android_hardware_Camera.cpp revision c62f9bd13327937aa2d2f20b44215397120634c1 
1/*
2**
3** Copyright 2008, The Android Open Source Project
4**
5** Licensed under the Apache License, Version 2.0 (the "License");
6** you may not use this file except in compliance with the License.
7** You may obtain a copy of the License at
8**
9**     http://www.apache.org/licenses/LICENSE-2.0
10**
11** Unless required by applicable law or agreed to in writing, software
12** distributed under the License is distributed on an "AS IS" BASIS,
13** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14** See the License for the specific language governing permissions and
15** limitations under the License.
16*/
17
18//#define LOG_NDEBUG 0
19#define LOG_TAG "Camera-JNI"
20#include <utils/Log.h>
21
22#include "jni.h"
23#include "JNIHelp.h"
24#include "android_runtime/AndroidRuntime.h"
25
26#include <ui/Surface.h>
27#include <ui/Camera.h>
28#include <utils/IMemory.h>
29
30using namespace android;
31
32enum CallbackMessageID {
33    kShutterCallback = 0,
34    kRawCallback = 1,
35    kJpegCallback = 2,
36    kPreviewCallback = 3,
37    kAutoFocusCallback = 4,
38    kErrorCallback = 5
39};
40
41enum CameraError {
42    kCameraErrorUnknown = 1,
43    kCameraErrorMediaServer = 100
44};
45
46
47struct fields_t {
48    jfieldID    context;
49    jfieldID    surface;
50    jmethodID   post_event;
51};
52
53static fields_t fields;
54static Mutex sLock;
55
56// provides persistent context for calls from native code to Java
57class JNICameraContext: public CameraListener
58{
59public:
60    JNICameraContext(JNIEnv* env, jobject weak_this, jclass clazz, const sp<Camera>& camera);
61    ~JNICameraContext() { release(); }
62    virtual void notify(int32_t msgType, int32_t ext1, int32_t ext2);
63    virtual void postData(int32_t msgType, const sp<IMemory>& dataPtr);
64    sp<Camera> getCamera() { Mutex::Autolock _l(mLock); return mCamera; }
65    void release();
66
67private:
68    void copyAndPost(JNIEnv* env, const sp<IMemory>& dataPtr, int msgType);
69
70    jobject     mCameraJObjectWeak;     // weak reference to java object
71    jclass      mCameraJClass;          // strong reference to java class
72    sp<Camera>  mCamera;                // strong reference to native object
73    Mutex       mLock;
74};
75
76sp<Camera> get_native_camera(JNIEnv *env, jobject thiz, JNICameraContext** pContext)
77{
78    sp<Camera> camera;
79    Mutex::Autolock _l(sLock);
80    JNICameraContext* context = reinterpret_cast<JNICameraContext*>(env->GetIntField(thiz, fields.context));
81    if (context != NULL) {
82        camera = context->getCamera();
83    }
84    LOGV("get_native_camera: context=%p, camera=%p", context, camera.get());
85    if (camera == 0) {
86        jniThrowException(env, "java/lang/RuntimeException", "Method called after release()");
87    }
88
89    if (pContext != NULL) *pContext = context;
90    return camera;
91}
92
93JNICameraContext::JNICameraContext(JNIEnv* env, jobject weak_this, jclass clazz, const sp<Camera>& camera)
94{
95    mCameraJObjectWeak = env->NewGlobalRef(weak_this);
96    mCameraJClass = (jclass)env->NewGlobalRef(clazz);
97    mCamera = camera;
98}
99
100void JNICameraContext::release()
101{
102    LOGV("release");
103    Mutex::Autolock _l(mLock);
104    JNIEnv *env = AndroidRuntime::getJNIEnv();
105
106    if (mCameraJObjectWeak != NULL) {
107        env->DeleteGlobalRef(mCameraJObjectWeak);
108        mCameraJObjectWeak = NULL;
109    }
110    if (mCameraJClass != NULL) {
111        env->DeleteGlobalRef(mCameraJClass);
112        mCameraJClass = NULL;
113    }
114    mCamera.clear();
115}
116
117void JNICameraContext::notify(int32_t msgType, int32_t ext1, int32_t ext2)
118{
119    LOGV("notify");
120
121    // VM pointer will be NULL if object is released
122    Mutex::Autolock _l(mLock);
123    if (mCameraJObjectWeak == NULL) {
124        LOGW("callback on dead camera object");
125        return;
126    }
127    JNIEnv *env = AndroidRuntime::getJNIEnv();
