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| 1 // Copyright 2015 The Chromium Authors. All rights reserved. | |
| 2 // Use of this source code is governed by a BSD-style license that can be | |
| 3 // found in the LICENSE file. | |
| 4 | |
| 5 #include "media/video/capture/linux/v4l2_capture_delegate.h" | |
| 6 | |
| 7 #include <poll.h> | |
| 8 #include <sys/fcntl.h> | |
| 9 #include <sys/ioctl.h> | |
| 10 #include <sys/mman.h> | |
| 11 | |
| 12 #include "base/bind.h" | |
| 13 #include "base/files/file_enumerator.h" | |
| 14 #include "base/posix/eintr_wrapper.h" | |
| 15 #include "base/strings/stringprintf.h" | |
| 16 #include "media/base/bind_to_current_loop.h" | |
| 17 #include "media/video/capture/linux/v4l2_capture_delegate_multi_plane.h" | |
| 18 #include "media/video/capture/linux/v4l2_capture_delegate_single_plane.h" | |
| 19 #include "media/video/capture/linux/video_capture_device_linux.h" | |
| 20 | |
| 21 namespace media { | |
| 22 | |
| 23 // Desired number of video buffers to allocate. The actual number of allocated | |
| 24 // buffers by v4l2 driver can be higher or lower than this number. | |
| 25 // kNumVideoBuffers should not be too small, or Chrome may not return enough | |
| 26 // buffers back to driver in time. | |
| 27 const uint32 kNumVideoBuffers = 4; | |
| 28 // Timeout in milliseconds v4l2_thread_ blocks waiting for a frame from the hw. | |
| 29 const int kCaptureTimeoutMs = 200; | |
| 30 // The number of continuous timeouts tolerated before treated as error. | |
| 31 const int kContinuousTimeoutLimit = 10; | |
| 32 // MJPEG is preferred if the requested width or height is larger than this. | |
| 33 const int kMjpegWidth = 640; | |
| 34 const int kMjpegHeight = 480; | |
| 35 // Typical framerate, in fps | |
| 36 const int kTypicalFramerate = 30; | |
| 37 | |
| 38 // V4L2 color formats supported by V4L2CaptureDelegate derived classes. | |
| 39 // This list is ordered by precedence of use -- but see caveats for MJPEG. | |
| 40 static struct{ | |
| 41 uint32_t fourcc; | |
| 42 VideoPixelFormat pixel_format; | |
| 43 size_t num_planes; | |
| 44 } const kSupportedFormatsAndPlanarity[] = { | |
| 45 {V4L2_PIX_FMT_YUV420, PIXEL_FORMAT_I420, 1}, | |
| 46 {V4L2_PIX_FMT_YUYV, PIXEL_FORMAT_YUY2, 1}, | |
| 47 {V4L2_PIX_FMT_UYVY, PIXEL_FORMAT_UYVY, 1}, | |
| 48 #if !defined(OS_OPENBSD) | |
| 49 // TODO(mcasas): add V4L2_PIX_FMT_YVU420M when available in bots. | |
| 50 {V4L2_PIX_FMT_YUV420M, PIXEL_FORMAT_I420, 3}, | |
| 51 #endif | |
| 52 // MJPEG is usually sitting fairly low since we don't want to have to decode. | |
| 53 // However, is needed for large resolutions due to USB bandwidth limitations, | |
| 54 // so GetListOfUsableFourCcs() can duplicate it on top, see that method. | |
| 55 {V4L2_PIX_FMT_MJPEG, PIXEL_FORMAT_MJPEG, 1}, | |
| 56 // JPEG works as MJPEG on some gspca webcams from field reports, see | |
| 57 // https://code.google.com/p/webrtc/issues/detail?id=529, put it as the least | |
| 58 // preferred format. | |
