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Unified Diff: media/video/capture/linux/v4l2_video_capture_delegate.cc

Issue 967793002: Linux Video Capture: Add V4L2VideoCaptureDelegate{Single,Multi}Plane. (Closed) Base URL: https://chromium.googlesource.com/chromium/src.git@master
Patch Set: posciak@ comments on PS5. Minor rebase of video_capture_controller_unittest.cc and BUILD.gn Created 5 years, 9 months ago
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Index: media/video/capture/linux/v4l2_video_capture_delegate.cc
diff --git a/media/video/capture/linux/v4l2_video_capture_delegate.cc b/media/video/capture/linux/v4l2_video_capture_delegate.cc
new file mode 100644
index 0000000000000000000000000000000000000000..a40ed6fe54ffed9ea58fe00d725b67103931a67b
--- /dev/null
+++ b/media/video/capture/linux/v4l2_video_capture_delegate.cc
@@ -0,0 +1,418 @@
+// Copyright 2015 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/v4l2_video_capture_delegate.h"
+
+#include <poll.h>
+#include <sys/fcntl.h>
+#include <sys/ioctl.h>
+#include <sys/mman.h>
+
+#include "base/bind.h"
+#include "base/files/file_enumerator.h"
+#include "base/posix/eintr_wrapper.h"
+#include "base/strings/stringprintf.h"
+#include "media/base/bind_to_current_loop.h"
+#include "media/video/capture/linux/v4l2_capture_delegate_multi_plane.h"
+#include "media/video/capture/linux/v4l2_capture_delegate_single_plane.h"
+#include "media/video/capture/linux/video_capture_device_linux.h"
+
+namespace media {
+
+// Max number of video buffers VideoCaptureDeviceLinux can allocate.
+const uint32_t kMaxVideoBuffers = 2;
+// Timeout in milliseconds v4l2_thread_ blocks waiting for a frame from the hw.
+const int kCaptureTimeoutMs = 200;
+// The number of continuous timeouts tolerated before treated as error.
+const int kContinuousTimeoutLimit = 10;
+// MJPEG is preferred if the requested width or height is larger than this.
+const int kMjpegWidth = 640;
+const int kMjpegHeight = 480;
+// Typical framerate, in fps
+const int kTypicalFramerate = 30;
+
+// V4L2 color formats supported by V4L2VideoCaptureDelegate derived classes.
+// This list is ordered by precedence of use -- but see caveats for MJPEG.
+static struct{
+ uint32_t fourcc;
+ VideoPixelFormat pixel_format;
+ size_t num_planes;
+} const kSupportedFormatsAndPlanarity[] = {
+ {V4L2_PIX_FMT_YUV420, PIXEL_FORMAT_I420, 1},
+ {V4L2_PIX_FMT_YUYV, PIXEL_FORMAT_YUY2, 1},
+ {V4L2_PIX_FMT_UYVY, PIXEL_FORMAT_UYVY, 1},
+#if !defined(OS_OPENBSD)
+ // TODO(mcasas): add V4L2_PIX_FMT_YVU420M when available in bots.
+ {V4L2_PIX_FMT_YUV420M, PIXEL_FORMAT_I420, 3},
+#endif
+ // MJPEG is usually sitting fairly low since we don't want to have to decode.
+ // However, is needed for large resolutions due to USB bandwidth limitations,
+ // so GetListOfUsableFourCcs() can duplicate it on top, see that method.
+ {V4L2_PIX_FMT_MJPEG, PIXEL_FORMAT_MJPEG, 1},
+ // JPEG works as MJPEG on some gspca webcams from field reports, see
+ // https://code.google.com/p/webrtc/issues/detail?id=529, put it as the least
+ // preferred format.