128    env->CallStaticVoidMethod(mCameraJClass, fields.post_event,
129            mCameraJObjectWeak, msgType, ext1, ext2);
130}
131
132void JNICameraContext::copyAndPost(JNIEnv* env, const sp<IMemory>& dataPtr, int msgType)
133{
134    jbyteArray obj = NULL;
135
136    // allocate Java byte array and copy data
137    if (dataPtr != NULL) {
138        ssize_t offset;
139        size_t size;
140        sp<IMemoryHeap> heap = dataPtr->getMemory(&offset, &size);
141        LOGV("postData: off=%d, size=%d", offset, size);
142        uint8_t *heapBase = (uint8_t*)heap->base();
143
144        if (heapBase != NULL) {
145            uint8_t *data = heapBase + offset;
146            obj = env->NewByteArray(size);
147            if (obj == NULL) {
148                LOGE("Couldn't allocate byte array for JPEG data");
149                env->ExceptionClear();
150            } else {
151                jbyte *bytes = env->GetByteArrayElements(obj, NULL);
152                memcpy(bytes, data, size);
153                env->ReleaseByteArrayElements(obj, bytes, 0);
154
155            }
156        } else {
157            LOGE("image heap is NULL");
158        }
159    }
160
161    // post image data to Java
162    env->CallStaticVoidMethod(mCameraJClass, fields.post_event,
163            mCameraJObjectWeak, msgType, 0, 0, obj);
164    if (obj) {
165        env->DeleteLocalRef(obj);
166    }
167}
168
169void JNICameraContext::postData(int32_t msgType, const sp<IMemory>& dataPtr)
170{
171    // VM pointer will be NULL if object is released
172    Mutex::Autolock _l(mLock);
173    JNIEnv *env = AndroidRuntime::getJNIEnv();
174
175    // return data based on callback type
176    switch(msgType) {
177    case CAMERA_MSG_VIDEO_FRAME:
178        // should never happen
179        break;
180    // don't return raw data to Java
181    case CAMERA_MSG_RAW_IMAGE:
182        LOGV("rawCallback");
183        env->CallStaticVoidMethod(mCameraJClass, fields.post_event,
184                mCameraJObjectWeak, msgType, 0, 0, NULL);
185        break;
186    default:
187        LOGV("dataCallback(%d, %p)", msgType, dataPtr.get());
188        copyAndPost(env, dataPtr, msgType);
189        break;
190    }
191}
192
193// connect to camera service
194static void android_hardware_Camera_native_setup(JNIEnv *env, jobject thiz, jobject weak_this)
195{
196    sp<Camera> camera = Camera::connect();
197
198    if (camera == NULL) {
199        jniThrowException(env, "java/lang/RuntimeException",
200                          "Fail to connect to camera service");
201        return;
202    }
203
204    // make sure camera hardware is alive
205    if (camera->getStatus() != NO_ERROR) {
206        jniThrowException(env, "java/lang/RuntimeException", "Camera initialization failed");
207        return;
208    }
209
210    jclass clazz = env->GetObjectClass(thiz);
211    if (clazz == NULL) {
212        jniThrowException(env, "java/lang/RuntimeException", "Can't find android/hardware/Camera");
213        return;
214    }
215
216    // We use a weak reference so the Camera object can be garbage collected.
217    // The reference is only used as a proxy for callbacks.
218    sp<JNICameraContext> context = new JNICameraContext(env, weak_this, clazz, camera);
219    context->incStrong(thiz);
220    camera->setListener(context);
221
222    // save context in opaque field
223    env->SetIntField(thiz, fields.context, (int)context.get());
224}
225
226// disconnect from camera service
227// It's okay to call this when the native camera context is already null.
228// This handles the case where the user has called release() and the
229// finalizer is invoked later.
230static void android_hardware_Camera_release(JNIEnv *env, jobject thiz)
231{
232    JNICameraContext* context = NULL;
233    sp<Camera> camera;
234    {
235        Mutex::Autolock _l(sLock);
236        context = reinterpret_cast<JNICameraContext*>(env->GetIntField(thiz, fields.context));
237
238        // Make sure we do not attempt to callback on a deleted Java object.