| 59 {V4L2_PIX_FMT_JPEG, PIXEL_FORMAT_MJPEG, 1}, | |
| 60 }; | |
| 61 | |
| 62 // static | |
| 63 scoped_refptr<V4L2CaptureDelegate> | |
| 64 V4L2CaptureDelegate::CreateV4L2CaptureDelegate( | |
| 65 const VideoCaptureDevice::Name& device_name, | |
| 66 const scoped_refptr<base::SingleThreadTaskRunner>& v4l2_task_runner, | |
| 67 int power_line_frequency) { | |
| 68 switch (device_name.capture_api_type()) { | |
| 69 case VideoCaptureDevice::Name::V4L2_SINGLE_PLANE: | |
| 70 return make_scoped_refptr(new V4L2CaptureDelegateSinglePlane( | |
| 71 device_name, v4l2_task_runner, power_line_frequency)); | |
| 72 case VideoCaptureDevice::Name::V4L2_MULTI_PLANE: | |
| 73 #if !defined(OS_OPENBSD) | |
| 74 return make_scoped_refptr(new V4L2CaptureDelegateMultiPlane( | |
| 75 device_name, v4l2_task_runner, power_line_frequency)); | |
| 76 default: | |
| 77 #endif | |
| 78 NOTIMPLEMENTED() << "Unknown V4L2 capture API type"; | |
| 79 return scoped_refptr<V4L2CaptureDelegate>(); | |
| 80 } | |
| 81 } | |
| 82 | |
| 83 //static | |
| 84 size_t V4L2CaptureDelegate::GetNumPlanesForFourCc(uint32_t fourcc) { | |
| 85 for (const auto& fourcc_and_pixel_format : kSupportedFormatsAndPlanarity) { | |
| 86 if (fourcc_and_pixel_format.fourcc == fourcc) | |
| 87 return fourcc_and_pixel_format.num_planes; | |
| 88 } | |
| 89 DVLOG(1) << "Unknown fourcc " << FourccToString(fourcc); | |
| 90 return 0; | |
| 91 } | |
| 92 | |
| 93 // static | |
| 94 VideoPixelFormat V4L2CaptureDelegate::V4l2FourCcToChromiumPixelFormat( | |
| 95 uint32_t v4l2_fourcc) { | |
| 96 for (const auto& fourcc_and_pixel_format : kSupportedFormatsAndPlanarity) { | |
| 97 if (fourcc_and_pixel_format.fourcc == v4l2_fourcc) | |
| 98 return fourcc_and_pixel_format.pixel_format; | |
| 99 } | |
| 100 // Not finding a pixel format is OK during device capabilities enumeration. | |
| 101 // Let the caller decide if PIXEL_FORMAT_UNKNOWN is an error or not. | |
| 102 DVLOG(1) << "Unsupported pixel format: " << FourccToString(v4l2_fourcc); | |
| 103 return PIXEL_FORMAT_UNKNOWN; | |
| 104 } | |
| 105 | |
| 106 // static | |
| 107 std::list<uint32_t> V4L2CaptureDelegate::GetListOfUsableFourCcs( | |
| 108 bool prefer_mjpeg) { | |
| 109 std::list<uint32_t> supported_formats; | |
| 110 for (const auto& format : kSupportedFormatsAndPlanarity) | |
| 111 supported_formats.push_back(format.fourcc); | |
| 112 | |
| 113 // Duplicate MJPEG on top of the list depending on |prefer_mjpeg|. | |
| 114 if (prefer_mjpeg) | |
| 115 supported_formats.push_front(V4L2_PIX_FMT_MJPEG); | |
| 116 | |
| 117 return supported_formats; | |
| 118 } | |
| 119 | |
| 120 //static | |
| 121 std::string V4L2CaptureDelegate::FourccToString(uint32_t fourcc) { | |
| 122 return base::StringPrintf("%c%c%c%c", fourcc & 0xFF, (fourcc >> 8) & 0xFF, | |
| 123 (fourcc >> 16) & 0xFF, (fourcc >> 24) & 0xFF); | |
| 124 } | |
| 125 | |
| 126 V4L2CaptureDelegate::BufferTracker::BufferTracker() { | |
| 127 } | |
| 128 | |
| 129 V4L2CaptureDelegate::BufferTracker::~BufferTracker() { | |
