *src, int len);
extern int ff_ac3_max_msb_abs_int16_sse2 (const int16_t *src, int len);
extern int ff_ac3_max_msb_abs_int16_ssse3 (const int16_t *src, int len);
extern void ff_ac3_lshift_int16_mmx (int16_t *src, unsigned int len, unsigned int shift);
extern void ff_ac3_lshift_int16_sse2(int16_t *src, unsigned int len, unsigned int shift);
extern void ff_ac3_rshift_int32_mmx (int32_t *src, unsigned int len, unsigned int shift);
extern void ff_ac3_rshift_int32_sse2(int32_t *src, unsigned int len, unsigned int shift);
av_cold void ff_ac3dsp_init_x86(AC3DSPContext *c)
{
int mm_flags = av_get_cpu_flags();
@ -40,6 +46,8 @@ av_cold void ff_ac3dsp_init_x86(AC3DSPContext *c)
if (mm_flags & AV_CPU_FLAG_MMX) {
c->ac3_exponent_min = ff_ac3_exponent_min_mmx;
c->ac3_max_msb_abs_int16 = ff_ac3_max_msb_abs_int16_mmx;
c->ac3_lshift_int16 = ff_ac3_lshift_int16_mmx;
c->ac3_rshift_int32 = ff_ac3_rshift_int32_mmx;
}
if (mm_flags & AV_CPU_FLAG_MMX2 && HAVE_MMX2) {
c->ac3_exponent_min = ff_ac3_exponent_min_mmxext;
@ -48,6 +56,10 @@ av_cold void ff_ac3dsp_init_x86(AC3DSPContext *c)
if (mm_flags & AV_CPU_FLAG_SSE2 && HAVE_SSE) {
c->ac3_exponent_min = ff_ac3_exponent_min_sse2;
c->ac3_max_msb_abs_int16 = ff_ac3_max_msb_abs_int16_sse2;
if (!(mm_flags & AV_CPU_FLAG_SSE2SLOW)) {
c->ac3_lshift_int16 = ff_ac3_lshift_int16_sse2;
c->ac3_rshift_int32 = ff_ac3_rshift_int32_sse2;
}
}
if (mm_flags & AV_CPU_FLAG_SSSE3 && HAVE_SSSE3) {
c->ac3_max_msb_abs_int16 = ff_ac3_max_msb_abs_int16_ssse3;