android_media_AudioRecord.cpp revision 4c3fc59b4d0c849016b17ce8e73540bdce847702 
1/*
2 * Copyright (C) 2008 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_NDEBUG 0
18
19#define LOG_TAG "AudioRecord-JNI"
20
21#include <inttypes.h>
22#include <jni.h>
23#include <JNIHelp.h>
24#include <android_runtime/AndroidRuntime.h>
25
26#include <utils/Log.h>
27#include <media/AudioRecord.h>
28
29#include "android_media_AudioFormat.h"
30#include "android_media_AudioErrors.h"
31
32// ----------------------------------------------------------------------------
33
34using namespace android;
35
36// ----------------------------------------------------------------------------
37static const char* const kClassPathName = "android/media/AudioRecord";
38static const char* const kAudioAttributesClassPathName = "android/media/AudioAttributes";
39
40struct audio_record_fields_t {
41    // these fields provide access from C++ to the...
42    jmethodID postNativeEventInJava; //... event post callback method
43    jfieldID  nativeRecorderInJavaObj; // provides access to the C++ AudioRecord object
44    jfieldID  nativeCallbackCookie;    // provides access to the AudioRecord callback data
45};
46struct audio_attributes_fields_t {
47    jfieldID  fieldRecSource;    // AudioAttributes.mSource
48    jfieldID  fieldFlags;        // AudioAttributes.mFlags
49    jfieldID  fieldFormattedTags;// AudioAttributes.mFormattedTags
50};
51static audio_attributes_fields_t javaAudioAttrFields;
52static audio_record_fields_t     javaAudioRecordFields;
53
54struct audiorecord_callback_cookie {
55    jclass      audioRecord_class;
56    jobject     audioRecord_ref;
57    bool        busy;
58    Condition   cond;
59};
60
61static Mutex sLock;
62static SortedVector <audiorecord_callback_cookie *> sAudioRecordCallBackCookies;
63
64// ----------------------------------------------------------------------------
65
66#define AUDIORECORD_ERROR_SETUP_ZEROFRAMECOUNT      -16
67#define AUDIORECORD_ERROR_SETUP_INVALIDCHANNELMASK -17
68#define AUDIORECORD_ERROR_SETUP_INVALIDFORMAT       -18
69#define AUDIORECORD_ERROR_SETUP_INVALIDSOURCE       -19
70#define AUDIORECORD_ERROR_SETUP_NATIVEINITFAILED    -20
71
72// ----------------------------------------------------------------------------
73static void recorderCallback(int event, void* user, void *info) {
74
75    audiorecord_callback_cookie *callbackInfo = (audiorecord_callback_cookie *)user;
76    {
77        Mutex::Autolock l(sLock);
78        if (sAudioRecordCallBackCookies.indexOf(callbackInfo) < 0) {
79            return;
80        }
81        callbackInfo->busy = true;
82    }
83
84    switch (event) {
85    case AudioRecord::EVENT_MARKER: {
86        JNIEnv *env = AndroidRuntime::getJNIEnv();
87        if (user != NULL && env != NULL) {
88            env->CallStaticVoidMethod(
89                callbackInfo->audioRecord_class,
90                javaAudioRecordFields.postNativeEventInJava,
91                callbackInfo->audioRecord_ref, event, 0,0, NULL);
92            if (env->ExceptionCheck()) {
93                env->ExceptionDescribe();
94                env->ExceptionClear();
95            }
96        }
97        } break;
98
99    case AudioRecord::EVENT_NEW_POS: {
100        JNIEnv *env = AndroidRuntime::getJNIEnv();
101        if (user != NULL && env != NULL) {
102            env->CallStaticVoidMethod(
103                callbackInfo->audioRecord_class,
104                javaAudioRecordFields.postNativeEventInJava,
105                callbackInfo->audioRecord_ref, event, 0,0, NULL);
106            if (env->ExceptionCheck()) {
107                env->ExceptionDescribe();
108                env->ExceptionClear();
109            }
110        }
111        } break;
112    }
113
114    {
115        Mutex::Autolock l(sLock);
116        callbackInfo->busy = false;
117        callbackInfo->cond.broadcast();
118    }
119}
120
