Support multiple video decoders and encoders

content/common/gpu/media/gpu_video_decode_accelerator.cc

Index: content/common/gpu/media/gpu_video_decode_accelerator.cc
diff --git a/content/common/gpu/media/gpu_video_decode_accelerator.cc b/content/common/gpu/media/gpu_video_decode_accelerator.cc
index 3d3a437751177dc61f38356e8e6d6ac9faf5911d..4943b97994524e841f7cf9dc669a71a6b59d9114 100644
--- a/content/common/gpu/media/gpu_video_decode_accelerator.cc
+++ b/content/common/gpu/media/gpu_video_decode_accelerator.cc
@@ -28,12 +28,15 @@
 #include "content/common/gpu/media/dxva_video_decode_accelerator.h"
 #elif defined(OS_MACOSX)
 #include "content/common/gpu/media/vt_video_decode_accelerator.h"
-#elif defined(OS_CHROMEOS) && defined(ARCH_CPU_ARMEL) && defined(USE_X11)
+#elif defined(OS_CHROMEOS)
+#if defined(USE_OZONE) || defined(ARCH_CPU_ARMEL)
 #include "content/common/gpu/media/v4l2_video_decode_accelerator.h"
 #include "content/common/gpu/media/v4l2_video_device.h"
-#elif defined(OS_CHROMEOS) && defined(ARCH_CPU_X86_FAMILY)
+#endif  // defined(USE_OZONE) || defined(ARCH_CPU_ARMEL)
+#if defined(ARCH_CPU_X86_FAMILY)
 #include "content/common/gpu/media/vaapi_video_decode_accelerator.h"
 #include "ui/gl/gl_implementation.h"
+#endif   // defined(ARCH_CPU_X86_FAMILY)
 #elif defined(USE_OZONE)
 #include "media/ozone/media_ozone_platform.h"
 #elif defined(OS_ANDROID)
@@ -244,66 +247,118 @@ void GpuVideoDecodeAccelerator::Initialize(
   }
 #endif
 
+  std::vector<GpuVideoDecodeAccelerator::CreateVDACb>
+      create_vda_cbs = CreateVDACbs();
+
+  for (size_t i = 0; i < create_vda_cbs.size(); ++i) {
+    video_decode_accelerator_ = create_vda_cbs[i].Run();
+    if (!video_decode_accelerator_ ||
+        !video_decode_accelerator_->Initialize(profile, this))
+      continue;
+
+    if (video_decode_accelerator_->CanDecodeOnIOThread()) {
+      filter_ = new MessageFilter(this, host_route_id_);
+      stub_->channel()->AddFilter(filter_.get());
+    }
+    SendCreateDecoderReply(init_done_msg, true);
+    return;
+  }
+  video_decode_accelerator_.reset();
+  NOTIMPLEMENTED() << "HW video decode acceleration not available.";
+  SendCreateDecoderReply(init_done_msg, false);
+}
+
+std::vector<GpuVideoDecodeAccelerator::CreateVDACb>
+GpuVideoDecodeAccelerator::CreateVDACbs() {
+  std::vector<GpuVideoDecodeAccelerator::CreateVDACb> create_vda_cbs;

[piman, 2015/01/05 23:50:05]

This seems overkill to allocate a vector and fill it up with callbacks.
Can't we simply have a static array of pointer-to-member-functions?

Something along the lines of:

typedef void (GpuVideoDecodeAccelerator:*CreateVDA)();
static const CreateVDA kCreateVDAs[] = {
  &GpuVideoDecodeAccelerator::CreateDXVAVDA,
  &GpuVideoDecodeAccelerator::CreateV4L2VDA,
   [...]
};

Then you just call this->*kCreateVDAs[i]() on line 254. (using arraysize instead
of vector size).

Bonus points if the array only includes the relevant factory methods (use ifdefs
to avoid code bloat)

[henryhsu, 2015/01/06 08:13:40]

CreateDXVAVDA functions are private and not static. So I remove callback and
keep to use a function to return a set of function pointers.

+  create_vda_cbs.push_back(base::Bind(
+      &GpuVideoDecodeAccelerator::CreateDXVAVDA, base::Unretained(this)));
+  create_vda_cbs.push_back(base::Bind(
+      &GpuVideoDecodeAccelerator::CreateV4L2VDA, base::Unretained(this)));
+  create_vda_cbs.push_back(base::Bind(
+      &GpuVideoDecodeAccelerator::CreateVaapiVDA, base::Unretained(this)));
+  create_vda_cbs.push_back(base::Bind(
+      &GpuVideoDecodeAccelerator::CreateVTVDA, base::Unretained(this)));
+  create_vda_cbs.push_back(base::Bind(
+      &GpuVideoDecodeAccelerator::CreateOzoneVDA, base::Unretained(this)));
+  create_vda_cbs.push_back(base::Bind(
+      &GpuVideoDecodeAccelerator::CreateAndroidVDA,
+      base::Unretained(this)));
+  return create_vda_cbs;
+}
+
+scoped_ptr<media::VideoDecodeAccelerator>
+GpuVideoDecodeAccelerator::CreateDXVAVDA() {
+  scoped_ptr<media::VideoDecodeAccelerator> decoder;
 #if defined(OS_WIN)
-  if (base::win::GetVersion() < base::win::VERSION_WIN7) {
+  if (base::win::GetVersion() >= base::win::VERSION_WIN7) {
+    DVLOG(0) << "Initializing DXVA HW decoder for windows.";
+    decoder.reset(new DXVAVideoDecodeAccelerator(make_context_current_));
+  } else {
     NOTIMPLEMENTED() << "HW video decode acceleration not available.";
-    SendCreateDecoderReply(init_done_msg, false);
-    return;
   }
-  DVLOG(0) << "Initializing DXVA HW decoder for windows.";
-  video_decode_accelerator_.reset(
-      new DXVAVideoDecodeAccelerator(make_context_current_));
-#elif defined(OS_MACOSX)
-  video_decode_accelerator_.reset(new VTVideoDecodeAccelerator(
-      static_cast<CGLContextObj>(
-          stub_->decoder()->GetGLContext()->GetHandle()),
-      make_context_current_));
-#elif defined(OS_CHROMEOS) && defined(ARCH_CPU_ARMEL) && defined(USE_X11)
+#endif
+  return decoder.Pass();
+}
+
+scoped_ptr<media::VideoDecodeAccelerator>
+GpuVideoDecodeAccelerator::CreateV4L2VDA() {
+  scoped_ptr<media::VideoDecodeAccelerator> decoder;
+#if defined(OS_CHROMEOS) && (defined(USE_OZONE) || defined(ARCH_CPU_ARMEL))
   scoped_ptr<V4L2Device> device = V4L2Device::Create(V4L2Device::kDecoder);
-  if (!device.get()) {
-    SendCreateDecoderReply(init_done_msg, false);
-    return;
+  if (device.get()) {
+    decoder.reset(new V4L2VideoDecodeAccelerator(
+        gfx::GLSurfaceEGL::GetHardwareDisplay(),
+        stub_->decoder()->GetGLContext()->GetHandle(),
+        weak_factory_for_io_.GetWeakPtr(),
+        make_context_current_,
+        device.Pass(),
+        io_message_loop_));
   }
-  video_decode_accelerator_.reset(new V4L2VideoDecodeAccelerator(
-      gfx::GLSurfaceEGL::GetHardwareDisplay(),
-      stub_->decoder()->GetGLContext()->GetHandle(),
-      weak_factory_for_io_.GetWeakPtr(),
-      make_context_current_,
-      device.Pass(),
-      io_message_loop_));
-#elif defined(OS_CHROMEOS) && defined(ARCH_CPU_X86_FAMILY)
-  video_decode_accelerator_.reset(
-      new VaapiVideoDecodeAccelerator(make_context_current_));
-#elif defined(USE_OZONE)
+#endif
+  return decoder.Pass();
+}
+
+scoped_ptr<media::VideoDecodeAccelerator>
+GpuVideoDecodeAccelerator::CreateVaapiVDA() {
+  scoped_ptr<media::VideoDecodeAccelerator> decoder;
+#if defined(OS_CHROMEOS) && defined(ARCH_CPU_X86_FAMILY)
+  decoder.reset(new VaapiVideoDecodeAccelerator(make_context_current_));
+#endif
+  return decoder.Pass();
+}
+
+scoped_ptr<media::VideoDecodeAccelerator>
+GpuVideoDecodeAccelerator::CreateVTVDA() {
+  scoped_ptr<media::VideoDecodeAccelerator> decoder;
+#if defined(OS_MACOSX)
+  decoder.reset(new VTVideoDecodeAccelerator(
+      static_cast<CGLContextObj>(stub_->decoder()->GetGLContext()->GetHandle()),
+      make_context_current_));
+#endif
+  return decoder.Pass();
+}
+
+scoped_ptr<media::VideoDecodeAccelerator>
+GpuVideoDecodeAccelerator::CreateOzoneVDA() {
+  scoped_ptr<media::VideoDecodeAccelerator> decoder;
+#if !defined(OS_CHROMEOS) && defined(USE_OZONE)
   media::MediaOzonePlatform* platform =
       media::MediaOzonePlatform::GetInstance();
-  video_decode_accelerator_.reset(platform->CreateVideoDecodeAccelerator(
-      make_context_current_));
-  if (!video_decode_accelerator_) {
-    SendCreateDecoderReply(init_done_msg, false);
-    return;
-  }
-#elif defined(OS_ANDROID)
-  video_decode_accelerator_.reset(new AndroidVideoDecodeAccelerator(
+  decoder.reset(platform->CreateVideoDecodeAccelerator(make_context_current_));
+#endif
+  return decoder.Pass();
+}
+
+scoped_ptr<media::VideoDecodeAccelerator>
+GpuVideoDecodeAccelerator::CreateAndroidVDA() {
+  scoped_ptr<media::VideoDecodeAccelerator> decoder;
+#if defined(OS_ANDROID)
+  decoder.reset(new AndroidVideoDecodeAccelerator(
       stub_->decoder()->AsWeakPtr(),
       make_context_current_));
-#else
-  NOTIMPLEMENTED() << "HW video decode acceleration not available.";
-  SendCreateDecoderReply(init_done_msg, false);
-  return;
 #endif
-
-  if (video_decode_accelerator_->CanDecodeOnIOThread()) {
-    filter_ = new MessageFilter(this, host_route_id_);
-    stub_->channel()->AddFilter(filter_.get());
-  }
-
-  if (!video_decode_accelerator_->Initialize(profile, this)) {
-    SendCreateDecoderReply(init_done_msg, false);
-    return;
-  }
-
-  SendCreateDecoderReply(init_done_msg, true);
+  return decoder.Pass();
 }
 
 // Runs on IO thread if video_decode_accelerator_->CanDecodeOnIOThread() is