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More fixes from Frank.
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@icculus
icculus committed Jul 3, 2002
1 parent 5d5938b commit 80e06aa
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Showing 3 changed files with 122 additions and 105 deletions.
201 changes: 106 additions & 95 deletions alt_audio_convert.c
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Expand Up @@ -159,10 +159,11 @@ int Sound_ConvertAudio( Sound_AudioCVT *Data )
/*-------------------------------------------------------------------------*/
static int expand8BitTo16BitSys( AdapterC Data, int length )
{
/* !!! Fixme: get rid of <<8 through pointer manipulation --frank */
int i;
Uint8* inp = Data.buffer;
Uint16* buffer = (Uint16*)Data.buffer;
for( i = length; i--; )
for( i = length - 1; i >= 0; i-- )
buffer[i] = inp[i]<<8;
return 2*length;
}
Expand All @@ -172,7 +173,7 @@ static int expand8BitTo16BitWrong( AdapterC Data, int length )
int i;
Uint8* inp = Data.buffer;
Uint16* buffer = (Uint16*)Data.buffer;
for( i = length; i--; )
for( i = length - 1; i >= 0; i--)
buffer[i] = inp[i];
return 2*length;
}
Expand All @@ -183,7 +184,7 @@ static int expand16BitToFloat( AdapterC Data, int length )
int i;
Sint16* inp = (Sint16*)Data.buffer;
float* buffer = (float*)Data.buffer;
for( i = length>>1; i--; )
for( i = length>>1 - 1; i >= 0; i-- )
buffer[i] = inp[i]*(1./32767);
return 2*length;
}
Expand All @@ -202,7 +203,7 @@ static int swapBytes( AdapterC Data, int length )
int i;
Uint16 a,b;
Uint16* buffer = (Uint16*) Data.buffer;
for( i = length>>1; i --; )
for( i = length>>1; i >= 0; i-- )
{
a = b = buffer[i];
buffer[i] = ( a << 8 ) | ( b >> 8 );
Expand Down Expand Up @@ -236,6 +237,7 @@ static int cut16BitSysTo8Bit( AdapterC Data, int length )
Uint16* inp = (Uint16*) Data.buffer;
Uint8* buffer = Data.buffer;
length >>= 1;
/* !!! FIXME: Get rid of the >>8 */
for( i = 0; i < length; i++ )
buffer[i] = inp[i]>>8;
return length;
Expand All @@ -248,7 +250,7 @@ static int cut16BitWrongTo8Bit( AdapterC Data, int length )
Uint8* buffer = Data.buffer;
length >>= 1;
for( i = 0; i < length; i++ )
buffer[i] = inp[i] & 0xff;
buffer[i] = inp[i];
return length;
}

Expand All @@ -258,10 +260,8 @@ static int changeSigned( AdapterC Data, int length, Uint32 XOR )
{
int i;
Uint32* buffer = (Uint32*) Data.buffer;
for( i = length>>2; i--; )
for( i = ( length - 1 ) >> 2; i >= 0; i-- )
buffer[i] ^= XOR;
for( i = 4*(length>>2); i < length; i++)
((Uint8*)buffer)[i] ^= ((Uint8*)&XOR)[i&3];
return length;
}

Expand Down Expand Up @@ -331,7 +331,7 @@ static int convertMonoToStereo16Bit( AdapterC Data, int length )
int i;
Uint16* buffer = (Uint16*) Data.buffer;
Uint16* dst = (Uint16*)Data.buffer + length - 2;
for( i = length>>1; i--; dst-=2 )
for( i = length>>1 - 1; i >= 0; i--, dst-=2 )
dst[0] = dst[1] = buffer[i];
return 2*length;
}
Expand All @@ -340,9 +340,9 @@ static int convertMonoToStereo8Bit( AdapterC Data, int length )
{
int i;
Uint8* buffer = Data.buffer;
Uint8* buffer1 = Data.buffer + 1;
for( i = length-1; i >= 0; i-- )
buffer[2*i] = buffer1[2*i] = buffer[i];
Uint8* dst = (Uint8*)Data.buffer + length - 2;
for( i = length - 1; i >= 0; i--, dst-=2 )
dst[0] = dst[1] = buffer[i];
return 2*length;
}

Expand All @@ -351,7 +351,7 @@ static int minus5dB( AdapterC Data, int length )
{
int i;
Sint16* buffer = (Sint16*) Data.buffer;
for(i = length>>1; i--; )
for(i = length>>1 - 1; i >= 0; i-- )
buffer[i]= (38084 * (int)buffer[i]) >> 16;
return length;
}
Expand All @@ -364,68 +364,83 @@ enum RateConverterType{
dblRate = 2
};

static void initRateConverterBuffer( RateConverterBuffer *rcb,
AdapterC* Data, int length, enum RateConverterType typ )
{
int size, minsize, dir;
int den[] = { 0, 1, 2};
int num[] = { 0, 2, 1};
int i;

den[incrsRate] = Data->filter->denominator;
num[incrsRate] = Data->filter->numerator;
const Fraction Half = {1, 2};
const Fraction Double = {2, 1};

