Add use_v4lplugin flag to enable v4l2 library

content/common/gpu/media/exynos_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.
 //
 
 #include <fcntl.h>
 #include <libdrm/drm_fourcc.h>
 #include <linux/videodev2.h>
 #include <poll.h>
 #include <sys/eventfd.h>
 #include <sys/ioctl.h>
 #include <sys/mman.h>
 
 #include "base/debug/trace_event.h"
 #include "base/files/scoped_file.h"
 #include "base/posix/eintr_wrapper.h"
 #include "content/common/gpu/media/exynos_v4l2_video_device.h"
 #include "ui/gl/gl_bindings.h"
 
+#ifdef USE_LIBV4L2
+#  include<libv4l2.h>

[Pawel Osciak, 2014/11/18 08:36:30]

No indent please. And space before '<'.

[henryhsu, 2014/11/19 03:49:47]

Done.

+#  include "content/common/gpu/media/v4l2_stubs.h"
+
+using content_common_gpu_media::kModuleV4l2;
+using content_common_gpu_media::InitializeStubs;
+using content_common_gpu_media::StubPathMap;
+
+static const base::FilePath::CharType kV4l2Lib[] =
+    FILE_PATH_LITERAL("libv4l2.so");
+#else
+#  define V4L2_DISABLE_CONVERSION 0x01
+#  define v4l2_close close

[Pawel Osciak, 2014/11/18 08:36:30]

No indent please.

[henryhsu, 2014/11/19 03:49:46]

Done.

+#  define v4l2_ioctl ioctl
+#  define v4l2_read read

[Pawel Osciak, 2014/11/18 08:36:29]

We don't use read or write.

[henryhsu, 2014/11/19 03:49:47]

Done.

+#  define v4l2_write write
+#  define v4l2_mmap mmap

[Pawel Osciak, 2014/11/18 08:36:30]

We don't want to do this if we don't do conversion, there is a lot of stuff
going on in there and the mmap call in the library doesn't seem to be checking
for the flag. Is there a fast path through v4l2_mmap if we passed
DISABLE_CONVERSION?
For now I'd remove this. Maybe we can have a patch for the library to ensure
DISABLE_CONVERSION is honored everywhere?

[henryhsu, 2014/11/19 03:49:47]

Agree. use mmap first and then add a patch at the next step.

+#  define v4l2_munmap munmap

[Pawel Osciak, 2014/11/18 08:36:30]

Ditto.

[henryhsu, 2014/11/19 03:49:46]

Done.

+int v4l2_fd_open(int fd, int v4l2_flags) {

[Pawel Osciak, 2014/11/18 08:36:30]

Better just ifdef the call out instead of this and the define for the flag.

[henryhsu, 2014/11/19 03:49:46]

Done.

+  return 0;
+}
+#endif
+
 namespace content {
 
 namespace {
 const char kDecoderDevice[] = "/dev/mfc-dec";
 const char kEncoderDevice[] = "/dev/mfc-enc";
 const char kImageProcessorDevice[] = "/dev/gsc1";
 }
 
 ExynosV4L2Device::ExynosV4L2Device(Type type)
     : type_(type),
       device_fd_(-1),
-      device_poll_interrupt_fd_(-1) {}
+      device_poll_interrupt_fd_(-1) {
+#ifdef USE_LIBV4L2

[Pawel Osciak, 2014/11/18 08:36:30]

Please extract this to PostSandboxInitialization(). See example at
https://code.google.com/p/chromium/codesearch#chromium/src/content/common/gpu...

[henryhsu, 2014/11/19 03:49:46]

Done.

+  StubPathMap paths;
+  paths[kModuleV4l2].push_back(kV4l2Lib);
+  if (!InitializeStubs(paths))
+    LOG(ERROR) << "Failed to initialize LIBV4L2 libs";

[Pawel Osciak, 2014/11/18 08:36:30]

Shouldn't this be a critical error? Please do this in Initialize() so that we
can return an error.

[henryhsu, 2014/11/19 03:49:46]

Done.

+#endif
+}
 
 ExynosV4L2Device::~ExynosV4L2Device() {
   if (device_poll_interrupt_fd_ != -1) {
-    close(device_poll_interrupt_fd_);
+    v4l2_close(device_poll_interrupt_fd_);

[Pawel Osciak, 2014/11/18 08:36:30]

We should not use v4l2_* functions on interrupt fd, this is not a v4l2 fd.

