myvtm/Framework/libtoolkit/wavfile.c

#include "precompile.h"
#ifdef _WIN32
/*this header is used by windows multi-media*/
#include <mmreg.h>
#endif 
#include "wavfile.h"
#include "memutil.h"

static const unsigned char pcm8toalaw[] = {
42,
42,42,42,43,43,43,43,40,40,40,40,41,41,41,41,46,
46,46,46,47,47,47,47,44,44,44,44,45,45,45,45,34,
34,34,34,35,35,35,35,32,32,32,32,33,33,33,33,38,
38,38,38,39,39,39,39,36,36,36,36,37,37,37,37,58,
58,59,59,56,56,57,57,62,62,63,63,60,60,61,61,50,
50,51,51,48,48,49,49,54,54,55,55,52,52,53,53,10,
11,8,9,14,15,12,13,2,3,0,1,6,7,4,5,26,
24,30,28,18,16,22,20,106,110,98,102,122,114,74,90,213,
197,245,253,229,225,237,233,149,151,145,147,157,159,153,155,133,
132,135,134,129,128,131,130,141,140,143,142,137,136,139,138,181,
181,180,180,183,183,182,182,177,177,176,176,179,179,178,178,189,
189,188,188,191,191,190,190,185,185,184,184,187,187,186,186,165,
165,165,165,164,164,164,164,167,167,167,167,166,166,166,166,161,
161,161,161,160,160,160,160,163,163,163,163,162,162,162,162,173,
173,173,173,172,172,172,172,175,175,175,175,174,174,174,174,169,
169,169,169,168,168,168,168,171,171,171,171,170,170,170,170,};
static const unsigned char pcm8tomulaw[] = {
0,
0,0,0,0,1,1,1,1,2,2,2,2,3,3,3,3,
4,4,4,4,5,5,5,5,6,6,6,6,7,7,7,7,
8,8,8,8,9,9,9,9,10,10,10,10,11,11,11,11,
12,12,12,12,13,13,13,13,14,14,14,14,15,15,15,15,
16,16,17,17,18,18,19,19,20,20,21,21,22,22,23,23,
24,24,25,25,26,26,27,27,28,28,29,29,30,30,31,31,
32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,
48,50,52,54,56,58,60,62,65,69,73,77,83,91,103,255,
231,219,211,205,201,197,193,190,188,186,184,182,180,178,176,175,
174,173,172,171,170,169,168,167,166,165,164,163,162,161,160,159,
159,158,158,157,157,156,156,155,155,154,154,153,153,152,152,151,
151,150,150,149,149,148,148,147,147,146,146,145,145,144,144,143,
143,143,143,142,142,142,142,141,141,141,141,140,140,140,140,139,
139,139,139,138,138,138,138,137,137,137,137,136,136,136,136,135,
135,135,135,134,134,134,134,133,133,133,133,132,132,132,132,131,
131,131,131,130,130,130,130,129,129,129,129,128,128,128,128,};
static const unsigned char alawtopcm8[] = {
106,
107,104,105,110,111,108,109,98,99,96,97,102,103,100,101,117,
117,116,116,119,119,118,118,113,113,112,112,115,115,114,114,42,
46,34,38,58,62,50,54,10,14,2,6,26,30,18,22,85,
87,81,83,93,95,89,91,69,71,65,67,77,79,73,75,126,
126,126,126,126,126,126,126,126,126,126,126,126,126,126,126,127,
127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,122,
122,122,122,123,123,123,123,120,120,120,120,121,121,121,121,125,
125,125,125,125,125,125,125,124,124,124,124,124,124,124,124,149,
148,151,150,145,144,147,146,157,156,159,158,153,152,155,154,138,
138,139,139,136,136,137,137,142,142,143,143,140,140,141,141,214,
210,222,218,198,194,206,202,246,242,254,250,230,226,238,234,171,
169,175,173,163,161,167,165,187,185,191,189,179,177,183,181,129,
129,129,129,129,129,129,129,129,129,129,129,129,129,129,129,128,
128,128,128,128,128,128,128,128,128,128,128,128,128,128,128,133,
133,133,133,132,132,132,132,135,135,135,135,134,134,134,134,130,
130,130,130,130,130,130,130,131,131,131,131,131,131,131,131,};