static void initStraigthBuffer( RateConverterBuffer *rcb,
int length, Fraction r, int dir )
{
int i, size, minsize;
size = 8 * _fsize;
dir = ~typ&1;
length >>= 1;
minsize = min( length, size );
minsize = min( size, length );

rcb->buffer = (Sint16*)( Data->buffer );
for( i = 0; i < minsize; i++ )
{
rcb->inbuffer[i] = rcb->buffer[length-size+i];
rcb->inbuffer[i+size] = 0;
rcb->inbuffer[i+2*size] = rcb->buffer[i];
}
for( ; i < size; i++ )
{
rcb->inbuffer[i] = 0;
rcb->inbuffer[i+size] = 0;
rcb->inbuffer[i+2*size] = 0;
}

if( Data->mode & SDL_SOUND_Loop )
length = max( length, size );
rcb->flength = rcb->llength = size;
rcb->clength = length - size;

if( dir )
{
// !!!FIXME: modulo length, take scale into account,
// check against the 'else' part
for( i = 0; i < size; i++ )
{
rcb->inbuffer[i] = rcb->buffer[length-size+i];
rcb->inbuffer[i+size] = rcb->buffer[i];
}
rcb->finp = rcb->linp = rcb->inbuffer + size;
if( size < 0 )
rcb->buffer += num[typ] * ( length + 2 * size ) / den[typ];
rcb->finp = rcb->inbuffer + 5 * size/2;
rcb->cinp = rcb->buffer + length - size/2;
rcb->linp = rcb->inbuffer + 3*size/2;
rcb->buffer += r.denominator * ( length + size )
/ r.numerator;
}
else
{
for( i = 0; i < minsize; i++ )
{
rcb->inbuffer[i] = rcb->buffer[length-size+i];
rcb->inbuffer[i+size] = 0;
rcb->inbuffer[i+2*size] = rcb->buffer[i];
}
for( ; i < size; i++ )
{
rcb->inbuffer[i] = 0;
rcb->inbuffer[i+size] = 0;
rcb->inbuffer[i+2*size] = 0;
}
rcb->flength = rcb->llength = size/2 + minsize/2;
rcb->clength = length - minsize;
rcb->finp = rcb->inbuffer + size/2;
rcb->cinp = rcb->buffer + size/2;
rcb->linp = rcb->inbuffer + 3*size/2;
}
}

if( dir )
{
rcb->finp = rcb->inbuffer + 2 * size + minsize/2;
rcb->cinp = rcb->buffer + length - minsize/2;
rcb->linp = rcb->inbuffer + size + minsize/2;
rcb->buffer += den[typ] * ( length + minsize ) / num[typ];
}
else
{
rcb->finp = rcb->inbuffer + size/2;
rcb->cinp = rcb->buffer + size/2;
rcb->linp = rcb->inbuffer + 3*size/2;
}
static void initLoopBuffer( RateConverterBuffer *rcb,
int length, Fraction r, int dir )
{
/* !!!FIXME: modulo length, take scale into account,
check against the Straight part -frank */
int i, size;
size = 8 * _fsize;
for( i = 0; i < size; i++ )
{
rcb->inbuffer[i] = rcb->buffer[length-size+i];
rcb->inbuffer[i+size] = rcb->buffer[i];
}
rcb->finp = rcb->linp = rcb->inbuffer + size;
if( size < 0 )
rcb->buffer += r.numerator * ( length + 2 * size )
/ r.denominator;
}

static void initRateConverterBuffer( RateConverterBuffer *rcb,
AdapterC* Data, int length, enum RateConverterType typ )
{
int size, minsize, dir;
Fraction Ratio[] = { {0,0}, {2,1}, {1,2} };

Ratio[incrsRate] = Data->filter->ratio;
dir = ~typ&1;
length >>= 1;
rcb->buffer = (Sint16*)( Data->buffer );

if( Data->mode & SDL_SOUND_Loop )
initLoopBuffer( rcb, length, Ratio[typ], dir );
else
initStraigthBuffer( rcb, length, Ratio[typ], dir );
}

static void nextRateConverterBuffer( RateConverterBuffer *rcb )
Expand Down Expand Up @@ -536,25 +551,16 @@ static int padSilence( AdapterC Data, int length )
if( Data.mode != SDL_SOUND_Loop )
mask = Data.filter->mask;
length = mask - ( ( length - 1 ) & mask );
zero = Data.filter->zero;

for( i = length>>2; i--; )
for( i = 0; i < length>>2; i++ )
buffer[i] = zero;
for( i = 4*(length>>2); i < length; i++)
((Uint8*)buffer)[i] ^= ((Uint8*)&zero)[i&3];
for( ; i < length; i++ )
((Uint8*)buffer)[i] = ((Uint8*)&zero)[i&3];

return length + ((Uint8*)buffer - Data.buffer);
}

/*-------------------------------------------------------------------------*/
typedef struct{
Sint16 numerator;
Sint16 denominator;
} Fraction;

const Fraction Half = {1, 2};
const Fraction Double = {2, 1};

