Linux Video Capture: Add V4L2VideoCaptureDelegate{Single,Multi}Plane.

media/video/capture/linux/video_capture_device_linux.cc

 // Copyright (c) 2012 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 "media/video/capture/linux/video_capture_device_linux.h"
 
-#include <errno.h>
-#include <fcntl.h>
-#include <poll.h>
 #if defined(OS_OPENBSD)
 #include <sys/videoio.h>
 #else
 #include <linux/videodev2.h>
 #endif
-#include <sys/ioctl.h>
-#include <sys/mman.h>
 
 #include <list>
 #include <string>
 
 #include "base/bind.h"
-#include "base/files/file_enumerator.h"
-#include "base/files/scoped_file.h"
-#include "base/posix/eintr_wrapper.h"
 #include "base/strings/stringprintf.h"
+#include "media/video/capture/linux/v4l2_capture_delegate.h"
 
 namespace media {
 
-#define GET_V4L2_FOURCC_CHAR(a, index) ((char)( ((a) >> (8 * index)) & 0xff))
-
-// Desired number of video buffers to allocate. The actual number of allocated
-// buffers by v4l2 driver can be higher or lower than this number.
-// kNumVideoBuffers should not be too small, or Chrome may not return enough
-// buffers back to driver in time.
-const uint32 kNumVideoBuffers = 4;
-// Timeout in milliseconds v4l2_thread_ blocks waiting for a frame from the hw.
-enum { kCaptureTimeoutMs = 200 };
-// The number of continuous timeouts tolerated before treated as error.
-enum { kContinuousTimeoutLimit = 10 };
-// MJPEG is preferred if the width or height is larger than this.
-enum { kMjpegWidth = 640 };
-enum { kMjpegHeight = 480 };
-// Typical framerate, in fps
-enum { kTypicalFramerate = 30 };
-
-class VideoCaptureDeviceLinux::V4L2CaptureDelegate
-    : public base::RefCountedThreadSafe<V4L2CaptureDelegate>{
- public:
-  V4L2CaptureDelegate(
-      const Name& device_name,
-      const scoped_refptr<base::SingleThreadTaskRunner>  v4l2_task_runner,
-      int power_line_frequency);
-
-  void AllocateAndStart(int width,
-                        int height,
-                        float frame_rate,
-                        scoped_ptr<Client> client);
-  void StopAndDeAllocate();
-  void SetRotation(int rotation);
-  bool DeAllocateVideoBuffers();
-
- private:
-  // Buffers used to receive captured frames from v4l2.
-  struct Buffer {
-    Buffer() : start(0), length(0) {}
-    void* start;
-    size_t length;
-  };
-
-  friend class base::RefCountedThreadSafe<V4L2CaptureDelegate>;
-   ~V4L2CaptureDelegate();
-
-  void DoCapture();
-  bool AllocateVideoBuffers();
-  void SetErrorState(const std::string& reason);
-
-  const scoped_refptr<base::SingleThreadTaskRunner> v4l2_task_runner_;
-
-  bool is_capturing_;
-  scoped_ptr<VideoCaptureDevice::Client> client_;
-  const Name device_name_;
-  base::ScopedFD device_fd_;  // File descriptor for the opened camera device.
-  Buffer* buffer_pool_;
-  int buffer_pool_size_;  // Number of allocated buffers.
-  int timeout_count_;
-  VideoCaptureFormat capture_format_;
-  const int power_line_frequency_;
-
-  // Clockwise rotation in degrees.  This value should be 0, 90, 180, or 270.
-  int rotation_;
-
-  DISALLOW_IMPLICIT_CONSTRUCTORS(V4L2CaptureDelegate);
-};
-
-// V4L2 color formats VideoCaptureDeviceLinux support.
-static const int32 kV4l2RawFmts[] = {
-  V4L2_PIX_FMT_YUV420,
-  V4L2_PIX_FMT_YUYV,
-  V4L2_PIX_FMT_UYVY
-};
-
 // USB VID and PID are both 4 bytes long.
 static const size_t kVidPidSize = 4;
 