[henryhsu, 2014/11/19 03:49:47]

Done.

     device_poll_interrupt_fd_ = -1;
   }
   if (device_fd_ != -1) {
-    close(device_fd_);
+    v4l2_close(device_fd_);
     device_fd_ = -1;
   }
 }
 
 int ExynosV4L2Device::Ioctl(int request, void* arg) {
-  return HANDLE_EINTR(ioctl(device_fd_, request, arg));
+  return HANDLE_EINTR(v4l2_ioctl(device_fd_, request, arg));
 }
 
 bool ExynosV4L2Device::Poll(bool poll_device, bool* event_pending) {
   struct pollfd pollfds[2];
   nfds_t nfds;
   int pollfd = -1;
 
   pollfds[0].fd = device_poll_interrupt_fd_;
   pollfds[0].events = POLLIN | POLLERR;
   nfds = 1;
@@ skipping 12 matching lines @@
   }
   *event_pending = (pollfd != -1 && pollfds[pollfd].revents & POLLPRI);
   return true;
 }
 
 void* ExynosV4L2Device::Mmap(void* addr,
                              unsigned int len,
                              int prot,
                              int flags,
                              unsigned int offset) {
-  return mmap(addr, len, prot, flags, device_fd_, offset);
+  return v4l2_mmap(addr, len, prot, flags, device_fd_, offset);
 }
 
 void ExynosV4L2Device::Munmap(void* addr, unsigned int len) {
-  munmap(addr, len);
+  v4l2_munmap(addr, len);
 }
 
 bool ExynosV4L2Device::SetDevicePollInterrupt() {
   DVLOG(3) << "SetDevicePollInterrupt()";
 
   const uint64 buf = 1;
-  if (HANDLE_EINTR(write(device_poll_interrupt_fd_, &buf, sizeof(buf))) == -1) {
+  if (HANDLE_EINTR(
+      v4l2_write(device_poll_interrupt_fd_, &buf, sizeof(buf))) == -1) {
     DPLOG(ERROR) << "SetDevicePollInterrupt(): write() failed";
     return false;
   }
   return true;
 }
 
 bool ExynosV4L2Device::ClearDevicePollInterrupt() {
   DVLOG(3) << "ClearDevicePollInterrupt()";
 
   uint64 buf;
-  if (HANDLE_EINTR(read(device_poll_interrupt_fd_, &buf, sizeof(buf))) == -1) {
+  if (HANDLE_EINTR(
+      v4l2_read(device_poll_interrupt_fd_, &buf, sizeof(buf))) == -1) {
     if (errno == EAGAIN) {
       // No interrupt flag set, and we're reading nonblocking.  Not an error.
       return true;
     } else {
       DPLOG(ERROR) << "ClearDevicePollInterrupt(): read() failed";
       return false;
     }
   }
   return true;
 }
@@ skipping 11 matching lines @@
       device_path = kImageProcessorDevice;
       break;
   }
 
   DVLOG(2) << "Initialize(): opening device: " << device_path;
   // Open the video device.
   device_fd_ = HANDLE_EINTR(open(device_path, O_RDWR | O_NONBLOCK | O_CLOEXEC));
   if (device_fd_ == -1) {
     return false;
   }
+  if (v4l2_fd_open(device_fd_, V4L2_DISABLE_CONVERSION) == -1) {

[Pawel Osciak, 2014/11/18 08:36:30]

Do we need to HANDLE_EINTR?

[henryhsu, 2014/11/19 03:49:47]

Done.

+    v4l2_close(device_fd_);
+    return false;
+  }
 
   device_poll_interrupt_fd_ = eventfd(0, EFD_NONBLOCK | EFD_CLOEXEC);
   if (device_poll_interrupt_fd_ == -1) {
     return false;
   }
   return true;
 }
 
 EGLImageKHR ExynosV4L2Device::CreateEGLImage(EGLDisplay egl_display,
                                              EGLContext /* egl_context */,
@@ skipping 60 matching lines @@
 }
 
 uint32 ExynosV4L2Device::PreferredOutputFormat() {
   // TODO(posciak): We should support "dontcare" returns here once we
   // implement proper handling (fallback, negotiation) for this in users.
   CHECK_EQ(type_, kDecoder);
   return V4L2_PIX_FMT_NV12M;
 }
 
 }  //  namespace content