Vladimir Chtchetkine | 4ed09fd | 2011-08-18 09:42:40 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2011 The Android Open Source Project |
| 3 | * |
| 4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
| 5 | * you may not use this file except in compliance with the License. |
| 6 | * You may obtain a copy of the License at |
| 7 | * |
| 8 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 9 | * |
| 10 | * Unless required by applicable law or agreed to in writing, software |
| 11 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 13 | * See the License for the specific language governing permissions and |
| 14 | * limitations under the License. |
| 15 | */ |
| 16 | |
| 17 | /* |
| 18 | * Contains code that is used to capture video frames from a camera device |
| 19 | * on Linux. This code uses V4L2 API to work with camera devices, and requires |
| 20 | * Linux kernel version at least 2.5 |
| 21 | */ |
| 22 | |
| 23 | #include <sys/mman.h> |
| 24 | #include <sys/stat.h> |
| 25 | #include <sys/ioctl.h> |
| 26 | #include <linux/videodev2.h> |
| 27 | #include "qemu-common.h" |
| 28 | #include "android/utils/debug.h" |
| 29 | #include "android/utils/misc.h" |
| 30 | #include "android/utils/system.h" |
| 31 | #include "android/camera/camera-capture.h" |
| 32 | #include "android/camera/camera-format-converters.h" |
| 33 | |
| 34 | #define D(...) VERBOSE_PRINT(camera,__VA_ARGS__) |
| 35 | #define W(...) VERBOSE_PRINT(camera,__VA_ARGS__) |
| 36 | #define E(...) VERBOSE_PRINT(camera,__VA_ARGS__) |
| 37 | #define D_ACTIVE VERBOSE_CHECK(camera) |
| 38 | |
| 39 | /* the T(...) macro is used to dump traffic */ |
| 40 | #define T_ACTIVE 0 |
| 41 | |
| 42 | #if T_ACTIVE |
| 43 | #define T(...) VERBOSE_PRINT(camera,__VA_ARGS__) |
| 44 | #else |
| 45 | #define T(...) ((void)0) |
| 46 | #endif |
| 47 | |
| 48 | #define CLEAR(x) memset (&(x), 0, sizeof(x)) |
| 49 | |
| 50 | /* Describes a framebuffer. */ |
| 51 | typedef struct CameraFrameBuffer { |
| 52 | /* Framebuffer data. */ |
| 53 | uint8_t* data; |
| 54 | /* Framebuffer data size. */ |
| 55 | size_t size; |
| 56 | } CameraFrameBuffer; |
| 57 | |
| 58 | /* Defines type of the I/O used to obtain frames from the device. */ |
| 59 | typedef enum CameraIoType { |
| 60 | /* Framebuffers are shared via memory mapping. */ |
| 61 | CAMERA_IO_MEMMAP, |
| 62 | /* Framebuffers are available via user pointers. */ |
| 63 | CAMERA_IO_USERPTR, |
| 64 | /* Framebuffers are to be read from the device. */ |
| 65 | CAMERA_IO_DIRECT |
| 66 | } CameraIoType; |
| 67 | |
| 68 | typedef struct LinuxCameraDevice LinuxCameraDevice; |
| 69 | /* |
| 70 | * Describes a connection to an actual camera device. |
| 71 | */ |
| 72 | struct LinuxCameraDevice { |
| 73 | /* Common header. */ |
| 74 | CameraDevice header; |
| 75 | |
| 76 | /* Camera device name. (default is /dev/video0) */ |
| 77 | char* device_name; |
| 78 | /* Input channel. (default is 0) */ |
| 79 | int input_channel; |
| 80 | /* Requested pixel format. */ |