121// ----------------------------------------------------------------------------
122static sp<AudioRecord> getAudioRecord(JNIEnv* env, jobject thiz)
123{
124    Mutex::Autolock l(sLock);
125    AudioRecord* const ar =
126            (AudioRecord*)env->GetLongField(thiz, javaAudioRecordFields.nativeRecorderInJavaObj);
127    return sp<AudioRecord>(ar);
128}
129
130static sp<AudioRecord> setAudioRecord(JNIEnv* env, jobject thiz, const sp<AudioRecord>& ar)
131{
132    Mutex::Autolock l(sLock);
133    sp<AudioRecord> old =
134            (AudioRecord*)env->GetLongField(thiz, javaAudioRecordFields.nativeRecorderInJavaObj);
135    if (ar.get()) {
136        ar->incStrong((void*)setAudioRecord);
137    }
138    if (old != 0) {
139        old->decStrong((void*)setAudioRecord);
140    }
141    env->SetLongField(thiz, javaAudioRecordFields.nativeRecorderInJavaObj, (jlong)ar.get());
142    return old;
143}
144
145// ----------------------------------------------------------------------------
146static jint
147android_media_AudioRecord_setup(JNIEnv *env, jobject thiz, jobject weak_this,
148        jobject jaa, jint sampleRateInHertz, jint channelMask,
149                // Java channel masks map directly to the native definition
150        jint audioFormat, jint buffSizeInBytes, jintArray jSession)
151{
152    //ALOGV(">> Entering android_media_AudioRecord_setup");
153    //ALOGV("sampleRate=%d, audioFormat=%d, channel mask=%x, buffSizeInBytes=%d",
154    //     sampleRateInHertz, audioFormat, channelMask, buffSizeInBytes);
155
156    if (jaa == 0) {
157        ALOGE("Error creating AudioRecord: invalid audio attributes");
158        return (jint) AUDIO_JAVA_ERROR;
159    }
160
161    if (!audio_is_input_channel(channelMask)) {
162        ALOGE("Error creating AudioRecord: channel mask %#x is not valid.", channelMask);
163        return (jint) AUDIORECORD_ERROR_SETUP_INVALIDCHANNELMASK;
164    }
165    uint32_t channelCount = audio_channel_count_from_in_mask(channelMask);
166
167    // compare the format against the Java constants
168    audio_format_t format = audioFormatToNative(audioFormat);
169    if (format == AUDIO_FORMAT_INVALID) {
170        ALOGE("Error creating AudioRecord: unsupported audio format %d.", audioFormat);
171        return (jint) AUDIORECORD_ERROR_SETUP_INVALIDFORMAT;
172    }
173
174    size_t bytesPerSample = audio_bytes_per_sample(format);
175
176    if (buffSizeInBytes == 0) {
177         ALOGE("Error creating AudioRecord: frameCount is 0.");
178        return (jint) AUDIORECORD_ERROR_SETUP_ZEROFRAMECOUNT;
179    }
180    size_t frameSize = channelCount * bytesPerSample;
181    size_t frameCount = buffSizeInBytes / frameSize;
182
183    jclass clazz = env->GetObjectClass(thiz);
184    if (clazz == NULL) {
185        ALOGE("Can't find %s when setting up callback.", kClassPathName);
186        return (jint) AUDIORECORD_ERROR_SETUP_NATIVEINITFAILED;
187    }
188
189    if (jSession == NULL) {
190        ALOGE("Error creating AudioRecord: invalid session ID pointer");
191        return (jint) AUDIO_JAVA_ERROR;
192    }
193
194    jint* nSession = (jint *) env->GetPrimitiveArrayCritical(jSession, NULL);
195    if (nSession == NULL) {
196        ALOGE("Error creating AudioRecord: Error retrieving session id pointer");
197        return (jint) AUDIO_JAVA_ERROR;
198    }
199    int sessionId = nSession[0];
200    env->ReleasePrimitiveArrayCritical(jSession, nSession, 0);
201    nSession = NULL;
202
203    // create an uninitialized AudioRecord object
204    sp<AudioRecord> lpRecorder = new AudioRecord();
205
206    audio_attributes_t *paa = NULL;
207    // read the AudioAttributes values
208    paa = (audio_attributes_t *) calloc(1, sizeof(audio_attributes_t));
209    const jstring jtags =
210            (jstring) env->GetObjectField(jaa, javaAudioAttrFields.fieldFormattedTags);
211    const char* tags = env->GetStringUTFChars(jtags, NULL);
