mirrors/pipewire
1
0
Fork 0
mirror of https://gitlab.freedesktop.org/pipewire/pipewire.git synced 2025-11-01 22:58:50 -04:00
Code Issues Projects Releases Packages Wiki Activity Actions

audioconvert: somewhat avoid precision loss in S32 to F32 conversion

Browse source 
At the very least, we should go through s25_32 intermediate
instead of s24_32, to avoid needlessly loosing 1 LSB precision bit.

That being said, i suspect it's still not doing the right thing.
Why are we silently dropping those 7 LSB bits?
Is that really the way to do it?
This commit is contained in:
Roman Lebedev 2024-06-14 02:00:27 +03:00
parent 175d533b56
commit c517865864
No known key found for this signature in database
GPG key ID: 083C3EBB4A1689E0
4 changed files with 38 additions and 46 deletions
Download patch file Download diff file Expand all files Collapse all files

34
spa/plugins/audioconvert/test-fmt-ops.c
View file

@ -335,10 +335,12 @@ static void test_s32_f32(void)
0x80000100, 0x40000000, 0xc0000000, 0x0080, 0xFFFFFF80, 0x0100,
0xFFFFFF00, 0x0200, 0xFFFFFE00
};
static const float out[] = { 0.e+00f, 9.9999988079071044921875e-01f, -1.e+00f,
static const float out[] = { 0.e+00f, 9.99999940395355224609375e-01f, -1.e+00f,
9.9999988079071044921875e-01f, -9.9999988079071044921875e-01f, 5.e-01f,
-5.e-01f, 0.e+00f, -1.1920928955078125e-07f, 1.1920928955078125e-07f,
-1.1920928955078125e-07f, 2.384185791015625e-07f, -2.384185791015625e-07f
-5.e-01f, 5.9604644775390625e-08f, -5.9604644775390625e-08f,
1.1920928955078125e-07f, -1.1920928955078125e-07f,
2.384185791015625e-07f, -2.384185791015625e-07f
};
run_test("test_s32_f32d", in, sizeof(in[0]), out, sizeof(out[0]), SPA_N_ELEMENTS(out),
@ -630,38 +632,28 @@ static void test_lossless_s25_32_to_f32_to_s25_32(void)
}
}
static void test_lossless_s25_32_to_s32_to_f32_to_s25_32_XFAIL(void)
static void test_lossless_s25_32_to_s32_to_f32_to_s25_32(void)
{
int32_t i;
int all_lossless = 1;
int32_t max_abs_err = -1;
fprintf(stderr, "test %s:\n", __func__);
for (i = S25_MIN; i <= S25_MAX; i+=1) {
float v = S32_TO_F32(S25_32_TO_S32(i));
int32_t t = F32_TO_S25_32(v);
all_lossless &= i == t;
max_abs_err = SPA_MAX(max_abs_err, SPA_ABS(i - t));
spa_assert_se(i == t);
}
spa_assert_se(!all_lossless);
spa_assert_se(max_abs_err == 1);
}
static void test_lossless_s25_32_to_s32_to_f32_to_s32_to_s25_32_XFAIL(void)
static void test_lossless_s25_32_to_s32_to_f32_to_s32_to_s25_32(void)
{
int32_t i;
int all_lossless = 1;
int32_t max_abs_err = -1;
fprintf(stderr, "test %s:\n", __func__);
for (i = S25_MIN; i <= S25_MAX; i+=1) {
float v = S32_TO_F32(S25_32_TO_S32(i));
int32_t t = S32_TO_S25_32(F32_TO_S32(v));
all_lossless &= i == t;
max_abs_err = SPA_MAX(max_abs_err, SPA_ABS(i - t));
spa_assert_se(i == t);
}
spa_assert_se(!all_lossless);
spa_assert_se(max_abs_err == 1);
}
static void test_lossless_s25_32_to_f32_to_s32_to_s25_32(void)
@ -681,7 +673,7 @@ static void test_lossless_s32(void)
int64_t i;
int32_t max_abs_err = -1;
const int32_t expected_max_abs_err = 255;
const int32_t expected_max_abs_err = 127;
fprintf(stderr, "test %s:\n", __func__);
for (i = S32_MIN; i < S32_MAX; i += (expected_max_abs_err >> 1)) {
float v = S32_TO_F32(i);
@ -708,7 +700,7 @@ static void test_lossless_s32_lossless_subset(void)
}
}
spa_assert_se(!all_lossless);
spa_assert_se(max_abs_err == 255);
spa_assert_se(max_abs_err == 127);
}
static void test_lossless_u32(void)
@ -875,8 +867,8 @@ int main(int argc, char *argv[])
test_lossless_s24();
test_lossless_u24();
test_lossless_s25_32_to_f32_to_s25_32();
test_lossless_s25_32_to_s32_to_f32_to_s25_32_XFAIL();
test_lossless_s25_32_to_s32_to_f32_to_s32_to_s25_32_XFAIL();
test_lossless_s25_32_to_s32_to_f32_to_s25_32();
test_lossless_s25_32_to_s32_to_f32_to_s32_to_s25_32();
test_lossless_s25_32_to_f32_to_s32_to_s25_32();
test_lossless_s32();
test_lossless_s32_lossless_subset();