• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
1 /*
2  * Copyright (C) 2017 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 // Uncomment LOG_NDEBUG to enable verbose logging, and uncomment both LOG_NDEBUG
18 // *and* LOG_NNDEBUG to enable very verbose logging.
19 
20 //#define LOG_NDEBUG 0
21 //#define LOG_NNDEBUG 0
22 
23 #define LOG_TAG "EmulatedCamera3_QemuSensor"
24 #define ATRACE_TAG ATRACE_TAG_CAMERA
25 
26 #ifdef LOG_NNDEBUG
27 #define ALOGVV(...) ALOGV(__VA_ARGS__)
28 #else
29 #define ALOGVV(...) ((void)0)
30 #endif
31 
32 #include "qemu-pipeline3/QemuSensor.h"
33 #include "system/camera_metadata.h"
34 #include <gralloc_cb_bp.h>
35 
36 #include <cmath>
37 #include <cstdlib>
38 #include <linux/videodev2.h>
39 #include <log/log.h>
40 #include <cutils/properties.h>
41 #include <ui/Rect.h>
42 #include <utils/Trace.h>
43 
44 namespace android {
45 
46 const nsecs_t QemuSensor::kExposureTimeRange[2] =
47         {1000L, 300000000L};  // 1 us - 0.3 sec
48 const nsecs_t QemuSensor::kFrameDurationRange[2] =
49         {33331760L, 300000000L};  // ~1/30 s - 0.3 sec
50 const nsecs_t QemuSensor::kMinVerticalBlank = 10000L;
51 
52 const int32_t QemuSensor::kSensitivityRange[2] = {100, 1600};
53 const uint32_t QemuSensor::kDefaultSensitivity = 100;
54 
55 const char QemuSensor::kHostCameraVerString[] = "ro.kernel.qemu.camera_protocol_ver";
56 
QemuSensor(const char * deviceName,uint32_t width,uint32_t height,GraphicBufferMapper * gbm)57 QemuSensor::QemuSensor(const char *deviceName, uint32_t width, uint32_t height,
58                        GraphicBufferMapper* gbm):
59         Thread(false),
60         mWidth(width),
61         mHeight(height),
62         mActiveArray{0, 0, width, height},
63         mLastRequestWidth(-1),
64         mLastRequestHeight(-1),
65         mCameraQemuClient(),
66         mDeviceName(deviceName),
67         mGBA(&GraphicBufferAllocator::get()),
68         mGBM(gbm),
69         mGotVSync(false),
70         mFrameDuration(kFrameDurationRange[0]),
71         mNextBuffers(nullptr),
72         mFrameNumber(0),
73         mCapturedBuffers(nullptr),
74         mListener(nullptr) {
75     mHostCameraVer = property_get_int32(kHostCameraVerString, 0);
76     ALOGV("QemuSensor created with pixel array %d x %d", width, height);
77 }
78 
~QemuSensor()79 QemuSensor::~QemuSensor() {
80     shutDown();
81 }
82 
startUp()83 status_t QemuSensor::startUp() {
84     ALOGV("%s: Entered", __FUNCTION__);
85 
86     mCapturedBuffers = nullptr;
87     status_t res = run("EmulatedQemuCamera3::QemuSensor",
88             ANDROID_PRIORITY_URGENT_DISPLAY);
89 
90     if (res != OK) {
91         ALOGE("Unable to start up sensor capture thread: %d", res);
92     }
93 
94     char connect_str[256];
95     snprintf(connect_str, sizeof(connect_str), "name=%s", mDeviceName);
96     res = mCameraQemuClient.connectClient(connect_str);
97     if (res != NO_ERROR) {
98         return res;
99     }
100 
101     res = mCameraQemuClient.queryConnect();
102     if (res == NO_ERROR) {
103         ALOGV("%s: Connected to device '%s'",
104                 __FUNCTION__, (const char*) mDeviceName);
105         mState = ECDS_CONNECTED;
106     } else {
107         ALOGE("%s: Connection to device '%s' failed",
108                 __FUNCTION__, (const char*) mDeviceName);
109     }
110 
111     return res;
112 }
113 
shutDown()114 status_t QemuSensor::shutDown() {
115     ALOGV("%s: Entered", __FUNCTION__);
116 
117     status_t res = requestExitAndWait();
118     if (res != OK) {
119         ALOGE("Unable to shut down sensor capture thread: %d", res);
120     }
121 
122     /* Stop the actual camera device. */
123     res = mCameraQemuClient.queryStop();
