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1 /*
2  * Copyright (C) 2013 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 #define LOG_TAG "CameraDeviceClient"
18 #define ATRACE_TAG ATRACE_TAG_CAMERA
19 // #define LOG_NDEBUG 0
20 
21 #include <cutils/properties.h>
22 #include <utils/Log.h>
23 #include <utils/Trace.h>
24 #include <gui/Surface.h>
25 #include <camera/camera2/CaptureRequest.h>
26 
27 #include "common/CameraDeviceBase.h"
28 #include "api2/CameraDeviceClient.h"
29 
30 
31 
32 namespace android {
33 using namespace camera2;
34 
CameraDeviceClientBase(const sp<CameraService> & cameraService,const sp<ICameraDeviceCallbacks> & remoteCallback,const String16 & clientPackageName,int cameraId,int cameraFacing,int clientPid,uid_t clientUid,int servicePid)35 CameraDeviceClientBase::CameraDeviceClientBase(
36         const sp<CameraService>& cameraService,
37         const sp<ICameraDeviceCallbacks>& remoteCallback,
38         const String16& clientPackageName,
39         int cameraId,
40         int cameraFacing,
41         int clientPid,
42         uid_t clientUid,
43         int servicePid) :
44     BasicClient(cameraService, remoteCallback->asBinder(), clientPackageName,
45                 cameraId, cameraFacing, clientPid, clientUid, servicePid),
46     mRemoteCallback(remoteCallback) {
47 }
48 
49 // Interface used by CameraService
50 
CameraDeviceClient(const sp<CameraService> & cameraService,const sp<ICameraDeviceCallbacks> & remoteCallback,const String16 & clientPackageName,int cameraId,int cameraFacing,int clientPid,uid_t clientUid,int servicePid)51 CameraDeviceClient::CameraDeviceClient(const sp<CameraService>& cameraService,
52                                    const sp<ICameraDeviceCallbacks>& remoteCallback,
53                                    const String16& clientPackageName,
54                                    int cameraId,
55                                    int cameraFacing,
56                                    int clientPid,
57                                    uid_t clientUid,
58                                    int servicePid) :
59     Camera2ClientBase(cameraService, remoteCallback, clientPackageName,
60                 cameraId, cameraFacing, clientPid, clientUid, servicePid),
61     mRequestIdCounter(0) {
62 
63     ATRACE_CALL();
64     ALOGI("CameraDeviceClient %d: Opened", cameraId);
65 }
66 
initialize(camera_module_t * module)67 status_t CameraDeviceClient::initialize(camera_module_t *module)
68 {
69     ATRACE_CALL();
70     status_t res;
71 
72     res = Camera2ClientBase::initialize(module);
73     if (res != OK) {
74         return res;
75     }
76 
77     String8 threadName;
78     mFrameProcessor = new FrameProcessorBase(mDevice);
79     threadName = String8::format("CDU-%d-FrameProc", mCameraId);
80     mFrameProcessor->run(threadName.string());
81 
82     mFrameProcessor->registerListener(FRAME_PROCESSOR_LISTENER_MIN_ID,
83                                       FRAME_PROCESSOR_LISTENER_MAX_ID,
84                                       /*listener*/this,
85                                       /*quirkSendPartials*/true);
86 
87     return OK;
88 }
89 
~CameraDeviceClient()90 CameraDeviceClient::~CameraDeviceClient() {
91 }
92 
submitRequest(sp<CaptureRequest> request,bool streaming)93 status_t CameraDeviceClient::submitRequest(sp<CaptureRequest> request,
94                                          bool streaming) {
95     ATRACE_CALL();
96     ALOGV("%s", __FUNCTION__);
97 
98     status_t res;
99 
100     if ( (res = checkPid(__FUNCTION__) ) != OK) return res;
101 
102     Mutex::Autolock icl(mBinderSerializationLock);
103 
104     if (!mDevice.get()) return DEAD_OBJECT;
105 
106     if (request == 0) {
107         ALOGE("%s: Camera %d: Sent null request. Rejecting request.",
108               __FUNCTION__, mCameraId);
109         return BAD_VALUE;
110     }
111 
112     CameraMetadata metadata(request->mMetadata);
113 
114     if (metadata.isEmpty()) {
115         ALOGE("%s: Camera %d: Sent empty metadata packet. Rejecting request.",
116                __FUNCTION__, mCameraId);
117         return BAD_VALUE;
118     } else if (request->mSurfaceList.size() == 0) {
119         ALOGE("%s: Camera %d: Requests must have at least one surface target. "
