vkencoder-private: replace packed headers with offset handling

Instead of holding all headers in an external array and add them into the
bitstream buffer before the encoding operation, adding extra memory and extra
copy operations, the encoder picture should specify the offset where the Vulkan
will start to add the bitstream slices/frame, because the element has written
already the headers until that offset.

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/8007>

subprojects/gst-plugins-bad/gst-libs/gst/vulkan/gstvkencoder-private.c

@@ -421,9 +421,8 @@ gst_vulkan_encoder_picture_new (GstVulkanEncoder * self, GstBuffer * in_buffer,
       VK_BUFFER_USAGE_VIDEO_ENCODE_DST_BIT_KHR, size_aligned);
   pic->width = width;
   pic->height = height;
-  pic->packed_headers =
-      g_ptr_array_new_with_free_func ((GDestroyNotify) gst_buffer_unref);
   pic->slotIndex = -1;
+  pic->offset = 0;
 
   pic->img_view = gst_vulkan_video_image_create_view (pic->in_buffer,
       priv->layered_dpb, TRUE, NULL);
@@ -460,8 +459,6 @@ gst_vulkan_encoder_picture_free (GstVulkanEncoderPicture * pic)
   gst_vulkan_image_view_unref (pic->dpb_view);
   pic->dpb_view = NULL;
 
-  g_clear_pointer (&pic->packed_headers, g_ptr_array_unref);
-
   g_free (pic);
 }
 
@@ -1080,8 +1077,6 @@ gst_vulkan_encoder_encode (GstVulkanEncoder * self,
   GstMemory *mem;
   int i;
   GstVulkanEncodeQueryResult *encode_res;
-  guint n_mems = 0;
-  gsize params_size = 0;
   VkVideoEncodeRateControlLayerInfoKHR rate_control_layer;
   VkVideoEncodeQualityLevelInfoKHR quality_level_info;
   VkVideoCodingControlInfoKHR coding_ctrl;
@@ -1249,22 +1244,8 @@ gst_vulkan_encoder_encode (GstVulkanEncoder * self,
     priv->first_encode_cmd = TRUE;
   }
 
-  /* Add the packed headers if present on head of the output buffer */
-  for (i = 0; pic->packed_headers && i < pic->packed_headers->len; i++) {
-    GstBuffer *buffer;
-    GstMapInfo info;
-    buffer = g_ptr_array_index (pic->packed_headers, i);
-    gst_buffer_map (buffer, &info, GST_MAP_READ);
-    GST_MEMDUMP ("params buffer", info.data, info.size);
-    gst_buffer_unmap (buffer, &info);
-    params_size += gst_buffer_get_size (buffer);
-    mem = gst_memory_copy (gst_buffer_peek_memory (buffer, 0), 0, -1);
-    gst_buffer_insert_memory (pic->out_buffer, i, mem);
-    n_mems++;
-  }
-  g_clear_pointer (&pic->packed_headers, g_ptr_array_unref);
   /* Peek the output memory to be used by VkVideoEncodeInfoKHR.dstBuffer */
-  mem = gst_buffer_peek_memory (pic->out_buffer, n_mems);
+  mem = gst_buffer_peek_memory (pic->out_buffer, 0);
 
   /* Attribute a free slot index to the picture to be used later as a reference.
    * The picture is kept until it remains useful to the encoding process.*/
@@ -1281,7 +1262,7 @@ gst_vulkan_encoder_encode (GstVulkanEncoder * self,
     .pNext = pic->codec_pic_info,
     .flags = 0x0,
     .dstBuffer = ((GstVulkanBufferMemory *) mem)->buffer,
-    .dstBufferOffset = 0,
+    .dstBufferOffset = pic->offset,
     .dstBufferRange = gst_memory_get_sizes (mem, NULL, NULL),
     .srcPictureResource = (VkVideoPictureResourceInfoKHR) { // SPEC: this should be separate
         .sType = VK_STRUCTURE_TYPE_VIDEO_PICTURE_RESOURCE_INFO_KHR,
@@ -1301,6 +1282,10 @@ gst_vulkan_encoder_encode (GstVulkanEncoder * self,
   };
   /* *INDENT-ON* */
 
+  encode_info.dstBufferRange -= encode_info.dstBufferOffset;
+  encode_info.dstBufferRange = GST_ROUND_DOWN_N (encode_info.dstBufferRange,
+      priv->caps.caps.minBitstreamBufferSizeAlignment);
+
   gst_vulkan_operation_add_dependency_frame (priv->exec, pic->in_buffer,
       VK_PIPELINE_STAGE_2_ALL_COMMANDS_BIT,
       VK_PIPELINE_STAGE_2_VIDEO_ENCODE_BIT_KHR);
@@ -1355,10 +1340,9 @@ gst_vulkan_encoder_encode (GstVulkanEncoder * self,
 
   gst_vulkan_operation_get_query (priv->exec, (gpointer *) & encode_res, &err);
   if (encode_res->status == VK_QUERY_RESULT_STATUS_COMPLETE_KHR) {
-    GST_INFO_OBJECT (self, "The frame %p has been encoded with size %lu",
+    GST_INFO_OBJECT (self, "The frame %p has been encoded with size %"
-        pic, encode_res->data_size + params_size);
+        G_GUINT64_FORMAT, pic, encode_res->data_size + pic->offset);
-    gst_buffer_resize (pic->out_buffer, encode_res->offset,
+    gst_buffer_set_size (pic->out_buffer, encode_res->data_size + pic->offset);
-        encode_res->data_size + params_size);
   } else {
     GST_ERROR_OBJECT (self,
         "The operation did not complete properly, query status = %d",

subprojects/gst-plugins-bad/gst-libs/gst/vulkan/gstvkencoder-private.h

@@ -41,7 +41,7 @@ typedef struct _GstVulkanEncoderPicture GstVulkanEncoderPicture;
 /**
  * GstVulkanEncoderPicture:
  * @slotIndex: slot index
- * @packed_headers: packed headers
+ * @offset: headers offset
  * @width: picture width
  * @height: picture height
  * @fps_n: fps numerator
@@ -57,8 +57,7 @@ struct _GstVulkanEncoderPicture
 {
   gint slotIndex;
 
-  /* picture parameters */
+  guint64 offset;
-  GPtrArray *packed_headers;
 
   gint width;
   gint height;