124     if (res == NO_ERROR) {
125         mState = ECDS_CONNECTED;
126         ALOGV("%s: Qemu camera device '%s' is stopped",
127                 __FUNCTION__, (const char*) mDeviceName);
128     } else {
129         ALOGE("%s: Unable to stop device '%s'",
130                 __FUNCTION__, (const char*) mDeviceName);
131     }
132 
133     return res;
134 }
135 
setFrameDuration(uint64_t ns)136 void QemuSensor::setFrameDuration(uint64_t ns) {
137     Mutex::Autolock lock(mControlMutex);
138     ALOGVV("Frame duration set to %f", ns/1000000.f);
139     mFrameDuration = ns;
140 }
141 
setDestinationBuffers(Buffers * buffers)142 void QemuSensor::setDestinationBuffers(Buffers *buffers) {
143     Mutex::Autolock lock(mControlMutex);
144     mNextBuffers = buffers;
145 }
146 
setFrameNumber(uint32_t frameNumber)147 void QemuSensor::setFrameNumber(uint32_t frameNumber) {
148     Mutex::Autolock lock(mControlMutex);
149     mFrameNumber = frameNumber;
150 }
151 
waitForVSync(nsecs_t reltime)152 bool QemuSensor::waitForVSync(nsecs_t reltime) {
153     int res;
154     Mutex::Autolock lock(mControlMutex);
155 
156     mGotVSync = false;
157     res = mVSync.waitRelative(mControlMutex, reltime);
158     if (res != OK && res != TIMED_OUT) {
159         ALOGE("%s: Error waiting for VSync signal: %d", __FUNCTION__, res);
160         return false;
161     }
162     return mGotVSync;
163 }
164 
waitForNewFrame(nsecs_t reltime,nsecs_t * captureTime)165 bool QemuSensor::waitForNewFrame(nsecs_t reltime, nsecs_t *captureTime) {
166     Mutex::Autolock lock(mReadoutMutex);
167     if (mCapturedBuffers == nullptr) {
168         int res;
169         res = mReadoutAvailable.waitRelative(mReadoutMutex, reltime);
170         if (res == TIMED_OUT) {
171             return false;
172         } else if (res != OK || mCapturedBuffers == nullptr) {
173             ALOGE("Error waiting for sensor readout signal: %d", res);
174             return false;
175         }
176     }
177     mReadoutComplete.signal();
178 
179     *captureTime = mCaptureTime;
180     mCapturedBuffers = nullptr;
181     return true;
182 }
183 
~QemuSensorListener()184 QemuSensor::QemuSensorListener::~QemuSensorListener() {
185 }
186 
setQemuSensorListener(QemuSensorListener * listener)187 void QemuSensor::setQemuSensorListener(QemuSensorListener *listener) {
188     Mutex::Autolock lock(mControlMutex);
189     mListener = listener;
190 }
191 
readyToRun()192 status_t QemuSensor::readyToRun() {
193     ALOGV("Starting up sensor thread");
194     mStartupTime = systemTime();
195     mNextCaptureTime = 0;
196     mNextCapturedBuffers = nullptr;
197     return OK;
198 }
199 
threadLoop()200 bool QemuSensor::threadLoop() {
201     ATRACE_CALL();
202     /*
203      * Stages are out-of-order relative to a single frame's processing, but
204      * in-order in time.
205      */
206 
207     /*
208      * Stage 1: Read in latest control parameters.
209      */
210     uint64_t frameDuration;
211     Buffers *nextBuffers;
212     uint32_t frameNumber;
213     QemuSensorListener *listener = nullptr;
214     {
215         // Lock while we're grabbing readout variables.
216         Mutex::Autolock lock(mControlMutex);
217         frameDuration = mFrameDuration;
218         nextBuffers = mNextBuffers;
219         frameNumber = mFrameNumber;
220         listener = mListener;
221         // Don't reuse a buffer set.
222         mNextBuffers = nullptr;
223 
224         // Signal VSync for start of readout.
225         ALOGVV("QemuSensor VSync");
226         mGotVSync = true;
227         mVSync.signal();
228     }
229 
230     /*
231      * Stage 3: Read out latest captured image.