static const unsigned char ulawtopcm8[] = {
2,6,10,14,18,22,26,30,34,38,42,46,50,
54,58,62,65,67,69,71,73,75,77,79,81,
83,85,87,89,91,93,95,97,98,99,100,101,
102,103,104,105,106,107,108,109,110,111,112,112,
113,113,114,114,115,115,116,116,117,117,118,118,
119,119,120,120,120,121,121,121,121,122,122,122,
122,123,123,123,123,124,124,124,124,124,124,125,
125,125,125,125,125,125,125,126,126,126,126,126,
126,126,126,126,126,126,126,127,127,127,127,127,
127,127,127,127,127,127,127,127,127,127,127,127,
127,127,127,127,127,127,128,253,249,245,241,237,
233,229,225,221,217,213,209,205,201,197,193,190,
188,186,184,182,180,178,176,174,172,170,168,166,
164,162,160,158,157,156,155,154,153,152,151,150,
149,148,147,146,145,144,143,143,142,142,141,141,
140,140,139,139,138,138,137,137,136,136,135,135,
135,134,134,134,134,133,133,133,133,132,132,132,
132,131,131,131,131,131,131,130,130,130,130,130,
130,130,130,129,129,129,129,129,129,129,129,129,
129,129,129,128,128,128,128,128,128,128,128,128,
128,128,128,128,128,128,128,128,128,128,128,128,
128,128,128,};

/* Copied from the CCITT G.711 specification */
static const uint8_t ulaw_to_alaw_table[256] =
{
     42,  43,  40,  41,  46,  47,  44,  45,  34,  35,  32,  33,  38,  39,  36,  37,
     58,  59,  56,  57,  62,  63,  60,  61,  50,  51,  48,  49,  54,  55,  52,  53,
     10,  11,   8,   9,  14,  15,  12,  13,   2,   3,   0,   1,   6,   7,   4,  26,
     27,  24,  25,  30,  31,  28,  29,  18,  19,  16,  17,  22,  23,  20,  21, 106,
    104, 105, 110, 111, 108, 109,  98,  99,  96,  97, 102, 103, 100, 101, 122, 120,
    126, 127, 124, 125, 114, 115, 112, 113, 118, 119, 116, 117,  75,  73,  79,  77,
     66,  67,  64,  65,  70,  71,  68,  69,  90,  91,  88,  89,  94,  95,  92,  93,
     82,  82,  83,  83,  80,  80,  81,  81,  86,  86,  87,  87,  84,  84,  85,  85,
    170, 171, 168, 169, 174, 175, 172, 173, 162, 163, 160, 161, 166, 167, 164, 165,
    186, 187, 184, 185, 190, 191, 188, 189, 178, 179, 176, 177, 182, 183, 180, 181,
    138, 139, 136, 137, 142, 143, 140, 141, 130, 131, 128, 129, 134, 135, 132, 154,
    155, 152, 153, 158, 159, 156, 157, 146, 147, 144, 145, 150, 151, 148, 149, 234,
    232, 233, 238, 239, 236, 237, 226, 227, 224, 225, 230, 231, 228, 229, 250, 248,
    254, 255, 252, 253, 242, 243, 240, 241, 246, 247, 244, 245, 203, 201, 207, 205,
    194, 195, 192, 193, 198, 199, 196, 197, 218, 219, 216, 217, 222, 223, 220, 221,
    210, 210, 211, 211, 208, 208, 209, 209, 214, 214, 215, 215, 212, 212, 213, 213
};

