android_hardware_Camera.cpp revision e3ea663686d42477e8b7585e2e3681a6ffd8d81a 
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 <binder/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
41struct fields_t {
42    jfieldID    context;
43    jfieldID    surface;
44    jmethodID   post_event;
45};
46
47static fields_t fields;
48static Mutex sLock;
49
50// provides persistent context for calls from native code to Java
51class JNICameraContext: public CameraListener
52{
53public:
54    JNICameraContext(JNIEnv* env, jobject weak_this, jclass clazz, const sp<Camera>& camera);
55    ~JNICameraContext() { release(); }
56    virtual void notify(int32_t msgType, int32_t ext1, int32_t ext2);
57    virtual void postData(int32_t msgType, const sp<IMemory>& dataPtr);
58    virtual void postDataTimestamp(nsecs_t timestamp, int32_t msgType, const sp<IMemory>& dataPtr);
59    sp<Camera> getCamera() { Mutex::Autolock _l(mLock); return mCamera; }
60    void release();
61
62private:
63    void copyAndPost(JNIEnv* env, const sp<IMemory>& dataPtr, int msgType);
64
65    jobject     mCameraJObjectWeak;     // weak reference to java object
66    jclass      mCameraJClass;          // strong reference to java class
67    sp<Camera>  mCamera;                // strong reference to native object
68    Mutex       mLock;
69};
70
71sp<Camera> get_native_camera(JNIEnv *env, jobject thiz, JNICameraContext** pContext)
72{
73    sp<Camera> camera;
74    Mutex::Autolock _l(sLock);
75    JNICameraContext* context = reinterpret_cast<JNICameraContext*>(env->GetIntField(thiz, fields.context));
76    if (context != NULL) {
77        camera = context->getCamera();
78    }
79    LOGV("get_native_camera: context=%p, camera=%p", context, camera.get());
80    if (camera == 0) {
81        jniThrowException(env, "java/lang/RuntimeException", "Method called after release()");
82    }
83
84    if (pContext != NULL) *pContext = context;
85    return camera;
86}
87
88JNICameraContext::JNICameraContext(JNIEnv* env, jobject weak_this, jclass clazz, const sp<Camera>& camera)
89{
90    mCameraJObjectWeak = env->NewGlobalRef(weak_this);
91    mCameraJClass = (jclass)env->NewGlobalRef(clazz);
92    mCamera = camera;
93}
94
95void JNICameraContext::release()
96{
97    LOGV("release");
98    Mutex::Autolock _l(mLock);
99    JNIEnv *env = AndroidRuntime::getJNIEnv();
100
101    if (mCameraJObjectWeak != NULL) {
102        env->DeleteGlobalRef(mCameraJObjectWeak);
103        mCameraJObjectWeak = NULL;
104    }
105    if (mCameraJClass != NULL) {
106        env->DeleteGlobalRef(mCameraJClass);
107        mCameraJClass = NULL;
108    }
109    mCamera.clear();
110}
111
112void JNICameraContext::notify(int32_t msgType, int32_t ext1, int32_t ext2)
113{
114    LOGV("notify");
115
116    // VM pointer will be NULL if object is released
117    Mutex::Autolock _l(mLock);
118    if (mCameraJObjectWeak == NULL) {
119        LOGW("callback on dead camera object");
120        return;
121    }
122    JNIEnv *env = AndroidRuntime::getJNIEnv();
123    env->CallStaticVoidMethod(mCameraJClass, fields.post_event,
124            mCameraJObjectWeak, msgType, ext1, ext2);
125}
126
127void JNICameraContext::copyAndPost(JNIEnv* env, const sp<IMemory>& dataPtr, int msgType)
128{
129    jbyteArray obj = NULL;
130
131    // allocate Java byte array and copy data
132    if (dataPtr != NULL) {
133        ssize_t offset;
134        size_t size;
135        sp<IMemoryHeap> heap = dataPtr->getMemory(&offset, &size);
136        LOGV("postData: off=%d, size=%d", offset, size);
137        uint8_t *heapBase = (uint8_t*)heap->base();
138
139        if (heapBase != NULL) {
