[FFmpeg-cvslog] ac3enc: add SIMD-optimized shifting functions for use with the fixed-point AC3 encoder
Justin Ruggles
git
Tue Mar 8 20:01:41 CET 2011
ffmpeg | branch: master | Justin Ruggles <justin.ruggles at gmail.com> | Tue Mar 8 13:18:57 2011 -0500| [cc4d3dd3e2171f63cd4297292349b58788fff260] | committer: Michael Niedermayer
ac3enc: add SIMD-optimized shifting functions for use with the fixed-point AC3 encoder
Signed-off-by: Michael Niedermayer <michaelni at gmx.at>
> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=cc4d3dd3e2171f63cd4297292349b58788fff260
---
libavcodec/ac3dsp.c | 26 +++++++++++++++
libavcodec/ac3dsp.h | 22 +++++++++++++
libavcodec/ac3enc_fixed.c | 44 ++------------------------
libavcodec/x86/ac3dsp.asm | 74 +++++++++++++++++++++++++++++++++++++++++++
libavcodec/x86/ac3dsp_mmx.c | 13 +++++++
5 files changed, 138 insertions(+), 41 deletions(-)
diff --git a/libavcodec/ac3dsp.c b/libavcodec/ac3dsp.c
index da3a123..05b1aa8 100644
--- a/libavcodec/ac3dsp.c
+++ b/libavcodec/ac3dsp.c
@@ -50,10 +50,36 @@ 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, int len, unsigned int shift)
+{
+ int i;
+
+ if (shift > 0) {
+ for (i = 0; i < len; i++)
+ src[i] <<= shift;
+ }
+}
+
+static void ac3_shift_int32_c(int32_t *src, int len, int shift)
+{
+ int i;
+
+ if (shift > 0) {
+ for (i = 0; i < len; i++)
+ src[i] <<= shift;
+ } else if (shift < 0) {
+ shift = -shift;
+ for (i = 0; i < len; i++)
+ src[i] >>= shift;
+ }
+}
+
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_shift_int32 = ac3_shift_int32_c;
if (HAVE_MMX)
ff_ac3dsp_init_x86(c);
diff --git a/libavcodec/ac3dsp.h b/libavcodec/ac3dsp.h
index a4f141f..62351e9 100644
--- a/libavcodec/ac3dsp.h
+++ b/libavcodec/ac3dsp.h
@@ -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, int len, unsigned int shift);
+
+ /**
+ * 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 shift amount (negative = right, positive = left)
+ * constraints: range [-31,31]
+ */
+ void (*ac3_shift_int32)(int32_t *src, int len, int shift);
} AC3DSPContext;
void ff_ac3dsp_init (AC3DSPContext *c);
diff --git a/libavcodec/ac3enc_fixed.c b/libavcodec/ac3enc_fixed.c
index e5853a3..0440407 100644
--- a/libavcodec/ac3enc_fixed.c
+++ b/libavcodec/ac3enc_fixed.c
@@ -278,44 +278,6 @@ 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;
- }
-}
-
-
-/**
- * Shift each value in an array by a specified amount.
- * @param src input array
- * @param n number of values in the array
- * @param shift shift amount (negative=right, positive=left)
- */
-static void shift_int32(int32_t *src, int n, int shift)
-{
- int i;
-
- if (shift > 0) {
- for (i = 0; i < n; i++)
- src[i] <<= shift;
- } else if (shift < 0) {
- shift = -shift;
- for (i = 0; i < n; i++)
- src[i] >>= shift;
- }
-}
-
-
-/**
* Normalize the input samples to use the maximum available precision.
* This assumes signed 16-bit input samples.