232      */
233 
234     Buffers *capturedBuffers = nullptr;
235     nsecs_t captureTime = 0;
236 
237     nsecs_t startRealTime = systemTime();
238     /*
239      * Stagefright cares about system time for timestamps, so base simulated
240      * time on that.
241      */
242     nsecs_t simulatedTime = startRealTime;
243     nsecs_t frameEndRealTime = startRealTime + frameDuration;
244 
245     if (mNextCapturedBuffers != nullptr) {
246         ALOGVV("QemuSensor starting readout");
247         /*
248          * Pretend we're doing readout now; will signal once enough time has
249          * elapsed.
250          */
251         capturedBuffers = mNextCapturedBuffers;
252         captureTime = mNextCaptureTime;
253     }
254 
255     /*
256      * TODO: Move this signal to another thread to simulate readout time
257      * properly.
258      */
259     if (capturedBuffers != nullptr) {
260         ALOGVV("QemuSensor readout complete");
261         Mutex::Autolock lock(mReadoutMutex);
262         if (mCapturedBuffers != nullptr) {
263             ALOGV("Waiting for readout thread to catch up!");
264             mReadoutComplete.wait(mReadoutMutex);
265         }
266 
267         mCapturedBuffers = capturedBuffers;
268         mCaptureTime = captureTime;
269         mReadoutAvailable.signal();
270         capturedBuffers = nullptr;
271     }
272 
273     /*
274      * Stage 2: Capture new image.
275      */
276     mNextCaptureTime = simulatedTime;
277     mNextCapturedBuffers = nextBuffers;
278 
279     if (mNextCapturedBuffers != nullptr) {
280 
281         int64_t timestamp = 0L;
282 
283         // Might be adding more buffers, so size isn't constant.
284         for (size_t i = 0; i < mNextCapturedBuffers->size(); ++i) {
285             const StreamBuffer &b = (*mNextCapturedBuffers)[i];
286             ALOGVV("QemuSensor capturing buffer %d: stream %d,"
287                     " %d x %d, format %x, stride %d, buf %p, img %p",
288                     i, b.streamId, b.width, b.height, b.format, b.stride,
289                     b.buffer, b.img);
290             switch (b.format) {
291                 case HAL_PIXEL_FORMAT_RGB_888:
292                     captureRGB(b.img, b.width, b.height, b.stride, &timestamp);
293                     break;
294                 case HAL_PIXEL_FORMAT_RGBA_8888:
295                     if (mHostCameraVer == 1) {
296                         captureRGBA(b.width, b.height, b.stride, &timestamp, b.buffer);
297                     } else {
298                         captureRGBA(b.img, b.width, b.height, b.stride, &timestamp);
299                     }
300                     break;
301                 case HAL_PIXEL_FORMAT_BLOB:
302                     if (b.dataSpace == HAL_DATASPACE_DEPTH) {
303                         ALOGE("%s: Depth clouds unsupported", __FUNCTION__);
304                     } else {
305                         /*
306                          * Add auxillary buffer of the right size. Assumes only
307                          * one BLOB (JPEG) buffer is in mNextCapturedBuffers.
308                          */
309                         StreamBuffer bAux;
310                         bAux.streamId = 0;
311                         bAux.width = b.width;
312                         bAux.height = b.height;
313                         bAux.format = HAL_PIXEL_FORMAT_YCbCr_420_888;
314                         bAux.stride = b.width;
315                         if (mHostCameraVer == 1) {
316                             const uint64_t usage =
317                                 GRALLOC_USAGE_HW_CAMERA_READ |
318                                 GRALLOC_USAGE_HW_CAMERA_WRITE |
319                                 GRALLOC_USAGE_HW_TEXTURE;
320                             const uint64_t graphicBufferId = 0; // not used
321                             const uint32_t layerCount = 1;
322                             buffer_handle_t handle;
323                             uint32_t stride;
324 
325                             status_t status = mGBA->allocate(
326                                 bAux.width, bAux.height, bAux.format,
327                                 layerCount, usage,
328                                 &handle, &stride,
329                                 graphicBufferId, "QemuSensor");
330                             if (status != OK) {
331                                 LOG_ALWAYS_FATAL("allocate failed");
332                             }
333 
334                             android_ycbcr ycbcr = {};
335                             mGBM->lockYCbCr(handle,
336                                             GRALLOC_USAGE_HW_CAMERA_WRITE,
337                                             Rect(0, 0, bAux.width, bAux.height),
338                                             &ycbcr);
339 
340                             bAux.buffer = new buffer_handle_t;
341                             *bAux.buffer = handle;
342                             bAux.img = (uint8_t*)ycbcr.y;
343                         } else {
344                             bAux.buffer = nullptr;
345                             // TODO: Reuse these.
