diff options
Diffstat (limited to 'Alc/ALu.c')
| -rw-r--r-- | Alc/ALu.c | 183 |
1 files changed, 138 insertions, 45 deletions
@@ -151,6 +151,27 @@ static inline HrtfDirectMixerFunc SelectHrtfMixer(void) } +/* Prior to VS2013, MSVC lacks the round() family of functions. */ +#if defined(_MSC_VER) && _MSC_VER < 1800 +static long lroundf(float val) +{ + if(val < 0.0) + return fastf2i(ceilf(val-0.5f)); + return fastf2i(floorf(val+0.5f)); +} +#endif + +/* This RNG method was created based on the math found in opusdec. It's quick, + * and starting with a seed value of 22222, is suitable for generating + * whitenoise. + */ +static inline ALuint dither_rng(ALuint *seed) +{ + *seed = (*seed * 96314165) + 907633515; + return *seed; +} + + static inline void aluCrossproduct(const ALfloat *inVector1, const ALfloat *inVector2, ALfloat *outVector) { outVector[0] = inVector1[1]*inVector2[2] - inVector1[2]*inVector2[1]; @@ -1544,37 +1565,57 @@ static void ApplyLimiter(struct OutputLimiter *Limiter, } } -static inline ALfloat aluF2F(ALfloat val) -{ return val; } -#define S25_MAX_NORM (16777215.0f/16777216.0f) -static inline ALint aluF2I(ALfloat val) +/* NOTE: Non-dithered conversions have unused extra parameters. */ +static inline ALfloat aluF2F(ALfloat val, ...) +{ return val; } +static inline ALint aluF2I(ALfloat val, ...) { /* Floats only have a 24-bit mantissa, so [-16777216, +16777216] is the max * integer range normalized floats can be safely converted to (a bit of the * exponent helps out, effectively giving 25 bits). */ - return fastf2i(clampf(val, -1.0f, S25_MAX_NORM)*16777216.0f)<<7; + return fastf2i(clampf(val*16777216.0f, -16777216.0f, 16777215.0f))<<7; +} +static inline ALshort aluF2S(ALfloat val, ...) +{ return fastf2i(clampf(val*32768.0f, -32768.0f, 32767.0f)); } +static inline ALbyte aluF2B(ALfloat val, ...) +{ return fastf2i(clampf(val*128.0f, -128.0f, 127.0f)); } + +/* Dithered conversion functions. Only applies to 8- and 16-bit output for now, + * as 32-bit int and float are at the limits of the rendered sample depth. This + * can change if the dithering bit depth becomes configurable (effectively + * quantizing to a lower bit depth than the output is capable of). + */ +static inline ALshort aluF2SDithered(ALfloat val, const ALfloat dither_val) +{ + val = val*32768.0f + dither_val; + return lroundf(clampf(val, -32768.0f, 32767.0f)); +} +static inline ALbyte aluF2BDithered(ALfloat val, const ALfloat dither_val) +{ + val = val*128.0f + dither_val; + return lroundf(clampf(val, -128.0f, 127.0f)); } -static inline ALuint aluF2UI(ALfloat val) -{ return aluF2I(val)+2147483648u; } - -#define S16_MAX_NORM (32767.0f/32768.0f) -static inline ALshort aluF2S(ALfloat val) -{ return fastf2i(clampf(val, -1.0f, S16_MAX_NORM)*32768.0f); } -static inline ALushort aluF2US(ALfloat val) -{ return aluF2S(val)+32768; } - -#define S8_MAX_NORM (127.0f/128.0f) -static inline ALbyte aluF2B(ALfloat val) -{ return fastf2i(clampf(val, -1.0f, S8_MAX_NORM)*128.0f); } -static inline ALubyte aluF2UB(ALfloat val) -{ return aluF2B(val)+128; } - -#define