120               "Rejecting request.", __FUNCTION__, mCameraId);
121         return BAD_VALUE;
122     }
123 
124     if (!enforceRequestPermissions(metadata)) {
125         // Callee logs
126         return PERMISSION_DENIED;
127     }
128 
129     /**
130      * Write in the output stream IDs which we calculate from
131      * the capture request's list of surface targets
132      */
133     Vector<int32_t> outputStreamIds;
134     outputStreamIds.setCapacity(request->mSurfaceList.size());
135     for (size_t i = 0; i < request->mSurfaceList.size(); ++i) {
136         sp<Surface> surface = request->mSurfaceList[i];
137 
138         if (surface == 0) continue;
139 
140         sp<IGraphicBufferProducer> gbp = surface->getIGraphicBufferProducer();
141         int idx = mStreamMap.indexOfKey(gbp->asBinder());
142 
143         // Trying to submit request with surface that wasn't created
144         if (idx == NAME_NOT_FOUND) {
145             ALOGE("%s: Camera %d: Tried to submit a request with a surface that"
146                   " we have not called createStream on",
147                   __FUNCTION__, mCameraId);
148             return BAD_VALUE;
149         }
150 
151         int streamId = mStreamMap.valueAt(idx);
152         outputStreamIds.push_back(streamId);
153         ALOGV("%s: Camera %d: Appending output stream %d to request",
154               __FUNCTION__, mCameraId, streamId);
155     }
156 
157     metadata.update(ANDROID_REQUEST_OUTPUT_STREAMS, &outputStreamIds[0],
158                     outputStreamIds.size());
159 
160     int32_t requestId = mRequestIdCounter++;
161     metadata.update(ANDROID_REQUEST_ID, &requestId, /*size*/1);
162     ALOGV("%s: Camera %d: Submitting request with ID %d",
163           __FUNCTION__, mCameraId, requestId);
164 
165     if (streaming) {
166         res = mDevice->setStreamingRequest(metadata);
167         if (res != OK) {
168             ALOGE("%s: Camera %d:  Got error %d after trying to set streaming "
169                   "request", __FUNCTION__, mCameraId, res);
170         } else {
171             mStreamingRequestList.push_back(requestId);
172         }
173     } else {
174         res = mDevice->capture(metadata);
175         if (res != OK) {
176             ALOGE("%s: Camera %d: Got error %d after trying to set capture",
177                   __FUNCTION__, mCameraId, res);
178         }
179     }
180 
181     ALOGV("%s: Camera %d: End of function", __FUNCTION__, mCameraId);
182     if (res == OK) {
183         return requestId;
184     }
185 
186     return res;
187 }
188 
cancelRequest(int requestId)189 status_t CameraDeviceClient::cancelRequest(int requestId) {
190     ATRACE_CALL();
191     ALOGV("%s, requestId = %d", __FUNCTION__, requestId);
192 
193     status_t res;
194 
195     if ( (res = checkPid(__FUNCTION__) ) != OK) return res;
196 
197     Mutex::Autolock icl(mBinderSerializationLock);
198 
199     if (!mDevice.get()) return DEAD_OBJECT;
200 
201     Vector<int>::iterator it, end;
202     for (it = mStreamingRequestList.begin(), end = mStreamingRequestList.end();
203          it != end; ++it) {
204         if (*it == requestId) {
205             break;
206         }
207     }
208 
209     if (it == end) {
210         ALOGE("%s: Camera%d: Did not find request id %d in list of streaming "
211               "requests", __FUNCTION__, mCameraId, requestId);
212         return BAD_VALUE;
213     }
214 
215     res = mDevice->clearStreamingRequest();
216 
217     if (res == OK) {
218         ALOGV("%s: Camera %d: Successfully cleared streaming request",
219               __FUNCTION__, mCameraId);
220         mStreamingRequestList.erase(it);
221     }
222 
223     return res;
224 }
225 
deleteStream(int streamId)226 status_t CameraDeviceClient::deleteStream(int streamId) {
227     ATRACE_CALL();
228     ALOGV("%s (streamId = 0x%x)", __FUNCTION__, streamId);
229 
230     status_t res;
231     if ( (res = checkPid(__FUNCTION__) ) != OK) return res;
232 
233     Mutex::Autolock icl(mBinderSerializationLock);
234 
235     if (!mDevice.get()) return DEAD_OBJECT;
236 
237     // Guard against trying to delete non-created streams
238     ssize_t index = NAME_NOT_FOUND;
239     for (size_t i = 0; i < mStreamMap.size(); ++i) {
240         if (streamId == mStreamMap.valueAt(i)) {
