summaryrefslogtreecommitdiffstats
path: root/xbmc/utils/IBufferObject.h
diff options
context:
space:
mode:
Diffstat (limited to 'xbmc/utils/IBufferObject.h')
-rw-r--r--xbmc/utils/IBufferObject.h131
1 files changed, 131 insertions, 0 deletions
diff --git a/xbmc/utils/IBufferObject.h b/xbmc/utils/IBufferObject.h
new file mode 100644
index 0000000..4588aff
--- /dev/null
+++ b/xbmc/utils/IBufferObject.h
@@ -0,0 +1,131 @@
+/*
+ * Copyright (C) 2017-2018 Team Kodi
+ * This file is part of Kodi - https://kodi.tv
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ * See LICENSES/README.md for more information.
+ */
+
+#pragma once
+
+#include <stdint.h>
+#include <string>
+
+/**
+ * @brief Interface to describe CBufferObjects.
+ *
+ * BufferObjects are used to abstract various memory types and present them
+ * with a generic interface. Typically on a posix system exists the concept
+ * of Direct Memory Access (DMA) which allows various systems to interact
+ * with a memory location directly without having to copy the data into
+ * userspace (ie. from kernel space). These DMA buffers are presented as
+ * file descriptors (fds) which can be passed around to gain access to
+ * the buffers memory location.
+ *
+ * In order to write to these buffer types typically the memory location has
+ * to be mapped into userspace via a call to mmap (or similar). This presents
+ * userspace with a memory location that can be initially written to (ie. by
+ * using memcpy or similar). Depending on the underlying implementation a
+ * stride might be specified if the memory type requires padding to a certain
+ * size (such as page size). The stride must be used when copying into the buffer.
+ *
+ * Some memory implementation may provide special memory layouts in which case
+ * modifiers are provided that describe tiling or compression. This should be
+ * transparent to the caller as the data copied into a BufferObject will likely
+ * be linear. The modifier will be needed when presenting the buffer via DRM or
+ * EGL even if it is linear.
+ *
+ */
+class IBufferObject
+{
+public:
+ virtual ~IBufferObject() = default;
+
+ /**
+ * @brief Create a BufferObject based on the format, width, and height of the desired buffer
+ *
+ * @param format framebuffer pixel formats are described using the fourcc codes defined in
+ * https://github.com/torvalds/linux/blob/master/include/uapi/drm/drm_fourcc.h
+ * @param width width of the requested buffer.
+ * @param height height of the requested buffer.
+ * @return true BufferObject creation was successful.
+ * @return false BufferObject creation was unsuccessful.
+ */
+ virtual bool CreateBufferObject(uint32_t format, uint32_t width, uint32_t height) = 0;
+
+ /**
+ * @brief Create a BufferObject based only on the size of the desired buffer. Not all
+ * CBufferObject implementations may support this. This method is required for
+ * use with the CAddonVideoCodec as it only knows the decoded buffer size.
+ *
+ * @param size of the requested buffer.
+ * @return true BufferObject creation was successful.
+ * @return false BufferObject creation was unsuccessful.
+ */
+ virtual bool CreateBufferObject(uint64_t size) = 0;
+
+ /**
+ * @brief Destroy a BufferObject.
+ *
+ */
+ virtual void DestroyBufferObject() = 0;
+
+ /**
+ * @brief Get the Memory location of the BufferObject. This method needs to be
+ * called to be able to copy data into the BufferObject.
+ *
+ * @return uint8_t* pointer to the memory location of the BufferObject.
+ */
+ virtual uint8_t *GetMemory() = 0;
+
+ /**
+ * @brief Release the mapped memory of the BufferObject. After calling this the memory
+ * location pointed to by GetMemory() will be invalid.
+ *
+ */
+ virtual void ReleaseMemory() = 0;
+
+ /**
+ * @brief Get the File Descriptor of the BufferObject. The fd is guaranteed to be
+ * available after calling CreateBufferObject().
+ *
+ * @return int fd for the BufferObject. Invalid if -1.
+ */
+ virtual int GetFd() = 0;
+
+ /**
+ * @brief Get the Stride of the BufferObject. The stride is guaranteed to be
+ * available after calling GetMemory().
+ *
+ * @return uint32_t stride of the BufferObject.
+ */
+ virtual uint32_t GetStride() = 0;
+
+ /**
+ * @brief Get the Modifier of the BufferObject. Format Modifiers further describe
+ * the buffer's format such as for tiling or compression.
+ * see https://github.com/torvalds/linux/blob/master/include/uapi/drm/drm_fourcc.h
+ *
+ * @return uint64_t modifier of the BufferObject. 0 means the layout is linear (default).
+ */
+ virtual uint64_t GetModifier() = 0;
+
+ /**
+ * @brief Must be called before reading/writing data to the BufferObject.
+ *
+ */
+ virtual void SyncStart() = 0;
+
+ /**
+ * @brief Must be called after reading/writing data to the BufferObject.
+ *
+ */
+ virtual void SyncEnd() = 0;
+
+ /**
+ * @brief Get the Name of the BufferObject type in use
+ *
+ * @return std::string name of the BufferObject type in use
+ */
+ virtual std::string GetName() const = 0;
+};