| 81 | uint32_t req_pixel_format; |
| 82 | |
| 83 | /* |
| 84 | * Set by the framework after initializing camera connection. |
| 85 | */ |
| 86 | |
| 87 | /* Handle to the opened camera device. */ |
| 88 | int handle; |
| 89 | /* Device capabilities. */ |
| 90 | struct v4l2_capability caps; |
| 91 | /* Actual pixel format reported by the device. */ |
| 92 | struct v4l2_pix_format actual_pixel_format; |
| 93 | /* Defines type of the I/O to use to retrieve frames from the device. */ |
| 94 | CameraIoType io_type; |
| 95 | /* Allocated framebuffers. */ |
| 96 | struct CameraFrameBuffer* framebuffers; |
| 97 | /* Actual number of allocated framebuffers. */ |
| 98 | int framebuffer_num; |
| 99 | }; |
| 100 | |
| 101 | /******************************************************************************* |
| 102 | * Helper routines |
| 103 | ******************************************************************************/ |
| 104 | |
| 105 | /* IOCTL wrapper. */ |
| 106 | static int |
| 107 | _xioctl(int fd, int request, void *arg) { |
| 108 | int r; |
| 109 | do { |
| 110 | r = ioctl(fd, request, arg); |
| 111 | } while (-1 == r && EINTR == errno); |
| 112 | return r; |
| 113 | } |
| 114 | |
| 115 | /******************************************************************************* |
| 116 | * CameraFrameBuffer routines |
| 117 | ******************************************************************************/ |
| 118 | |
| 119 | /* Frees array of framebuffers, depending on the I/O method the array has been |
| 120 | * initialized for. |
| 121 | * Note that this routine doesn't frees the array itself. |
| 122 | * Param: |
| 123 | * fb, num - Array data, and its size. |
| 124 | * io_type - Type of the I/O the array has been initialized for. |
| 125 | */ |
| 126 | static void |
| 127 | _free_framebuffers(CameraFrameBuffer* fb, int num, CameraIoType io_type) |
| 128 | { |
| 129 | if (fb != NULL) { |
| 130 | int n; |
| 131 | |
| 132 | switch (io_type) { |
| 133 | case CAMERA_IO_MEMMAP: |
| 134 | /* Unmap framebuffers. */ |
| 135 | for (n = 0; n < num; n++) { |
| 136 | if (fb[n].data != NULL) { |
| 137 | munmap(fb[n].data, fb[n].size); |
| 138 | fb[n].data = NULL; |
| 139 | fb[n].size = 0; |
| 140 | } |
| 141 | } |
| 142 | break; |
| 143 | |
| 144 | case CAMERA_IO_USERPTR: |
| 145 | case CAMERA_IO_DIRECT: |
| 146 | /* Free framebuffers. */ |
| 147 | for (n = 0; n < num; n++) { |
| 148 | if (fb[n].data != NULL) { |
| 149 | free(fb[n].data); |
| 150 | fb[n].data = NULL; |
| 151 | fb[n].size = 0; |
| 152 | } |
| 153 | } |
| 154 | break; |
| 155 | |
| 156 | default: |
| 157 | E("Invalid I/O type %d", io_type); |
| 158 | break; |
| 159 | } |
| 160 | } |
| 161 | } |
| 162 | |
| 163 | /******************************************************************************* |
| 164 | * CameraDevice routines |
| 165 | ******************************************************************************/ |
| 166 | |
| 167 | /* Allocates an instance of LinuxCameraDevice structure. |