241             index = i;
242             break;
243         }
244     }
245 
246     if (index == NAME_NOT_FOUND) {
247         ALOGW("%s: Camera %d: Invalid stream ID (%d) specified, no stream "
248               "created yet", __FUNCTION__, mCameraId, streamId);
249         return BAD_VALUE;
250     }
251 
252     // Also returns BAD_VALUE if stream ID was not valid
253     res = mDevice->deleteStream(streamId);
254 
255     if (res == BAD_VALUE) {
256         ALOGE("%s: Camera %d: Unexpected BAD_VALUE when deleting stream, but we"
257               " already checked and the stream ID (%d) should be valid.",
258               __FUNCTION__, mCameraId, streamId);
259     } else if (res == OK) {
260         mStreamMap.removeItemsAt(index);
261 
262         ALOGV("%s: Camera %d: Successfully deleted stream ID (%d)",
263               __FUNCTION__, mCameraId, streamId);
264     }
265 
266     return res;
267 }
268 
createStream(int width,int height,int format,const sp<IGraphicBufferProducer> & bufferProducer)269 status_t CameraDeviceClient::createStream(int width, int height, int format,
270                       const sp<IGraphicBufferProducer>& bufferProducer)
271 {
272     ATRACE_CALL();
273     ALOGV("%s (w = %d, h = %d, f = 0x%x)", __FUNCTION__, width, height, format);
274 
275     status_t res;
276     if ( (res = checkPid(__FUNCTION__) ) != OK) return res;
277 
278     Mutex::Autolock icl(mBinderSerializationLock);
279 
280     if (!mDevice.get()) return DEAD_OBJECT;
281 
282     // Don't create multiple streams for the same target surface
283     {
284         ssize_t index = mStreamMap.indexOfKey(bufferProducer->asBinder());
285         if (index != NAME_NOT_FOUND) {
286             ALOGW("%s: Camera %d: Buffer producer already has a stream for it "
287                   "(ID %d)",
288                   __FUNCTION__, mCameraId, index);
289             return ALREADY_EXISTS;
290         }
291     }
292 
293     // HACK b/10949105
294     // Query consumer usage bits to set async operation mode for
295     // GLConsumer using controlledByApp parameter.
296     bool useAsync = false;
297     int32_t consumerUsage;
298     if ((res = bufferProducer->query(NATIVE_WINDOW_CONSUMER_USAGE_BITS,
299             &consumerUsage)) != OK) {
300         ALOGE("%s: Camera %d: Failed to query consumer usage", __FUNCTION__,
301               mCameraId);
302         return res;
303     }
304     if (consumerUsage & GraphicBuffer::USAGE_HW_TEXTURE) {
305         ALOGW("%s: Camera %d: Forcing asynchronous mode for stream",
306                 __FUNCTION__, mCameraId);
307         useAsync = true;
308     }
309 
310     sp<IBinder> binder;
311     sp<ANativeWindow> anw;
312     if (bufferProducer != 0) {
313         binder = bufferProducer->asBinder();
314         anw = new Surface(bufferProducer, useAsync);
315     }
316 
317     // TODO: remove w,h,f since we are ignoring them
318 
319     if ((res = anw->query(anw.get(), NATIVE_WINDOW_WIDTH, &width)) != OK) {
320         ALOGE("%s: Camera %d: Failed to query Surface width", __FUNCTION__,
321               mCameraId);
322         return res;
323     }
324     if ((res = anw->query(anw.get(), NATIVE_WINDOW_HEIGHT, &height)) != OK) {
325         ALOGE("%s: Camera %d: Failed to query Surface height", __FUNCTION__,
326               mCameraId);
327         return res;
328     }
329     if ((res = anw->query(anw.get(), NATIVE_WINDOW_FORMAT, &format)) != OK) {
330         ALOGE("%s: Camera %d: Failed to query Surface format", __FUNCTION__,
331               mCameraId);
332         return res;
333     }
334 
335     // FIXME: remove this override since the default format should be
336     //       IMPLEMENTATION_DEFINED. b/9487482
337     if (format >= HAL_PIXEL_FORMAT_RGBA_8888 &&
338         format <= HAL_PIXEL_FORMAT_BGRA_8888) {
339         ALOGW("%s: Camera %d: Overriding format 0x%x to IMPLEMENTATION_DEFINED",
340               __FUNCTION__, mCameraId, format);
341         format = HAL_PIXEL_FORMAT_IMPLEMENTATION_DEFINED;
342     }
343 
344     // TODO: add startConfigure/stopConfigure call to CameraDeviceBase
345     // this will make it so Camera3Device doesn't call configure_streams
346     // after each call, but only once we are done with all.