+ {V4L2_PIX_FMT_JPEG, PIXEL_FORMAT_MJPEG, 1},
+};
+
+// static
+scoped_refptr<V4L2VideoCaptureDelegate>
+V4L2VideoCaptureDelegate::CreateV4L2VideoCaptureDelegate(
+ const VideoCaptureDevice::Name& device_name,
+ const scoped_refptr<base::SingleThreadTaskRunner>& v4l2_task_runner,
+ int power_line_frequency) {
+ switch (device_name.capture_api_type()) {
+ case VideoCaptureDevice::Name::V4L2_SINGLE_PLANE:
+ return make_scoped_refptr(new V4L2CaptureDelegateSinglePlane(
+ device_name, v4l2_task_runner, power_line_frequency));
+ case VideoCaptureDevice::Name::V4L2_MULTI_PLANE:
+#if !defined(OS_OPENBSD)
+ return make_scoped_refptr(new V4L2CaptureDelegateMultiPlane(
+ device_name, v4l2_task_runner, power_line_frequency));
+ default:
+#endif
+ NOTIMPLEMENTED() << "Unknown V4L2 capture API type";
+ return scoped_refptr<V4L2VideoCaptureDelegate>();
+ }
+}
+
+//static
+size_t V4L2VideoCaptureDelegate::GetNumPlanesForFourCc(uint32_t fourcc) {
+ for (const auto& fourcc_and_pixel_format : kSupportedFormatsAndPlanarity) {
+ if (fourcc_and_pixel_format.fourcc == fourcc)
+ return fourcc_and_pixel_format.num_planes;
+ }
+ DVLOG(1) << "Unknown fourcc " << FourccToString(fourcc);
+ return 0;
+}
+
+// static
+VideoPixelFormat V4L2VideoCaptureDelegate::V4l2FourCcToChromiumPixelFormat(
+ uint32_t v4l2_fourcc) {
+ for (const auto& fourcc_and_pixel_format : kSupportedFormatsAndPlanarity) {
+ if (fourcc_and_pixel_format.fourcc == v4l2_fourcc)
+ return fourcc_and_pixel_format.pixel_format;
+ }
+ // Not finding a pixel format is OK during device capabilities enumeration.
+ // Let the caller decide if PIXEL_FORMAT_UNKNOWN is an error or not.
+ DVLOG(1) << "Unsupported pixel format: " << FourccToString(v4l2_fourcc);
+ return PIXEL_FORMAT_UNKNOWN;
+}
+
+// static
+std::list<uint32_t> V4L2VideoCaptureDelegate::GetListOfUsableFourCcs(
+ bool prefer_mjpeg) {
+ std::list<uint32_t> supported_formats;
+ for (const auto& format : kSupportedFormatsAndPlanarity)
+ supported_formats.push_back(format.fourcc);
+
+ // Duplicate MJPEG on top of the list depending on |prefer_mjpeg|.
+ if (prefer_mjpeg)
+ supported_formats.push_front(V4L2_PIX_FMT_MJPEG);
+
+ return supported_formats;
+}
+
+//static
+std::string V4L2VideoCaptureDelegate::FourccToString(uint32_t fourcc) {
+ return base::StringPrintf("%c%c%c%c", fourcc & 0xFF, (fourcc >> 8) & 0xFF,
+ (fourcc >> 16) & 0xFF, (fourcc >> 24) & 0xFF);
+}
+
+V4L2VideoCaptureDelegate::BufferTracker::BufferTracker() {
+}
+
+V4L2VideoCaptureDelegate::BufferTracker::~BufferTracker() {
+ for (const auto& plane : planes_) {
+ if (plane.start == nullptr)
+ continue;
+ const int result = munmap(plane.start, plane.length);
+ PLOG_IF(ERROR, result < 0) << "Error munmap()ing V4L2 buffer";
+ }
+}
+
+void V4L2VideoCaptureDelegate::BufferTracker::AddMmapedPlane(void* const start,
+ size_t length) {
+ Plane plane;
+ plane.start = start;
+ plane.length = length;
+ planes_.push_back(plane);
+}
+
+V4L2VideoCaptureDelegate::V4L2VideoCaptureDelegate(
+ const VideoCaptureDevice::Name& device_name,
+ const scoped_refptr<base::SingleThreadTaskRunner>& v4l2_task_runner,
+ int power_line_frequency)
+ : capture_type_((device_name.capture_api_type() ==
+ VideoCaptureDevice::Name::V4L2_SINGLE_PLANE)
+ ? V4L2_BUF_TYPE_VIDEO_CAPTURE