| 168 | * Return: |
| 169 | * Allocated instance of LinuxCameraDevice structure. Note that this routine |
| 170 | * also sets 'opaque' field in the 'header' structure to point back to the |
| 171 | * containing LinuxCameraDevice instance. |
| 172 | */ |
| 173 | static LinuxCameraDevice* |
| 174 | _camera_device_alloc(void) |
| 175 | { |
| 176 | LinuxCameraDevice* cd; |
| 177 | |
| 178 | ANEW0(cd); |
| 179 | memset(cd, 0, sizeof(*cd)); |
| 180 | cd->header.opaque = cd; |
| 181 | cd->handle = -1; |
| 182 | |
| 183 | return cd; |
| 184 | } |
| 185 | |
| 186 | /* Uninitializes and frees CameraDevice structure. |
| 187 | */ |
| 188 | static void |
| 189 | _camera_device_free(LinuxCameraDevice* lcd) |
| 190 | { |
| 191 | if (lcd != NULL) { |
| 192 | /* Closing handle will also disconnect from the driver. */ |
| 193 | if (lcd->handle >= 0) { |
| 194 | close(lcd->handle); |
| 195 | } |
| 196 | if (lcd->device_name != NULL) { |
| 197 | free(lcd->device_name); |
| 198 | } |
| 199 | if (lcd->framebuffers != NULL) { |
| 200 | _free_framebuffers(lcd->framebuffers, lcd->framebuffer_num, |
| 201 | lcd->io_type); |
| 202 | free(lcd->framebuffers); |
| 203 | } |
| 204 | AFREE(lcd); |
| 205 | } else { |
| 206 | W("%s: No descriptor", __FUNCTION__); |
| 207 | } |
| 208 | } |
| 209 | |
| 210 | /* Memory maps buffers and shares mapped memory with the device. |
| 211 | * Return: |
| 212 | * 0 Framebuffers have been mapped. |
| 213 | * -1 A critical error has ocurred. |
| 214 | * 1 Memory mapping is not available. |
| 215 | */ |
| 216 | static int |
| 217 | _camera_device_mmap_framebuffer(LinuxCameraDevice* cd) |
| 218 | { |
| 219 | struct v4l2_requestbuffers req; |
| 220 | CLEAR(req); |
| 221 | req.count = 4; |
| 222 | req.type = V4L2_BUF_TYPE_VIDEO_CAPTURE; |
| 223 | req.memory = V4L2_MEMORY_MMAP; |
| 224 | |
| 225 | /* Request memory mapped buffers. Note that device can return less buffers |
| 226 | * than requested. */ |
| 227 | if(_xioctl(cd->handle, VIDIOC_REQBUFS, &req)) { |
| 228 | if (EINVAL == errno) { |
| 229 | D("%s: %s does not support memory mapping", |
| 230 | __FUNCTION__, cd->device_name); |
| 231 | return 1; |
| 232 | } else { |
| 233 | E("%s: VIDIOC_REQBUFS has failed: %s", |
| 234 | __FUNCTION__, strerror(errno)); |
| 235 | return -1; |
| 236 | } |
| 237 | } |
| 238 | |
| 239 | /* Allocate framebuffer array. */ |
| 240 | cd->framebuffers = calloc(req.count, sizeof(CameraFrameBuffer)); |
| 241 | if (cd->framebuffers == NULL) { |
| 242 | E("%s: Not enough memory to allocate framebuffer array", __FUNCTION__); |
| 243 | return -1; |
| 244 | } |
| 245 | |
| 246 | /* Map every framebuffer to the shared memory, and queue it |
| 247 | * with the device. */ |
| 248 | for(cd->framebuffer_num = 0; cd->framebuffer_num < req.count; |
| 249 | cd->framebuffer_num++) { |
| 250 | /* Map framebuffer. */ |
| 251 | struct v4l2_buffer buf; |
| 252 | CLEAR(buf); |
| 253 | buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE; |