212    // copying array size -1, char array for tags was calloc'd, no need to NULL-terminate it
213    strncpy(paa->tags, tags, AUDIO_ATTRIBUTES_TAGS_MAX_SIZE - 1);
214    env->ReleaseStringUTFChars(jtags, tags);
215    paa->source = (audio_source_t) env->GetIntField(jaa, javaAudioAttrFields.fieldRecSource);
216    paa->flags = (audio_flags_mask_t)env->GetIntField(jaa, javaAudioAttrFields.fieldFlags);
217    ALOGV("AudioRecord_setup for source=%d tags=%s flags=%08x", paa->source, paa->tags, paa->flags);
218
219    audio_input_flags_t flags = AUDIO_INPUT_FLAG_NONE;
220    if (paa->flags & AUDIO_FLAG_HW_HOTWORD) {
221        flags = AUDIO_INPUT_FLAG_HW_HOTWORD;
222    }
223    // create the callback information:
224    // this data will be passed with every AudioRecord callback
225    audiorecord_callback_cookie *lpCallbackData = new audiorecord_callback_cookie;
226    lpCallbackData->audioRecord_class = (jclass)env->NewGlobalRef(clazz);
227    // we use a weak reference so the AudioRecord object can be garbage collected.
228    lpCallbackData->audioRecord_ref = env->NewGlobalRef(weak_this);
229    lpCallbackData->busy = false;
230
231    const status_t status = lpRecorder->set(paa->source,
232        sampleRateInHertz,
233        format,        // word length, PCM
234        channelMask,
235        frameCount,
236        recorderCallback,// callback_t
237        lpCallbackData,// void* user
238        0,             // notificationFrames,
239        true,          // threadCanCallJava
240        sessionId,
241        AudioRecord::TRANSFER_DEFAULT,
242        flags,
243        paa);
244
245    if (status != NO_ERROR) {
246        ALOGE("Error creating AudioRecord instance: initialization check failed with status %d.",
247                status);
248        goto native_init_failure;
249    }
250
251    nSession = (jint *) env->GetPrimitiveArrayCritical(jSession, NULL);
252    if (nSession == NULL) {
253        ALOGE("Error creating AudioRecord: Error retrieving session id pointer");
254        goto native_init_failure;
255    }
256    // read the audio session ID back from AudioRecord in case a new session was created during set()
257    nSession[0] = lpRecorder->getSessionId();
258    env->ReleasePrimitiveArrayCritical(jSession, nSession, 0);
259    nSession = NULL;
260
261    {   // scope for the lock
262        Mutex::Autolock l(sLock);
263        sAudioRecordCallBackCookies.add(lpCallbackData);
264    }
265    // save our newly created C++ AudioRecord in the "nativeRecorderInJavaObj" field
266    // of the Java object
267    setAudioRecord(env, thiz, lpRecorder);
268
269    // save our newly created callback information in the "nativeCallbackCookie" field
270    // of the Java object (in mNativeCallbackCookie) so we can free the memory in finalize()
271    env->SetLongField(thiz, javaAudioRecordFields.nativeCallbackCookie, (jlong)lpCallbackData);
272
273    return (jint) AUDIO_JAVA_SUCCESS;
274
275    // failure:
276native_init_failure:
277    env->DeleteGlobalRef(lpCallbackData->audioRecord_class);
278    env->DeleteGlobalRef(lpCallbackData->audioRecord_ref);
279    delete lpCallbackData;
280    env->SetLongField(thiz, javaAudioRecordFields.nativeCallbackCookie, 0);
281
282    return (jint) AUDIORECORD_ERROR_SETUP_NATIVEINITFAILED;
283}
284
285
286
287// ----------------------------------------------------------------------------
288static jint
289android_media_AudioRecord_start(JNIEnv *env, jobject thiz, jint event, jint triggerSession)
290{
291    sp<AudioRecord> lpRecorder = getAudioRecord(env, thiz);
292    if (lpRecorder == NULL ) {
293        jniThrowException(env, "java/lang/IllegalStateException", NULL);
294        return (jint) AUDIO_JAVA_ERROR;
295    }
296
297    return nativeToJavaStatus(
298            lpRecorder->start((AudioSystem::sync_event_t)event, triggerSession));
299}
300
301