140            uint8_t *data = heapBase + offset;
141            obj = env->NewByteArray(size);
142            if (obj == NULL) {
143                LOGE("Couldn't allocate byte array for JPEG data");
144                env->ExceptionClear();
145            } else {
146                env->SetByteArrayRegion(obj, 0, size, data);
147            }
148        } else {
149            LOGE("image heap is NULL");
150        }
151    }
152
153    // post image data to Java
154    env->CallStaticVoidMethod(mCameraJClass, fields.post_event,
155            mCameraJObjectWeak, msgType, 0, 0, obj);
156    if (obj) {
157        env->DeleteLocalRef(obj);
158    }
159}
160
161void JNICameraContext::postData(int32_t msgType, const sp<IMemory>& dataPtr)
162{
163    // VM pointer will be NULL if object is released
164    Mutex::Autolock _l(mLock);
165    JNIEnv *env = AndroidRuntime::getJNIEnv();
166    if (mCameraJObjectWeak == NULL) {
167        LOGW("callback on dead camera object");
168        return;
169    }
170
171    // return data based on callback type
172    switch(msgType) {
173    case CAMERA_MSG_VIDEO_FRAME:
174        // should never happen
175        break;
176    // don't return raw data to Java
177    case CAMERA_MSG_RAW_IMAGE:
178        LOGV("rawCallback");
179        env->CallStaticVoidMethod(mCameraJClass, fields.post_event,
180                mCameraJObjectWeak, msgType, 0, 0, NULL);
181        break;
182    default:
183        LOGV("dataCallback(%d, %p)", msgType, dataPtr.get());
184        copyAndPost(env, dataPtr, msgType);
185        break;
186    }
187}
188
189void JNICameraContext::postDataTimestamp(nsecs_t timestamp, int32_t msgType, const sp<IMemory>& dataPtr)
190{
191    // TODO: plumb up to Java. For now, just drop the timestamp
192    postData(msgType, dataPtr);
193}
194
195// connect to camera service
196static void android_hardware_Camera_native_setup(JNIEnv *env, jobject thiz, jobject weak_this)
197{
198    sp<Camera> camera = Camera::connect();
199
200    if (camera == NULL) {
201        jniThrowException(env, "java/lang/RuntimeException",
202                          "Fail to connect to camera service");
203        return;
204    }
205
206    // make sure camera hardware is alive
207    if (camera->getStatus() != NO_ERROR) {
208        jniThrowException(env, "java/lang/RuntimeException", "Camera initialization failed");
209        return;
210    }
211
212    jclass clazz = env->GetObjectClass(thiz);
213    if (clazz == NULL) {
214        jniThrowException(env, "java/lang/RuntimeException", "Can't find android/hardware/Camera");
215        return;
216    }
217
218    // We use a weak reference so the Camera object can be garbage collected.
219    // The reference is only used as a proxy for callbacks.
220    sp<JNICameraContext> context = new JNICameraContext(env, weak_this, clazz, camera);
221    context->incStrong(thiz);
222    camera->setListener(context);
223
224    // save context in opaque field
225    env->SetIntField(thiz, fields.context, (int)context.get());
226}
227
228// disconnect from camera service
229// It's okay to call this when the native camera context is already null.
230// This handles the case where the user has called release() and the
231// finalizer is invoked later.
232static void android_hardware_Camera_release(JNIEnv *env, jobject thiz)
233{
234    JNICameraContext* context = NULL;
235    sp<Camera> camera;
236    {
237        Mutex::Autolock _l(sLock);
238        context = reinterpret_cast<JNICameraContext*>(env->GetIntField(thiz, fields.context));
239
240        // Make sure we do not attempt to callback on a deleted Java object.
