PeerStreamer

/*

 * copyright (c) 2006 Michael Niedermayer <michaelni@gmx.at>

 *

 * This file is part of FFmpeg.

 *

 * FFmpeg 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.

 *

 * FFmpeg 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 FFmpeg; if not, write to the Free Software

 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

 */

/**

 * @file libavutil/common.h

 * common internal and external API header

 */

#ifndef AVUTIL_COMMON_H

#define AVUTIL_COMMON_H

#include <ctype.h>

#include <errno.h>

#include <inttypes.h>

#include <limits.h>

#include <math.h>

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#ifdef __GNUC__

#    define AV_GCC_VERSION_AT_LEAST(x,y) (__GNUC__ > x || __GNUC__ == x && __GNUC_MINOR__ >= y)

#else

#    define AV_GCC_VERSION_AT_LEAST(x,y) 0

#endif

#ifndef av_always_inline

#if AV_GCC_VERSION_AT_LEAST(3,1)

#    define av_always_inline __attribute__((always_inline)) inline

#else

#    define av_always_inline inline

#endif

#endif

#ifndef av_noinline

#if AV_GCC_VERSION_AT_LEAST(3,1)

#    define av_noinline __attribute__((noinline))

#else

#    define av_noinline

#endif

#endif

#ifndef av_pure

#if AV_GCC_VERSION_AT_LEAST(3,1)

#    define av_pure __attribute__((pure))

#else

#    define av_pure

#endif

#endif

#ifndef av_const

#if AV_GCC_VERSION_AT_LEAST(2,6)

#    define av_const __attribute__((const))

#else

#    define av_const

#endif

#endif

#ifndef av_cold

#if (!defined(__ICC) || __ICC > 1110) && AV_GCC_VERSION_AT_LEAST(4,3)

#    define av_cold __attribute__((cold))

#else

#    define av_cold

#endif

#endif

#ifndef av_flatten

#if (!defined(__ICC) || __ICC > 1110) && AV_GCC_VERSION_AT_LEAST(4,1)

#    define av_flatten __attribute__((flatten))

#else

#    define av_flatten

#endif

#endif

#ifndef attribute_deprecated

#if AV_GCC_VERSION_AT_LEAST(3,1)

#    define attribute_deprecated __attribute__((deprecated))

#else

#    define attribute_deprecated

#endif

#endif

#ifndef av_unused

#if defined(__GNUC__)

#    define av_unused __attribute__((unused))

#else

#    define av_unused

#endif

#endif

#ifndef av_uninit

#if defined(__GNUC__) && !defined(__ICC)

#    define av_uninit(x) x=x

#else

#    define av_uninit(x) x

#endif

#endif

//rounded division & shift

#define RSHIFT(a,b) ((a) > 0 ? ((a) + ((1<<(b))>>1))>>(b) : ((a) + ((1<<(b))>>1)-1)>>(b))

/* assume b>0 */

#define ROUNDED_DIV(a,b) (((a)>0 ? (a) + ((b)>>1) : (a) - ((b)>>1))/(b))

#define FFABS(a) ((a) >= 0 ? (a) : (-(a)))

#define FFSIGN(a) ((a) > 0 ? 1 : -1)

#define FFMAX(a,b) ((a) > (b) ? (a) : (b))

#define FFMAX3(a,b,c) FFMAX(FFMAX(a,b),c)

#define FFMIN(a,b) ((a) > (b) ? (b) : (a))

#define FFMIN3(a,b,c) FFMIN(FFMIN(a,b),c)

#define FFSWAP(type,a,b) do{type SWAP_tmp= b; b= a; a= SWAP_tmp;}while(0)

#define FF_ARRAY_ELEMS(a) (sizeof(a) / sizeof((a)[0]))

#define FFALIGN(x, a) (((x)+(a)-1)&~((a)-1))

/* misc math functions */

extern const uint8_t ff_log2_tab[256];

static inline av_const int av_log2(unsigned int v)

{

    int n = 0;

    if (v & 0xffff0000) {

        v >>= 16;

        n += 16;

    }

    if (v & 0xff00) {

        v >>= 8;

        n += 8;

    }

    n += ff_log2_tab[v];

    return n;

}

static inline av_const int av_log2_16bit(unsigned int v)

{

    int n = 0;

    if (v & 0xff00) {

        v >>= 8;

        n += 8;

    }

    n += ff_log2_tab[v];

    return n;

}

/**

 * Clips a signed integer value into the amin-amax range.