302// ----------------------------------------------------------------------------
303static void
304android_media_AudioRecord_stop(JNIEnv *env, jobject thiz)
305{
306    sp<AudioRecord> lpRecorder = getAudioRecord(env, thiz);
307    if (lpRecorder == NULL ) {
308        jniThrowException(env, "java/lang/IllegalStateException", NULL);
309        return;
310    }
311
312    lpRecorder->stop();
313    //ALOGV("Called lpRecorder->stop()");
314}
315
316
317// ----------------------------------------------------------------------------
318
319#define CALLBACK_COND_WAIT_TIMEOUT_MS 1000
320static void android_media_AudioRecord_release(JNIEnv *env,  jobject thiz) {
321    sp<AudioRecord> lpRecorder = setAudioRecord(env, thiz, 0);
322    if (lpRecorder == NULL) {
323        return;
324    }
325    ALOGV("About to delete lpRecorder: %p", lpRecorder.get());
326    lpRecorder->stop();
327
328    audiorecord_callback_cookie *lpCookie = (audiorecord_callback_cookie *)env->GetLongField(
329        thiz, javaAudioRecordFields.nativeCallbackCookie);
330
331    // reset the native resources in the Java object so any attempt to access
332    // them after a call to release fails.
333    env->SetLongField(thiz, javaAudioRecordFields.nativeCallbackCookie, 0);
334
335    // delete the callback information
336    if (lpCookie) {
337        Mutex::Autolock l(sLock);
338        ALOGV("deleting lpCookie: %p", lpCookie);
339        while (lpCookie->busy) {
340            if (lpCookie->cond.waitRelative(sLock,
341                                            milliseconds(CALLBACK_COND_WAIT_TIMEOUT_MS)) !=
342                                                    NO_ERROR) {
343                break;
344            }
345        }
346        sAudioRecordCallBackCookies.remove(lpCookie);
347        env->DeleteGlobalRef(lpCookie->audioRecord_class);
348        env->DeleteGlobalRef(lpCookie->audioRecord_ref);
349        delete lpCookie;
350    }
351}
352
353
354// ----------------------------------------------------------------------------
355static void android_media_AudioRecord_finalize(JNIEnv *env,  jobject thiz) {
356    android_media_AudioRecord_release(env, thiz);
357}
358
359
360// ----------------------------------------------------------------------------
361static jint android_media_AudioRecord_readInByteArray(JNIEnv *env,  jobject thiz,
362                                                        jbyteArray javaAudioData,
363                                                        jint offsetInBytes, jint sizeInBytes) {
364    jbyte* recordBuff = NULL;
365    // get the audio recorder from which we'll read new audio samples
366    sp<AudioRecord> lpRecorder = getAudioRecord(env, thiz);
367    if (lpRecorder == NULL) {
368        ALOGE("Unable to retrieve AudioRecord object, can't record");
369        return 0;
370    }
371
372    if (!javaAudioData) {
373        ALOGE("Invalid Java array to store recorded audio, can't record");
374        return 0;
375    }
376
377    // get the pointer to where we'll record the audio
378    // NOTE: We may use GetPrimitiveArrayCritical() when the JNI implementation changes in such
379    // a way that it becomes much more efficient. When doing so, we will have to prevent the
380    // AudioSystem callback to be called while in critical section (in case of media server
381    // process crash for instance)
382    recordBuff = (jbyte *)env->GetByteArrayElements(javaAudioData, NULL);
383
384    if (recordBuff == NULL) {
385        ALOGE("Error retrieving destination for recorded audio data, can't record");
386        return 0;
387    }
388
389    // read the new audio data from the native AudioRecord object
390    ssize_t recorderBuffSize = lpRecorder->frameCount()*lpRecorder->frameSize();
391    ssize_t readSize = lpRecorder->read(recordBuff + offsetInBytes,
392                                        sizeInBytes > (jint)recorderBuffSize ?
