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lavc/audiodsp: fix aliasing violation 

Even though they have the same size, and typically the same alignment,
uint32_t and float are under no circumstances compatible types in C.

The casts from float * to uint32_t * are invalid here. Insofar as the
resulting pointers are dereferenced, this is undefined behaviour.
This patch uses av_float2int() / av_int2float() instead.
This commit is contained in:
Rémi Denis-Courmont 2022-09-13 18:56:27 +03:00
parent 51945d5ace
commit 97c3c9974c
1 changed files with 20 additions and 20 deletions
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40
libavcodec/audiodsp.c
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@ -22,36 +22,36 @@
#include "libavutil/common.h"
#include "audiodsp.h"
static inline uint32_t clipf_c_one(uint32_t a, uint32_t mini,
uint32_t maxi, uint32_t maxisign)
static inline float clipf_c_one(float a, uint32_t mini,
uint32_t maxi, uint32_t maxisign)
{
if (a > mini)
return mini;
else if ((a ^ (1U << 31)) > maxisign)
return maxi;
uint32_t ai = av_float2int(a);
if (ai > mini)
return av_int2float(mini);
else if ((ai ^ (1U << 31)) > maxisign)
return av_int2float(maxi);
else
return a;
}
static void vector_clipf_c_opposite_sign(float *dst, const float *src,
float *min, float *max, int len)
float min, float max, int len)
{
int i;
uint32_t mini = *(uint32_t *) min;
uint32_t maxi = *(uint32_t *) max;
uint32_t mini = av_float2int(min);
uint32_t maxi = av_float2int(max);
uint32_t maxisign = maxi ^ (1U << 31);
uint32_t *dsti = (uint32_t *) dst;
const uint32_t *srci = (const uint32_t *) src;
for (i = 0; i < len; i += 8) {
dsti[i + 0] = clipf_c_one(srci[i + 0], mini, maxi, maxisign);
dsti[i + 1] = clipf_c_one(srci[i + 1], mini, maxi, maxisign);
dsti[i + 2] = clipf_c_one(srci[i + 2], mini, maxi, maxisign);
dsti[i + 3] = clipf_c_one(srci[i + 3], mini, maxi, maxisign);
dsti[i + 4] = clipf_c_one(srci[i + 4], mini, maxi, maxisign);
dsti[i + 5] = clipf_c_one(srci[i + 5], mini, maxi, maxisign);
dsti[i + 6] = clipf_c_one(srci[i + 6], mini, maxi, maxisign);
dsti[i + 7] = clipf_c_one(srci[i + 7], mini, maxi, maxisign);
dst[i + 0] = clipf_c_one(src[i + 0], mini, maxi, maxisign);
dst[i + 1] = clipf_c_one(src[i + 1], mini, maxi, maxisign);
dst[i + 2] = clipf_c_one(src[i + 2], mini, maxi, maxisign);
dst[i + 3] = clipf_c_one(src[i + 3], mini, maxi, maxisign);
dst[i + 4] = clipf_c_one(src[i + 4], mini, maxi, maxisign);
dst[i + 5] = clipf_c_one(src[i + 5], mini, maxi, maxisign);
dst[i + 6] = clipf_c_one(src[i + 6], mini, maxi, maxisign);
dst[i + 7] = clipf_c_one(src[i + 7], mini, maxi, maxisign);
}
}
@ -61,7 +61,7 @@ static void vector_clipf_c(float *dst, const float *src, int len,
int i;
if (min < 0 && max > 0) {
vector_clipf_c_opposite_sign(dst, src, &min, &max, len);
vector_clipf_c_opposite_sign(dst, src, min, max, len);
} else {
for (i = 0; i < len; i += 8) {
dst[i] = av_clipf(src[i], min, max);