 // /sys/class/video4linux/video{N}/device is a symlink to the corresponding
 // USB device info directory.
 static const char kVidPathTemplate[] =
     "/sys/class/video4linux/%s/device/../idVendor";
 static const char kPidPathTemplate[] =
     "/sys/class/video4linux/%s/device/../idProduct";
 
 static bool ReadIdFile(const std::string path, std::string* id) {
   char id_buf[kVidPidSize];
   FILE* file = fopen(path.c_str(), "rb");
   if (!file)
     return false;
   const bool success = fread(id_buf, kVidPidSize, 1, file) == 1;
   fclose(file);
   if (!success)
     return false;
   id->append(id_buf, kVidPidSize);
   return true;
 }
 
-// This function translates Video4Linux pixel formats to Chromium pixel formats,
-// should only support those listed in GetListOfUsableFourCCs.
+// Translates Video4Linux pixel formats to Chromium pixel formats.
 // static
 VideoPixelFormat VideoCaptureDeviceLinux::V4l2FourCcToChromiumPixelFormat(
     uint32 v4l2_fourcc) {
-  const struct {
-    uint32 fourcc;
-    VideoPixelFormat pixel_format;
-  } kFourCcAndChromiumPixelFormat[] = {
-    {V4L2_PIX_FMT_YUV420, PIXEL_FORMAT_I420},
-    {V4L2_PIX_FMT_YUYV, PIXEL_FORMAT_YUY2},
-    {V4L2_PIX_FMT_UYVY, PIXEL_FORMAT_UYVY},
-    {V4L2_PIX_FMT_MJPEG, PIXEL_FORMAT_MJPEG},
-    {V4L2_PIX_FMT_JPEG, PIXEL_FORMAT_MJPEG},
-  };
-  for (const auto& fourcc_and_pixel_format : kFourCcAndChromiumPixelFormat) {
-    if (fourcc_and_pixel_format.fourcc == v4l2_fourcc)
-      return fourcc_and_pixel_format.pixel_format;
-  }
-  DVLOG(1) << "Unsupported pixel format: "
-           << GET_V4L2_FOURCC_CHAR(v4l2_fourcc, 0)
-           << GET_V4L2_FOURCC_CHAR(v4l2_fourcc, 1)
-           << GET_V4L2_FOURCC_CHAR(v4l2_fourcc, 2)
-           << GET_V4L2_FOURCC_CHAR(v4l2_fourcc, 3);
-  return PIXEL_FORMAT_UNKNOWN;
+  return V4L2CaptureDelegate::V4l2FourCcToChromiumPixelFormat(v4l2_fourcc);
 }
 
+// Gets a list of usable Four CC formats prioritised.
 // static
-std::list<int> VideoCaptureDeviceLinux::GetListOfUsableFourCCs(
+std::list<uint32_t> VideoCaptureDeviceLinux::GetListOfUsableFourCCs(
     bool favour_mjpeg) {
-  std::list<int> fourccs;
-  for (size_t i = 0; i < arraysize(kV4l2RawFmts); ++i)
-    fourccs.push_back(kV4l2RawFmts[i]);
-  if (favour_mjpeg)
-    fourccs.push_front(V4L2_PIX_FMT_MJPEG);
-  else
-    fourccs.push_back(V4L2_PIX_FMT_MJPEG);
-
-  // JPEG works as MJPEG on some gspca webcams from field reports.
-  // Put it as the least preferred format.
-  fourccs.push_back(V4L2_PIX_FMT_JPEG);
-  return fourccs;
+  return V4L2CaptureDelegate::GetListOfUsableFourCcs(favour_mjpeg);
 }
 
 const std::string VideoCaptureDevice::Name::GetModel() const {
   // |unique_id| is of the form "/dev/video2".  |file_name| is "video2".
   const std::string dev_dir = "/dev/";
   DCHECK_EQ(0, unique_id_.compare(0, dev_dir.length(), dev_dir));
   const std::string file_name =
       unique_id_.substr(dev_dir.length(), unique_id_.length());
 
   const std::string vidPath =
@@ skipping 23 matching lines @@
   v4l2_thread_.Stop();
 }
 