| 130 for (const auto& plane : planes_) { | |
| 131 if (plane.start == nullptr) | |
| 132 continue; | |
| 133 const int result = munmap(plane.start, plane.length); | |
| 134 PLOG_IF(ERROR, result < 0) << "Error munmap()ing V4L2 buffer"; | |
| 135 } | |
| 136 } | |
| 137 | |
| 138 void V4L2CaptureDelegate::BufferTracker::AddMmapedPlane(uint8_t* const start, | |
| 139 size_t length) { | |
| 140 Plane plane; | |
| 141 plane.start = start; | |
| 142 plane.length = length; | |
| 143 planes_.push_back(plane); | |
| 144 } | |
| 145 | |
| 146 V4L2CaptureDelegate::V4L2CaptureDelegate( | |
| 147 const VideoCaptureDevice::Name& device_name, | |
| 148 const scoped_refptr<base::SingleThreadTaskRunner>& v4l2_task_runner, | |
| 149 int power_line_frequency) | |
| 150 : capture_type_((device_name.capture_api_type() == | |
| 151 VideoCaptureDevice::Name::V4L2_SINGLE_PLANE) | |
| 152 ? V4L2_BUF_TYPE_VIDEO_CAPTURE | |
| 153 : V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE), | |
| 154 v4l2_task_runner_(v4l2_task_runner), | |
| 155 device_name_(device_name), | |
| 156 power_line_frequency_(power_line_frequency), | |
| 157 is_capturing_(false), | |
| 158 timeout_count_(0), | |
| 159 rotation_(0) { | |
| 160 } | |
| 161 | |
| 162 V4L2CaptureDelegate::~V4L2CaptureDelegate() { | |
| 163 } | |
| 164 | |
| 165 void V4L2CaptureDelegate::AllocateAndStart( | |
| 166 int width, | |
| 167 int height, | |
| 168 float frame_rate, | |
| 169 scoped_ptr<VideoCaptureDevice::Client> client) { | |
| 170 DCHECK(v4l2_task_runner_->BelongsToCurrentThread()); | |
| 171 DCHECK(client); | |
| 172 client_ = client.Pass(); | |
| 173 | |
| 174 // Need to open camera with O_RDWR after Linux kernel 3.3. | |
| 175 device_fd_.reset(HANDLE_EINTR(open(device_name_.id().c_str(), O_RDWR))); | |
| 176 if (!device_fd_.is_valid()) { | |
| 177 SetErrorState("Failed to open V4L2 device driver file."); | |
| 178 return; | |
| 179 } | |
| 180 | |
| 181 v4l2_capability cap = {}; | |
| 182 if (!((HANDLE_EINTR(ioctl(device_fd_.get(), VIDIOC_QUERYCAP, &cap)) == 0) && | |
| 183 ((cap.capabilities & V4L2_CAP_VIDEO_CAPTURE || | |
| 184 cap.capabilities & V4L2_CAP_VIDEO_CAPTURE_MPLANE) && | |
| 185 !(cap.capabilities & V4L2_CAP_VIDEO_OUTPUT) && | |
| 186 !(cap.capabilities & V4L2_CAP_VIDEO_OUTPUT_MPLANE)))) { | |
| 187 device_fd_.reset(); | |
| 188 SetErrorState("This is not a V4L2 video capture device"); | |
| 189 return; | |
| 190 } | |
| 191 | |
| 192 // Get supported video formats in preferred order. | |
| 193 // For large resolutions, favour mjpeg over raw formats. | |
| 194 const std::list<uint32_t>& desired_v4l2_formats = | |
| 195 GetListOfUsableFourCcs(width > kMjpegWidth || height > kMjpegHeight); | |
| 196 std::list<uint32_t>::const_iterator best = desired_v4l2_formats.end(); | |
| 197 | |
| 198 v4l2_fmtdesc fmtdesc = {}; | |
| 199 fmtdesc.type = capture_type_; | |
| 200 for (; HANDLE_EINTR(ioctl(device_fd_.get(), VIDIOC_ENUM_FMT, &fmtdesc)) == 0; | |
| 201 ++fmtdesc.index) { | |
