lavu: add av_ctz() for trailing zero bit count

Justin Ruggles committed 14 years ago

Commit dfde8a31 parent 6a744d25 files · +65 −2Browse files

Unified · Split

5 files

@@ -13,6 +13,9 @@ libavutil: 2012-10-22 · 12 unmodified lines
13		13
14	API changes, most recent first:	14	API changes, most recent first:
15		15
		16	2012-xx-xx - xxxxxxx - lavu 52.1.0 - intmath.h
		17	Add av_ctz() for trailing zero bit count
		18
16	2012-10-18 - xxxxxxx - lavu 51.45.0 - error.h	19	2012-10-18 - xxxxxxx - lavu 51.45.0 - error.h
17	Add AVERROR_EXPERIMENTAL	20	Add AVERROR_EXPERIMENTAL
18		21

        float_dsp.o                                                      \
        imgutils.o                                                       \
        intfloat_readwrite.o                                             \
+       intmath.o                                                        \
        lfg.o                                                            \
        lls.o                                                            \
        log.o                                                            \
-       log2.o                                                           \
        log2_tab.o                                                       \
        mathematics.o                                                    \
        md5.o                                                            \

libavutil/intmath.crenamed from libavutil/log2.c+5−0

@@ -32,3 +32,8 @@ int av_log2_16bit(unsigned v) · 31 unmodified lines
32	{	32	{
33	return ff_log2_16bit(v);	33	return ff_log2_16bit(v);
34	}	34	}
		35
		36	int av_ctz(int v)
		37	{
		38	return ff_ctz(v);
		39	}

@@ -85,6 +85,61 @@ static av_always_inline av_const int ff_log2_16bit_c(unsigned int v) · 84 unmodified lines
85	#define av_log2 ff_log2	85	#define av_log2 ff_log2
86	#define av_log2_16bit ff_log2_16bit	86	#define av_log2_16bit ff_log2_16bit
87		87
		88	/**
		89	* @}
		90	*/
		91
		92	/**
		93	* @addtogroup lavu_math
		94	* @{
		95	*/
		96
		97	#if HAVE_FAST_CLZ && AV_GCC_VERSION_AT_LEAST(3,4)
		98	#ifndef ff_ctz
		99	#define ff_ctz(v) __builtin_ctz(v)
		100	#endif
		101	#endif
		102
		103	#ifndef ff_ctz
		104	#define ff_ctz ff_ctz_c
		105	static av_always_inline av_const int ff_ctz_c(int v)
		106	{
		107	int c;
		108
		109	if (v & 0x1)
		110	return 0;
		111
		112	c = 1;
		113	if (!(v & 0xffff)) {
		114	v >>= 16;
		115	c += 16;
		116	}
		117	if (!(v & 0xff)) {
		118	v >>= 8;
		119	c += 8;
		120	}
		121	if (!(v & 0xf)) {
		122	v >>= 4;
		123	c += 4;
		124	}
		125	if (!(v & 0x3)) {
		126	v >>= 2;
		127	c += 2;
		128	}
		129	c -= v & 0x1;
		130
		131	return c;
		132	}
		133	#endif
		134
		135	/**
		136	* Trailing zero bit count.
		137	*
		138	* @param v input value. If v is 0, the result is undefined.
		139	* @return the number of trailing 0-bits
		140	*/
		141	int av_ctz(int v);
		142
88	/**	143	/**
89	* @}	144	* @}
90	*/	145	*/

@@ -37,7 +37,7 @@ · 36 unmodified lines
37	*/	37	*/
38		38
39	#define LIBAVUTIL_VERSION_MAJOR 52	39	#define LIBAVUTIL_VERSION_MAJOR 52
40	#define LIBAVUTIL_VERSION_MINOR 0	40	#define LIBAVUTIL_VERSION_MINOR 1
41	#define LIBAVUTIL_VERSION_MICRO 0	41	#define LIBAVUTIL_VERSION_MICRO 0
42		42
43	#define LIBAVUTIL_VERSION_INT AV_VERSION_INT(LIBAVUTIL_VERSION_MAJOR, \	43	#define LIBAVUTIL_VERSION_INT AV_VERSION_INT(LIBAVUTIL_VERSION_MAJOR, \

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