DECL_TEMPLATE(T, func) \ -static void Write_##T(const ALfloatBUFFERSIZE *InBuffer, ALvoid *OutBuffer, \ - DistanceComp *distcomp, ALsizei SamplesToDo, \ - ALsizei numchans) \ + +/* Define unsigned output variations. */ +#define DECL_TEMPLATE(T, Name, func, O) \ +static inline T Name(ALfloat val, const ALfloat dither_val) \ +{ return func(val, dither_val)+O; } + +DECL_TEMPLATE(ALubyte, aluF2UB, aluF2B, 128) +DECL_TEMPLATE(ALushort, aluF2US, aluF2S, 32768) +DECL_TEMPLATE(ALuint, aluF2UI, aluF2I, 2147483648u) +DECL_TEMPLATE(ALubyte, aluF2UBDithered, aluF2BDithered, 128) +DECL_TEMPLATE(ALushort, aluF2USDithered, aluF2SDithered, 32768) + +#undef DECL_TEMPLATE + +#define DECL_TEMPLATE(T, D, func) \ +static void Write##T##D(const ALfloatBUFFERSIZE *InBuffer, ALvoid *OutBuffer, \ + DistanceComp *distcomp, \ + const ALfloat *restrict DitherValues, \ + ALsizei SamplesToDo, ALsizei numchans) \ { \ ALsizei i, j; \ for(j = 0;j < numchans;j++) \ @@ -1589,15 +1630,15 @@ static void Write_##T(const ALfloatBUFFERSIZE *InBuffer, ALvoid *OutBuffer, \ if(SamplesToDo >= base) \ { \ for(i = 0;i < base;i++) \ - out[i*numchans] = func(distbuf[i]*gain); \ + out[i*numchans] = func(distbuf[i]*gain, DitherValues[i]); \ for(;i < SamplesToDo;i++) \ - out[i*numchans] = func(in[i-base]*gain); \ + out[i*numchans] = func(in[i-base]*gain, DitherValues[i]); \ memcpy(distbuf, &in[SamplesToDo-base], base*sizeof(ALfloat)); \ } \ else \ { \ for(i = 0;i < SamplesToDo;i++) \ - out[i*numchans] = func(distbuf[i]*gain); \ + out[i*numchans] = func(distbuf[i]*gain, DitherValues[i]); \ memmove(distbuf, distbuf+SamplesToDo, \ (base-SamplesToDo)*sizeof(ALfloat)); \ memcpy(distbuf+base-SamplesToDo, in, \ @@ -1605,17 +1646,22 @@ static void Write_##T(const ALfloatBUFFERSIZE *InBuffer, ALvoid *OutBuffer, \ } \ } \ else for(i = 0;i < SamplesToDo;i++) \ - out[i*numchans] = func(in[i]); \ + out[i*numchans] = func(in[i], DitherValues[i]); \ } \ } -DECL_TEMPLATE(ALfloat, aluF2F) -DECL_TEMPLATE(ALuint, aluF2UI) -DECL_TEMPLATE(ALint, aluF2I) -DECL_TEMPLATE(ALushort, aluF2US) -DECL_TEMPLATE(ALshort, aluF2S) -DECL_TEMPLATE(ALubyte, aluF2UB) -DECL_TEMPLATE(ALbyte, aluF2B) +DECL_TEMPLATE(ALfloat, /*no dither*/, aluF2F) +DECL_TEMPLATE(ALuint, /*no dither*/, aluF2UI) +DECL_TEMPLATE(ALint, /*no dither*/, aluF2I) +DECL_TEMPLATE(ALushort, /*no dither*/, aluF2US) +DECL_TEMPLATE(ALshort, /*no dither*/, aluF2S) +DECL_TEMPLATE(ALubyte, /*no dither*/, aluF2UB) +DECL_TEMPLATE(ALbyte, /*no dither*/, aluF2B) + +DECL_TEMPLATE(ALushort, _Dithered, aluF2USDithered) +DECL_TEMPLATE(ALshort, _Dithered, aluF2SDithered) +DECL_TEMPLATE(ALubyte, _Dithered, aluF2UBDithered) +DECL_TEMPLATE(ALbyte, _Dithered, aluF2BDithered) #undef DECL_TEMPLATE @@ -1792,6 +1838,7 @@ void aluMixData(ALCdevice *device, ALvoid *buffer, ALsizei size) ALsizei OutChannels = device->RealOut.NumChannels; struct OutputLimiter *Limiter = device->Limiter; DistanceComp *DistComp; + ALfloat *DitherValues; if(Limiter) { @@ -1804,33 +1851,79 @@ void aluMixData(ALCdevice *device, ALvoid *buffer, ALsizei size) ); } + /* Dithering. Step 1, generate