239        env->SetIntField(thiz, fields.context, 0);
240    }
241
242    // clean up if release has not been called before
243    if (context != NULL) {
244        camera = context->getCamera();
245        context->release();
246        LOGV("native_release: context=%p camera=%p", context, camera.get());
247
248        // clear callbacks
249        if (camera != NULL) {
250            camera->setPreviewCallbackFlags(FRAME_CALLBACK_FLAG_NOOP);
251            camera->disconnect();
252        }
253
254        // remove context to prevent further Java access
255        context->decStrong(thiz);
256    }
257}
258
259static void android_hardware_Camera_setPreviewDisplay(JNIEnv *env, jobject thiz, jobject jSurface)
260{
261    LOGV("setPreviewDisplay");
262    sp<Camera> camera = get_native_camera(env, thiz, NULL);
263    if (camera == 0) return;
264
265    sp<Surface> surface = reinterpret_cast<Surface*>(env->GetIntField(jSurface, fields.surface));
266    if (camera->setPreviewDisplay(surface) != NO_ERROR) {
267        jniThrowException(env, "java/io/IOException", "setPreviewDisplay failed");
268    }
269}
270
271static void android_hardware_Camera_startPreview(JNIEnv *env, jobject thiz)
272{
273    LOGV("startPreview");
274    sp<Camera> camera = get_native_camera(env, thiz, NULL);
275    if (camera == 0) return;
276
277    if (camera->startPreview() != NO_ERROR) {
278        jniThrowException(env, "java/lang/RuntimeException", "startPreview failed");
279        return;
280    }
281}
282
283static void android_hardware_Camera_stopPreview(JNIEnv *env, jobject thiz)
284{
285    LOGV("stopPreview");
286    sp<Camera> c = get_native_camera(env, thiz, NULL);
287    if (c == 0) return;
288
289    c->stopPreview();
290}
291
292static bool android_hardware_Camera_previewEnabled(JNIEnv *env, jobject thiz)
293{
294    LOGV("previewEnabled");
295    sp<Camera> c = get_native_camera(env, thiz, NULL);
296    if (c == 0) return false;
297
298    return c->previewEnabled();
299}
300
301static void android_hardware_Camera_setHasPreviewCallback(JNIEnv *env, jobject thiz, jboolean installed, jboolean oneshot)
302{
303    // Important: Only install preview_callback if the Java code has called
304    // setPreviewCallback() with a non-null value, otherwise we'd pay to memcpy
305    // each preview frame for nothing.
306    JNICameraContext* context;
307    sp<Camera> camera = get_native_camera(env, thiz, &context);
308    if (camera == 0) return;
309
310    int callback_flag;
311    if (installed) {
312        callback_flag = oneshot ? FRAME_CALLBACK_FLAG_BARCODE_SCANNER : FRAME_CALLBACK_FLAG_CAMERA;
313    } else {
314        callback_flag = FRAME_CALLBACK_FLAG_NOOP;
315    }
316    camera->setPreviewCallbackFlags(callback_flag);
317}
318
319static void android_hardware_Camera_autoFocus(JNIEnv *env, jobject thiz)
320{
321    LOGV("autoFocus");
322    JNICameraContext* context;
323    sp<Camera> c = get_native_camera(env, thiz, &context);
324    if (c == 0) return;
325
326    if (c->autoFocus() != NO_ERROR) {
327        jniThrowException(env, "java/lang/RuntimeException", "autoFocus failed");
328    }
329}
330
331static void android_hardware_Camera_takePicture(JNIEnv *env, jobject thiz)
332{
333    LOGV("takePicture");
334    JNICameraContext* context;
335    sp<Camera> camera = get_native_camera(env, thiz, &context);
336    if (camera == 0) return;
337
338    if (camera->takePicture() != NO_ERROR) {
339        jniThrowException(env, "java/lang/RuntimeException", "takePicture failed");
340        return;
341    }
342}
343
344static void android_hardware_Camera_setParameters(JNIEnv *env, jobject thiz, jstring params)
345{
346    LOGV("setParameters");
347    sp<Camera> camera = get_native_camera(env, thiz, NULL);
348    if (camera == 0) return;
349
350    const jchar* str = env->GetStringCritical(params, 0);
351    String8 params8;
352    if (params) {
353        params8 = String8(str, env->GetStringLength(params));
354        env->ReleaseStringCritical(params, str);
355    }
356    if (camera->setParameters(params8) != NO_ERROR) {
357        jniThrowException(env, "java/lang/RuntimeException", "setParameters failed");
358        return;
359    }
360}
361
362static jstring android_hardware_Camera_getParameters(JNIEnv *env, jobject thiz)
363{
364    LOGV("getParameters");