/* These transcoding tables are copied from the CCITT G.711 specification. To achieve
   optimal results, do not change them. */

static const uint8_t alaw_to_ulaw_table[256] =
{
     42,  43,  40,  41,  46,  47,  44,  45,  34,  35,  32,  33,  38,  39,  36,  37,
     57,  58,  55,  56,  61,  62,  59,  60,  49,  50,  47,  48,  53,  54,  51,  52,
     10,  11,   8,   9,  14,  15,  12,  13,   2,   3,   0,   1,   6,   7,   4,   5,
     26,  27,  24,  25,  30,  31,  28,  29,  18,  19,  16,  17,  22,  23,  20,  21,
     98,  99,  96,  97, 102, 103, 100, 101,  93,  93,  92,  92,  95,  95,  94,  94,
    116, 118, 112, 114, 124, 126, 120, 122, 106, 107, 104, 105, 110, 111, 108, 109,
     72,  73,  70,  71,  76,  77,  74,  75,  64,  65,  63,  63,  68,  69,  66,  67,
     86,  87,  84,  85,  90,  91,  88,  89,  79,  79,  78,  78,  82,  83,  80,  81,
    170, 171, 168, 169, 174, 175, 172, 173, 162, 163, 160, 161, 166, 167, 164, 165,
    185, 186, 183, 184, 189, 190, 187, 188, 177, 178, 175, 176, 181, 182, 179, 180,
    138, 139, 136, 137, 142, 143, 140, 141, 130, 131, 128, 129, 134, 135, 132, 133,
    154, 155, 152, 153, 158, 159, 156, 157, 146, 147, 144, 145, 150, 151, 148, 149,
    226, 227, 224, 225, 230, 231, 228, 229, 221, 221, 220, 220, 223, 223, 222, 222,
    244, 246, 240, 242, 252, 254, 248, 250, 234, 235, 232, 233, 238, 239, 236, 237,
    200, 201, 198, 199, 204, 205, 202, 203, 192, 193, 191, 191, 196, 197, 194, 195,
    214, 215, 212, 213, 218, 219, 216, 217, 207, 207, 206, 206, 210, 211, 208, 209
};

static __inline uint8_t alaw_to_ulaw(uint8_t alaw)
{
    return alaw_to_ulaw_table[alaw];
}
/*- End of function --------------------------------------------------------*/

static __inline uint8_t ulaw_to_alaw(uint8_t ulaw)
{
    return ulaw_to_alaw_table[ulaw];
}
/*- End of function --------------------------------------------------------*/


static __inline int top_bit(unsigned int bits)
{
#if defined(SPANDSP_USE_86_ASM)
    int res;

    __asm__ (" xorl %[res],%[res];\n"
             " decl %[res];\n"
             " bsrl %[bits],%[res]\n"
             : [res] "=&r" (res)
             : [bits] "rm" (bits));
    return res;
#elif defined(__ppc__)  ||   defined(__powerpc__)
    int res;

    __asm__ ("cntlzw %[res],%[bits];\n"
             : [res] "=&r" (res)
             : [bits] "r" (bits));
    return 31 - res;
#elif defined(_M_IX86)
    /* Visual Studio i386 */
    __asm
    {
        xor eax, eax
        dec eax
        bsr eax, bits
    }
#elif defined(_M_X64)
    /* Visual Studio x86_64 */
    /* TODO: Need the appropriate x86_64 code */
    int res;

    if (bits == 0)
        return -1;
    res = 0;
    if (bits & 0xFFFF0000)
    {
        bits &= 0xFFFF0000;
        res += 16;
    }
    if (bits & 0xFF00FF00)
    {
        bits &= 0xFF00FF00;
        res += 8;
    }
    if (bits & 0xF0F0F0F0)
    {
        bits &= 0xF0F0F0F0;
        res += 4;
    }
    if (bits & 0xCCCCCCCC)
    {
        bits &= 0xCCCCCCCC;
        res += 2;
    }
    if (bits & 0xAAAAAAAA)
    {
        bits &= 0xAAAAAAAA;
        res += 1;
    }
    return res;
#else
    int res;

    if (bits == 0)
        return -1;
    res = 0;
    if (bits & 0xFFFF0000)
    {
        bits &= 0xFFFF0000;
        res += 16;
    }
    if (bits & 0xFF00FF00)
    {
        bits &= 0xFF00FF00;
        res += 8;
    }
    if (bits & 0xF0F0F0F0)
    {
        bits &= 0xF0F0F0F0;
        res += 4;
    }
    if (bits & 0xCCCCCCCC)
    {
        bits &= 0xCCCCCCCC;
        res += 2;
    }
    if (bits & 0xAAAAAAAA)
    {
        bits &= 0xAAAAAAAA;
        res += 1;
    }
    return res;
#endif
}
/*- End of function --------------------------------------------------------*/