| 202 best = std::find(desired_v4l2_formats.begin(), best, fmtdesc.pixelformat); | |
| 203 } | |
| 204 if (best == desired_v4l2_formats.end()) { | |
| 205 SetErrorState("Failed to find a supported camera format."); | |
| 206 return; | |
| 207 } | |
| 208 | |
| 209 DVLOG(1) << "Chosen pixel format is " << FourccToString(*best); | |
| 210 | |
| 211 video_fmt_.type = capture_type_; | |
| 212 if (!FillV4L2Format(&video_fmt_, width, height, *best)) { | |
| 213 SetErrorState("Failed filling in V4L2 Format"); | |
| 214 return; | |
| 215 } | |
| 216 | |
| 217 if (HANDLE_EINTR(ioctl(device_fd_.get(), VIDIOC_S_FMT, &video_fmt_)) < 0) { | |
| 218 SetErrorState("Failed to set video capture format"); | |
| 219 return; | |
| 220 } | |
| 221 const VideoPixelFormat pixel_format = | |
| 222 V4l2FourCcToChromiumPixelFormat(video_fmt_.fmt.pix.pixelformat); | |
| 223 if (pixel_format == PIXEL_FORMAT_UNKNOWN) { | |
| 224 SetErrorState("Unsupported pixel format"); | |
| 225 return; | |
| 226 } | |
| 227 | |
| 228 // Set capture framerate in the form of capture interval. | |
| 229 v4l2_streamparm streamparm = {}; | |
| 230 streamparm.type = capture_type_; | |
| 231 // The following line checks that the driver knows about framerate get/set. | |
| 232 if (HANDLE_EINTR(ioctl(device_fd_.get(), VIDIOC_G_PARM, &streamparm)) >= 0) { | |
| 233 // Now check if the device is able to accept a capture framerate set. | |
| 234 if (streamparm.parm.capture.capability & V4L2_CAP_TIMEPERFRAME) { | |
| 235 // |frame_rate| is float, approximate by a fraction. | |
| 236 streamparm.parm.capture.timeperframe.numerator = | |
| 237 media::kFrameRatePrecision; | |
| 238 streamparm.parm.capture.timeperframe.denominator = | |
| 239 (frame_rate) ? (frame_rate * media::kFrameRatePrecision) | |
| 240 : (kTypicalFramerate * media::kFrameRatePrecision); | |
| 241 | |
| 242 if (HANDLE_EINTR(ioctl(device_fd_.get(), VIDIOC_S_PARM, &streamparm)) < | |
| 243 0) { | |
| 244 SetErrorState("Failed to set camera framerate"); | |
| 245 return; | |
| 246 } | |
| 247 DVLOG(2) << "Actual camera driverframerate: " | |
| 248 << streamparm.parm.capture.timeperframe.denominator << "/" | |
| 249 << streamparm.parm.capture.timeperframe.numerator; | |
| 250 } | |
| 251 } | |
| 252 // TODO(mcasas): what should be done if the camera driver does not allow | |
| 253 // framerate configuration, or the actual one is different from the desired? | |
| 254 | |
| 255 // Set anti-banding/anti-flicker to 50/60Hz. May fail due to not supported | |
| 256 // operation (|errno| == EINVAL in this case) or plain failure. | |
| 257 if ((power_line_frequency_ == V4L2_CID_POWER_LINE_FREQUENCY_50HZ) || | |
| 258 (power_line_frequency_ == V4L2_CID_POWER_LINE_FREQUENCY_60HZ) || | |
| 259 (power_line_frequency_ == V4L2_CID_POWER_LINE_FREQUENCY_AUTO)) { | |
| 260 struct v4l2_control control = {}; | |
| 261 control.id = V4L2_CID_POWER_LINE_FREQUENCY; | |
| 262 control.value = power_line_frequency_; | |
| 263 const int retval = | |
| 264 HANDLE_EINTR(ioctl(device_fd_.get(), VIDIOC_S_CTRL, &control)); | |
