This does all the actual bit counting as a final step.
x86 benchmarks:
50% faster in function count_mantissa_bits()
16% faster in function bit_alloc()
---
libavcodec/ac3dsp.c | 33 ++++++++--------
libavcodec/ac3dsp.h | 4 +-
libavcodec/ac3enc.c | 78 +++++++++++++++++++++-----------------
libavcodec/arm/Makefile | 1 -
libavcodec/arm/ac3dsp_arm.S | 52 -------------------------
libavcodec/arm/ac3dsp_init_arm.c | 2 -
6 files changed, 63 insertions(+), 107 deletions(-)
delete mode 100644 libavcodec/arm/ac3dsp_arm.S
diff --git a/libavcodec/ac3dsp.c b/libavcodec/ac3dsp.c
index e3ca37e..374dd6e 100644
--- a/libavcodec/ac3dsp.c
+++ b/libavcodec/ac3dsp.c
@@ -128,24 +128,25 @@ static void ac3_bit_alloc_calc_bap_c(int16_t *mask, int16_t *psd,
} while (end > ff_ac3_band_start_tab[band++]);
}
-static int ac3_compute_mantissa_size_c(int mant_cnt[5], uint8_t *bap,
- int nb_coefs)
-{
- int bits, b, i;
+DECLARE_ALIGNED(16, const uint16_t, ff_ac3_bap_bits)[16] = {
+ 0, 0, 0, 3, 0, 4, 5, 6, 7, 8, 9, 10, 11, 12, 14, 16
+};
- bits = 0;
- for (i = 0; i < nb_coefs; i++) {
- b = bap[i];
- if (b <= 4) {
- // bap=1 to bap=4 will be counted in compute_mantissa_size_final
- mant_cnt[b]++;
- } else if (b <= 13) {
- // bap=5 to bap=13 use (bap-1) bits
- bits += b - 1;
- } else {
- // bap=14 uses 14 bits and bap=15 uses 16 bits
- bits += (b == 14) ? 14 : 16;
- }
+static int ac3_compute_mantissa_size_c(uint16_t mant_cnt[6][16])
+{
+ int blk, bap;
+ int bits = 0;
+
+ for (blk = 0; blk < AC3_MAX_BLOCKS; blk++) {
+ // bap=1 : 3 mantissas in 5 bits
+ bits += (mant_cnt[blk][1] / 3) * 5;
+ // bap=2 : 3 mantissas in 7 bits
+ // bap=4 : 2 mantissas in 7 bits
+ bits += ((mant_cnt[blk][2] / 3) + (mant_cnt[blk][4] >> 1)) * 7;
+
+ bits += mant_cnt[blk][3] * 3;
+ for (bap = 5; bap < 16; bap++)
+ bits += mant_cnt[blk][bap] * ff_ac3_bap_bits[bap];
}
return bits;
}
diff --git a/libavcodec/ac3dsp.h b/libavcodec/ac3dsp.h
index b750767..228b105 100644
--- a/libavcodec/ac3dsp.h
+++ b/libavcodec/ac3dsp.h
@@ -24,6 +24,8 @@
#include <stdint.h>
+extern const uint16_t ff_ac3_bap_bits[16];
+
typedef struct AC3DSPContext {
/**
* Set each encoded exponent in a block to the minimum of itself and the
@@ -104,7 +106,7 @@ typedef struct AC3DSPContext {
/**
* Calculate the number of bits needed to encode a set of mantissas.
*/
- int (*compute_mantissa_size)(int mant_cnt[5], uint8_t *bap, int nb_coefs);
+ int (*compute_mantissa_size)(uint16_t mant_cnt[6][16]);
void (*extract_exponents)(uint8_t *exp, int32_t *coef, int nb_coefs);
} AC3DSPContext;
diff --git a/libavcodec/ac3enc.c b/libavcodec/ac3enc.c
index bb3490a..fbaa1c8 100644
--- a/libavcodec/ac3enc.c
+++ b/libavcodec/ac3enc.c
@@ -945,22 +945,6 @@ static void count_frame_bits(AC3EncodeContext *s)
/**
- * Finalize the mantissa bit count by adding in the grouped mantissas.
- */
-static int compute_mantissa_size_final(int mant_cnt[5])
-{
- // bap=1 : 3 mantissas in 5 bits
- int bits = (mant_cnt[1] / 3) * 5;
- // bap=2 : 3 mantissas in 7 bits
- // bap=4 : 2 mantissas in 7 bits
- bits += ((mant_cnt[2] / 3) + (mant_cnt[4] >> 1)) * 7;
- // bap=3 : each mantissa is 3 bits
- bits += mant_cnt[3] * 3;
- return bits;
-}
-
-
-/**
* Calculate masking curve based on the final exponents.
* Also calculate the power spectral densities to use in future calculations.
*/
@@ -1008,30 +992,54 @@ static void reset_block_bap(AC3EncodeContext *s)
/**
- * Count the number of mantissa bits in the frame based on the bap values.
+ * Initialize mantissa counts.
+ * These are set so that they are padded to the next whole group size when bits
+ * are counted in compute_mantissa_size.
