VAVDA: Redesign stage 1.

content/common/gpu/media/vaapi_wrapper.h

+// Copyright (c) 2013 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+//
+// This file contains an implementation of VaapiWrapper, used by
+// VaapiVideoDecodeAccelerator and VaapiH264Decoder to interface
+// with libva (VA-API library for hardware video decode).
+
+#ifndef CONTENT_COMMON_GPU_MEDIA_VAAPI_WRAPPER_H_
+#define CONTENT_COMMON_GPU_MEDIA_VAAPI_WRAPPER_H_
+
+#include "base/callback.h"
+#include "base/memory/ref_counted.h"
+#include "base/synchronization/lock.h"
+#include "content/common/content_export.h"
+#include "content/common/gpu/media/va_surface.h"
+#include "media/base/video_decoder_config.h"
+#include "third_party/libva/va/va.h"
+#include "third_party/libva/va/va_x11.h"
+#include "ui/gfx/size.h"
+
+namespace content {
+
+// This class handles VA-API calls and ensures proper locking of VA-API calls
+// to libva, the userspace shim to the HW decoder driver. libva is not
+// thread-safe, so we have to perform locking ourselves. This class is fully
+// synchronous and its methods can be called from any thread and may wait on
+// the va_lock_ while other, concurrent calls run.
+//
+// This class is responsible for managing VAAPI connection, contexts and state.
+// It is also responsible for managing and freeing VABuffers (not VASurfaces),
+// which are used to queue decode parameters and slice data to the HW decoder,
+// as well as underlying memory for VASurfaces themselves.
+class CONTENT_EXPORT VaapiWrapper {
+ public:
+  // |report_error_to_uma_cb| will be called independently from reporting
+  // errors to clients via method return values.
+  static scoped_ptr<VaapiWrapper> Create(
+      media::VideoCodecProfile profile,
+      Display* x_display,
+      const base::Closure& report_error_to_uma_cb);
+
+  ~VaapiWrapper();
+
+  // Create |num_surfaces| backing surfaces in driver for VASurfaces, each
+  // of size |size|. Returns true when successful, with the created IDs in
+  // |va_surfaces| to be managed and later wrapped in VASurfaces.
+  // The client must DestroySurfaces() each time before calling this method
+  // again to free the allocated surfaces first, but is not required to do so
+  // at destruction time, as this will be done automatically from
+  // the destructor.
+  bool CreateSurfaces(gfx::Size size,
+                      size_t num_surfaces,
+                      std::vector<VASurfaceID>* va_surfaces);
+
+  // Free all memory allocated in CreateSurfaces.
+  void DestroySurfaces();
+
+  // Submit parameters or slice data of |va_buffer_type|, copying them from
+  // |buffer| of size |size|, into HW decoder. The data in |buffer| is no
+  // longer needed and can be freed after this method returns.
+  // Data submitted via this method awaits in the HW decoder until
+  // DecodeAndDestroyPendingBuffers is called to execute or
+  // DestroyPendingBuffers is used to cancel a pending decode.
+  bool SubmitBuffer(VABufferType va_buffer_type, size_t size, void* buffer);
+
+  // Cancel and destroy all buffers queued to the HW decoder via SubmitBuffer.
+  // Useful when a pending decode is to be cancelled (on reset or error).
+  void DestroyPendingBuffers();
+
+  // Execute decode in hardware into |va_surface_id} and destroy pending
+  // buffers. Return false if SubmitDecode() fails.
+  bool DecodeAndDestroyPendingBuffers(VASurfaceID va_surface_id);
+
+  // Put data from |va_surface_id| into |x_pixmap| of size |size|,
+  // converting/scaling to it.
+  bool PutSurfaceIntoPixmap(VASurfaceID va_surface_id,
+                            Pixmap x_pixmap,
+                            gfx::Size dest_size);
+
+  // Do any necessary initialization before the sandbox is enabled.
+  static void PreSandboxInitialization();
+
+ private:
+  VaapiWrapper();
+
+  bool Initialize(media::VideoCodecProfile profile,
+                  Display* x_display,
+                  const base::Closure& report_error__to_uma_cb);
+  void Deinitialize();
+
+  // Execute decode in hardware and destroy pending buffers. Return false if
+  // vaapi driver refuses to accept parameter or slice buffers submitted
+  // by client or if decode fails in hardware.
+  bool SubmitDecode(VASurfaceID va_surface_id);
+
+  // Lazily initialize static data after sandbox is enabled.  Return false on
+  // init failure.
+  static bool PostSandboxInitialization();
+
+  // Libva is not thread safe, so we have to do locking for it ourselves.
+  // This lock is to be taken for the duration of all VA-API calls and for
+  // the entire decode execution sequence in DecodeAndDestroyPendingBuffers().
+  base::Lock va_lock_;
+
+  // Allocated ids for VASurfaces.
+  std::vector<VASurfaceID> va_surface_ids_;
+
+  // VA handles.
+  // Both valid after successful Initialize() and until Deinitialize().
+  VADisplay va_display_;
+  VAConfigID va_config_id_;
+  // Created for the current set of va_surface_ids_ in CreateSurfaces() and
+  // valid until DestroySurfaces().
+  VAContextID va_context_id_;
+
+  // Data queued up for HW decoder, to be committed on next HW decode.
+  std::vector<VABufferID> pending_slice_bufs_;
+  std::vector<VABufferID> pending_va_bufs_;
+
+  // Called to report decoding errors to UMA. Errors to clients are reported via
+  // return values from public methods.
+  base::Closure report_error_to_uma_cb_;
+
+  // Has static initialization of pre-sandbox components completed successfully?
+  static bool pre_sandbox_init_done_;
+
+  DISALLOW_COPY_AND_ASSIGN(VaapiWrapper);
+};
+
+}  // namespace content
+
+#endif  // CONTENT_COMMON_GPU_MEDIA_VAAPI_WRAPPER_H_