347 
348     int streamId = -1;
349     if (format == HAL_PIXEL_FORMAT_BLOB) {
350         // JPEG buffers need to be sized for maximum possible compressed size
351         CameraMetadata staticInfo = mDevice->info();
352         camera_metadata_entry_t entry = staticInfo.find(ANDROID_JPEG_MAX_SIZE);
353         if (entry.count == 0) {
354             ALOGE("%s: Camera %d: Can't find maximum JPEG size in "
355                     "static metadata!", __FUNCTION__, mCameraId);
356             return INVALID_OPERATION;
357         }
358         int32_t maxJpegSize = entry.data.i32[0];
359         res = mDevice->createStream(anw, width, height, format, maxJpegSize,
360                 &streamId);
361     } else {
362         // All other streams are a known size
363         res = mDevice->createStream(anw, width, height, format, /*size*/0,
364                 &streamId);
365     }
366 
367     if (res == OK) {
368         mStreamMap.add(bufferProducer->asBinder(), streamId);
369 
370         ALOGV("%s: Camera %d: Successfully created a new stream ID %d",
371               __FUNCTION__, mCameraId, streamId);
372 
373         /**
374          * Set the stream transform flags to automatically
375          * rotate the camera stream for preview use cases.
376          */
377         int32_t transform = 0;
378         res = getRotationTransformLocked(&transform);
379 
380         if (res != OK) {
381             // Error logged by getRotationTransformLocked.
382             return res;
383         }
384 
385         res = mDevice->setStreamTransform(streamId, transform);
386         if (res != OK) {
387             ALOGE("%s: Failed to set stream transform (stream id %d)",
388                   __FUNCTION__, streamId);
389             return res;
390         }
391 
392         return streamId;
393     }
394 
395     return res;
396 }
397 
398 // Create a request object from a template.
createDefaultRequest(int templateId,CameraMetadata * request)399 status_t CameraDeviceClient::createDefaultRequest(int templateId,
400                                                   /*out*/
401                                                   CameraMetadata* request)
402 {
403     ATRACE_CALL();
404     ALOGV("%s (templateId = 0x%x)", __FUNCTION__, templateId);
405 
406     status_t res;
407     if ( (res = checkPid(__FUNCTION__) ) != OK) return res;
408 
409     Mutex::Autolock icl(mBinderSerializationLock);
410 
411     if (!mDevice.get()) return DEAD_OBJECT;
412 
413     CameraMetadata metadata;
414     if ( (res = mDevice->createDefaultRequest(templateId, &metadata) ) == OK &&
415         request != NULL) {
416 
417         request->swap(metadata);
418     }
419 
420     return res;
421 }
422 
getCameraInfo(CameraMetadata * info)423 status_t CameraDeviceClient::getCameraInfo(/*out*/CameraMetadata* info)
424 {
425     ATRACE_CALL();
426     ALOGV("%s", __FUNCTION__);
427 
428     status_t res = OK;
429 
430     if ( (res = checkPid(__FUNCTION__) ) != OK) return res;
431 
432     Mutex::Autolock icl(mBinderSerializationLock);
433 
434     if (!mDevice.get()) return DEAD_OBJECT;
435 
436     if (info != NULL) {
437         *info = mDevice->info(); // static camera metadata
438         // TODO: merge with device-specific camera metadata
439     }
440 
441     return res;
442 }
443 
waitUntilIdle()444 status_t CameraDeviceClient::waitUntilIdle()
445 {
446     ATRACE_CALL();
447     ALOGV("%s", __FUNCTION__);
448 
449     status_t res = OK;
450     if ( (res = checkPid(__FUNCTION__) ) != OK) return res;
451 
452     Mutex::Autolock icl(mBinderSerializationLock);
453 
454     if (!mDevice.get()) return DEAD_OBJECT;
455 
456     // FIXME: Also need check repeating burst.