/*! \brief Find the bit position of the lowest set bit in a word
    \param bits The word to be searched
    \return The bit number of the lowest set bit, or -1 if the word is zero. */
static __inline int bottom_bit(unsigned int bits)
{
    int res;
    
#if defined(SPANDSP_USE_86_ASM)
    __asm__ (" xorl %[res],%[res];\n"
             " decl %[res];\n"
             " bsfl %[bits],%[res]\n"
             : [res] "=&r" (res)
             : [bits] "rm" (bits));
    return res;
#else
    if (bits == 0)
        return -1;
    res = 31;
    if (bits & 0x0000FFFF)
    {
        bits &= 0x0000FFFF;
        res -= 16;
    }
    if (bits & 0x00FF00FF)
    {
        bits &= 0x00FF00FF;
        res -= 8;
    }
    if (bits & 0x0F0F0F0F)
    {
        bits &= 0x0F0F0F0F;
        res -= 4;
    }
    if (bits & 0x33333333)
    {
        bits &= 0x33333333;
        res -= 2;
    }
    if (bits & 0x55555555)
    {
        bits &= 0x55555555;
        res -= 1;
    }
    return res;
#endif
}

#define ULAW_BIAS        0x84

/*! \brief Encode a linear sample to u-law
    \param linear The sample to encode.
    \return The u-law value.
*/
static __inline uint8_t linear_to_ulaw(int linear)
{
    uint8_t u_val;
    int mask;
    int seg;

    /* Get the sign and the magnitude of the value. */
    if (linear >= 0)
    {
        linear = ULAW_BIAS + linear;
        mask = 0xFF;
    }
    else
    {
        linear = ULAW_BIAS - linear;
        mask = 0x7F;
    }

    seg = top_bit(linear | 0xFF) - 7;

    /*
     * Combine the sign, segment, quantization bits,
     * and complement the code word.
     */
    if (seg >= 8)
        u_val = (uint8_t) (0x7F ^ mask);
    else
        u_val = (uint8_t) (((seg << 4) | ((linear >> (seg + 3)) & 0xF)) ^ mask);
#ifdef ULAW_ZEROTRAP
    /* Optional ITU trap */
    if (u_val == 0)
        u_val = 0x02;
#endif
    return  u_val;
}


/*! The A-law alternate mark inversion mask */
#define ALAW_AMI_MASK       0x55

/*! \brief Encode a linear sample to A-law
    \param linear The sample to encode.
    \return The A-law value.
*/
static __inline uint8_t linear_to_alaw(int linear)
{
    int mask;
    int seg;
    
    if (linear >= 0)
    {
        /* Sign (bit 7) bit = 1 */
        mask = ALAW_AMI_MASK | 0x80;
    }
    else
    {
        /* Sign (bit 7) bit = 0 */
        mask = ALAW_AMI_MASK;
        linear = -linear - 1;
    }

    /* Convert the scaled magnitude to segment number. */
    seg = top_bit(linear | 0xFF) - 7;
    if (seg >= 8)
    {
        if (linear >= 0)
        {
            /* Out of range. Return maximum value. */
            return (uint8_t) (0x7F ^ mask);
        }
        /* We must be just a tiny step below zero */
        return (uint8_t) (0x00 ^ mask);
    }
    /* Combine the sign, segment, and quantization bits. */
    return (uint8_t) (((seg << 4) | ((linear >> ((seg)  ?  (seg + 3)  :  4)) & 0x0F)) ^ mask);
}
/*- End of function --------------------------------------------------------*/

struct wavfile_t
{
	HANDLE hFile;
	int isread;
	int clock; // 8k or 16k
	int samplebit; // 8 or 16
	int format_tag;
	int file_format_tag;
	int file_samplebit;
	int file_clock;
};

static int read_wav_header(HANDLE hFile, int *clock, int *samplebit, int *format_tag)
{
	DWORD dw;
	DWORD dwByteRead;
	DWORD dwFileLen;
	DWORD dwFormatLen;
	WAVEFORMATEX fmt;