241        env->SetIntField(thiz, fields.context, 0);
242    }
243
244    // clean up if release has not been called before
245    if (context != NULL) {
246        camera = context->getCamera();
247        context->release();
248        LOGV("native_release: context=%p camera=%p", context, camera.get());
249
250        // clear callbacks
251        if (camera != NULL) {
252            camera->setPreviewCallbackFlags(FRAME_CALLBACK_FLAG_NOOP);
253            camera->disconnect();
254        }
255
256        // remove context to prevent further Java access
257        context->decStrong(thiz);
258    }
259}
260
261static void android_hardware_Camera_setPreviewDisplay(JNIEnv *env, jobject thiz, jobject jSurface)
262{
263    LOGV("setPreviewDisplay");
264    sp<Camera> camera = get_native_camera(env, thiz, NULL);
265    if (camera == 0) return;
266
267    sp<Surface> surface = NULL;
268    if (jSurface != NULL) {
269        surface = reinterpret_cast<Surface*>(env->GetIntField(jSurface, fields.surface));
270    }
271    if (camera->setPreviewDisplay(surface) != NO_ERROR) {
272        jniThrowException(env, "java/io/IOException", "setPreviewDisplay failed");
273    }
274}
275
276static void android_hardware_Camera_startPreview(JNIEnv *env, jobject thiz)
277{
278    LOGV("startPreview");
279    sp<Camera> camera = get_native_camera(env, thiz, NULL);
280    if (camera == 0) return;
281
282    if (camera->startPreview() != NO_ERROR) {
283        jniThrowException(env, "java/lang/RuntimeException", "startPreview failed");
284        return;
285    }
286}
287
288static void android_hardware_Camera_stopPreview(JNIEnv *env, jobject thiz)
289{
290    LOGV("stopPreview");
291    sp<Camera> c = get_native_camera(env, thiz, NULL);
292    if (c == 0) return;
293
294    c->stopPreview();
295}
296
297static bool android_hardware_Camera_previewEnabled(JNIEnv *env, jobject thiz)
298{
299    LOGV("previewEnabled");
300    sp<Camera> c = get_native_camera(env, thiz, NULL);
301    if (c == 0) return false;
302
303    return c->previewEnabled();
304}
305
306static void android_hardware_Camera_setHasPreviewCallback(JNIEnv *env, jobject thiz, jboolean installed, jboolean oneshot)
307{
308    // Important: Only install preview_callback if the Java code has called
309    // setPreviewCallback() with a non-null value, otherwise we'd pay to memcpy
310    // each preview frame for nothing.
311    JNICameraContext* context;
312    sp<Camera> camera = get_native_camera(env, thiz, &context);
313    if (camera == 0) return;
314
315    int callback_flag;
316    if (installed) {
317        callback_flag = oneshot ? FRAME_CALLBACK_FLAG_BARCODE_SCANNER : FRAME_CALLBACK_FLAG_CAMERA;
318    } else {
319        callback_flag = FRAME_CALLBACK_FLAG_NOOP;
320    }
321    camera->setPreviewCallbackFlags(callback_flag);
322}
323
324static void android_hardware_Camera_autoFocus(JNIEnv *env, jobject thiz)
325{
326    LOGV("autoFocus");
327    JNICameraContext* context;
328    sp<Camera> c = get_native_camera(env, thiz, &context);
329    if (c == 0) return;
330
331    if (c->autoFocus() != NO_ERROR) {
332        jniThrowException(env, "java/lang/RuntimeException", "autoFocus failed");
333    }
334}
335
336static void android_hardware_Camera_takePicture(JNIEnv *env, jobject thiz)
337{
338    LOGV("takePicture");
339    JNICameraContext* context;
340    sp<Camera> camera = get_native_camera(env, thiz, &context);
341    if (camera == 0) return;
342
343    if (camera->takePicture() != NO_ERROR) {
344        jniThrowException(env, "java/lang/RuntimeException", "takePicture failed");
345        return;
346    }
347}
348
349static void android_hardware_Camera_setParameters(JNIEnv *env, jobject thiz, jstring params)
350{
351    LOGV("setParameters");
352    sp<Camera> camera = get_native_camera(env, thiz, NULL);
353    if (camera == 0) return;
354
355    const jchar* str = env->GetStringCritical(params, 0);
356    String8 params8;
357    if (params) {
358        params8 = String8(str, env->GetStringLength(params));
359        env->ReleaseStringCritical(params, str);
360    }
361    if (camera->setParameters(params8) != NO_ERROR) {
362        jniThrowException(env, "java/lang/RuntimeException", "setParameters failed");
363        return;
364    }
365}
366
367static jstring android_hardware_Camera_getParameters(JNIEnv *env, jobject thiz)
368{
369    LOGV("getParameters");