457     if (!mStreamingRequestList.isEmpty()) {
458         ALOGE("%s: Camera %d: Try to waitUntilIdle when there are active streaming requests",
459               __FUNCTION__, mCameraId);
460         return INVALID_OPERATION;
461     }
462     res = mDevice->waitUntilDrained();
463     ALOGV("%s Done", __FUNCTION__);
464 
465     return res;
466 }
467 
flush()468 status_t CameraDeviceClient::flush() {
469     ATRACE_CALL();
470     ALOGV("%s", __FUNCTION__);
471 
472     status_t res = OK;
473     if ( (res = checkPid(__FUNCTION__) ) != OK) return res;
474 
475     Mutex::Autolock icl(mBinderSerializationLock);
476 
477     if (!mDevice.get()) return DEAD_OBJECT;
478 
479     return mDevice->flush();
480 }
481 
dump(int fd,const Vector<String16> & args)482 status_t CameraDeviceClient::dump(int fd, const Vector<String16>& args) {
483     String8 result;
484     result.appendFormat("CameraDeviceClient[%d] (%p) PID: %d, dump:\n",
485             mCameraId,
486             getRemoteCallback()->asBinder().get(),
487             mClientPid);
488     result.append("  State: ");
489 
490     // TODO: print dynamic/request section from most recent requests
491     mFrameProcessor->dump(fd, args);
492 
493     return dumpDevice(fd, args);
494 }
495 
496 
notifyError()497 void CameraDeviceClient::notifyError() {
498     // Thread safe. Don't bother locking.
499     sp<ICameraDeviceCallbacks> remoteCb = getRemoteCallback();
500 
501     if (remoteCb != 0) {
502         remoteCb->onDeviceError(ICameraDeviceCallbacks::ERROR_CAMERA_DEVICE);
503     }
504 }
505 
notifyIdle()506 void CameraDeviceClient::notifyIdle() {
507     // Thread safe. Don't bother locking.
508     sp<ICameraDeviceCallbacks> remoteCb = getRemoteCallback();
509 
510     if (remoteCb != 0) {
511         remoteCb->onDeviceIdle();
512     }
513 }
514 
notifyShutter(int requestId,nsecs_t timestamp)515 void CameraDeviceClient::notifyShutter(int requestId,
516         nsecs_t timestamp) {
517     // Thread safe. Don't bother locking.
518     sp<ICameraDeviceCallbacks> remoteCb = getRemoteCallback();
519     if (remoteCb != 0) {
520         remoteCb->onCaptureStarted(requestId, timestamp);
521     }
522 }
523 
524 // TODO: refactor the code below this with IProCameraUser.
525 // it's 100% copy-pasted, so lets not change it right now to make it easier.
526 
detachDevice()527 void CameraDeviceClient::detachDevice() {
528     if (mDevice == 0) return;
529 
530     ALOGV("Camera %d: Stopping processors", mCameraId);
531 
532     mFrameProcessor->removeListener(FRAME_PROCESSOR_LISTENER_MIN_ID,
533                                     FRAME_PROCESSOR_LISTENER_MAX_ID,
534                                     /*listener*/this);
535     mFrameProcessor->requestExit();
536     ALOGV("Camera %d: Waiting for threads", mCameraId);
537     mFrameProcessor->join();
538     ALOGV("Camera %d: Disconnecting device", mCameraId);
539 
540     // WORKAROUND: HAL refuses to disconnect while there's streams in flight
541     {
542         mDevice->clearStreamingRequest();
543 
544         status_t code;
545         if ((code = mDevice->waitUntilDrained()) != OK) {
546             ALOGE("%s: waitUntilDrained failed with code 0x%x", __FUNCTION__,
547                   code);
548         }
549     }
550 
551     Camera2ClientBase::detachDevice();
552 }
553 
554 /** Device-related methods */
onFrameAvailable(int32_t requestId,const CameraMetadata & frame)555 void CameraDeviceClient::onFrameAvailable(int32_t requestId,
556         const CameraMetadata& frame) {
557     ATRACE_CALL();
558     ALOGV("%s", __FUNCTION__);
559 
560     // Thread-safe. No lock necessary.