*/
-static int count_mantissa_bits(AC3EncodeContext *s)
+static void count_mantissa_bits_init(uint16_t mant_cnt[AC3_MAX_BLOCKS][16])
{
- int blk, ch;
- int mantissa_bits;
- int mant_cnt[5];
+ int blk;
- mantissa_bits = 0;
for (blk = 0; blk < AC3_MAX_BLOCKS; blk++) {
- // initialize grouped mantissa counts. these are set so that they are
- // padded to the next whole group size when bits are counted in
- // compute_mantissa_size_final
- mant_cnt[0] = mant_cnt[3] = 0;
- mant_cnt[1] = mant_cnt[2] = 2;
- mant_cnt[4] = 1;
- for (ch = 0; ch < s->channels; ch++) {
- mantissa_bits += s->ac3dsp.compute_mantissa_size(mant_cnt,
- s->blocks[blk].exp_ref_block[ch]->bap[ch],
- s->nb_coefs[ch]);
- }
- mantissa_bits += compute_mantissa_size_final(mant_cnt);
+ memset(mant_cnt[blk], 0, sizeof(mant_cnt[blk]));
+ mant_cnt[blk][1] = mant_cnt[blk][2] = 2;
+ mant_cnt[blk][4] = 1;
+ }
+}
+
+
+/**
+ * Update mantissa bit counts for all blocks in 1 channel in a given bandwidth
+ * range.
+ */
+static void count_mantissa_bits_update_ch(AC3EncodeContext *s, int ch,
+ uint16_t mant_cnt[AC3_MAX_BLOCKS][16],
+ int start, int end)
+{
+ int blk, i;
+
+ for (blk = 0; blk < AC3_MAX_BLOCKS; blk++) {
+ uint8_t *bap = s->blocks[blk].exp_ref_block[ch]->bap[ch];
+ for (i = start; i < end; i++)
+ mant_cnt[blk][bap[i]]++;
}
- return mantissa_bits;
+}
+
+
+/**
+ * Count the number of mantissa bits in the frame based on the bap values.
+ */
+static int count_mantissa_bits(AC3EncodeContext *s)
+{
+ int ch;
+ LOCAL_ALIGNED_16(uint16_t, mant_cnt,[AC3_MAX_BLOCKS][16]);
+
+ count_mantissa_bits_init(mant_cnt);
+
+ for (ch = 0; ch < s->channels; ch++)
+ count_mantissa_bits_update_ch(s, ch, mant_cnt, 0, s->nb_coefs[ch]);
+
+ return s->ac3dsp.compute_mantissa_size(mant_cnt);
}
diff --git a/libavcodec/arm/Makefile b/libavcodec/arm/Makefile
index a5abfdd..a5a5dfa 100644
--- a/libavcodec/arm/Makefile
+++ b/libavcodec/arm/Makefile
@@ -1,5 +1,4 @@
OBJS-$(CONFIG_AC3DSP) += arm/ac3dsp_init_arm.o \
- arm/ac3dsp_arm.o
OBJS-$(CONFIG_DCA_DECODER) += arm/dcadsp_init_arm.o \
diff --git a/libavcodec/arm/ac3dsp_arm.S b/libavcodec/arm/ac3dsp_arm.S
deleted file mode 100644
index d7d498e..0000000
--- a/libavcodec/arm/ac3dsp_arm.S
+++ /dev/null
@@ -1,52 +0,0 @@
-/*
- * Copyright (c) 2011 Mans Rullgard <[email protected]>
- *
- * This file is part of Libav.
- *
- * Libav 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.
- *
- * Libav 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 Libav; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
- */
-
-#include "asm.S"
-
-function ff_ac3_compute_mantissa_size_arm, export=1
- push {r4-r8,lr}
- ldm r0, {r4-r8}
- mov r3, r0
- mov r0, #0
-1:
- ldrb lr, [r1], #1
- subs r2, r2, #1
- blt 2f
- cmp lr, #4
- bgt 3f
- subs lr, lr, #1
- addlt r4, r4, #1
- addeq r5, r5, #1
- ble 1b
- subs lr, lr, #2
- addlt r6, r6, #1
- addeq r7, r7, #1
- addgt r8, r8, #1
- b 1b
-3:
- cmp lr, #14
- sublt lr, lr, #1
- addgt r0, r0, #16
- addle r0, r0, lr
- b 1b
-2:
- stm r3, {r4-r8}
- pop {r4-r8,pc}
-endfunc
diff --git a/libavcodec/arm/ac3dsp_init_arm.c b/libavcodec/arm/ac3dsp_init_arm.c
index fd78e1e..4414dc8 100644
--- a/libavcodec/arm/ac3dsp_init_arm.c
+++ b/libavcodec/arm/ac3dsp_init_arm.c
@@ -39,8 +39,6 @@ int ff_ac3_compute_mantissa_size_arm(int cnt[5], uint8_t *bap, int nb_coefs);
av_cold void ff_ac3dsp_init_arm(AC3DSPContext *c, int bit_exact)
{
- c->compute_mantissa_size = ff_ac3_compute_mantissa_size_arm;
-
if (HAVE_ARMV6) {
c->bit_alloc_calc_bap = ff_ac3_bit_alloc_calc_bap_armv6;
}
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