| 254 | buf.memory = V4L2_MEMORY_MMAP; |
| 255 | buf.index = cd->framebuffer_num; |
| 256 | if(_xioctl(cd->handle, VIDIOC_QUERYBUF, &buf) < 0) { |
| 257 | E("%s: VIDIOC_QUERYBUF has failed: %s", |
| 258 | __FUNCTION__, strerror(errno)); |
| 259 | return -1; |
| 260 | } |
| 261 | cd->framebuffers[cd->framebuffer_num].size = buf.length; |
| 262 | cd->framebuffers[cd->framebuffer_num].data = |
| 263 | mmap(NULL, buf.length, PROT_READ | PROT_WRITE, MAP_SHARED, |
| 264 | cd->handle, buf.m.offset); |
| 265 | if (MAP_FAILED == cd->framebuffers[cd->framebuffer_num].data) { |
| 266 | E("%s: Memory mapping has failed: %s", |
| 267 | __FUNCTION__, strerror(errno)); |
| 268 | return -1; |
| 269 | } |
| 270 | |
| 271 | /* Queue the mapped buffer. */ |
| 272 | CLEAR(buf); |
| 273 | buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE; |
| 274 | buf.memory = V4L2_MEMORY_MMAP; |
| 275 | buf.index = cd->framebuffer_num; |
| 276 | if (_xioctl(cd->handle, VIDIOC_QBUF, &buf) < 0) { |
| 277 | E("%s: VIDIOC_QBUF has failed: %s", __FUNCTION__, strerror(errno)); |
| 278 | return -1; |
| 279 | } |
| 280 | } |
| 281 | |
| 282 | cd->io_type = CAMERA_IO_MEMMAP; |
| 283 | |
| 284 | return 0; |
| 285 | } |
| 286 | |
| 287 | /* Allocates frame buffers and registers them with the device. |
| 288 | * Return: |
| 289 | * 0 Framebuffers have been mapped. |
| 290 | * -1 A critical error has ocurred. |
| 291 | * 1 Device doesn't support user pointers. |
| 292 | */ |
| 293 | static int |
| 294 | _camera_device_user_framebuffer(LinuxCameraDevice* cd) |
| 295 | { |
| 296 | struct v4l2_requestbuffers req; |
| 297 | CLEAR (req); |
| 298 | req.count = 4; |
| 299 | req.type = V4L2_BUF_TYPE_VIDEO_CAPTURE; |
| 300 | req.memory = V4L2_MEMORY_USERPTR; |
| 301 | |
| 302 | /* Request user buffers. Note that device can return less buffers |
| 303 | * than requested. */ |
| 304 | if(_xioctl(cd->handle, VIDIOC_REQBUFS, &req)) { |
| 305 | if (EINVAL == errno) { |
| 306 | D("%s: %s does not support user pointers", |
| 307 | __FUNCTION__, cd->device_name); |
| 308 | return 1; |
| 309 | } else { |
| 310 | E("%s: VIDIOC_REQBUFS has failed: %s", |
| 311 | __FUNCTION__, strerror(errno)); |
| 312 | return -1; |
| 313 | } |
| 314 | } |
| 315 | |
| 316 | /* Allocate framebuffer array. */ |
| 317 | cd->framebuffers = calloc(req.count, sizeof(CameraFrameBuffer)); |
| 318 | if (cd->framebuffers == NULL) { |
| 319 | E("%s: Not enough memory to allocate framebuffer array", __FUNCTION__); |
| 320 | return -1; |
| 321 | } |
| 322 | |
| 323 | /* Allocate buffers, queueing them wit the device at the same time */ |
| 324 | for(cd->framebuffer_num = 0; cd->framebuffer_num < req.count; |
| 325 | cd->framebuffer_num++) { |
| 326 | cd->framebuffers[cd->framebuffer_num].size = |
| 327 | cd->actual_pixel_format.sizeimage; |
| 328 | cd->framebuffers[cd->framebuffer_num].data = |
| 329 | malloc(cd->framebuffers[cd->framebuffer_num].size); |
| 330 | if (cd->framebuffers[cd->framebuffer_num].data == NULL) { |
