audioconvert: ensure alignment

Allocate a little bit more data to ensure alignment and overread of the
dither data.
Ensure sse2 can load aligned data in all cases.
This commit is contained in:
Wim Taymans 2022-06-27 17:18:23 +02:00
parent b41d52cfd1
commit 00998ffd7e
4 changed files with 19 additions and 18 deletions

View file

@ -49,7 +49,7 @@ void dither_f32_c(struct dither *dt, void * SPA_RESTRICT dst[],
uint32_t i, n, m, chunk;
const float **s = (const float**)src;
float **d = (float**)dst;
float *t = dt->dither;
float *dither = dt->dither;
chunk = SPA_MIN(n_samples, dt->dither_size);
update_dither_c(dt, chunk);
@ -62,7 +62,7 @@ void dither_f32_c(struct dither *dt, void * SPA_RESTRICT dst[],
const float *si = &s[i][n];
for (m = 0; m < chunk; m++)
di[m] = si[m] + t[m];
di[m] = si[m] + dither[m];
}
}
}

View file

@ -29,25 +29,25 @@
static inline void update_dither_sse2(struct dither *dt, uint32_t n_samples)
{
uint32_t n;
const uint32_t *r = dt->random;
const uint32_t *r = SPA_PTR_ALIGN(dt->random, 16, uint32_t);
float *dither = SPA_PTR_ALIGN(dt->dither, 16, float);
__m128 scale = _mm_set1_ps(dt->scale), out[1];
__m128i in[1], t[1];
for (n = 0; n < n_samples; n += 4) {
/* 32 bit xorshift PRNG, see https://en.wikipedia.org/wiki/Xorshift */
in[0] = _mm_loadu_si128((__m128i*)r);
in[0] = _mm_load_si128((__m128i*)r);
t[0] = _mm_slli_epi32(in[0], 13);
in[0] = _mm_xor_si128(in[0], t[0]);
t[0] = _mm_srli_epi32(in[0], 17);
in[0] = _mm_xor_si128(in[0], t[0]);
t[0] = _mm_slli_epi32(in[0], 5);
in[0] = _mm_xor_si128(in[0], t[0]);
_mm_storeu_si128((__m128i*)r, in[0]);
_mm_store_si128((__m128i*)r, in[0]);
out[0] = _mm_cvtepi32_ps(in[0]);
out[0] = _mm_mul_ps(out[0], scale);
_mm_storeu_ps(&dt->dither[n], out[0]);
_mm_store_ps(&dither[n], out[0]);
}
}
@ -57,7 +57,7 @@ void dither_f32_sse2(struct dither *dt, void * SPA_RESTRICT dst[],
uint32_t i, n, m, chunk, unrolled;
const float **s = (const float**)src;
float **d = (float**)dst;
float *t = dt->dither;
float *dither = SPA_PTR_ALIGN(dt->dither, 16, float);
__m128 in[4];
chunk = SPA_MIN(n_samples, dt->dither_size);
@ -81,17 +81,17 @@ void dither_f32_sse2(struct dither *dt, void * SPA_RESTRICT dst[],
in[1] = _mm_load_ps(&si[m + 4]);
in[2] = _mm_load_ps(&si[m + 8]);
in[3] = _mm_load_ps(&si[m + 12]);
in[0] = _mm_add_ps(in[0], _mm_load_ps(&t[m ]));
in[1] = _mm_add_ps(in[1], _mm_load_ps(&t[m + 4]));
in[2] = _mm_add_ps(in[2], _mm_load_ps(&t[m + 8]));
in[3] = _mm_add_ps(in[3], _mm_load_ps(&t[m + 12]));
in[0] = _mm_add_ps(in[0], _mm_load_ps(&dither[m ]));
in[1] = _mm_add_ps(in[1], _mm_load_ps(&dither[m + 4]));
in[2] = _mm_add_ps(in[2], _mm_load_ps(&dither[m + 8]));
in[3] = _mm_add_ps(in[3], _mm_load_ps(&dither[m + 12]));
_mm_store_ps(&di[m ], in[0]);
_mm_store_ps(&di[m + 4], in[1]);
_mm_store_ps(&di[m + 8], in[2]);
_mm_store_ps(&di[m + 12], in[3]);
}
for (; m < chunk; m++)
di[m] = si[m] + t[m];
di[m] = si[m] + dither[m];
}
}
}

View file

@ -85,14 +85,14 @@ int dither_init(struct dither *d)
d->scale = 1.0f / (1ULL << (31 + d->intensity));
d->dither_size = DITHER_SIZE;
d->dither = calloc(d->dither_size + 8, sizeof(float));
d->dither = calloc(d->dither_size + DITHER_OPS_MAX_OVERREAD +
DITHER_OPS_MAX_ALIGN / sizeof(float), sizeof(float));
if (d->dither == NULL)
return -errno;
for (i = 0; i < SPA_N_ELEMENTS(d->random); i++)
d->random[i] = random();
d->free = impl_dither_free;
d->process = info->process;
return 0;

View file

@ -29,6 +29,9 @@
#include <spa/utils/string.h>
#include <spa/param/audio/raw.h>
#define DITHER_OPS_MAX_ALIGN 16
#define DITHER_OPS_MAX_OVERREAD 16
struct dither {
uint32_t intensity;
#define DITHER_METHOD_NONE 0
@ -45,7 +48,7 @@ struct dither {
const void * SPA_RESTRICT src[], uint32_t n_samples);
void (*free) (struct dither *d);
uint32_t random[16];
uint32_t random[16 + DITHER_OPS_MAX_ALIGN/sizeof(uint32_t)];
float *dither;
uint32_t dither_size;
float scale;
@ -83,8 +86,6 @@ void dither_##name##_##arch(struct dither *d, \
const void * SPA_RESTRICT src[], \
uint32_t n_samples);
#define DITHER_OPS_MAX_ALIGN 16
DEFINE_FUNCTION(f32, c);
#if defined(HAVE_SSE2)
DEFINE_FUNCTION(f32, sse2);