[FFmpeg-devel] [PATCH 09/18] vulkan_ffv1: fix reset shader dependencies

[Lynne]

Without a barrier upfront, the reset shader may read data fields not
yet set by the setup shader.
---
 libavcodec/vulkan_ffv1.c | 36 +++++++++++++++++-------------------
 1 file changed, 17 insertions(+), 19 deletions(-)

diff --git a/libavcodec/vulkan_ffv1.c b/libavcodec/vulkan_ffv1.c
index ccff927200..d90db291aa 100644
--- a/libavcodec/vulkan_ffv1.c
+++ b/libavcodec/vulkan_ffv1.c
@@ -375,31 +375,29 @@ static int vk_ffv1_end_frame(AVCodecContext *avctx)
     fp->tmp_data = NULL;
 
     /* Entry barrier for the slice state */
-    if (!(f->picture.f->flags & AV_FRAME_FLAG_KEY)) {
-        buf_bar[nb_buf_bar++] = (VkBufferMemoryBarrier2) {
-            .sType = VK_STRUCTURE_TYPE_BUFFER_MEMORY_BARRIER_2,
-            .srcStageMask = slice_state->stage,
-            .dstStageMask = VK_PIPELINE_STAGE_2_COMPUTE_SHADER_BIT,
-            .srcAccessMask = slice_state->access,
-            .dstAccessMask = VK_ACCESS_2_SHADER_STORAGE_WRITE_BIT,
-            .srcQueueFamilyIndex = VK_QUEUE_FAMILY_IGNORED,
-            .dstQueueFamilyIndex = VK_QUEUE_FAMILY_IGNORED,
-            .buffer = slice_state->buf,
-            .offset = 0,
-            .size = VK_WHOLE_SIZE,
-        };
-    }
+    buf_bar[nb_buf_bar++] = (VkBufferMemoryBarrier2) {
+        .sType = VK_STRUCTURE_TYPE_BUFFER_MEMORY_BARRIER_2,
+        .srcStageMask = slice_state->stage,
+        .dstStageMask = VK_PIPELINE_STAGE_2_COMPUTE_SHADER_BIT,
+        .srcAccessMask = slice_state->access,
+        .dstAccessMask = VK_ACCESS_2_SHADER_STORAGE_READ_BIT |
+                         VK_ACCESS_2_SHADER_STORAGE_WRITE_BIT,
+        .srcQueueFamilyIndex = VK_QUEUE_FAMILY_IGNORED,
+        .dstQueueFamilyIndex = VK_QUEUE_FAMILY_IGNORED,
+        .buffer = slice_state->buf,
+        .offset = 0,
+        .size = fp->slice_data_size*f->slice_count,
+    };
 
     vk->CmdPipelineBarrier2(exec->buf, &(VkDependencyInfo) {
         .sType = VK_STRUCTURE_TYPE_DEPENDENCY_INFO,
         .pBufferMemoryBarriers = buf_bar,
         .bufferMemoryBarrierCount = nb_buf_bar,
     });
-    if (nb_buf_bar) {
-        slice_state->stage = buf_bar[1].dstStageMask;
-        slice_state->access = buf_bar[1].dstAccessMask;
-        nb_buf_bar = 0;
-    }
+    slice_state->stage = buf_bar[0].dstStageMask;
+    slice_state->access = buf_bar[0].dstAccessMask;
+    nb_buf_bar = 0;
+    nb_img_bar = 0;
 
     /* Setup shader */
     ff_vk_shader_update_desc_buffer(&ctx->s, exec, &fv->setup,
-- 
2.47.2