*
@@ -324,7 +286,7 @@ static void shift_int32(int32_t *src, int n, int shift)
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);
+ s->ac3dsp.ac3_lshift_int16(s->windowed_samples, AC3_WINDOW_SIZE, v);
return 9 - v;
}
@@ -339,8 +301,8 @@ 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++) {
- shift_int32(block->mdct_coef[ch], AC3_MAX_COEFS,
- block->coeff_shift[ch]);
+ s->ac3dsp.ac3_shift_int32(block->mdct_coef[ch], AC3_MAX_COEFS,
+ block->coeff_shift[ch]);
}
}
}
diff --git a/libavcodec/x86/ac3dsp.asm b/libavcodec/x86/ac3dsp.asm
index b1eeca9..a7ec6cb 100644
--- a/libavcodec/x86/ac3dsp.asm
+++ b/libavcodec/x86/ac3dsp.asm
@@ -133,3 +133,77 @@ 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_shift_int32()
+;-----------------------------------------------------------------------------
+
+%macro AC3_SHIFT_4MM 3 ; src/dst, shift instruction, shift amount
+ mova m1, [%1 ]
+ mova m2, [%1+mmsize ]
+ mova m3, [%1+mmsize*2]
+ mova m4, [%1+mmsize*3]
+ %2 m1, %3
+ %2 m2, %3
+ %2 m3, %3
+ %2 m4, %3
+ mova [%1 ], m1
+ mova [%1+mmsize ], m2
+ mova [%1+mmsize*2], m3
+ mova [%1+mmsize*3], m4
+ add %1, mmsize*4
+%endmacro
+
+;-----------------------------------------------------------------------------
+; void ff_ac3_lshift_int16(int16_t *src, int len, unsigned int shift)
+;-----------------------------------------------------------------------------
+
+%macro AC3_LSHIFT_INT16 1
+cglobal ac3_lshift_int16_%1, 3,3,5, src, len, shift
+ test shiftd, shiftd
+ jz .end
+ movd m0, shiftd
+ ALIGN 8
+.loop:
+ AC3_SHIFT_4MM srcq, psllw, m0
+ sub lend, mmsize*2
+ ja .loop
+.end:
+ REP_RET
+%endmacro
+
+INIT_MMX
+AC3_LSHIFT_INT16 mmx
+INIT_XMM
+AC3_LSHIFT_INT16 sse2
+
+;-----------------------------------------------------------------------------
+; void ff_ac3_shift_int32(int32_t *src, int len, int shift)
+;-----------------------------------------------------------------------------
+
+%macro AC3_SHIFT_INT32 1
+cglobal ac3_shift_int32_%1, 3,3,5, src, len, shift
+ test shiftd, shiftd
+ je .end
+ js .shift_right
+ movd m0, shiftd
+.loop_left:
+ AC3_SHIFT_4MM srcq, pslld, m0
+ sub lend, mmsize
+ ja .loop_left
+ jmp .end
+.shift_right:
+ neg shiftd
+ movd m0, shiftd
+.loop_right:
+ AC3_SHIFT_4MM srcq, psrad, m0
+ sub lend, mmsize
+ ja .loop_right
+.end:
+ REP_RET
+%endmacro
+
+INIT_MMX
+AC3_SHIFT_INT32 mmx
+INIT_XMM
+AC3_SHIFT_INT32 sse2
diff --git a/libavcodec/x86/ac3dsp_mmx.c b/libavcodec/x86/ac3dsp_mmx.c
index d8af59c..7560d34 100644
--- a/libavcodec/x86/ac3dsp_mmx.c
+++ b/libavcodec/x86/ac3dsp_mmx.c
@@ -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, int len, unsigned int lshift);
+extern void ff_ac3_lshift_int16_sse2(int16_t *src, int len, unsigned int lshift);
+
+extern void ff_ac3_shift_int32_mmx (int32_t *src, int len, int shift);
+extern void ff_ac3_shift_int32_sse2(int32_t *src, int len, 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_shift_int32 = ff_ac3_shift_int32_mmx;
}
if (mm_flags & AV_CPU_FLAG_MMX2 && HAVE_MMX2) {
c->ac3_exponent_min = ff_ac3_exponent_min_mmxext;
@@ -48,6 +56,11 @@ 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_shift_int32 = ff_ac3_shift_int32_sse2;
+ }
}
if (mm_flags & AV_CPU_FLAG_SSSE3 && HAVE_SSSE3) {
c->ac3_max_msb_abs_int16 = ff_ac3_max_msb_abs_int16_ssse3;
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