 * @param a value to clip

 * @param amin minimum value of the clip range

 * @param amax maximum value of the clip range

 * @return clipped value

 */

static inline av_const int av_clip(int a, int amin, int amax)

{

    if      (a < amin) return amin;

    else if (a > amax) return amax;

    else               return a;

}

/**

 * Clips a signed integer value into the 0-255 range.

 * @param a value to clip

 * @return clipped value

 */

static inline av_const uint8_t av_clip_uint8(int a)

{

    if (a&(~255)) return (-a)>>31;

    else          return a;

}

/**

 * Clips a signed integer value into the -32768,32767 range.

 * @param a value to clip

 * @return clipped value

 */

static inline av_const int16_t av_clip_int16(int a)

{

    if ((a+32768) & ~65535) return (a>>31) ^ 32767;

    else                    return a;

}

/**

 * Clips a float value into the amin-amax range.

 * @param a value to clip

 * @param amin minimum value of the clip range

 * @param amax maximum value of the clip range

 * @return clipped value

 */

static inline av_const float av_clipf(float a, float amin, float amax)

{

    if      (a < amin) return amin;

    else if (a > amax) return amax;

    else               return a;

}

#define MKTAG(a,b,c,d) (a | (b << 8) | (c << 16) | (d << 24))

#define MKBETAG(a,b,c,d) (d | (c << 8) | (b << 16) | (a << 24))

/*!

 * \def GET_UTF8(val, GET_BYTE, ERROR)

 * Converts a UTF-8 character (up to 4 bytes long) to its 32-bit UCS-4 encoded form

 * \param val is the output and should be of type uint32_t. It holds the converted

 * UCS-4 character and should be a left value.

 * \param GET_BYTE gets UTF-8 encoded bytes from any proper source. It can be

 * a function or a statement whose return value or evaluated value is of type

 * uint8_t. It will be executed up to 4 times for values in the valid UTF-8 range,

 * and up to 7 times in the general case.

 * \param ERROR action that should be taken when an invalid UTF-8 byte is returned

 * from GET_BYTE. It should be a statement that jumps out of the macro,

 * like exit(), goto, return, break, or continue.

 */

#define GET_UTF8(val, GET_BYTE, ERROR)\

    val= GET_BYTE;\

    {\

        int ones= 7 - av_log2(val ^ 255);\

        if(ones==1)\

            ERROR\

        val&= 127>>ones;\

        while(--ones > 0){\

            int tmp= GET_BYTE - 128;\

            if(tmp>>6)\

                ERROR\

            val= (val<<6) + tmp;\

        }\

    }

/*!

 * \def PUT_UTF8(val, tmp, PUT_BYTE)

 * Converts a 32-bit Unicode character to its UTF-8 encoded form (up to 4 bytes long).

 * \param val is an input-only argument and should be of type uint32_t. It holds

 * a UCS-4 encoded Unicode character that is to be converted to UTF-8. If

 * val is given as a function it is executed only once.

 * \param tmp is a temporary variable and should be of type uint8_t. It

 * represents an intermediate value during conversion that is to be

 * output by PUT_BYTE.

 * \param PUT_BYTE writes the converted UTF-8 bytes to any proper destination.

 * It could be a function or a statement, and uses tmp as the input byte.

 * For example, PUT_BYTE could be "*output++ = tmp;" PUT_BYTE will be

 * executed up to 4 times for values in the valid UTF-8 range and up to

 * 7 times in the general case, depending on the length of the converted

 * Unicode character.

 */

#define PUT_UTF8(val, tmp, PUT_BYTE)\

    {\

        int bytes, shift;\

        uint32_t in = val;\

        if (in < 0x80) {\

            tmp = in;\

            PUT_BYTE\

        } else {\

            bytes = (av_log2(in) + 4) / 5;\

            shift = (bytes - 1) * 6;\

            tmp = (256 - (256 >> bytes)) | (in >> shift);\

            PUT_BYTE\

            while (shift >= 6) {\

                shift -= 6;\

                tmp = 0x80 | ((in >> shift) & 0x3f);\

                PUT_BYTE\

            }\

        }\

    }

#include "mem.h"

#ifdef HAVE_AV_CONFIG_H

#    include "config.h"

#    include "internal.h"

#endif /* HAVE_AV_CONFIG_H */

#endif /* AVUTIL_COMMON_H */