| 331 | E("%s: Not enough memory to allocate framebuffer", __FUNCTION__); |
| 332 | return -1; |
| 333 | } |
| 334 | |
| 335 | /* Queue the user buffer. */ |
| 336 | struct v4l2_buffer buf; |
| 337 | CLEAR(buf); |
| 338 | buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE; |
| 339 | buf.memory = V4L2_MEMORY_USERPTR; |
| 340 | buf.m.userptr = cd->framebuffers[cd->framebuffer_num].data; |
| 341 | buf.length = cd->framebuffers[cd->framebuffer_num].size; |
| 342 | if (_xioctl(cd->handle, VIDIOC_QBUF, &buf) < 0) { |
| 343 | E("%s: VIDIOC_QBUF has failed: %s", __FUNCTION__, strerror(errno)); |
| 344 | return -1; |
| 345 | } |
| 346 | } |
| 347 | |
| 348 | cd->io_type = CAMERA_IO_USERPTR; |
| 349 | |
| 350 | return 0; |
| 351 | } |
| 352 | |
| 353 | /* Allocate frame buffer for direct read from the device. |
| 354 | * Return: |
| 355 | * 0 Framebuffers have been mapped. |
| 356 | * -1 A critical error has ocurred. |
| 357 | * 1 Memory mapping is not available. |
| 358 | */ |
| 359 | static int |
| 360 | _camera_device_direct_framebuffer(LinuxCameraDevice* cd) |
| 361 | { |
| 362 | /* Allocate framebuffer array. */ |
| 363 | cd->framebuffer_num = 1; |
| 364 | cd->framebuffers = malloc(sizeof(CameraFrameBuffer)); |
| 365 | if (cd->framebuffers == NULL) { |
| 366 | E("%s: Not enough memory to allocate framebuffer array", __FUNCTION__); |
| 367 | return -1; |
| 368 | } |
| 369 | |
| 370 | cd->framebuffers[0].size = cd->actual_pixel_format.sizeimage; |
| 371 | cd->framebuffers[0].data = malloc(cd->framebuffers[0].size); |
| 372 | if (cd->framebuffers[0].data == NULL) { |
| 373 | E("%s: Not enough memory to allocate framebuffer", __FUNCTION__); |
| 374 | return -1; |
| 375 | } |
| 376 | |
| 377 | cd->io_type = CAMERA_IO_DIRECT; |
| 378 | |
| 379 | return 0; |
| 380 | } |
| 381 | |
| 382 | static int |
| 383 | _camera_device_open(LinuxCameraDevice* cd) |
| 384 | { |
| 385 | struct stat st; |
| 386 | |
| 387 | if (stat(cd->device_name, &st)) { |
| 388 | E("%s: Cannot identify camera device '%s': %s", |
| 389 | __FUNCTION__, cd->device_name, strerror(errno)); |
| 390 | return -1; |
| 391 | } |
| 392 | |
| 393 | if (!S_ISCHR(st.st_mode)) { |
| 394 | E("%s: %s is not a device", __FUNCTION__, cd->device_name); |
| 395 | return -1; |
| 396 | } |
| 397 | |
| 398 | /* Open handle to the device, and query device capabilities. */ |
| 399 | cd->handle = open(cd->device_name, O_RDWR | O_NONBLOCK, 0); |
| 400 | if (cd->handle < 0) { |
| 401 | E("%s: Cannot open camera device '%s': %s\n", |
| 402 | __FUNCTION__, cd->device_name, strerror(errno)); |
| 403 | return -1; |
| 404 | } |
| 405 | if (_xioctl(cd->handle, VIDIOC_QUERYCAP, &cd->caps) < 0) { |
| 406 | if (EINVAL == errno) { |
| 407 | E("%s: Camera '%s' is not a V4L2 device", |
| 408 | __FUNCTION__, cd->device_name); |
| 409 | close(cd->handle); |
| 410 | cd->handle = -1; |
| 411 | return -1; |
| 412 | } else { |
| 413 | E("%s: Unable to query camera '%s' capabilities", |
| 414 | __FUNCTION__, cd->device_name); |