346                             bAux.img = new uint8_t[b.width * b.height * 3];
347                         }
348                         mNextCapturedBuffers->push_back(bAux);
349                     }
350                     break;
351                 case HAL_PIXEL_FORMAT_YCbCr_420_888:
352                     if (mHostCameraVer == 1) {
353                         captureYU12(b.width, b.height, b.stride, &timestamp, b.buffer);
354                     } else {
355                         captureYU12(b.img, b.width, b.height, b.stride, &timestamp);
356                     }
357                     break;
358                 default:
359                     ALOGE("%s: Unknown/unsupported format %x, no output",
360                             __FUNCTION__, b.format);
361                     break;
362             }
363         }
364         if (timestamp != 0UL) {
365           mNextCaptureTime = timestamp;
366         }
367         // Note: we have to do this after the actual capture so that the
368         // capture time is accurate as reported from QEMU.
369         if (listener != nullptr) {
370             listener->onQemuSensorEvent(frameNumber, QemuSensorListener::EXPOSURE_START,
371                                         mNextCaptureTime);
372         }
373     }
374 
375     ALOGVV("QemuSensor vertical blanking interval");
376     nsecs_t workDoneRealTime = systemTime();
377     const nsecs_t timeAccuracy = 2e6;  // 2 ms of imprecision is ok.
378     if (workDoneRealTime < frameEndRealTime - timeAccuracy) {
379         timespec t;
380         t.tv_sec = (frameEndRealTime - workDoneRealTime) / 1000000000L;
381         t.tv_nsec = (frameEndRealTime - workDoneRealTime) % 1000000000L;
382 
383         int ret;
384         do {
385             ret = nanosleep(&t, &t);
386         } while (ret != 0);
387     }
388     ALOGVV("Frame cycle took %d ms, target %d ms",
389             (int) ((systemTime() - startRealTime) / 1000000),
390             (int) (frameDuration / 1000000));
391     return true;
392 }
393 
captureRGBA(uint8_t * img,uint32_t width,uint32_t height,uint32_t stride,int64_t * timestamp)394 void QemuSensor::captureRGBA(uint8_t *img, uint32_t width, uint32_t height,
395         uint32_t stride, int64_t *timestamp) {
396     ATRACE_CALL();
397     status_t res;
398     if (width != (uint32_t)mLastRequestWidth ||
399         height != (uint32_t)mLastRequestHeight) {
400         ALOGI("%s: Dimensions for the current request (%dx%d) differ "
401               "from the previous request (%dx%d). Restarting camera",
402                 __FUNCTION__, width, height, mLastRequestWidth,
403                 mLastRequestHeight);
404 
405         if (mLastRequestWidth != -1 || mLastRequestHeight != -1) {
406             // We only need to stop the camera if this isn't the first request.
407 
408             // Stop the camera device.
409             res = mCameraQemuClient.queryStop();
410             if (res == NO_ERROR) {
411                 mState = ECDS_CONNECTED;
412                 ALOGV("%s: Qemu camera device '%s' is stopped",
413                         __FUNCTION__, (const char*) mDeviceName);
414             } else {
415                 ALOGE("%s: Unable to stop device '%s'",
416                         __FUNCTION__, (const char*) mDeviceName);
417             }
418         }
419 
420         /*
421          * Host Camera always assumes V4L2_PIX_FMT_RGB32 as the preview format,
422          * and asks for the video format from the pixFmt parameter, which is
423          * V4L2_PIX_FMT_YUV420 in our implementation.
424          */
425         uint32_t pixFmt = V4L2_PIX_FMT_YUV420;
426         res = mCameraQemuClient.queryStart(pixFmt, width, height);
427         if (res == NO_ERROR) {
428             mLastRequestWidth = width;
429             mLastRequestHeight = height;
430             ALOGV("%s: Qemu camera device '%s' is started for %.4s[%dx%d] frames",
431                     __FUNCTION__, (const char*) mDeviceName,
432                     reinterpret_cast<const char*>(&pixFmt),
433                     mWidth, mHeight);
434             mState = ECDS_STARTED;
435         } else {
436             ALOGE("%s: Unable to start device '%s' for %.4s[%dx%d] frames",
437                     __FUNCTION__, (const char*) mDeviceName,
438                     reinterpret_cast<const char*>(&pixFmt),
439                     mWidth, mHeight);
440             return;
441         }
442     }
443     if (width != stride) {
444         ALOGW("%s: expect stride (%d), actual stride (%d)", __FUNCTION__,
445               width, stride);
446     }
447 
448     // Since the format is V4L2_PIX_FMT_RGB32, we need 4 bytes per pixel.
