when we mix into a 16bit accumulator make sure we clamp before we scale with a volume to avoid range faults when multiplying

This commit is contained in:
Lennart Poettering 2008-10-02 02:29:56 +02:00
parent 08cf9db0d1
commit ea82dec294
2 changed files with 8 additions and 6 deletions

View file

@ -214,8 +214,8 @@ size_t pa_mix(
m->ptr = (uint8_t*) m->ptr + sizeof(int16_t);
}
sum = (sum * linear[channel]) / 0x10000;
sum = PA_CLAMP_UNLIKELY(sum, -0x8000, 0x7FFF);
sum = (sum * linear[channel]) / 0x10000;
*((int16_t*) data) = (int16_t) sum;
data = (uint8_t*) data + sizeof(int16_t);
@ -253,8 +253,8 @@ size_t pa_mix(
m->ptr = (uint8_t*) m->ptr + sizeof(int16_t);
}
sum = (sum * linear[channel]) / 0x10000;
sum = PA_CLAMP_UNLIKELY(sum, -0x8000, 0x7FFF);
sum = (sum * linear[channel]) / 0x10000;
*((int16_t*) data) = PA_INT16_SWAP((int16_t) sum);
data = (uint8_t*) data + sizeof(int16_t);
@ -411,8 +411,8 @@ size_t pa_mix(
m->ptr = (uint8_t*) m->ptr + 1;
}
sum = (sum * linear[channel]) / 0x10000;
sum = PA_CLAMP_UNLIKELY(sum, -0x8000, 0x7FFF);
sum = (sum * linear[channel]) / 0x10000;
*((uint8_t*) data) = (uint8_t) st_14linear2ulaw((int16_t) sum >> 2);
data = (uint8_t*) data + 1;
@ -450,8 +450,8 @@ size_t pa_mix(
m->ptr = (uint8_t*) m->ptr + 1;
}
sum = (sum * linear[channel]) / 0x10000;
sum = PA_CLAMP_UNLIKELY(sum, -0x8000, 0x7FFF);
sum = (sum * linear[channel]) / 0x10000;
*((uint8_t*) data) = (uint8_t) st_13linear2alaw((int16_t) sum >> 3);
data = (uint8_t*) data + 1;

View file

@ -221,6 +221,8 @@ int main(int argc, char *argv[]) {
i.length = pa_memblock_get_length(i.memblock);
i.index = 0;
dump_block(&a, &i);
/* Make a copy */
j = i;
pa_memblock_ref(j.memblock);
@ -229,6 +231,8 @@ int main(int argc, char *argv[]) {
/* Adjust volume of the copy */
pa_volume_memchunk(&j, &a, &v);
dump_block(&a, &j);
m[0].chunk = i;
m[0].volume.values[0] = PA_VOLUME_NORM;
m[0].volume.channels = a.channels;
@ -244,8 +248,6 @@ int main(int argc, char *argv[]) {
pa_mix(m, 2, ptr, k.length, &a, NULL, FALSE);
pa_memblock_release(k.memblock);
dump_block(&a, &i);
dump_block(&a, &j);
dump_block(&a, &k);
pa_memblock_unref(i.memblock);