Changeset 294803 in webkit

Timestamp:

May 25, 2022 10:22:59 AM (2 years ago)

Author:

zan@falconsigh.net

Message:

[Linux] GBMBufferSwapchain should only conditionally create linear-formatted buffer objects
​https://bugs.webkit.org/show_bug.cgi?id=240637

Reviewed by Adrian Perez de Castro.

Spawning new gbm_bo objects should not default to requesting linear-storage
buffers. Instead, these should only be created when necessary, e.g. when
copying software-decoded video data into these buffers.

By default, no GBM flags are used. When required, the linear-storage requirement
is enscribed in the new flags field of the GBMBufferSwapchain::BufferDescription
object and acted upon in the GBMBufferSwapchain::getBuffer() call, using the
GBM_BO_USE_LINEAR flag in the gbm_bo_create() call.

The DMABuf-specific sink in MediaPlayerPrivateGStreamer is the only place at the
moment where linear-storage buffers are used since software-decoded material
originates here and is stored in linear memory.

• Source/WebCore/platform/graphics/gbm/GBMBufferSwapchain.cpp:

(WebCore::GBMBufferSwapchain::getBuffer):

• Source/WebCore/platform/graphics/gbm/GBMBufferSwapchain.h:
• Source/WebCore/platform/graphics/gbm/GraphicsContextGLGBM.cpp:

(WebCore::GraphicsContextGLANGLE::makeContextCurrent):

• Source/WebCore/platform/graphics/gstreamer/MediaPlayerPrivateGStreamer.cpp:

(WebCore::MediaPlayerPrivateGStreamer::pushDMABufToCompositor):

Canonical link: ​https://commits.webkit.org/250959@main

Location:

trunk/Source/WebCore/platform/graphics

Files:

• gbm/GBMBufferSwapchain.cpp (modified) (3 diffs)
• gbm/GBMBufferSwapchain.h (modified) (1 diff)
• gbm/GraphicsContextGLGBM.cpp (modified) (1 diff)
• gstreamer/MediaPlayerPrivateGStreamer.cpp (modified) (1 diff)

trunk/Source/WebCore/platform/graphics/gbm/GBMBufferSwapchain.cpp

@@ -49 +49 @@
     // If the description of the requested buffers has changed, update the description to the new one and wreck the existing buffers.
     // This should handle changes in format or dimension of the buffers.
-    if (description.format.fourcc != m_array.description.format.fourcc || description.width != m_array.description.width || description.height != m_array.description.height) {
+    if (description.format.fourcc != m_array.description.format.fourcc || description.width != m_array.description.width || description.height != m_array.description.height || description.flags != m_array.description.flags) {
         m_array.description = description;
         m_array.object = { };
@@ -96 +96 @@
             }
 
+            uint32_t boFlags = 0;
+            if (description.flags & BufferDescription::LinearStorage)
+                boFlags |= GBM_BO_USE_LINEAR;
+
             // For each plane, we spawn a gbm_bo object of the appropriate size and format.
             // TODO: GBM_BO_USE_LINEAR will be needed when transferring memory into the bo (e.g. copying
@@ -101 +105 @@
             for (unsigned i = 0; i < buffer->m_description.format.numPlanes; ++i) {
                 auto& plane = buffer->m_planes[i];
-                plane.bo = gbm_bo_create(device.device(), plane.width, plane.height, uint32_t(plane.fourcc), GBM_BO_USE_LINEAR);
+                plane.bo = gbm_bo_create(device.device(), plane.width, plane.height, uint32_t(plane.fourcc), boFlags);
                 plane.stride = gbm_bo_get_stride(plane.bo);
             }

trunk/Source/WebCore/platform/graphics/gbm/GBMBufferSwapchain.h

@@ -65 +65 @@
 
     struct BufferDescription {
+        enum Flags : uint32_t {
+            NoFlags = 0,
+            LinearStorage = 1 << 0,
+        };
+
         DMABufFormat format { };
         uint32_t width { 0 };
         uint32_t height  { 0 };
+        uint32_t flags { NoFlags };
     };
 

trunk/Source/WebCore/platform/graphics/gbm/GraphicsContextGLGBM.cpp

@@ -99 +99 @@
                 .width = std::clamp<uint32_t>(size.width(), 0, UINT_MAX),
                 .height = std::clamp<uint32_t>(size.height(), 0, UINT_MAX),
+                .flags = GBMBufferSwapchain::BufferDescription::NoFlags,
             });
 

trunk/Source/WebCore/platform/graphics/gstreamer/MediaPlayerPrivateGStreamer.cpp

@@ -3141 +3141 @@
 
     // If the decoder is exporting raw memory, we have to use the swapchain to allocate appropriate buffers
-    // and copy over the data for each plane.
+    // and copy over the data for each plane. For that to work, linear-storage buffer is required.
     GBMBufferSwapchain::BufferDescription bufferDescription {
-        DMABufFormat::create(fourccValue(GST_VIDEO_INFO_FORMAT(&videoInfo))),
-        static_cast<uint32_t>GST_VIDEO_INFO_WIDTH(&videoInfo), static_cast<uint32_t>GST_VIDEO_INFO_HEIGHT(&videoInfo),
+        .format = DMABufFormat::create(fourccValue(GST_VIDEO_INFO_FORMAT(&videoInfo))),
+        .width = static_cast<uint32_t>GST_VIDEO_INFO_WIDTH(&videoInfo),
+        .height = static_cast<uint32_t>GST_VIDEO_INFO_HEIGHT(&videoInfo),
+        .flags = GBMBufferSwapchain::BufferDescription::LinearStorage,
     };
     if (bufferDescription.format.fourcc == DMABufFormat::FourCC::Invalid)