449       size_t bufferSize = width * height * 4;
450       // Apply no white balance or exposure compensation.
451       float whiteBalance[] = {1.0f, 1.0f, 1.0f};
452       float exposureCompensation = 1.0f;
453       // Read from webcam.
454       mCameraQemuClient.queryFrame(nullptr, img, 0, bufferSize, whiteBalance[0],
455               whiteBalance[1], whiteBalance[2],
456               exposureCompensation, timestamp);
457 
458     ALOGVV("RGBA sensor image captured");
459 }
460 
captureRGBA(uint32_t width,uint32_t height,uint32_t stride,int64_t * timestamp,buffer_handle_t * handle)461 void QemuSensor::captureRGBA(uint32_t width, uint32_t height,
462         uint32_t stride, int64_t *timestamp, buffer_handle_t* handle) {
463     ATRACE_CALL();
464     status_t res;
465     if (mLastRequestWidth == -1 || mLastRequestHeight == -1) {
466         uint32_t pixFmt = V4L2_PIX_FMT_YUV420;
467         res = mCameraQemuClient.queryStart();
468         if (res == NO_ERROR) {
469             mLastRequestWidth = width;
470             mLastRequestHeight = height;
471             ALOGV("%s: Qemu camera device '%s' is started for %.4s[%dx%d] frames",
472                     __FUNCTION__, (const char*) mDeviceName,
473                     reinterpret_cast<const char*>(&pixFmt),
474                     mWidth, mHeight);
475             mState = ECDS_STARTED;
476         } else {
477             ALOGE("%s: Unable to start device '%s' for %.4s[%dx%d] frames",
478                     __FUNCTION__, (const char*) mDeviceName,
479                     reinterpret_cast<const char*>(&pixFmt),
480                     mWidth, mHeight);
481             return;
482         }
483     }
484     if (width != stride) {
485         ALOGW("%s: expect stride (%d), actual stride (%d)", __FUNCTION__,
486               width, stride);
487     }
488 
489     float whiteBalance[] = {1.0f, 1.0f, 1.0f};
490     float exposureCompensation = 1.0f;
491     const cb_handle_t* cb = cb_handle_t::from(*handle);
492     LOG_ALWAYS_FATAL_IF(!cb, "Unexpected buffer handle");
493     const uint64_t offset = cb->getMmapedOffset();
494     mCameraQemuClient.queryFrame(width, height, V4L2_PIX_FMT_RGB32, offset,
495                                  whiteBalance[0], whiteBalance[1], whiteBalance[2],
496                                  exposureCompensation, timestamp);
497 
498     ALOGVV("RGBA sensor image captured");
499 }
500 
captureRGB(uint8_t * img,uint32_t width,uint32_t height,uint32_t stride,int64_t * timestamp)501 void QemuSensor::captureRGB(uint8_t *img, uint32_t width, uint32_t height, uint32_t stride, int64_t *timestamp) {
502     ALOGE("%s: Not implemented", __FUNCTION__);
503 }
504 
captureYU12(uint8_t * img,uint32_t width,uint32_t height,uint32_t stride,int64_t * timestamp)505 void QemuSensor::captureYU12(uint8_t *img, uint32_t width, uint32_t height, uint32_t stride,
506                              int64_t *timestamp) {
507     ATRACE_CALL();
508     status_t res;
509     if (width != (uint32_t)mLastRequestWidth ||
510         height != (uint32_t)mLastRequestHeight) {
511         ALOGI("%s: Dimensions for the current request (%dx%d) differ "
512               "from the previous request (%dx%d). Restarting camera",
513                 __FUNCTION__, width, height, mLastRequestWidth,
514                 mLastRequestHeight);
515 
516         if (mLastRequestWidth != -1 || mLastRequestHeight != -1) {
517             // We only need to stop the camera if this isn't the first request.
518             // Stop the camera device.