| 265 if (retval != 0) | |
| 266 DVLOG(1) << "Error setting power line frequency removal"; | |
| 267 } | |
| 268 | |
| 269 capture_format_.frame_size.SetSize(video_fmt_.fmt.pix.width, | |
| 270 video_fmt_.fmt.pix.height); | |
| 271 capture_format_.frame_rate = frame_rate; | |
| 272 capture_format_.pixel_format = pixel_format; | |
| 273 | |
| 274 v4l2_requestbuffers r_buffer = {}; | |
| 275 r_buffer.type = capture_type_; | |
| 276 r_buffer.memory = V4L2_MEMORY_MMAP; | |
| 277 r_buffer.count = kNumVideoBuffers; | |
| 278 if (HANDLE_EINTR(ioctl(device_fd_.get(), VIDIOC_REQBUFS, &r_buffer)) < 0) { | |
| 279 SetErrorState("Error requesting MMAP buffers from V4L2"); | |
| 280 return; | |
| 281 } | |
| 282 for (unsigned int i = 0; i < r_buffer.count; ++i) { | |
| 283 if (!MapAndQueueBuffer(i)) { | |
| 284 SetErrorState("Allocate buffer failed"); | |
| 285 return; | |
| 286 } | |
| 287 } | |
| 288 | |
| 289 if (HANDLE_EINTR(ioctl(device_fd_.get(), VIDIOC_STREAMON, &capture_type_)) | |
| 290 < 0) { | |
| 291 SetErrorState("VIDIOC_STREAMON failed"); | |
| 292 return; | |
| 293 } | |
| 294 | |
| 295 is_capturing_ = true; | |
| 296 // Post task to start fetching frames from v4l2. | |
| 297 v4l2_task_runner_->PostTask( | |
| 298 FROM_HERE, base::Bind(&V4L2CaptureDelegate::DoCapture, this)); | |
| 299 } | |
| 300 | |
| 301 void V4L2CaptureDelegate::StopAndDeAllocate() { | |
| 302 DCHECK(v4l2_task_runner_->BelongsToCurrentThread()); | |
| 303 // The order is important: stop streaming, clear |buffer_pool_|, | |
| 304 // thus munmap()ing the v4l2_buffers, and then return them to the OS. | |
| 305 if (HANDLE_EINTR(ioctl(device_fd_.get(), VIDIOC_STREAMOFF, &capture_type_)) | |
| 306 < 0) { | |
| 307 SetErrorState("VIDIOC_STREAMOFF failed"); | |
| 308 return; | |
| 309 } | |
| 310 | |
| 311 buffer_tracker_pool_.clear(); | |
| 312 | |
| 313 v4l2_requestbuffers r_buffer = {}; | |
| 314 r_buffer.type = capture_type_; | |
| 315 r_buffer.memory = V4L2_MEMORY_MMAP; | |
| 316 r_buffer.count = 0; | |
| 317 if (HANDLE_EINTR(ioctl(device_fd_.get(), VIDIOC_REQBUFS, &r_buffer)) < 0) | |
| 318 SetErrorState("Failed to VIDIOC_REQBUFS with count = 0"); | |
| 319 | |
| 320 // At this point we can close the device. | |
| 321 // This is also needed for correctly changing settings later via VIDIOC_S_FMT. | |
| 322 device_fd_.reset(); | |
| 323 is_capturing_ = false; | |
| 324 client_.reset(); | |
| 325 } | |
| 326 | |
| 327 void V4L2CaptureDelegate::SetRotation(int rotation) { | |
| 328 DCHECK(v4l2_task_runner_->BelongsToCurrentThread()); | |
| 329 DCHECK(rotation >= 0 && rotation < 360 && rotation % 90 == 0); | |
| 330 rotation_ = rotation; | |
| 331 } | |
| 332 | |
| 333 bool V4L2CaptureDelegate::MapAndQueueBuffer(int index) { | |
| 334 v4l2_buffer buffer; | |
| 335 FillV4L2Buffer(&buffer, index); | |
| 336 | |
| 337 if (HANDLE_EINTR(ioctl(device_fd_.get(), VIDIOC_QUERYBUF, &buffer)) < 0) { | |
| 338 DLOG(ERROR) << "Error querying status of a MMAP V4L2 buffer"; | |