| 415 | close(cd->handle); |
| 416 | cd->handle = -1; |
| 417 | return -1; |
| 418 | } |
| 419 | } |
| 420 | |
| 421 | /* Make sure that camera supports minimal requirements. */ |
| 422 | if (!(cd->caps.capabilities & V4L2_CAP_VIDEO_CAPTURE)) { |
| 423 | E("%s: Camera '%s' is not a video capture device", |
| 424 | __FUNCTION__, cd->device_name); |
| 425 | close(cd->handle); |
| 426 | cd->handle = -1; |
| 427 | return -1; |
| 428 | } |
| 429 | |
| 430 | return 0; |
| 431 | } |
| 432 | |
| 433 | /******************************************************************************* |
| 434 | * CameraDevice API |
| 435 | ******************************************************************************/ |
| 436 | |
| 437 | CameraDevice* |
| 438 | camera_device_open(const char* name, |
| 439 | int inp_channel, |
| 440 | uint32_t pixel_format) |
| 441 | { |
| 442 | struct v4l2_cropcap cropcap; |
| 443 | struct v4l2_crop crop; |
| 444 | struct v4l2_format fmt; |
| 445 | LinuxCameraDevice* cd; |
| 446 | |
| 447 | /* Allocate and initialize the descriptor. */ |
| 448 | cd = _camera_device_alloc(); |
| 449 | cd->device_name = name != NULL ? ASTRDUP(name) : ASTRDUP("/dev/video0"); |
| 450 | cd->input_channel = inp_channel; |
| 451 | cd->req_pixel_format = pixel_format; |
| 452 | |
| 453 | /* Open the device. */ |
| 454 | if (_camera_device_open(cd)) { |
| 455 | _camera_device_free(cd); |
| 456 | return NULL; |
| 457 | } |
| 458 | |
| 459 | /* Select video input, video standard and tune here. */ |
| 460 | cropcap.type = V4L2_BUF_TYPE_VIDEO_CAPTURE; |
| 461 | _xioctl(cd->handle, VIDIOC_CROPCAP, &cropcap); |
| 462 | crop.type = V4L2_BUF_TYPE_VIDEO_CAPTURE; |
| 463 | crop.c = cropcap.defrect; /* reset to default */ |
| 464 | _xioctl (cd->handle, VIDIOC_S_CROP, &crop); |
| 465 | |
| 466 | /* Image settings. */ |
| 467 | CLEAR(fmt); |
| 468 | fmt.type = V4L2_BUF_TYPE_VIDEO_CAPTURE; |
| 469 | fmt.fmt.pix.width = 0; |
| 470 | fmt.fmt.pix.height = 0; |
| 471 | fmt.fmt.pix.pixelformat = 0; |
| 472 | if (_xioctl(cd->handle, VIDIOC_G_FMT, &fmt) < 0) { |
| 473 | E("%s: Unable to obtain pixel format", __FUNCTION__); |
| 474 | _camera_device_free(cd); |
| 475 | return NULL; |
| 476 | } |
| 477 | if (_xioctl(cd->handle, VIDIOC_S_FMT, &fmt) < 0) { |
| 478 | char fmt_str[5]; |
| 479 | memcpy(fmt_str, &cd->req_pixel_format, 4); |
| 480 | fmt_str[4] = '\0'; |
| 481 | E("%s: Camera '%s' does not support requested pixel format '%s'", |
| 482 | __FUNCTION__, cd->device_name, fmt_str); |
| 483 | _camera_device_free(cd); |
| 484 | return NULL; |
| 485 | } |
| 486 | /* VIDIOC_S_FMT has changed some properties of the structure, adjusting them |
| 487 | * to the actual values, supported by the device. */ |
| 488 | memcpy(&cd->actual_pixel_format, &fmt.fmt.pix, |
| 489 | sizeof(cd->actual_pixel_format)); |
| 490 | { |
| 491 | char fmt_str[5]; |
| 492 | memcpy(fmt_str, &cd->req_pixel_format, 4); |
| 493 | fmt_str[4] = '\0'; |
| 494 | D("%s: Camera '%s' uses pixel format '%s'", |