561     sp<ICameraDeviceCallbacks> remoteCb = mRemoteCallback;
562     if (remoteCb != NULL) {
563         ALOGV("%s: frame = %p ", __FUNCTION__, &frame);
564         remoteCb->onResultReceived(requestId, frame);
565     }
566 }
567 
568 // TODO: move to Camera2ClientBase
enforceRequestPermissions(CameraMetadata & metadata)569 bool CameraDeviceClient::enforceRequestPermissions(CameraMetadata& metadata) {
570 
571     const int pid = IPCThreadState::self()->getCallingPid();
572     const int selfPid = getpid();
573     camera_metadata_entry_t entry;
574 
575     /**
576      * Mixin default important security values
577      * - android.led.transmit = defaulted ON
578      */
579     CameraMetadata staticInfo = mDevice->info();
580     entry = staticInfo.find(ANDROID_LED_AVAILABLE_LEDS);
581     for(size_t i = 0; i < entry.count; ++i) {
582         uint8_t led = entry.data.u8[i];
583 
584         switch(led) {
585             case ANDROID_LED_AVAILABLE_LEDS_TRANSMIT: {
586                 uint8_t transmitDefault = ANDROID_LED_TRANSMIT_ON;
587                 if (!metadata.exists(ANDROID_LED_TRANSMIT)) {
588                     metadata.update(ANDROID_LED_TRANSMIT,
589                                     &transmitDefault, 1);
590                 }
591                 break;
592             }
593         }
594     }
595 
596     // We can do anything!
597     if (pid == selfPid) {
598         return true;
599     }
600 
601     /**
602      * Permission check special fields in the request
603      * - android.led.transmit = android.permission.CAMERA_DISABLE_TRANSMIT
604      */
605     entry = metadata.find(ANDROID_LED_TRANSMIT);
606     if (entry.count > 0 && entry.data.u8[0] != ANDROID_LED_TRANSMIT_ON) {
607         String16 permissionString =
608             String16("android.permission.CAMERA_DISABLE_TRANSMIT_LED");
609         if (!checkCallingPermission(permissionString)) {
610             const int uid = IPCThreadState::self()->getCallingUid();
611             ALOGE("Permission Denial: "
612                   "can't disable transmit LED pid=%d, uid=%d", pid, uid);
613             return false;
614         }
615     }
616 
617     return true;
618 }
619 
getRotationTransformLocked(int32_t * transform)620 status_t CameraDeviceClient::getRotationTransformLocked(int32_t* transform) {
621     ALOGV("%s: begin", __FUNCTION__);
622 
623     if (transform == NULL) {
624         ALOGW("%s: null transform", __FUNCTION__);
625         return BAD_VALUE;
626     }
627 
628     *transform = 0;
629 
630     const CameraMetadata& staticInfo = mDevice->info();
631     camera_metadata_ro_entry_t entry = staticInfo.find(ANDROID_SENSOR_ORIENTATION);
632     if (entry.count == 0) {
633         ALOGE("%s: Camera %d: Can't find android.sensor.orientation in "
634                 "static metadata!", __FUNCTION__, mCameraId);
635         return INVALID_OPERATION;
636     }
637 
638     int32_t& flags = *transform;
639 
640     int orientation = entry.data.i32[0];
641     switch (orientation) {
642         case 0:
643             flags = 0;
644             break;
645         case 90:
646             flags = NATIVE_WINDOW_TRANSFORM_ROT_90;
647             break;
648         case 180:
649             flags = NATIVE_WINDOW_TRANSFORM_ROT_180;
650             break;
651         case 270:
652             flags = NATIVE_WINDOW_TRANSFORM_ROT_270;
653             break;
654         default:
655             ALOGE("%s: Invalid HAL android.sensor.orientation value: %d",
656                   __FUNCTION__, orientation);
657             return INVALID_OPERATION;
658     }
659 
660     /**
661      * This magic flag makes surfaceflinger un-rotate the buffers
662      * to counter the extra global device UI rotation whenever the user
663      * physically rotates the device.
664      *
665      * By doing this, the camera buffer always ends up aligned
666      * with the physical camera for a "see through" effect.
667      *
668      * In essence, the buffer only gets rotated during preview use-cases.
669      * The user is still responsible to re-create streams of the proper
670      * aspect ratio, or the preview will end up looking non-uniformly
671      * stretched.
672      */
673     flags |= NATIVE_WINDOW_TRANSFORM_INVERSE_DISPLAY;
674 
675     ALOGV("%s: final transform = 0x%x", __FUNCTION__, flags);
676 
677     return OK;
678 }
679 
680 } // namespace android
681