+ : V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE),
+ v4l2_task_runner_(v4l2_task_runner),
+ device_name_(device_name),
+ power_line_frequency_(power_line_frequency),
+ is_capturing_(false),
+ timeout_count_(0),
+ rotation_(0) {
+}
+
+V4L2VideoCaptureDelegate::~V4L2VideoCaptureDelegate() {
+}
+
+void V4L2VideoCaptureDelegate::AllocateAndStart(
+ int width,
+ int height,
+ float frame_rate,
+ scoped_ptr<VideoCaptureDevice::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;
+ }
+
+ 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_CAPTURE_MPLANE) &&
+ !(cap.capabilities & V4L2_CAP_VIDEO_OUTPUT) &&
+ !(cap.capabilities & V4L2_CAP_VIDEO_OUTPUT_MPLANE)))) {
+ 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<uint32_t>& desired_v4l2_formats =
+ GetListOfUsableFourCcs(width > kMjpegWidth || height > kMjpegHeight);
+ std::list<uint32_t>::const_iterator best = desired_v4l2_formats.end();
+
+ v4l2_fmtdesc fmtdesc = {};
+ fmtdesc.type = capture_type_;
+ 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;
+ }
+
+ DVLOG(1) << "Chosen pixel format is " << FourccToString(*best);
+
+ v4l2_format video_fmt = {};
+ video_fmt.type = capture_type_;
+ if (!FillV4L2Format(&video_fmt, width, height, *best)) {
+ SetErrorState("Failed filling in V4L2 Format");
+ return;
+ }
+
+ if (HANDLE_EINTR(ioctl(device_fd_.get(), VIDIOC_S_FMT, &video_fmt)) < 0) {
+ SetErrorState("Failed to set video capture format");
+ return;
+ }
+ const VideoPixelFormat pixel_format =
+ V4l2FourCcToChromiumPixelFormat(video_fmt.fmt.pix.pixelformat);
+ if (pixel_format == PIXEL_FORMAT_UNKNOWN) {
+ SetErrorState("Unsupported pixel format");
+ return;
+ }
+
+ // Set capture framerate in the form of capture interval.
+ v4l2_streamparm streamparm = {};
+ streamparm.type = capture_type_;
+ // 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_ == V4L2_CID_POWER_LINE_FREQUENCY_50HZ) ||
+ (power_line_frequency_ == V4L2_CID_POWER_LINE_FREQUENCY_60HZ) ||
+ (power_line_frequency_ == V4L2_CID_POWER_LINE_FREQUENCY_AUTO)) {
+ struct v4l2_control control = {};
+ control.id = V4L2_CID_POWER_LINE_FREQUENCY;
+ control.value = power_line_frequency_;
+ const int retval =
+ HANDLE_EINTR(ioctl(device_fd_.get(), VIDIOC_S_CTRL, &control));
+ if (retval != 0)
+ DVLOG(1) << "Error setting power line frequency removal";
+ }
+
+ 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 = pixel_format;
+
+ v4l2_requestbuffers r_buffer = {};
+ r_buffer.type = capture_type_;
+ r_buffer.memory = V4L2_MEMORY_MMAP;
+ r_buffer.count = kMaxVideoBuffers;
+ if (HANDLE_EINTR(ioctl(device_fd_.get(), VIDIOC_REQBUFS, &r_buffer)) < 0) {
+ SetErrorState("Error requesting MMAP buffers from V4L2");
+ return;
+ }
+ DCHECK_EQ(r_buffer.count, kMaxVideoBuffers);
+ for (unsigned int i = 0; i < r_buffer.count; ++i) {
+ if (!MapAndQueueBuffer(i)) {
+ SetErrorState("Allocate buffer failed");
+ return;
+ }
+ }
+
+ if (HANDLE_EINTR(ioctl(device_fd_.get(), VIDIOC_STREAMON, &capture_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(&V4L2VideoCaptureDelegate::DoCapture, this));
+}
+
+void V4L2VideoCaptureDelegate::StopAndDeAllocate() {
+ DCHECK(v4l2_task_runner_->BelongsToCurrentThread());
+ // The order is important: stop streaming, clear |buffer_pool_|,
+ // thus munmap()ing the v4l2_buffers, and then return them to the OS.