| 495 | __FUNCTION__, cd->device_name, fmt_str); |
| 496 | } |
| 497 | |
| 498 | return &cd->header; |
| 499 | } |
| 500 | |
| 501 | int |
| 502 | camera_device_start_capturing(CameraDevice* ccd) |
| 503 | { |
| 504 | LinuxCameraDevice* cd; |
| 505 | |
| 506 | /* Sanity checks. */ |
| 507 | if (ccd == NULL || ccd->opaque == NULL) { |
| 508 | E("%s: Invalid camera device descriptor", __FUNCTION__); |
| 509 | return -1; |
| 510 | } |
| 511 | cd = (LinuxCameraDevice*)ccd->opaque; |
| 512 | |
| 513 | /* |
| 514 | * Lets initialize frame buffers, and see what kind of I/O we're going to |
| 515 | * use to retrieve frames. |
| 516 | */ |
| 517 | |
| 518 | /* First, lets see if we can do mapped I/O (as most performant one). */ |
| 519 | int r = _camera_device_mmap_framebuffer(cd); |
| 520 | if (r < 0) { |
| 521 | /* Some critical error has ocurred. Bail out. */ |
| 522 | return -1; |
| 523 | } else if (r > 0) { |
| 524 | /* Device doesn't support memory mapping. Retrieve to the next performant |
| 525 | * one: preallocated user buffers. */ |
| 526 | r = _camera_device_user_framebuffer(cd); |
| 527 | if (r < 0) { |
| 528 | /* Some critical error has ocurred. Bail out. */ |
| 529 | return -1; |
| 530 | } else if (r > 0) { |
| 531 | /* The only thing left for us is direct reading from the device. */ |
| 532 | if (!(cd->caps.capabilities & V4L2_CAP_READWRITE)) { |
| 533 | E("%s: Device '%s' doesn't support direct read", |
| 534 | __FUNCTION__, cd->device_name); |
| 535 | return -1; |
| 536 | } |
| 537 | r = _camera_device_direct_framebuffer(cd); |
| 538 | if (r != 0) { |
| 539 | /* Any error at this point is a critical one. */ |
| 540 | return -1; |
| 541 | } |
| 542 | } |
| 543 | } |
| 544 | |
| 545 | /* Start capturing from the device. */ |
| 546 | if (cd->io_type != CAMERA_IO_DIRECT) { |
| 547 | enum v4l2_buf_type type; |
| 548 | type = V4L2_BUF_TYPE_VIDEO_CAPTURE; |
| 549 | if (_xioctl (cd->handle, VIDIOC_STREAMON, &type) < 0) { |
| 550 | E("%s: VIDIOC_STREAMON has failed: %s", |
| 551 | __FUNCTION__, strerror(errno)); |
| 552 | return -1; |
| 553 | } |
| 554 | } |
| 555 | |
| 556 | return 0; |
| 557 | } |
| 558 | |
| 559 | int |
| 560 | camera_device_stop_capturing(CameraDevice* ccd) |
| 561 | { |
| 562 | enum v4l2_buf_type type; |
| 563 | LinuxCameraDevice* cd; |
| 564 | |
| 565 | /* Sanity checks. */ |
| 566 | if (ccd == NULL || ccd->opaque == NULL) { |
| 567 | E("%s: Invalid camera device descriptor", __FUNCTION__); |
| 568 | return -1; |
| 569 | } |
| 570 | cd = (LinuxCameraDevice*)ccd->opaque; |
| 571 | |
| 572 | switch (cd->io_type) { |
| 573 | case CAMERA_IO_DIRECT: |
| 574 | /* Nothing to do. */ |
| 575 | break; |
| 576 | |
| 577 | case CAMERA_IO_MEMMAP: |
| 578 | case CAMERA_IO_USERPTR: |
| 579 | type = V4L2_BUF_TYPE_VIDEO_CAPTURE; |
| 580 | if (_xioctl(cd->handle, VIDIOC_STREAMOFF, &type) < 0) { |
| 581 | E("%s: VIDIOC_STREAMOFF has failed: %s", |
| 582 | __FUNCTION__, strerror(errno)); |
| 583 | return -1; |
| 584 | } |
| 585 | break; |
| 586 | default: |