 void VideoCaptureDeviceLinux::AllocateAndStart(
     const VideoCaptureParams& params,
     scoped_ptr<VideoCaptureDevice::Client> client) {
   DCHECK(!capture_impl_);
   if (v4l2_thread_.IsRunning())
     return;  // Wrong state.
   v4l2_thread_.Start();
-  capture_impl_ = new V4L2CaptureDelegate(device_name_,
-                                          v4l2_thread_.message_loop_proxy(),
-                                          GetPowerLineFrequencyForLocation());
+
+  const int line_frequency =
+      TranslatePowerLineFrequencyToV4L2(GetPowerLineFrequencyForLocation());
+  capture_impl_ = V4L2CaptureDelegate::CreateV4L2CaptureDelegate(
+      device_name_, v4l2_thread_.message_loop_proxy(), line_frequency);
+  if (!capture_impl_) {
+    client->OnError("Failed to create VideoCaptureDelegate");
+    return;
+  }
   v4l2_thread_.message_loop()->PostTask(
       FROM_HERE,
-      base::Bind(
-          &VideoCaptureDeviceLinux::V4L2CaptureDelegate::AllocateAndStart,
-          capture_impl_,
-          params.requested_format.frame_size.width(),
-          params.requested_format.frame_size.height(),
-          params.requested_format.frame_rate,
-          base::Passed(&client)));
+      base::Bind(&V4L2CaptureDelegate::AllocateAndStart, capture_impl_,
+                 params.requested_format.frame_size.width(),
+                 params.requested_format.frame_size.height(),
+                 params.requested_format.frame_rate, base::Passed(&client)));
 }
 
 void VideoCaptureDeviceLinux::StopAndDeAllocate() {
   if (!v4l2_thread_.IsRunning())
     return;  // Wrong state.
   v4l2_thread_.message_loop()->PostTask(
       FROM_HERE,
-      base::Bind(
-          &VideoCaptureDeviceLinux::V4L2CaptureDelegate::StopAndDeAllocate,
-          capture_impl_));
+      base::Bind(&V4L2CaptureDelegate::StopAndDeAllocate, capture_impl_));
   v4l2_thread_.Stop();
-  // TODO(mcasas): VCDLinux called DeAllocateVideoBuffers() a second time after
-  // stopping |v4l2_thread_| to make sure buffers were completely deallocated.
-  // Investigate if that's needed, otherwise remove the following line and make
-  // V4L2CaptureDelegate::DeAllocateVideoBuffers() private.
-  capture_impl_->DeAllocateVideoBuffers();
+
   capture_impl_ = NULL;
 }
 
 void VideoCaptureDeviceLinux::SetRotation(int rotation) {
   if (v4l2_thread_.IsRunning()) {
     v4l2_thread_.message_loop()->PostTask(
-        FROM_HERE,
-        base::Bind(
-            &VideoCaptureDeviceLinux::V4L2CaptureDelegate::SetRotation,
-            capture_impl_,
-            rotation));
+        FROM_HERE, base::Bind(&V4L2CaptureDelegate::SetRotation,
+                              capture_impl_, rotation));
   }
 }
 
