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authorBen Avison <bavison@riscosopen.org>2014-03-19 17:26:19 +0000
committerMichael Niedermayer <michaelni@gmx.at>2014-03-19 22:24:32 +0100
commite555e1bc39ea71d46a07d0bb847fb426c2dd4d80 (patch)
treef4d8af339856d209c70010982ad53a52549cddba /libavcodec/mlpdec.c
parentf502234f9341bf8fa9773ba47c613bcb2b84a31f (diff)
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truehd: tune VLC decoding for ARM.
Profiling on a Raspberry Pi revealed the best performance to correspond with VLC_BITS = 5. Results for overall audio decode and the get_vlc2 function in particular are as follows: Before After Mean StdDev Mean StdDev Confidence Change 6:2 total 348.8 20.1 339.6 15.1 88.8% +2.7% (insignificant) 6:2 function 38.1 8.1 26.4 4.1 100.0% +44.5% 8:2 total 339.1 15.4 324.5 15.5 99.4% +4.5% 8:2 function 33.8 7.0 27.3 5.6 99.7% +23.6% 6:6 total 604.6 20.8 572.8 20.6 100.0% +5.6% 6:6 function 95.8 8.4 68.9 8.2 100.0% +39.1% 8:8 total 766.4 17.6 741.5 21.2 100.0% +3.4% 8:8 function 106.0 11.4 86.1 9.9 100.0% +23.1% Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
Diffstat (limited to 'libavcodec/mlpdec.c')
-rw-r--r--libavcodec/mlpdec.c13
1 files changed, 10 insertions, 3 deletions
diff --git a/libavcodec/mlpdec.c b/libavcodec/mlpdec.c
index 93ed55212f..cbd900073f 100644
--- a/libavcodec/mlpdec.c
+++ b/libavcodec/mlpdec.c
@@ -37,9 +37,16 @@
#include "mlp_parser.h"
#include "mlpdsp.h"
#include "mlp.h"
+#include "config.h"
/** number of bits used for VLC lookup - longest Huffman code is 9 */
+#if ARCH_ARM == 1
+#define VLC_BITS 5
+#define VLC_STATIC_SIZE 64
+#else
#define VLC_BITS 9
+#define VLC_STATIC_SIZE 512
+#endif
typedef struct SubStream {
/// Set if a valid restart header has been read. Otherwise the substream cannot be decoded.
@@ -193,13 +200,13 @@ static av_cold void init_static(void)
if (!huff_vlc[0].bits) {
INIT_VLC_STATIC(&huff_vlc[0], VLC_BITS, 18,
&ff_mlp_huffman_tables[0][0][1], 2, 1,
- &ff_mlp_huffman_tables[0][0][0], 2, 1, 512);
+ &ff_mlp_huffman_tables[0][0][0], 2, 1, VLC_STATIC_SIZE);
INIT_VLC_STATIC(&huff_vlc[1], VLC_BITS, 16,
&ff_mlp_huffman_tables[1][0][1], 2, 1,
- &ff_mlp_huffman_tables[1][0][0], 2, 1, 512);
+ &ff_mlp_huffman_tables[1][0][0], 2, 1, VLC_STATIC_SIZE);
INIT_VLC_STATIC(&huff_vlc[2], VLC_BITS, 15,
&ff_mlp_huffman_tables[2][0][1], 2, 1,
- &ff_mlp_huffman_tables[2][0][0], 2, 1, 512);
+ &ff_mlp_huffman_tables[2][0][0], 2, 1, VLC_STATIC_SIZE);
}
ff_mlp_init_crc();