365    sp<Camera> camera = get_native_camera(env, thiz, NULL);
366    if (camera == 0) return 0;
367
368    return env->NewStringUTF(camera->getParameters().string());
369}
370
371static void android_hardware_Camera_reconnect(JNIEnv *env, jobject thiz)
372{
373    LOGV("reconnect");
374    sp<Camera> camera = get_native_camera(env, thiz, NULL);
375    if (camera == 0) return;
376
377    if (camera->reconnect() != NO_ERROR) {
378        jniThrowException(env, "java/io/IOException", "reconnect failed");
379        return;
380    }
381}
382
383static jint android_hardware_Camera_lock(JNIEnv *env, jobject thiz)
384{
385    LOGV("lock");
386    sp<Camera> camera = get_native_camera(env, thiz, NULL);
387    if (camera == 0) return INVALID_OPERATION;
388    return (jint) camera->lock();
389}
390
391static jint android_hardware_Camera_unlock(JNIEnv *env, jobject thiz)
392{
393    LOGV("unlock");
394    sp<Camera> camera = get_native_camera(env, thiz, NULL);
395    if (camera == 0) return INVALID_OPERATION;
396    return (jint) camera->unlock();
397}
398
399//-------------------------------------------------
400
401static JNINativeMethod camMethods[] = {
402  { "native_setup",
403    "(Ljava/lang/Object;)V",
404    (void*)android_hardware_Camera_native_setup },
405  { "native_release",
406    "()V",
407    (void*)android_hardware_Camera_release },
408  { "setPreviewDisplay",
409    "(Landroid/view/Surface;)V",
410    (void *)android_hardware_Camera_setPreviewDisplay },
411  { "startPreview",
412    "()V",
413    (void *)android_hardware_Camera_startPreview },
414  { "stopPreview",
415    "()V",
416    (void *)android_hardware_Camera_stopPreview },
417  { "previewEnabled",
418    "()Z",
419    (void *)android_hardware_Camera_previewEnabled },
420  { "setHasPreviewCallback",
421    "(ZZ)V",
422    (void *)android_hardware_Camera_setHasPreviewCallback },
423  { "native_autoFocus",
424    "()V",
425    (void *)android_hardware_Camera_autoFocus },
426  { "native_takePicture",
427    "()V",
428    (void *)android_hardware_Camera_takePicture },
429  { "native_setParameters",
430    "(Ljava/lang/String;)V",
431    (void *)android_hardware_Camera_setParameters },
432  { "native_getParameters",
433    "()Ljava/lang/String;",
434    (void *)android_hardware_Camera_getParameters },
435  { "reconnect",
436    "()V",
437    (void*)android_hardware_Camera_reconnect },
438  { "lock",
439    "()I",
440    (void*)android_hardware_Camera_lock },
441  { "unlock",
442    "()I",
443    (void*)android_hardware_Camera_unlock },
444};
445
446struct field {
447    const char *class_name;
448    const char *field_name;
449    const char *field_type;
450    jfieldID   *jfield;
451};
452
453static int find_fields(JNIEnv *env, field *fields, int count)
454{
455    for (int i = 0; i < count; i++) {
456        field *f = &fields[i];
457        jclass clazz = env->FindClass(f->class_name);
458        if (clazz == NULL) {
459            LOGE("Can't find %s", f->class_name);
460            return -1;
461        }
462
463        jfieldID field = env->GetFieldID(clazz, f->field_name, f->field_type);
464        if (field == NULL) {
465            LOGE("Can't find %s.%s", f->class_name, f->field_name);
466            return -1;
467        }
468
469        *(f->jfield) = field;
470    }
471
472    return 0;
473}
474
475// Get all the required offsets in java class and register native functions
476int register_android_hardware_Camera(JNIEnv *env)
477{
478    field fields_to_find[] = {
479        { "android/hardware/Camera", "mNativeContext",   "I", &fields.context },
480        { "android/view/Surface",    "mSurface",         "I", &fields.surface }
481    };
482
483    if (find_fields(env, fields_to_find, NELEM(fields_to_find)) < 0)
484        return -1;
485
486    jclass clazz = env->FindClass("android/hardware/Camera");
487    fields.post_event = env->GetStaticMethodID(clazz, "postEventFromNative",
488                                               "(Ljava/lang/Object;IIILjava/lang/Object;)V");
489    if (fields.post_event == NULL) {
490        LOGE("Can't find android/hardware/Camera.postEventFromNative");
491        return -1;
492    }
493
494
495    // Register native functions
496    return AndroidRuntime::registerNativeMethods(env, "android/hardware/Camera",
497                                              camMethods, NELEM(camMethods));
498}
499
500