-VideoCaptureDeviceLinux::V4L2CaptureDelegate::V4L2CaptureDelegate(
-        const Name& device_name,
-        const scoped_refptr<base::SingleThreadTaskRunner> v4l2_task_runner,
-        int power_line_frequency)
-    : v4l2_task_runner_(v4l2_task_runner),
-      is_capturing_(false),
-      device_name_(device_name),
-      buffer_pool_(NULL),
-      buffer_pool_size_(0),
-      timeout_count_(0),
-      power_line_frequency_(power_line_frequency),
-      rotation_(0) {
-}
-
-VideoCaptureDeviceLinux::V4L2CaptureDelegate::~V4L2CaptureDelegate() {
-  DCHECK(!client_);
-}
-
-void VideoCaptureDeviceLinux::V4L2CaptureDelegate::AllocateAndStart(
-    int width,
-    int height,
-    float frame_rate,
-    scoped_ptr<Client> client) {
-  DCHECK(v4l2_task_runner_->BelongsToCurrentThread());
-  DCHECK(client);
-  client_ = client.Pass();
-
-  // Need to open camera with O_RDWR after Linux kernel 3.3.
-  device_fd_.reset(HANDLE_EINTR(open(device_name_.id().c_str(), O_RDWR)));
-  if (!device_fd_.is_valid()) {
-    SetErrorState("Failed to open V4L2 device driver file.");
-    return;
+// static
+int VideoCaptureDeviceLinux::TranslatePowerLineFrequencyToV4L2(int frequency) {
+  switch (frequency) {
+    case kPowerLine50Hz:
+      return V4L2_CID_POWER_LINE_FREQUENCY_50HZ;
+    case kPowerLine60Hz:
+      return V4L2_CID_POWER_LINE_FREQUENCY_60HZ;
+    default:
+      // If we have no idea of the frequency, at least try and set it to AUTO.
+      return V4L2_CID_POWER_LINE_FREQUENCY_AUTO;
   }
-
-  v4l2_capability cap = {};
-  if (!((HANDLE_EINTR(ioctl(device_fd_.get(), VIDIOC_QUERYCAP, &cap)) == 0) &&
-      (cap.capabilities & V4L2_CAP_VIDEO_CAPTURE &&
-      !(cap.capabilities & V4L2_CAP_VIDEO_OUTPUT)))) {
-    device_fd_.reset();
-    SetErrorState("This is not a V4L2 video capture device");
-    return;
-  }
-
-  // Get supported video formats in preferred order.
-  // For large resolutions, favour mjpeg over raw formats.
-  const std::list<int>& desired_v4l2_formats =
-      GetListOfUsableFourCCs(width > kMjpegWidth || height > kMjpegHeight);
-  std::list<int>::const_iterator best = desired_v4l2_formats.end();
-
-  v4l2_fmtdesc fmtdesc = {};
-  fmtdesc.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
-  for (; HANDLE_EINTR(ioctl(device_fd_.get(), VIDIOC_ENUM_FMT, &fmtdesc)) == 0;
-       ++fmtdesc.index) {
-    best = std::find(desired_v4l2_formats.begin(), best, fmtdesc.pixelformat);
-  }
-  if (best == desired_v4l2_formats.end()) {
-    SetErrorState("Failed to find a supported camera format.");
-    return;
-  }
-
-  v4l2_format video_fmt = {};
-  video_fmt.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
-  video_fmt.fmt.pix.sizeimage = 0;
-  video_fmt.fmt.pix.width = width;
-  video_fmt.fmt.pix.height = height;
-  video_fmt.fmt.pix.pixelformat = *best;
-  if (HANDLE_EINTR(ioctl(device_fd_.get(), VIDIOC_S_FMT, &video_fmt)) < 0) {
-    SetErrorState("Failed to set video capture format");
-    return;
-  }
-
-  // Set capture framerate in the form of capture interval.
-  v4l2_streamparm streamparm = {};
-  streamparm.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
-  // The following line checks that the driver knows about framerate get/set.
-  if (HANDLE_EINTR(ioctl(device_fd_.get(), VIDIOC_G_PARM, &streamparm)) >= 0) {
-    // Now check if the device is able to accept a capture framerate set.
-    if (streamparm.parm.capture.capability & V4L2_CAP_TIMEPERFRAME) {
-      // |frame_rate| is float, approximate by a fraction.
-      streamparm.parm.capture.timeperframe.numerator =
-          media::kFrameRatePrecision;
-      streamparm.parm.capture.timeperframe.denominator = (frame_rate) ?
-          (frame_rate * media::kFrameRatePrecision) :
-          (kTypicalFramerate * media::kFrameRatePrecision);
-
-      if (HANDLE_EINTR(ioctl(device_fd_.get(), VIDIOC_S_PARM, &streamparm)) <
-          0) {
-        SetErrorState("Failed to set camera framerate");
-        return;
-      }
-      DVLOG(2) << "Actual camera driverframerate: "
-               << streamparm.parm.capture.timeperframe.denominator << "/"
-               << streamparm.parm.capture.timeperframe.numerator;
-    }
-  }
-  // TODO(mcasas): what should be done if the camera driver does not allow
-  // framerate configuration, or the actual one is different from the desired?
-
-  // Set anti-banding/anti-flicker to 50/60Hz. May fail due to not supported
-  // operation (|errno| == EINVAL in this case) or plain failure.
-  if ((power_line_frequency_ == kPowerLine50Hz) ||
-      (power_line_frequency_ == kPowerLine60Hz)) {
-    struct v4l2_control control = {};
-    control.id = V4L2_CID_POWER_LINE_FREQUENCY;
-    control.value = (power_line_frequency_ == kPowerLine50Hz)
-                        ? V4L2_CID_POWER_LINE_FREQUENCY_50HZ
-                        : V4L2_CID_POWER_LINE_FREQUENCY_60HZ;
-    HANDLE_EINTR(ioctl(device_fd_.get(), VIDIOC_S_CTRL, &control));
-  }
-
-  capture_format_.frame_size.SetSize(video_fmt.fmt.pix.width,
-                                     video_fmt.fmt.pix.height);
-  capture_format_.frame_rate = frame_rate;
-  capture_format_.pixel_format =
-      V4l2FourCcToChromiumPixelFormat(video_fmt.fmt.pix.pixelformat);
-
-  if (!AllocateVideoBuffers()) {
-    SetErrorState("Allocate buffer failed (Cannot recover from this error)");
-    return;
-  }
-
-  const v4l2_buf_type type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
-  if (HANDLE_EINTR(ioctl(device_fd_.get(), VIDIOC_STREAMON, &type)) < 0) {
-    SetErrorState("VIDIOC_STREAMON failed");
-    return;
-  }
-
-  is_capturing_ = true;
-  // Post task to start fetching frames from v4l2.
-  v4l2_task_runner_->PostTask(
-      FROM_HERE,
-      base::Bind(&VideoCaptureDeviceLinux::V4L2CaptureDelegate::DoCapture,
-                 this));
-}
-
-void VideoCaptureDeviceLinux::V4L2CaptureDelegate::StopAndDeAllocate() {
-  DCHECK(v4l2_task_runner_->BelongsToCurrentThread());
-
-  const v4l2_buf_type type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
-  if (HANDLE_EINTR(ioctl(device_fd_.get(), VIDIOC_STREAMOFF, &type)) < 0) {
-    SetErrorState("VIDIOC_STREAMOFF failed");
-    return;
-  }
-  // We don't dare to deallocate the buffers if we can't stop the capture
-  // device.
-  if (!DeAllocateVideoBuffers())
-    SetErrorState("Failed to reset buffers");
-
-  // We need to close and open the device if we want to change the settings.
-  // Otherwise VIDIOC_S_FMT will return error. Sad but true.
-  device_fd_.reset();
-  is_capturing_ = false;
-  client_.reset();
-}
-
-void VideoCaptureDeviceLinux::V4L2CaptureDelegate::SetRotation(int rotation) {
-  DCHECK(v4l2_task_runner_->BelongsToCurrentThread());
-  DCHECK(rotation >= 0 && rotation < 360 && rotation % 90 == 0);
-  rotation_ = rotation;
-}
-
-void VideoCaptureDeviceLinux::V4L2CaptureDelegate::DoCapture() {
-  DCHECK(v4l2_task_runner_->BelongsToCurrentThread());
-  if (!is_capturing_)
-    return;
-
-  pollfd device_pfd = {};
-  device_pfd.fd = device_fd_.get();
-  device_pfd.events = POLLIN;
-  const int result = HANDLE_EINTR(poll(&device_pfd, 1, kCaptureTimeoutMs));
-  if (result < 0) {
-    SetErrorState("Poll failed");
-    return;
-  }
-  // Check if poll() timed out; track the amount of times it did in a row and
-  // throw an error if it times out too many times.