+ if (HANDLE_EINTR(ioctl(device_fd_.get(), VIDIOC_STREAMOFF, &capture_type_))
+ < 0) {
+ SetErrorState("VIDIOC_STREAMOFF failed");
+ return;
+ }
+
+ buffer_tracker_pool_.clear();
+
+ v4l2_requestbuffers r_buffer = {};
+ r_buffer.type = capture_type_;
+ r_buffer.memory = V4L2_MEMORY_MMAP;
+ r_buffer.count = 0;
+ if (HANDLE_EINTR(ioctl(device_fd_.get(), VIDIOC_REQBUFS, &r_buffer)) < 0)
+ SetErrorState("Failed to VIDIOC_REQBUFS with count = 0");
+
+ // At this point we can close the device.
+ // This is also needed for correctly changing settings later via VIDIOC_S_FMT.
+ device_fd_.reset();
+ is_capturing_ = false;
+ client_.reset();
+}
+
+void V4L2VideoCaptureDelegate::SetRotation(int rotation) {
+ DCHECK(v4l2_task_runner_->BelongsToCurrentThread());
+ DCHECK(rotation >= 0 && rotation < 360 && rotation % 90 == 0);
+ rotation_ = rotation;
+}
+
+bool V4L2VideoCaptureDelegate::MapAndQueueBuffer(int index) {
+ v4l2_buffer buffer;
+ FillV4L2Buffer(&buffer, index);
+
+ if (HANDLE_EINTR(ioctl(device_fd_.get(), VIDIOC_QUERYBUF, &buffer)) < 0) {
+ DLOG(ERROR) << "Error querying status of a MMAP V4L2 buffer";
+ return false;
+ }
+
+ const scoped_refptr<BufferTracker>& buffer_tracker = CreateBufferTracker();
+ if (!buffer_tracker->Init(device_fd_.get(), buffer)) {
+ DLOG(ERROR) << "Error creating BufferTracker";
+ return false;
+ }
+ buffer_tracker_pool_.push_back(buffer_tracker);
+
+ // 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 into the driver";
+ return false;
+ }
+ return true;
+}
+
+void V4L2VideoCaptureDelegate::FillV4L2Buffer(v4l2_buffer* buffer,
+ int i) const {
+ memset(buffer, 0, sizeof(*buffer));
+ buffer->memory = V4L2_MEMORY_MMAP;
+ buffer->index = i;
+ FinishFillingV4L2Buffer(buffer);
+}
+
+void V4L2VideoCaptureDelegate::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;
+ }
+
+ // Deenqueue, send and reenqueue a buffer if the driver has filled one in.
+ if (device_pfd.revents & POLLIN) {
+ v4l2_buffer buffer;
+ FillV4L2Buffer(&buffer, 0);
+
+ if (HANDLE_EINTR(ioctl(device_fd_.get(), VIDIOC_DQBUF, &buffer)) < 0) {
+ SetErrorState("Failed to dequeue capture buffer");
+ return;
+ }
+
+ SendBuffer(buffer_tracker_pool_[buffer.index]);
+
+ if (HANDLE_EINTR(ioctl(device_fd_.get(), VIDIOC_QBUF, &buffer)) < 0) {
+ SetErrorState("Failed to enqueue capture buffer");
+ return;
+ }
+ }
+
+ v4l2_task_runner_->PostTask(
+ FROM_HERE, base::Bind(&V4L2VideoCaptureDelegate::DoCapture, this));
+}
+
+void V4L2VideoCaptureDelegate::SetErrorState(const std::string& reason) {
+ DCHECK(v4l2_task_runner_->BelongsToCurrentThread());
+ is_capturing_ = false;
+ client_->OnError(reason);
+}
+
+} // namespace media

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