lavfi/vulkan: use av_get_random_seed instead of rand

We need at least a few bits of entropy to determine the start index of each
queue, in order to let filters run in parallel as much as possible, and
rand() is not thread safe and disrupts any external API's usage of rand,
so instead replace it with av_get_random_seed.
While it has more overhead than rand, we only run it once per filter upon init.

diff --git a/libavfilter/vf_avgblur_vulkan.c b/libavfilter/vf_avgblur_vulkan.c
index 12d57e0875619ffc109194478349caf66b46eec7..89763345d9a9f134a4764b4fad85573064baffe3 100644 (file)
--- a/libavfilter/vf_avgblur_vulkan.c
+++ b/libavfilter/vf_avgblur_vulkan.c
@@ -16,6 +16,7 @@
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
+#include "libavutil/random_seed.h"
 #include "libavutil/opt.h"
 #include "vulkan.h"
 #include "internal.h"
@@ -99,7 +100,7 @@ static av_cold int init_filter(AVFilterContext *ctx, AVFrame *in)
 
     s->vkctx.queue_family_idx = s->vkctx.hwctx->queue_family_comp_index;
     s->vkctx.queue_count = GET_QUEUE_COUNT(s->vkctx.hwctx, 0, 1, 0);
-    s->vkctx.cur_queue_idx = rand() % s->vkctx.queue_count;
+    s->vkctx.cur_queue_idx = av_get_random_seed() % s->vkctx.queue_count;
 
     { /* Create shader for the horizontal pass */
         desc_i[0].updater = s->input_images;

diff --git a/libavfilter/vf_chromaber_vulkan.c b/libavfilter/vf_chromaber_vulkan.c
index 1bee5e10f8a16be77bae11efdefbebd6517f0d5c..12dfebb1fefcdd5f34b45d23a9c76ee238c5e607 100644 (file)
--- a/libavfilter/vf_chromaber_vulkan.c
+++ b/libavfilter/vf_chromaber_vulkan.c
@@ -16,6 +16,7 @@
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
+#include "libavutil/random_seed.h"
 #include "libavutil/opt.h"
 #include "vulkan.h"
 #include "internal.h"
@@ -75,7 +76,7 @@ static av_cold int init_filter(AVFilterContext *ctx, AVFrame *in)
 
     s->vkctx.queue_family_idx = s->vkctx.hwctx->queue_family_comp_index;
     s->vkctx.queue_count = GET_QUEUE_COUNT(s->vkctx.hwctx, 0, 1, 0);
-    s->vkctx.cur_queue_idx = rand() % s->vkctx.queue_count;
+    s->vkctx.cur_queue_idx = av_get_random_seed() % s->vkctx.queue_count;
 
     s->pl = ff_vk_create_pipeline(ctx);
     if (!s->pl)

diff --git a/libavfilter/vf_overlay_vulkan.c b/libavfilter/vf_overlay_vulkan.c
index 60a73564563d0644e90f52f06dc88296aad77bb7..60ca85fd08527b4363ab2c25d9801773861dd98c 100644 (file)
--- a/libavfilter/vf_overlay_vulkan.c
+++ b/libavfilter/vf_overlay_vulkan.c
@@ -16,6 +16,7 @@
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
+#include "libavutil/random_seed.h"
 #include "libavutil/opt.h"
 #include "vulkan.h"
 #include "internal.h"
@@ -89,7 +90,7 @@ static av_cold int init_filter(AVFilterContext *ctx)
 
     s->vkctx.queue_family_idx = s->vkctx.hwctx->queue_family_comp_index;
     s->vkctx.queue_count = GET_QUEUE_COUNT(s->vkctx.hwctx, 0, 1, 0);
-    s->vkctx.cur_queue_idx = rand() % s->vkctx.queue_count;
+    s->vkctx.cur_queue_idx = av_get_random_seed() % s->vkctx.queue_count;
 
     { /* Create the shader */
         const int planes = av_pix_fmt_count_planes(s->vkctx.output_format);

diff --git a/libavfilter/vf_scale_vulkan.c b/libavfilter/vf_scale_vulkan.c
index 9b2e5b92f6af490f217c93b7e5d266d7b9dc9aa1..35ea2e1e5d28d52af5434cceff6620ce0367829c 100644 (file)
--- a/libavfilter/vf_scale_vulkan.c
+++ b/libavfilter/vf_scale_vulkan.c
@@ -16,6 +16,7 @@
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
+#include "libavutil/random_seed.h"
 #include "libavutil/opt.h"
 #include "vulkan.h"
 #include "scale_eval.h"
@@ -117,7 +118,7 @@ static av_cold int init_filter(AVFilterContext *ctx, AVFrame *in)
 
     s->vkctx.queue_family_idx = s->vkctx.hwctx->queue_family_comp_index;
     s->vkctx.queue_count = GET_QUEUE_COUNT(s->vkctx.hwctx, 0, 1, 0);
-    s->vkctx.cur_queue_idx = rand() % s->vkctx.queue_count;
+    s->vkctx.cur_queue_idx = av_get_random_seed() % s->vkctx.queue_count;
 
     switch (s->scaler) {
     case F_NEAREST: