Add support for Tegra V4L2 VDA

content/common/gpu/media/tegra_v4l2_video_device.cc

+// Copyright 2014 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.
+//

[sheu, 2014/03/06 08:51:34]

Extra comment line here.

[shivdasp, 2014/03/06 11:10:09]

Done.

+
+#include <dlfcn.h>
+#include <fcntl.h>
+
+#include "base/debug/trace_event.h"
+#include "base/posix/eintr_wrapper.h"
+#include "content/common/gpu/media/tegra_v4l2_video_device.h"
+#include "ui/gl/gl_bindings.h"
+
+namespace content {
+
+namespace {
+const char kDevice[] = "/dev/tegra_avpchannel";
+}
+
+typedef int32 (*TegraV4L2Open)(const char* name, int32 flags);
+typedef int32 (*TegraV4L2Close)(int32 fd);
+typedef int32 (*TegraV4L2Ioctl)(int32 fd, unsigned long cmd, ...);
+typedef int32 (*TegraV4L2Poll)(int32 fd, bool poll_device, bool* event_pending);
+typedef int32 (*TegraV4L2SetDevicePollInterrupt)(int32 fd);
+typedef int32 (*TegraV4L2ClearDevicePollInterrupt)(int32 fd);
+typedef void* (*TegraV4L2Mmap)(void* addr,
+                               size_t length,
+                               int prot,
+                               int flags,
+                               int fd,
+                               unsigned int offset);
+typedef int32 (*TegraV4L2Munmap)(void* addr, size_t length);
+typedef int32 (*TegraV4L2UseEglImage)(int fd,
+                                      unsigned int buffer_index,
+                                      void* egl_image);
+
+#define TEGRAV4L2_SYM(name) TegraV4L2##name TegraV4L2_##name = NULL
+
+TEGRAV4L2_SYM(Open);
+TEGRAV4L2_SYM(Close);
+TEGRAV4L2_SYM(Ioctl);
+TEGRAV4L2_SYM(Poll);
+TEGRAV4L2_SYM(SetDevicePollInterrupt);
+TEGRAV4L2_SYM(ClearDevicePollInterrupt);
+TEGRAV4L2_SYM(Mmap);
+TEGRAV4L2_SYM(Munmap);
+TEGRAV4L2_SYM(UseEglImage);
+
+#undef TEGRAV4L2_SYM
+
+TegraV4L2Device::TegraV4L2Device(EGLContext egl_context)
+    : device_fd_(-1), egl_context_(egl_context) {}
+
+TegraV4L2Device::~TegraV4L2Device() {
+  if (device_fd_ != -1) {
+    TegraV4L2_Close(device_fd_);
+    device_fd_ = -1;
+  }
+}
+
+int TegraV4L2Device::Ioctl(int flags, void* arg) {
+  return TegraV4L2_Ioctl(device_fd_, flags, arg);

[sheu, 2014/03/06 08:51:34]

No HANDLE_EINTR wrapper needed for this?

[shivdasp, 2014/03/06 11:10:09]

Done.

+}
+
+bool TegraV4L2Device::Poll(bool poll_device, bool* event_pending) {
+  if (TegraV4L2_Poll(device_fd_, poll_device, event_pending) == -1) {

[sheu, 2014/03/06 08:51:34]

No HANDLE_EINTR wrapper needed for this?

[shivdasp, 2014/03/06 11:10:09]

Done.

+    DLOG(ERROR) << "TegraV4L2Poll returned -1 ";
+    return false;
+  }
+  return true;
+}
+
+void* TegraV4L2Device::Mmap(void* addr,
+                            unsigned int len,
+                            int prot,
+                            int flags,
+                            unsigned int offset) {
+  return TegraV4L2_Mmap(addr, len, prot, flags, device_fd_, offset);
+}
+
+void TegraV4L2Device::Munmap(void* addr, unsigned int len) {
+  TegraV4L2_Munmap(addr, len);
+}
+
+bool TegraV4L2Device::SetDevicePollInterrupt() {
+  if (HANDLE_EINTR(TegraV4L2_SetDevicePollInterrupt(device_fd_)) == -1) {
+    DLOG(ERROR) << "Error in calling TegraV4L2SetDevicePollInterrupt";
+    return false;
+  }
+  return true;
+}
+
+bool TegraV4L2Device::ClearDevicePollInterrupt() {
+  if (HANDLE_EINTR(TegraV4L2_ClearDevicePollInterrupt(device_fd_)) == -1) {
+    DLOG(ERROR) << "Error in calling TegraV4L2ClearDevicePollInterrupt";
+    return false;
+  }
+  return true;
+}
+
+bool TegraV4L2Device::Initialize() {
+#define TEGRAV4L2_DLSYM_OR_RETURN_ON_ERROR(name)          \
+  do {                                                    \
+    TegraV4L2_##name = reinterpret_cast<TegraV4L2##name>( \
+        dlsym(RTLD_DEFAULT, "TegraV4L2_" #name));         \
+    if (TegraV4L2_##name == NULL) {                       \
+      LOG(ERROR) << "Failed to dlsym TegraV4L2_" #name;   \
+      return false;                                       \
+    }                                                     \
+  } while (0)
+
+  TEGRAV4L2_DLSYM_OR_RETURN_ON_ERROR(Open);
+  TEGRAV4L2_DLSYM_OR_RETURN_ON_ERROR(Close);
+  TEGRAV4L2_DLSYM_OR_RETURN_ON_ERROR(Ioctl);
+  TEGRAV4L2_DLSYM_OR_RETURN_ON_ERROR(Poll);
+  TEGRAV4L2_DLSYM_OR_RETURN_ON_ERROR(SetDevicePollInterrupt);
+  TEGRAV4L2_DLSYM_OR_RETURN_ON_ERROR(ClearDevicePollInterrupt);
+  TEGRAV4L2_DLSYM_OR_RETURN_ON_ERROR(Mmap);
+  TEGRAV4L2_DLSYM_OR_RETURN_ON_ERROR(Munmap);
+  TEGRAV4L2_DLSYM_OR_RETURN_ON_ERROR(UseEglImage);

[sheu, 2014/03/06 08:51:34]

Can this sort of thing be done once at startup time?

[shivdasp, 2014/03/06 11:10:09]

Initialize() is called when the V4L2Device is created which is the earliest.
Else will have to do it in a static method and have it called from somewhere.
On 2014/03/06 08:51:34, sheu wrote:

[sheu, 2014/03/07 00:18:08]

We could do this once statically similar to how VaapiWrapper does it.

+#undef TEGRAV4L2_DLSYM
+
+  device_fd_ =
+      HANDLE_EINTR(TegraV4L2_Open(kDevice, O_RDWR | O_NONBLOCK | O_CLOEXEC));
+  if (device_fd_ == -1) {
+    DLOG(ERROR) << "Unable to open tegra_v4l2_open ";
+    return false;
+  }
+  return true;
+}
+
+EGLImageKHR TegraV4L2Device::CreateEGLImage(EGLDisplay egl_display,
+                                            EGLint[] /*attrib*/,
+                                            unsigned int texture_id,
+                                            unsigned int buffer_index) {
+  EGLint attr = EGL_NONE;
+  EGLImageKHR egl_image = eglCreateImageKHR(egl_display,
+                                            egl_context_,
+                                            EGL_GL_TEXTURE_2D_KHR,
+                                            (EGLClientBuffer)(texture_id),

[sheu, 2014/03/06 08:51:34]

static_cast<>; we don't use C-style casts.

[shivdasp, 2014/03/06 11:10:09]

Done.

+                                            &attr);
+  if (egl_image == EGL_NO_IMAGE_KHR) {
+    return egl_image;
+  }
+  if (TegraV4L2_UseEglImage(device_fd_, buffer_index, egl_image) != 0) {
+    eglDestroyImageKHR(egl_display, egl_image);
+    egl_image = EGL_NO_IMAGE_KHR;
+  }
+  return egl_image;

[sheu, 2014/03/06 08:51:34]

So as I understand it:

In the Exynos case, we export buffers from the video stack and import them to
the graphics stack.
In the Tegra case, we export buffers from the graphics stack and import them to
the tegrav4l2 lib, which does with them what it wants.  Responsibility for
tracking ownership and making sure things don't leak then rests with the
tegrav4l2 lib.

Sound about right?

[shivdasp, 2014/03/06 11:10:09]

Yes that's right. tegrav4l2lib takes care of destroying them internally.
On 2014/03/06 08:51:34, sheu wrote:

+}
+
+unsigned int TegraV4L2Device::GetTextureTarget() { return GL_TEXTURE_2D; }
+
+}  //  namespace content