370    sp<Camera> camera = get_native_camera(env, thiz, NULL);
371    if (camera == 0) return 0;
372
373    return env->NewStringUTF(camera->getParameters().string());
374}
375
376static void android_hardware_Camera_reconnect(JNIEnv *env, jobject thiz)
377{
378    LOGV("reconnect");
379    sp<Camera> camera = get_native_camera(env, thiz, NULL);
380    if (camera == 0) return;
381
382    if (camera->reconnect() != NO_ERROR) {
383        jniThrowException(env, "java/io/IOException", "reconnect failed");
384        return;
385    }
386}
387
388static jint android_hardware_Camera_lock(JNIEnv *env, jobject thiz)
389{
390    LOGV("lock");
391    sp<Camera> camera = get_native_camera(env, thiz, NULL);
392    if (camera == 0) return INVALID_OPERATION;
393    return (jint) camera->lock();
394}
395
396static jint android_hardware_Camera_unlock(JNIEnv *env, jobject thiz)
397{
398    LOGV("unlock");
399    sp<Camera> camera = get_native_camera(env, thiz, NULL);
400    if (camera == 0) return INVALID_OPERATION;
401    return (jint) camera->unlock();
402}
403
404//-------------------------------------------------
405
406static JNINativeMethod camMethods[] = {
407  { "native_setup",
408    "(Ljava/lang/Object;)V",
409    (void*)android_hardware_Camera_native_setup },
410  { "native_release",
411    "()V",
412    (void*)android_hardware_Camera_release },
413  { "setPreviewDisplay",
414    "(Landroid/view/Surface;)V",
415    (void *)android_hardware_Camera_setPreviewDisplay },
416  { "startPreview",
417    "()V",
418    (void *)android_hardware_Camera_startPreview },
419  { "stopPreview",
420    "()V",
421    (void *)android_hardware_Camera_stopPreview },
422  { "previewEnabled",
423    "()Z",
424    (void *)android_hardware_Camera_previewEnabled },
425  { "setHasPreviewCallback",
426    "(ZZ)V",
427    (void *)android_hardware_Camera_setHasPreviewCallback },
428  { "native_autoFocus",
429    "()V",
430    (void *)android_hardware_Camera_autoFocus },
431  { "native_takePicture",
432    "()V",
433    (void *)android_hardware_Camera_takePicture },
434  { "native_setParameters",
435    "(Ljava/lang/String;)V",
436    (void *)android_hardware_Camera_setParameters },
437  { "native_getParameters",
438    "()Ljava/lang/String;",
439    (void *)android_hardware_Camera_getParameters },
440  { "reconnect",
441    "()V",
442    (void*)android_hardware_Camera_reconnect },
443  { "lock",
444    "()I",
445    (void*)android_hardware_Camera_lock },
446  { "unlock",
447    "()I",
448    (void*)android_hardware_Camera_unlock },
449};
450
451struct field {
452    const char *class_name;
453    const char *field_name;
454    const char *field_type;
455    jfieldID   *jfield;
456};
457
458static int find_fields(JNIEnv *env, field *fields, int count)
459{
460    for (int i = 0; i < count; i++) {
461        field *f = &fields[i];
462        jclass clazz = env->FindClass(f->class_name);
463        if (clazz == NULL) {
464            LOGE("Can't find %s", f->class_name);
465            return -1;
466        }
467
468        jfieldID field = env->GetFieldID(clazz, f->field_name, f->field_type);
469        if (field == NULL) {
470            LOGE("Can't find %s.%s", f->class_name, f->field_name);
471            return -1;
472        }
473
474        *(f->jfield) = field;
475    }
476
477    return 0;
478}
479
480// Get all the required offsets in java class and register native functions
481int register_android_hardware_Camera(JNIEnv *env)
482{
483    field fields_to_find[] = {
484        { "android/hardware/Camera", "mNativeContext",   "I", &fields.context },
485        { "android/view/Surface",    "mSurface",         "I", &fields.surface }
486    };
487
488    if (find_fields(env, fields_to_find, NELEM(fields_to_find)) < 0)
489        return -1;
490
491    jclass clazz = env->FindClass("android/hardware/Camera");
492    fields.post_event = env->GetStaticMethodID(clazz, "postEventFromNative",
493                                               "(Ljava/lang/Object;IIILjava/lang/Object;)V");
494    if (fields.post_event == NULL) {
495        LOGE("Can't find android/hardware/Camera.postEventFromNative");
496        return -1;
497    }
498
499
500    // Register native functions
501    return AndroidRuntime::registerNativeMethods(env, "android/hardware/Camera",
502                                              camMethods, NELEM(camMethods));
503}
504
505