-  if (result == 0) {
-    timeout_count_++;
-    if (timeout_count_ >= kContinuousTimeoutLimit) {
-      SetErrorState("Multiple continuous timeouts while read-polling.");
-      timeout_count_ = 0;
-      return;
-    }
-  } else {
-    timeout_count_ = 0;
-  }
-
-  // Check if the driver has filled a buffer.
-  if (device_pfd.revents & POLLIN) {
-    v4l2_buffer buffer = {};
-     buffer.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
-     buffer.memory = V4L2_MEMORY_MMAP;
-    if (HANDLE_EINTR(ioctl(device_fd_.get(), VIDIOC_DQBUF, &buffer)) < 0) {
-      SetErrorState("Failed to dequeue capture buffer");
-      return;
-    }
-    client_->OnIncomingCapturedData(
-        static_cast<uint8*>(buffer_pool_[buffer.index].start),
-        buffer.bytesused,
-        capture_format_,
-        rotation_,
-        base::TimeTicks::Now());
-
-    if (HANDLE_EINTR(ioctl(device_fd_.get(), VIDIOC_QBUF, &buffer)) < 0)
-      SetErrorState("Failed to enqueue capture buffer");
-  }
-
-  v4l2_task_runner_->PostTask(
-      FROM_HERE,
-      base::Bind(&VideoCaptureDeviceLinux::V4L2CaptureDelegate::DoCapture,
-                 this));
-}
-
-bool VideoCaptureDeviceLinux::V4L2CaptureDelegate::AllocateVideoBuffers() {
-  v4l2_requestbuffers r_buffer = {};
-  r_buffer.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
-  r_buffer.memory = V4L2_MEMORY_MMAP;
-  r_buffer.count = kNumVideoBuffers;
-  if (HANDLE_EINTR(ioctl(device_fd_.get(), VIDIOC_REQBUFS, &r_buffer)) < 0) {
-    DLOG(ERROR) << "Error requesting MMAP buffers from V4L2";
-    return false;
-  }
-  buffer_pool_size_ = r_buffer.count;
-  buffer_pool_ = new Buffer[buffer_pool_size_];
-  for (unsigned int i = 0; i < r_buffer.count; ++i) {
-    v4l2_buffer buffer = {};
-    buffer.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
-    buffer.memory = V4L2_MEMORY_MMAP;
-    buffer.index = i;
-    buffer.length = 1;
-    if (HANDLE_EINTR(ioctl(device_fd_.get(), VIDIOC_QUERYBUF, &buffer)) < 0) {
-      DLOG(ERROR) << "Error querying status of a MMAP V4L2 buffer";
-      return false;
-    }
-
-    // Some devices require mmap() to be called with both READ and WRITE.
-    // See http://crbug.com/178582.
-    buffer_pool_[i].start = mmap(NULL, buffer.length, PROT_READ | PROT_WRITE,
-        MAP_SHARED, device_fd_.get(), buffer.m.offset);
-    if (buffer_pool_[i].start == MAP_FAILED) {
-      DLOG(ERROR) << "Error mmmap()ing a V4L2 buffer into userspace";
-      return false;
-    }
-
-    buffer_pool_[i].length = buffer.length;
-    // Enqueue the buffer in the drivers incoming queue.
-    if (HANDLE_EINTR(ioctl(device_fd_.get(), VIDIOC_QBUF, &buffer)) < 0) {
-      DLOG(ERROR)
-          << "Error enqueuing a V4L2 buffer back to the drivers incoming queue";
-      return false;
-    }
-  }
-  return true;
-}
-
-bool VideoCaptureDeviceLinux::V4L2CaptureDelegate::DeAllocateVideoBuffers() {
-  if (!buffer_pool_)
-    return true;
-
-  for (int i = 0; i < buffer_pool_size_; ++i)
-    munmap(buffer_pool_[i].start, buffer_pool_[i].length);
-
-  v4l2_requestbuffers r_buffer = {};
-  r_buffer.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
-  r_buffer.memory = V4L2_MEMORY_MMAP;
-  r_buffer.count = 0;
-  if (HANDLE_EINTR(ioctl(device_fd_.get(), VIDIOC_REQBUFS, &r_buffer)) < 0)
-    return false;
-
-  delete [] buffer_pool_;
-  buffer_pool_ = NULL;
-  buffer_pool_size_ = 0;
-  return true;
-}
-
-void VideoCaptureDeviceLinux::V4L2CaptureDelegate::SetErrorState(
-    const std::string& reason) {
-  DCHECK(v4l2_task_runner_->BelongsToCurrentThread());
-  is_capturing_ = false;
-  client_->OnError(reason);
 }
 
 }  // namespace media