	SetFilePointer(hFile, 0, NULL, FILE_END);
	dwFileLen = SetFilePointer(hFile, 0, NULL, FILE_CURRENT);
	SetFilePointer(hFile, 0, NULL, FILE_BEGIN);

	ReadFile(hFile, &dw, sizeof(dw), &dwByteRead, NULL);
	if (dw != 'FFIR')
		return -1;
	ReadFile(hFile, &dw, sizeof(dw), &dwByteRead, NULL);
	if (dw != dwFileLen-8)
		return -1;
	ReadFile(hFile, &dw, sizeof(dw), &dwByteRead, NULL);
	if (dw != 'EVAW')
		return -1;
	ReadFile(hFile, &dw, sizeof(dw), &dwByteRead, NULL);
	if (dw != ' tmf')
		return -1;
	ReadFile(hFile, &dwFormatLen, sizeof(dwFormatLen), &dwByteRead, NULL);
	if (dwFormatLen < 16)
		return -1;
	ReadFile(hFile, &fmt, dwFormatLen, &dwByteRead, NULL);
	*format_tag = (int)fmt.wFormatTag;
	if (fmt.nChannels != 1)
		return -1;
	if (fmt.nSamplesPerSec == 8000)
		*clock = 8000;
	else if (fmt.nSamplesPerSec == 16000)
		*clock = 16000;
	else
		return -1; // not supported
	*samplebit = (int)fmt.wBitsPerSample;
	ReadFile(hFile, &dw, sizeof(dw), &dwByteRead, NULL);
	while (dw != 'atad') { // is not data chunk
		DWORD tmp;
		ReadFile(hFile, &tmp, sizeof(tmp), &dwByteRead, NULL);
		SetFilePointer(hFile, tmp, NULL, FILE_CURRENT);
		ReadFile(hFile, &dw, sizeof(dw), &dwByteRead, NULL);
	}
	ReadFile(hFile, &dw, sizeof(dw), &dwByteRead, NULL);

	return 0;
}

static int write_wav_header(HANDLE hFile, int clock, int samplebit, int format_tag)
{
	WORD wFormat;
	WORD wBitsPerSample;
	DWORD dw;
	DWORD dwByteWritten;
	WAVEFORMATEX fmt;
	DWORD dwFmtSize = sizeof(fmt);

	wFormat = (WORD)format_tag;
	wBitsPerSample = (WORD)samplebit;

	if (wFormat == WAVE_FORMAT_PCM) {
		dwFmtSize -= 2;
	}

	dw = 'FFIR'; // riff chunk
	WriteFile(hFile, &dw, sizeof(dw), &dwByteWritten, NULL);
	dw = 0x7fffffff; // riff chunk size
	WriteFile(hFile, &dw, sizeof(dw), &dwByteWritten, NULL);
	dw = 'EVAW'; // format 
	WriteFile(hFile, &dw, sizeof(dw), &dwByteWritten, NULL);
	dw = ' tmf'; // fmt subchunk
	WriteFile(hFile, &dw, sizeof(dw), &dwByteWritten, NULL);
	dw = dwFmtSize;
	WriteFile(hFile, &dw, sizeof(dw), &dwByteWritten, NULL);
	fmt.wFormatTag = wFormat;
	fmt.nChannels = 1;
	fmt.nSamplesPerSec = (DWORD)clock;
	fmt.nBlockAlign = 2;
	fmt.wBitsPerSample = wBitsPerSample;
	fmt.cbSize = 0;
	fmt.nAvgBytesPerSec = fmt.nSamplesPerSec * wBitsPerSample / 8;
	WriteFile(hFile, &fmt, dwFmtSize, &dwByteWritten, NULL);
	dw = 'atad'; // data chunk
	WriteFile(hFile, &dw, sizeof(dw), &dwByteWritten, NULL);
	dw = 0x7fffffff; // data chunk size
	WriteFile(hFile, &dw, sizeof(dw), &dwByteWritten, NULL);

