[FFmpeg-cvslog] dca: ARMv6 optimised decode_blockcode()
Mans Rullgard
git at videolan.org
Sat Nov 26 01:17:41 CET 2011
ffmpeg | branch: master | Mans Rullgard <mans at mansr.com> | Sun Oct 23 17:39:49 2011 +0100| [00a856e3f95214c54a878b7cbd6e8ae8c5ce3ca9] | committer: Mans Rullgard
dca: ARMv6 optimised decode_blockcode()
This is a hand-tuned version of the code with impossible parts of
the FASTDIV function ommitted.
2-5% faster overall on Cortex-A8.
Signed-off-by: Mans Rullgard <mans at mansr.com>
> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=00a856e3f95214c54a878b7cbd6e8ae8c5ce3ca9
---
libavcodec/arm/dca.h | 55 ++++++++++++++++++++++++++++++++++++++++++++++++++
libavcodec/dca.c | 27 +++++++++++++++---------
2 files changed, 72 insertions(+), 10 deletions(-)
diff --git a/libavcodec/arm/dca.h b/libavcodec/arm/dca.h
index 38c8d1f..9ff7f7c 100644
--- a/libavcodec/arm/dca.h
+++ b/libavcodec/arm/dca.h
@@ -23,6 +23,61 @@
#include <stdint.h>
#include "config.h"
+#include "libavutil/intmath.h"
+
+#if HAVE_ARMV6 && HAVE_INLINE_ASM
+
+#define decode_blockcodes decode_blockcodes
+static inline int decode_blockcodes(int code1, int code2, int levels,
+ int *values)
+{
+ int v0, v1, v2, v3, v4, v5;
+
+ __asm__ ("smmul %8, %14, %18 \n"
+ "smmul %11, %15, %18 \n"
+ "smlabb %14, %8, %17, %14 \n"
+ "smlabb %15, %11, %17, %15 \n"
+ "smmul %9, %8, %18 \n"
+ "smmul %12, %11, %18 \n"
+ "sub %14, %14, %16, lsr #1 \n"
+ "sub %15, %15, %16, lsr #1 \n"
+ "smlabb %8, %9, %17, %8 \n"
+ "smlabb %11, %12, %17, %11 \n"
+ "smmul %10, %9, %18 \n"
+ "smmul %13, %12, %18 \n"
+ "str %14, %0 \n"
+ "str %15, %4 \n"
+ "sub %8, %8, %16, lsr #1 \n"
+ "sub %11, %11, %16, lsr #1 \n"
+ "smlabb %9, %10, %17, %9 \n"
+ "smlabb %12, %13, %17, %12 \n"
+ "smmul %14, %10, %18 \n"
+ "smmul %15, %13, %18 \n"
+ "str %8, %1 \n"
+ "str %11, %5 \n"
+ "sub %9, %9, %16, lsr #1 \n"
+ "sub %12, %12, %16, lsr #1 \n"
+ "smlabb %10, %14, %17, %10 \n"
+ "smlabb %13, %15, %17, %13 \n"
+ "str %9, %2 \n"
+ "str %12, %6 \n"
+ "sub %10, %10, %16, lsr #1 \n"
+ "sub %13, %13, %16, lsr #1 \n"
+ "str %10, %3 \n"
+ "str %13, %7 \n"
+ : "=m"(values[0]), "=m"(values[1]),
+ "=m"(values[2]), "=m"(values[3]),
+ "=m"(values[4]), "=m"(values[5]),
+ "=m"(values[6]), "=m"(values[7]),
+ "=&r"(v0), "=&r"(v1), "=&r"(v2),
+ "=&r"(v3), "=&r"(v4), "=&r"(v5),
+ "+&r"(code1), "+&r"(code2)
+ : "r"(levels - 1), "r"(-levels), "r"(ff_inverse[levels]));
+
+ return code1 | code2;
+}
+
+#endif
#if HAVE_NEON && HAVE_INLINE_ASM && HAVE_ASM_MOD_Y
diff --git a/libavcodec/dca.c b/libavcodec/dca.c
index 7f7bcf9..b310638 100644
--- a/libavcodec/dca.c
+++ b/libavcodec/dca.c
@@ -1038,6 +1038,7 @@ static void dca_downmix(float *samples, int srcfmt,
}
+#ifndef decode_blockcodes
/* Very compact version of the block code decoder that does not use table
* look-up but is slightly slower */
static int decode_blockcode(int code, int levels, int *values)
@@ -1051,13 +1052,15 @@ static int decode_blockcode(int code, int levels, int *values)
code = div;
}
- if (code == 0)
- return 0;
- else {
- av_log(NULL, AV_LOG_ERROR, "ERROR: block code look-up failed\n");
- return AVERROR_INVALIDDATA;
- }
+ return code;
+}
+
+static int decode_blockcodes(int code1, int code2, int levels, int *values)
+{
+ return decode_blockcode(code1, levels, values) |
+ decode_blockcode(code2, levels, values + 4);
}
+#endif
static const uint8_t abits_sizes[7] = { 7, 10, 12, 13, 15, 17, 19 };
static const uint8_t abits_levels[7] = { 3, 5, 7, 9, 13, 17, 25 };
@@ -1125,16 +1128,20 @@ static int dca_subsubframe(DCAContext * s, int base_channel, int block_index)
if (abits >= 11 || !dca_smpl_bitalloc[abits].vlc[sel].table){
if (abits <= 7){
/* Block code */
- int block_code1, block_code2, size, levels;
+ int block_code1, block_code2, size, levels, err;
size = abits_sizes[abits-1];
levels = abits_levels[abits-1];
block_code1 = get_bits(&s->gb, size);
- /* FIXME Should test return value */
- decode_blockcode(block_code1, levels, block);
block_code2 = get_bits(&s->gb, size);
- decode_blockcode(block_code2, levels, &block[4]);
+ err = decode_blockcodes(block_code1, block_code2,
+ levels, block);
+ if (err) {
+ av_log(s->avctx, AV_LOG_ERROR,
+ "ERROR: block code look-up failed\n");
+ return AVERROR_INVALIDDATA;
+ }
}else{
/* no coding */
for (m = 0; m < 8; m++)
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