whitenoise (uniform distribution of + * random values between -1 and +1). Use NFCtrlData for random + * value storage. Step 2 is to add the noise to the samples, before + * rounding and after scaling up to the desired quantization depth, + * which occurs in the sample conversion stage. + */ + if(!device->DitherEnabled) + memset(device->NFCtrlData, 0, SamplesToDo*sizeof(ALfloat)); + else + { + ALuint dither_seed = device->DitherSeed; + ALsizei i; + + for(i = 0;i < SamplesToDo;i++) + { + ALuint rng0 = dither_rng(&dither_seed); + ALuint rng1 = dither_rng(&dither_seed); + device->NFCtrlData[i] = (ALfloat)(rng0*(1.0/UINT_MAX) - rng1*(1.0/UINT_MAX)); + } + device->DitherSeed = dither_seed; + } + DitherValues = device->NFCtrlData; + DistComp = device->ChannelDelay; -#define WRITE(T, a, b, c, d, e) do { \ - Write_##T(SAFE_CONST(ALfloatBUFFERSIZE*,(a)), (b), (c), (d), (e)); \ - buffer = (T*)buffer + (d)*(e); \ +#define WRITE(T, D, a, b, c, d, e, f) do { \ + Write##T##D(SAFE_CONST(ALfloatBUFFERSIZE*,(a)), (b), (c), (d), (e), (f)); \ + buffer = (T*)buffer + (e)*(f); \ } while(0) switch(device->FmtType) { case DevFmtByte: - WRITE(ALbyte, OutBuffer, buffer, DistComp, SamplesToDo, OutChannels); + if(device->DitherEnabled) + WRITE(ALbyte, _Dithered, OutBuffer, buffer, DistComp, DitherValues, + SamplesToDo, OutChannels); + else + WRITE(ALbyte, /*no dither*/, OutBuffer, buffer, DistComp, DitherValues, + SamplesToDo, OutChannels); break; case DevFmtUByte: - WRITE(ALubyte, OutBuffer, buffer, DistComp, SamplesToDo, OutChannels); + if(device->DitherEnabled) + WRITE(ALubyte, _Dithered, OutBuffer, buffer, DistComp, DitherValues, + SamplesToDo, OutChannels); + else + WRITE(ALubyte, /*no dither*/, OutBuffer, buffer, DistComp, DitherValues, + SamplesToDo, OutChannels); break; case DevFmtShort: - WRITE(ALshort, OutBuffer, buffer, DistComp, SamplesToDo, OutChannels); + if(device->DitherEnabled) + WRITE(ALshort, _Dithered, OutBuffer, buffer, DistComp, DitherValues, + SamplesToDo, OutChannels); + else + WRITE(ALshort, /*no dither*/, OutBuffer, buffer, DistComp, DitherValues, + SamplesToDo, OutChannels); break; case DevFmtUShort: - WRITE(ALushort, OutBuffer, buffer, DistComp, SamplesToDo, OutChannels); + if(device->DitherEnabled) + WRITE(ALushort, _Dithered, OutBuffer, buffer, DistComp, DitherValues, + SamplesToDo, OutChannels); + else + WRITE(ALushort, /*no dither*/, OutBuffer, buffer, DistComp, DitherValues, + SamplesToDo, OutChannels); break; case DevFmtInt: - WRITE(ALint, OutBuffer, buffer, DistComp, SamplesToDo, OutChannels); + WRITE(ALint, /*no dither*/, OutBuffer, buffer, DistComp, DitherValues, + SamplesToDo, OutChannels); break; case DevFmtUInt: - WRITE(ALuint, OutBuffer, buffer, DistComp, SamplesToDo, OutChannels); + WRITE(ALuint, /*no dither*/, OutBuffer, buffer, DistComp, DitherValues, + SamplesToDo, OutChannels); break; case DevFmtFloat: - WRITE(ALfloat, OutBuffer, buffer, DistComp, SamplesToDo, OutChannels); + WRITE(ALfloat, /*no dither*/, OutBuffer, buffer, DistComp, DitherValues, + SamplesToDo, OutChannels); break; } #undef WRITE |