	return 0;
}

static int write_wav_header_end(HANDLE hFile, int ispcm16)
{
	DWORD dwByteWritten;
	DWORD dw;
	DWORD dwFileLen;
	DWORD dwDataChunkOffset;
	if (hFile == INVALID_HANDLE_VALUE)
		return -1;
	dwDataChunkOffset = (ispcm16 ? 44 : 46);
	SetFilePointer(hFile, 0, NULL, FILE_END);
	dwFileLen = SetFilePointer(hFile, 0, NULL, FILE_CURRENT);
	dw = dwFileLen - 8; // riff chunk size
	SetFilePointer(hFile, 4, NULL, FILE_BEGIN);
	WriteFile(hFile, &dw, sizeof(dw), &dwByteWritten, NULL);
	dw = dwFileLen - dwDataChunkOffset; // data chunk size
	SetFilePointer(hFile, dwDataChunkOffset-4, NULL, FILE_BEGIN);
	WriteFile(hFile, &dw, sizeof(dw), &dwByteWritten, NULL);
	SetFilePointer(hFile, 0, NULL, FILE_END);
	return 0;
}

static int read_wav_frame(HANDLE hFile, DWORD dwFrameSize, unsigned char *buf)
{
	DWORD dwByteRead;
	BOOL bRet;

	bRet = ReadFile(hFile, buf, dwFrameSize, &dwByteRead, NULL);
	if (!bRet || dwByteRead == 0) {
		return -1;
	}

	if (dwByteRead < dwFrameSize) {
		memset(buf+dwByteRead, 0, dwFrameSize-dwByteRead);
	}

	return 0;
}

static int write_wav_frame(HANDLE hFile, const char *buf, DWORD size)
{
	DWORD dwByteWritten;
	BOOL bRet = WriteFile(hFile, buf, size, &dwByteWritten, NULL);
	return bRet ? 0 : -1;
}

TOOLKIT_API int wavfile_probe_format(const char *file, int *p_clock, int *p_samplebit, int *format_tag)
{
	HANDLE hFile;
	int clock;
	int tag;
	int samplebit;

	if (!file)
		return -1;

	hFile = CreateFileA(file, 
		GENERIC_READ, 
		FILE_SHARE_READ, 
		NULL, 
		OPEN_EXISTING, 
		FILE_ATTRIBUTE_NORMAL, 
		NULL);
	if (hFile == INVALID_HANDLE_VALUE)
		return -1;

	if (read_wav_header(hFile, &clock, &samplebit, &tag) != 0) {
		CloseHandle(hFile);
		return -1;
	}

	CloseHandle(hFile);

	if (p_clock)
		*p_clock = clock;
	if (format_tag)
		*format_tag = tag;
	if (p_samplebit)
		*p_samplebit = samplebit;

	return 0;
}

TOOLKIT_API int wavfile_open(const char *file, 
						  int isread, 
						  int clock, 
						  int samplebit,
						  int format_tag, 
						  wavfile_t **p_wavfile)
{
	wavfile_t *wavfile;

	wavfile = ZALLOC_T(wavfile_t);
	wavfile->clock = clock;
	wavfile->format_tag = format_tag;
	wavfile->samplebit = samplebit;
	wavfile->isread = !!isread;
	wavfile->hFile = CreateFileA(file, 
		isread ? GENERIC_READ : GENERIC_WRITE, FILE_SHARE_READ, 
		NULL,
		isread ? OPEN_EXISTING : OPEN_ALWAYS, 
		FILE_ATTRIBUTE_NORMAL, 
		NULL);
	if (wavfile->hFile == INVALID_HANDLE_VALUE)
		return -1;
	if (isread) {
		int read_clock;
		int read_format_tag;
		int read_samplebit;
		if (read_wav_header(wavfile->hFile, &read_clock, &read_samplebit, &read_format_tag) != 0) {
			CloseHandle(wavfile->hFile);
			return -1;
		}
		wavfile->file_clock = read_clock;
		wavfile->file_format_tag = read_format_tag;
		wavfile->file_samplebit = read_samplebit;
	} else {
		if (write_wav_header(wavfile->hFile, clock, samplebit, format_tag) != 0) {
			CloseHandle(wavfile->hFile);
			return -1;
		}
	}

