swscale/utils: Fix potential race when initializing xyz tables

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
This commit is contained in:
Andreas Rheinhardt 2025-05-24 16:02:04 +02:00
parent 1c78db8ffc
commit 54c865fbec

View File

@ -692,13 +692,35 @@ static void fill_rgb2yuv_table(SwsInternal *c, const int table[4], int dstRange)
AV_WL16(p + 16*4 + 2*i, map[i] >= 0 ? c->input_rgb2yuv_table[map[i]] : 0);
}
static int fill_xyztables(SwsInternal *c)
#if CONFIG_SMALL
static void init_xyz_tables(uint16_t xyzgamma_tab[4096], uint16_t xyzgammainv_tab[65536],
uint16_t rgbgamma_tab[65536], uint16_t rgbgammainv_tab[4096])
#else
static uint16_t xyzgamma_tab[4096], rgbgammainv_tab[4096];
static uint16_t rgbgamma_tab[65536], xyzgammainv_tab[65536];
static av_cold void init_xyz_tables(void)
#endif
{
int i;
double xyzgamma = XYZ_GAMMA;
double rgbgamma = 1.0 / RGB_GAMMA;
double xyzgamma = XYZ_GAMMA;
double rgbgamma = 1.0 / RGB_GAMMA;
double xyzgammainv = 1.0 / XYZ_GAMMA;
double rgbgammainv = RGB_GAMMA;
/* set input gamma vectors */
for (int i = 0; i < 4096; i++) {
xyzgamma_tab[i] = lrint(pow(i / 4095.0, xyzgamma) * 65535.0);
rgbgammainv_tab[i] = lrint(pow(i / 4095.0, rgbgammainv) * 65535.0);
}
/* set output gamma vectors */
for (int i = 0; i < 65536; i++) {
rgbgamma_tab[i] = lrint(pow(i / 65535.0, rgbgamma) * 4095.0);
xyzgammainv_tab[i] = lrint(pow(i / 65535.0, xyzgammainv) * 4095.0);
}
}
static int fill_xyztables(SwsInternal *c)
{
static const int16_t xyz2rgb_matrix[3][4] = {
{13270, -6295, -2041},
{-3969, 7682, 170},
@ -707,10 +729,7 @@ static int fill_xyztables(SwsInternal *c)
{1689, 1464, 739},
{ 871, 2929, 296},
{ 79, 488, 3891} };
#if !CONFIG_SMALL
static uint16_t xyzgamma_tab[4096], rgbgammainv_tab[4096];
static uint16_t rgbgamma_tab[65536], xyzgammainv_tab[65536];
#endif
if (c->xyzgamma)
return 0;
@ -724,26 +743,16 @@ static int fill_xyztables(SwsInternal *c)
c->rgbgammainv = c->xyzgamma + 4096;
c->rgbgamma = c->rgbgammainv + 4096;
c->xyzgammainv = c->rgbgamma + 65536;
init_xyz_tables(c->xyzgamma, c->xyzgammainv, c->rgbgamma, c->rgbgammainv);
#else
c->xyzgamma = xyzgamma_tab;
c->rgbgamma = rgbgamma_tab;
c->xyzgammainv = xyzgammainv_tab;
c->rgbgammainv = rgbgammainv_tab;
if (xyzgamma_tab[4095])
return 0;
static AVOnce xyz_init_static_once = AV_ONCE_INIT;
ff_thread_once(&xyz_init_static_once, init_xyz_tables);
#endif
/* set input gamma vectors */
for (i = 0; i < 4096; i++) {
c->xyzgamma[i] = lrint(pow(i / 4095.0, xyzgamma) * 65535.0);
c->rgbgammainv[i] = lrint(pow(i / 4095.0, rgbgammainv) * 65535.0);
}
/* set output gamma vectors */
for (i = 0; i < 65536; i++) {
c->rgbgamma[i] = lrint(pow(i / 65535.0, rgbgamma) * 4095.0);
c->xyzgammainv[i] = lrint(pow(i / 65535.0, xyzgammainv) * 4095.0);
}
return 0;
}