| 339 return false; | |
| 340 } | |
| 341 | |
| 342 const scoped_refptr<BufferTracker>& buffer_tracker = CreateBufferTracker(); | |
| 343 if (!buffer_tracker->Init(device_fd_.get(), buffer)) { | |
| 344 DLOG(ERROR) << "Error creating BufferTracker"; | |
| 345 return false; | |
| 346 } | |
| 347 buffer_tracker_pool_.push_back(buffer_tracker); | |
| 348 | |
| 349 // Enqueue the buffer in the drivers incoming queue. | |
| 350 if (HANDLE_EINTR(ioctl(device_fd_.get(), VIDIOC_QBUF, &buffer)) < 0) { | |
| 351 DLOG(ERROR) << "Error enqueuing a V4L2 buffer back into the driver"; | |
| 352 return false; | |
| 353 } | |
| 354 return true; | |
| 355 } | |
| 356 | |
| 357 void V4L2CaptureDelegate::FillV4L2Buffer(v4l2_buffer* buffer, | |
| 358 int i) const { | |
| 359 memset(buffer, 0, sizeof(*buffer)); | |
| 360 buffer->memory = V4L2_MEMORY_MMAP; | |
| 361 buffer->index = i; | |
| 362 FinishFillingV4L2Buffer(buffer); | |
| 363 } | |
| 364 | |
| 365 void V4L2CaptureDelegate::DoCapture() { | |
| 366 DCHECK(v4l2_task_runner_->BelongsToCurrentThread()); | |
| 367 if (!is_capturing_) | |
| 368 return; | |
| 369 | |
| 370 pollfd device_pfd = {}; | |
| 371 device_pfd.fd = device_fd_.get(); | |
| 372 device_pfd.events = POLLIN; | |
| 373 const int result = HANDLE_EINTR(poll(&device_pfd, 1, kCaptureTimeoutMs)); | |
| 374 if (result < 0) { | |
| 375 SetErrorState("Poll failed"); | |
| 376 return; | |
| 377 } | |
| 378 // Check if poll() timed out; track the amount of times it did in a row and | |
| 379 // throw an error if it times out too many times. | |
| 380 if (result == 0) { | |
| 381 timeout_count_++; | |
| 382 if (timeout_count_ >= kContinuousTimeoutLimit) { | |
| 383 SetErrorState("Multiple continuous timeouts while read-polling."); | |
| 384 timeout_count_ = 0; | |
| 385 return; | |
| 386 } | |
| 387 } else { | |
| 388 timeout_count_ = 0; | |
| 389 } | |
| 390 | |
| 391 // Deenqueue, send and reenqueue a buffer if the driver has filled one in. | |
| 392 if (device_pfd.revents & POLLIN) { | |
| 393 v4l2_buffer buffer; | |
| 394 FillV4L2Buffer(&buffer, 0); | |
| 395 | |
| 396 if (HANDLE_EINTR(ioctl(device_fd_.get(), VIDIOC_DQBUF, &buffer)) < 0) { | |
| 397 SetErrorState("Failed to dequeue capture buffer"); | |
| 398 return; | |
| 399 } | |
| 400 | |
| 401 SendBuffer(buffer_tracker_pool_[buffer.index], video_fmt_); | |
| 402 | |
| 403 if (HANDLE_EINTR(ioctl(device_fd_.get(), VIDIOC_QBUF, &buffer)) < 0) { | |
| 404 SetErrorState("Failed to enqueue capture buffer"); | |
| 405 return; | |
| 406 } | |
| 407 } | |
| 408 | |
| 409 v4l2_task_runner_->PostTask( | |
| 410 FROM_HERE, base::Bind(&V4L2CaptureDelegate::DoCapture, this)); | |
| 411 } | |
| 412 | |
| 413 void V4L2CaptureDelegate::SetErrorState(const std::string& reason) { | |
| 414 DCHECK(v4l2_task_runner_->BelongsToCurrentThread()); | |
| 415 is_capturing_ = false; | |
| 416 client_->OnError(reason); | |
| 417 } | |
| 418 | |
| 419 } // namespace media | |
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