/* gives a maximal error of 3% and typical less than 0.2% */
static Fraction findFraction( float Value )
{
Expand Down Expand Up @@ -623,13 +629,14 @@ static float calculateVarFilter( Sint16* dst,
const float fg = -.018 + .5 * Ratio;
const float omega = 2 * M_PI * fg;
fprintf( stderr, " phase: %6g \n", phase );
phase -= 63;
phase += 63;
for( i = 0; i < 64; i++)
{
w = scale * ( KaiserWindow7[i] * ( i + 1 ));
dst[i] = w * sinc( omega * (i+phase) );
dst[127-i] = w * sinc( omega * (127-i+phase) );
dst[i] = w * sinc( omega * (i-phase) );
dst[127-i] = w * sinc( omega * (127-i-phase) );
}
fprintf( stderr, " center: %6d %6d \n", dst[63], dst[64] );
return fg;
}

Expand All @@ -644,10 +651,9 @@ static Fraction setupVarFilter( VarFilter* filter, float Ratio )
Scale = 0.0084778;
Ratio = min( Ratio, 0.97 );

filter->ratio = IRatio;
n = IRatio.numerator;
d = IRatio.denominator;
filter->denominator = d;
filter->numerator = n;
rd = 1. / d;

fprintf( stderr, "Filter:\n" );
Expand Down Expand Up @@ -685,14 +691,19 @@ static void initSize( Sound_AudioCVT *Data )
}

/*-------------------------------------------------------------------------*/
const Adapter doubleRate[2] = { doubleRateMono, doubleRateStereo };
const Adapter halfRate[2] = { halfRateMono, halfRateStereo };
const Adapter increaseRate[2] = { increaseRateMono, increaseRateStereo };
const Adapter decreaseRate[2] = { decreaseRateMono, decreaseRateStereo };

static void createRateConverter( Sound_AudioCVT *Data, int* fip,
int SrcRate, int DestRate, int Channel )
{
Fraction f;
int filter_index = *fip;
int VarPos = 0;
int Mono = 2 - Channel;
float Ratio = DestRate;
int c = Channel - 1;
*fip = -1;


Expand All @@ -707,32 +718,28 @@ static void createRateConverter( Sound_AudioCVT *Data, int* fip,

while( Ratio > 64./31.)
{
Data->adapter[filter_index++] =
Mono ? doubleRateMono : doubleRateStereo;
Ratio /= 2.;
Data->adapter[filter_index++] = doubleRate[c];
adjustSize( Data, _fsize, Double );
}

while( Ratio < 31./64. )
{
Data->adapter[filter_index++] =
Mono ? halfRateMono : halfRateStereo;
Ratio *= 2;
Data->adapter[filter_index++] = halfRate[c];
adjustSize( Data, _fsize, Half );
}

if( Ratio > 1. )
{
Data->adapter[VarPos] = increaseRate[c];
f = setupVarFilter( &Data->filter, Ratio );
Data->adapter[VarPos] =
Mono ? increaseRateMono : increaseRateStereo;
adjustSize( Data, _fsize, f );
}
else
{
Data->adapter[filter_index++] = decreaseRate[c];
f = setupVarFilter( &Data->filter, Ratio );
Data->adapter[filter_index++] =
Mono ? decreaseRateMono : decreaseRateStereo;
adjustSize( Data, _fsize, f );
}
*fip = filter_index;
Expand Down Expand Up @@ -871,11 +878,15 @@ int BuildAudioCVT( Sound_AudioCVT *Data,
int filter_index = 0;

if( Data == NULL ) return -1;
if( dst.size < 8 ) return -1;

initSize( Data );
Data->filter.denominator = 0;
Data->filter.ratio.denominator = 0;
Data->filter.zero = getSilenceValue( dst.format );
Data->filter.mask = dst.size - 1;



/* Check channels */
if( src.channels < 1 || src.channels > 2 ||
dst.channels < 1 || dst.channels > 2 ) goto error_exit;
Expand Down Expand Up @@ -996,16 +1007,17 @@ static void show_AudioCVT( Sound_AudioCVT *Data )
}
fprintf( stderr, " Error: NULL adapter missing\n" );
sucess_exit:
if( Data->filter.denominator )
if( Data->filter.ratio.denominator )
{
fprintf( stderr, "Variable Rate Converter:\n"
" numerator: %3d\n"
" denominator: %3d\n",
Data->filter.denominator, Data->filter.numerator );
Data->filter.ratio.denominator,
Data->filter.ratio.numerator );

fprintf( stderr, " increment sequence:\n"
" " );
for( i = 0; i < Data->filter.denominator; i++ )
for( i = 0; i < Data->filter.ratio.denominator; i++ )
fprintf( stderr, "%1d ", Data->filter.incr[i] );

fprintf( stderr, "\n" );
Expand Down Expand Up @@ -1051,6 +1063,5 @@ int Sound_BuildAudioCVT(Sound_AudioCVT *Data,
show_AudioCVT( Data );
fprintf (stderr, "\n"
"return value: %d \n\n\n", ret );

return ret;
}

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