519             res = mCameraQemuClient.queryStop();
520             if (res == NO_ERROR) {
521                 mState = ECDS_CONNECTED;
522                 ALOGV("%s: Qemu camera device '%s' is stopped",
523                         __FUNCTION__, (const char*) mDeviceName);
524             } else {
525                 ALOGE("%s: Unable to stop device '%s'",
526                         __FUNCTION__, (const char*) mDeviceName);
527             }
528         }
529 
530         /*
531          * Host Camera always assumes V4L2_PIX_FMT_RGB32 as the preview format,
532          * and asks for the video format from the pixFmt parameter, which is
533          * V4L2_PIX_FMT_YUV420 in our implementation.
534          */
535         uint32_t pixFmt = V4L2_PIX_FMT_YUV420;
536         res = mCameraQemuClient.queryStart(pixFmt, width, height);
537         if (res == NO_ERROR) {
538             mLastRequestWidth = width;
539             mLastRequestHeight = height;
540             ALOGV("%s: Qemu camera device '%s' is started for %.4s[%dx%d] frames",
541                     __FUNCTION__, (const char*) mDeviceName,
542                     reinterpret_cast<const char*>(&pixFmt),
543                     mWidth, mHeight);
544             mState = ECDS_STARTED;
545         } else {
546             ALOGE("%s: Unable to start device '%s' for %.4s[%dx%d] frames",
547                     __FUNCTION__, (const char*) mDeviceName,
548                     reinterpret_cast<const char*>(&pixFmt),
549                     mWidth, mHeight);
550             return;
551         }
552     }
553     if (width != stride) {
554         ALOGW("%s: expect stride (%d), actual stride (%d)", __FUNCTION__,
555               width, stride);
556     }
557 
558     // Calculate the buffer size for YUV420.
559     size_t bufferSize = (width * height * 12) / 8;
560     // Apply no white balance or exposure compensation.
561     float whiteBalance[] = {1.0f, 1.0f, 1.0f};
562     float exposureCompensation = 1.0f;
563     // Read video frame from webcam.
564     mCameraQemuClient.queryFrame(img, nullptr, bufferSize, 0, whiteBalance[0],
565             whiteBalance[1], whiteBalance[2],
566             exposureCompensation, timestamp);
567 
568     ALOGVV("YUV420 sensor image captured");
569 }
570 
captureYU12(uint32_t width,uint32_t height,uint32_t stride,int64_t * timestamp,buffer_handle_t * handle)571 void QemuSensor::captureYU12(uint32_t width, uint32_t height, uint32_t stride,
572                              int64_t *timestamp, buffer_handle_t* handle) {
573     ATRACE_CALL();
574     status_t res;
575     if (mLastRequestWidth == -1 || mLastRequestHeight == -1) {
576         uint32_t pixFmt = V4L2_PIX_FMT_YUV420;
577         res = mCameraQemuClient.queryStart();
578         if (res == NO_ERROR) {
579             mLastRequestWidth = width;
580             mLastRequestHeight = height;
581             ALOGV("%s: Qemu camera device '%s' is started for %.4s[%dx%d] frames",
582                     __FUNCTION__, (const char*) mDeviceName,
583                     reinterpret_cast<const char*>(&pixFmt),
584                     mWidth, mHeight);
585             mState = ECDS_STARTED;
586         } else {
587             ALOGE("%s: Unable to start device '%s' for %.4s[%dx%d] frames",
588                     __FUNCTION__, (const char*) mDeviceName,
589                     reinterpret_cast<const char*>(&pixFmt),
590                     mWidth, mHeight);
591             return;
592         }
593     }
594     if (width != stride) {
595         ALOGW("%s: expect stride (%d), actual stride (%d)", __FUNCTION__,
596               width, stride);
597     }
598 
599     float whiteBalance[] = {1.0f, 1.0f, 1.0f};
600     float exposureCompensation = 1.0f;
601     const cb_handle_t* cb = cb_handle_t::from(*handle);
602     LOG_ALWAYS_FATAL_IF(!cb, "Unexpected buffer handle");
603     const uint64_t offset = cb->getMmapedOffset();
604     mCameraQemuClient.queryFrame(width, height, V4L2_PIX_FMT_YUV420, offset,
605                                  whiteBalance[0], whiteBalance[1], whiteBalance[2],
606                                  exposureCompensation, timestamp);
607     ALOGVV("YUV420 sensor image captured");
608 }
609 
610 }; // end of namespace android
611