| 587 | E("%s: Unknown I/O method: %d", __FUNCTION__, cd->io_type); |
| 588 | return -1; |
| 589 | } |
| 590 | |
| 591 | if (cd->framebuffers != NULL) { |
| 592 | _free_framebuffers(cd->framebuffers, cd->framebuffer_num, cd->io_type); |
| 593 | free(cd->framebuffers); |
| 594 | cd->framebuffers = NULL; |
| 595 | cd->framebuffer_num = 0; |
| 596 | } |
| 597 | return 0; |
| 598 | } |
| 599 | |
| 600 | int |
| 601 | camera_device_read_frame(CameraDevice* ccd, uint8_t* buff) |
| 602 | { |
| 603 | LinuxCameraDevice* cd; |
| 604 | |
| 605 | /* Sanity checks. */ |
| 606 | if (ccd == NULL || ccd->opaque == NULL) { |
| 607 | E("%s: Invalid camera device descriptor", __FUNCTION__); |
| 608 | return -1; |
| 609 | } |
| 610 | cd = (LinuxCameraDevice*)ccd->opaque; |
| 611 | |
| 612 | if (cd->io_type == CAMERA_IO_DIRECT) { |
| 613 | /* Read directly from the device. */ |
| 614 | size_t total_read_bytes = 0; |
| 615 | do { |
| 616 | int read_bytes = |
| 617 | read(cd->handle, buff + total_read_bytes, |
| 618 | cd->actual_pixel_format.sizeimage - total_read_bytes); |
| 619 | if (read_bytes < 0) { |
| 620 | switch (errno) { |
| 621 | case EIO: |
| 622 | case EAGAIN: |
| 623 | continue; |
| 624 | default: |
| 625 | E("%s: Unable to read from the device: %s", |
| 626 | __FUNCTION__, strerror(errno)); |
| 627 | return -1; |
| 628 | } |
| 629 | } |
| 630 | total_read_bytes += read_bytes; |
| 631 | } while (total_read_bytes < cd->actual_pixel_format.sizeimage); |
| 632 | return 0; |
| 633 | } else { |
| 634 | /* Dequeue next buffer from the device. */ |
| 635 | struct v4l2_buffer buf; |
| 636 | CLEAR(buf); |
| 637 | buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE; |
| 638 | buf.memory = cd->io_type == CAMERA_IO_MEMMAP ? V4L2_MEMORY_MMAP : |
| 639 | V4L2_MEMORY_USERPTR; |
| 640 | if (_xioctl(cd->handle, VIDIOC_DQBUF, &buf) < 0) { |
| 641 | switch (errno) { |
| 642 | case EAGAIN: |
| 643 | return 1; |
| 644 | |
| 645 | case EIO: |
| 646 | /* Could ignore EIO, see spec. */ |
| 647 | /* fall through */ |
| 648 | default: |
| 649 | E("%s: VIDIOC_DQBUF has failed: %s", |
| 650 | __FUNCTION__, strerror(errno)); |
| 651 | return 1; |
| 652 | } |
| 653 | } |
| 654 | /* Copy frame to the buffer. */ |
| 655 | memcpy(buff, cd->framebuffers[buf.index].data, |
| 656 | cd->framebuffers[buf.index].size); |
| 657 | /* Requeue the buffer with the device. */ |
| 658 | if (_xioctl(cd->handle, VIDIOC_QBUF, &buf) < 0) { |
| 659 | D("%s: VIDIOC_QBUF has failed: %s", |
| 660 | __FUNCTION__, strerror(errno)); |
| 661 | } |
| 662 | return 0; |
| 663 | } |
| 664 | } |
| 665 | |
| 666 | void |
| 667 | camera_device_close(CameraDevice* ccd) |
| 668 | { |
| 669 | LinuxCameraDevice* cd; |
| 670 | |
| 671 | /* Sanity checks. */ |
| 672 | if (ccd != NULL && ccd->opaque != NULL) { |
| 673 | cd = (LinuxCameraDevice*)ccd->opaque; |
| 674 | _camera_device_free(cd); |
| 675 | } else { |
| 676 | E("%s: Invalid camera device descriptor", __FUNCTION__); |
| 677 | } |
| 678 | } |