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Add non M4 audiomixer support

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This commit is contained in:
gamblor21 2021-03-25 17:30:40 -05:00
parent 2373e64780
commit 0b212e2243
2 changed files with 45 additions and 2 deletions
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3
ports/raspberrypi/mpconfigport.mk
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@ -46,8 +46,7 @@ CIRCUITPY_AUDIOBUSIO ?= 1
CIRCUITPY_AUDIOCORE ?= 1
CIRCUITPY_AUDIOPWMIO ?= 1
# These libraries require Cortex M4+ for fancy math instructions.
CIRCUITPY_AUDIOMIXER ?= 0
CIRCUITPY_AUDIOMIXER = 1
INTERNAL_LIBM = 1

44
shared-module/audiomixer/Mixer.c
View File

@ -103,11 +103,28 @@ void audiomixer_mixer_reset_buffer(audiomixer_mixer_obj_t *self,
__attribute__((always_inline))
static inline uint32_t add16signed(uint32_t a, uint32_t b) {
#if (defined(__ARM_ARCH_7EM__) && (__ARM_ARCH_7EM__ == 1)) // Cortex-M4 w/FPU
return __QADD16(a, b);
#else
uint32_t result = 0;
for (int8_t i = 0; i < 2; i++) {
int16_t ai = a >> (sizeof(int16_t) * 8 * i);
int16_t bi = b >> (sizeof(int16_t) * 8 * i);
int32_t intermediate = (int32_t)ai + bi / 2;
if (intermediate > SHRT_MAX) {
intermediate = SHRT_MAX;
} else if (intermediate < SHRT_MIN) {
intermediate = SHRT_MIN;
}
result |= (((uint32_t)intermediate) & 0xffff) << (sizeof(int16_t) * 8 * i);
}
return result;
#endif
}
__attribute__((always_inline))
static inline uint32_t mult16signed(uint32_t val, int32_t mul) {
#if (defined(__ARM_ARCH_7EM__) && (__ARM_ARCH_7EM__ == 1)) // Cortex-M4 w/FPU
mul <<= 16;
int32_t hi, lo;
enum { bits = 16 }; // saturate to 16 bits
@ -118,18 +135,45 @@ static inline uint32_t mult16signed(uint32_t val, int32_t mul) {
asm volatile ("ssat %0, %1, %2, asr %3" : "=r" (hi) : "I" (bits), "r" (hi), "I" (shift));
asm volatile ("pkhbt %0, %1, %2, lsl #16" : "=r" (val) : "r" (lo), "r" (hi)); // pack
return val;
#else
uint32_t result = 0;
float mod_mul = (float)mul / (float)((1 << 15) - 1);
for (int8_t i = 0; i < 2; i++) {
int16_t ai = (val >> (sizeof(uint16_t) * 8 * i)) - 0x8000;
int32_t intermediate = ai * mod_mul;
if (intermediate > SHRT_MAX) {
intermediate = SHRT_MAX;
} else if (intermediate < SHRT_MIN) {
intermediate = SHRT_MIN;
}
result |= (((uint32_t)intermediate) + 0x8000) << (sizeof(int16_t) * 8 * i);
}
return result;
#endif
}
static inline uint32_t tounsigned8(uint32_t val) {
#if (defined(__ARM_ARCH_7EM__) && (__ARM_ARCH_7EM__ == 1)) // Cortex-M4 w/FPU
return __UADD8(val, 0x80808080);
#else
return val ^ 0x80808080;
#endif
}
static inline uint32_t tounsigned16(uint32_t val) {
#if (defined(__ARM_ARCH_7EM__) && (__ARM_ARCH_7EM__ == 1)) // Cortex-M4 w/FPU
return __UADD16(val, 0x80008000);
#else
return val ^ 0x80008000;
#endif
}
static inline uint32_t tosigned16(uint32_t val) {
#if (defined(__ARM_ARCH_7EM__) && (__ARM_ARCH_7EM__ == 1)) // Cortex-M4 w/FPU
return __UADD16(val, 0x80008000);
#else
return val ^ 0x80008000;
#endif
}
static inline uint32_t unpack8(uint16_t val) {