	*p_wavfile = wavfile;

	return 0;
}

TOOLKIT_API int wavfile_close(wavfile_t *wavfile)
{
	if (!wavfile->isread)
		write_wav_header_end(wavfile->hFile, wavfile->samplebit == 16);
	CloseHandle(wavfile->hFile);
	wavfile->hFile = INVALID_HANDLE_VALUE;
	free(wavfile);
	return 0;
}

TOOLKIT_API int wavfile_get_native_handle(wavfile_t *wavfile, HANDLE *p_handle)
{
	*p_handle = wavfile->hFile;
	return 0;
}

TOOLKIT_API int wavfile_write(wavfile_t *wavfile, const void *buf, int size)
{
	if (write_wav_frame(wavfile->hFile, buf, size) != 0)
		return -1;
	return 0;
}

TOOLKIT_API int wavfile_read(wavfile_t *wavfile, void *buf, int size)
{
	int i;

	if (wavfile->file_format_tag == wavfile->format_tag) {
		if (wavfile->file_samplebit == wavfile->samplebit) {
			if (read_wav_frame(wavfile->hFile, size, buf) != 0)
				return -1;
		} else if (wavfile->file_samplebit == 16) {
			short tmp[256];
			if (read_wav_frame(wavfile->hFile, 2*size, (unsigned char*)&tmp[0]) != 0)
				return -1;
			if (wavfile->format_tag == WAVE_FORMAT_PCM) {
				for (i = 0; i < size; ++i)
					*((unsigned char*)buf + i) = (tmp[i] >> 8) + 128;
			} else if (wavfile->format_tag == WAVE_FORMAT_ALAW) {
				for (i = 0; i < size; ++i)
					*((unsigned char*)buf + i) = linear_to_alaw(tmp[i]);
			} else if (wavfile->format_tag == WAVE_FORMAT_MULAW) {
				for (i = 0; i < size; ++i)
					*((unsigned char*)buf + i) = linear_to_alaw(tmp[i]);
			} else {
				return -1;
			}
		} else {
			return -1;
		}
	} else if (wavfile->file_samplebit == wavfile->samplebit && wavfile->samplebit == 8) {
		if (read_wav_frame(wavfile->hFile, size, buf) != 0)
			return -1;
		if (wavfile->file_format_tag == WAVE_FORMAT_PCM) {
			if (wavfile->format_tag == WAVE_FORMAT_ALAW) {
				for (i = 0; i < size; ++i)
					*((unsigned char*)buf + i) = pcm8toalaw[*((unsigned char*)buf+i)];
			} else if (wavfile->format_tag == WAVE_FORMAT_MULAW) {
				for (i = 0; i < size; ++i)
					*((unsigned char*)buf + i) = pcm8tomulaw[*((unsigned char*)buf+i)];
			} else {
				return -1;
			}
		} else if (wavfile->file_format_tag == WAVE_FORMAT_ALAW) {
			if (wavfile->format_tag == WAVE_FORMAT_MULAW) {
				for (i = 0; i < size; ++i)
					*((unsigned char*)buf + i) = alaw_to_ulaw(*((unsigned char*)buf+i));
			} else if (wavfile->format_tag == WAVE_FORMAT_PCM) {
				for (i = 0; i < size; ++i)
					*((unsigned char*)buf + i) = alawtopcm8[*((unsigned char*)buf+i)];
			} else {
				return -1;
			}
		} else if (wavfile->file_format_tag == WAVE_FORMAT_MULAW) {
			if (wavfile->format_tag == WAVE_FORMAT_ALAW) {
				for (i = 0; i < size; ++i)
					*((unsigned char*)buf + i) = ulaw_to_alaw(*((unsigned char*)buf+i));
			} else if (wavfile->format_tag == WAVE_FORMAT_PCM) {
				for (i = 0; i < size; ++i)
					*((unsigned char*)buf + i) = ulawtopcm8[*((unsigned char*)buf+i)];
			} else {
				return -1;
			}
		} else {
			return -1;
		}
	} else {
		return -1;
	}

	return 0;
}

// PCM16, PCMA, PCMU, PCM8