393                                            (jint)recorderBuffSize : sizeInBytes );
394    env->ReleaseByteArrayElements(javaAudioData, recordBuff, 0);
395
396    if (readSize < 0) {
397        readSize = (jint)AUDIO_JAVA_INVALID_OPERATION;
398    }
399    return (jint) readSize;
400}
401
402// ----------------------------------------------------------------------------
403static jint android_media_AudioRecord_readInShortArray(JNIEnv *env,  jobject thiz,
404                                                        jshortArray javaAudioData,
405                                                        jint offsetInShorts, jint sizeInShorts) {
406
407    jshort* recordBuff = NULL;
408    // get the audio recorder from which we'll read new audio samples
409    sp<AudioRecord> lpRecorder = getAudioRecord(env, thiz);
410    if (lpRecorder == NULL) {
411        ALOGE("Unable to retrieve AudioRecord object, can't record");
412        return 0;
413    }
414
415    if (!javaAudioData) {
416        ALOGE("Invalid Java array to store recorded audio, can't record");
417        return 0;
418    }
419
420    // get the pointer to where we'll record the audio
421    // NOTE: We may use GetPrimitiveArrayCritical() when the JNI implementation changes in such
422    // a way that it becomes much more efficient. When doing so, we will have to prevent the
423    // AudioSystem callback to be called while in critical section (in case of media server
424    // process crash for instance)
425    recordBuff = (jshort *)env->GetShortArrayElements(javaAudioData, NULL);
426
427    if (recordBuff == NULL) {
428        ALOGE("Error retrieving destination for recorded audio data, can't record");
429        return 0;
430    }
431
432    // read the new audio data from the native AudioRecord object
433    const size_t recorderBuffSize = lpRecorder->frameCount()*lpRecorder->frameSize();
434    const size_t sizeInBytes = sizeInShorts * sizeof(short);
435    ssize_t readSize = lpRecorder->read(recordBuff + offsetInShorts,
436                                        sizeInBytes > recorderBuffSize ?
437                                            recorderBuffSize : sizeInBytes);
438
439    env->ReleaseShortArrayElements(javaAudioData, recordBuff, 0);
440
441    if (readSize < 0) {
442        readSize = (jint)AUDIO_JAVA_INVALID_OPERATION;
443    } else {
444        readSize /= sizeof(short);
445    }
446    return (jint) readSize;
447}
448
449// ----------------------------------------------------------------------------
450static jint android_media_AudioRecord_readInDirectBuffer(JNIEnv *env,  jobject thiz,
451                                                  jobject jBuffer, jint sizeInBytes) {
452    // get the audio recorder from which we'll read new audio samples
453    sp<AudioRecord> lpRecorder = getAudioRecord(env, thiz);
454    if (lpRecorder==NULL)
455        return 0;
456
457    // direct buffer and direct access supported?
458    long capacity = env->GetDirectBufferCapacity(jBuffer);
459    if (capacity == -1) {
460        // buffer direct access is not supported
461        ALOGE("Buffer direct access is not supported, can't record");
462        return 0;
463    }
464    //ALOGV("capacity = %ld", capacity);
465    jbyte* nativeFromJavaBuf = (jbyte*) env->GetDirectBufferAddress(jBuffer);
466    if (nativeFromJavaBuf==NULL) {
467        ALOGE("Buffer direct access is not supported, can't record");
468        return 0;
469    }
470
471    // read new data from the recorder
472    ssize_t readSize = lpRecorder->read(nativeFromJavaBuf,
473                                   capacity < sizeInBytes ? capacity : sizeInBytes);
474    if (readSize < 0) {
475        readSize = (jint)AUDIO_JAVA_INVALID_OPERATION;
476    }
477    return (jint)readSize;
478}
479
480
481// ----------------------------------------------------------------------------
482static jint android_media_AudioRecord_set_marker_pos(JNIEnv *env,  jobject thiz,
483        jint markerPos) {
484
485    sp<AudioRecord> lpRecorder = getAudioRecord(env, thiz);
486    if (lpRecorder == NULL) {
487        jniThrowException(env, "java/lang/IllegalStateException",
488            "Unable to retrieve AudioRecord pointer for setMarkerPosition()");
489        return (jint)AUDIO_JAVA_ERROR;
490    }
491    return nativeToJavaStatus( lpRecorder->setMarkerPosition(markerPos) );
492}
493
494
495// ----------------------------------------------------------------------------
496static jint android_media_AudioRecord_get_marker_pos(JNIEnv *env,  jobject thiz) {
497
498    sp<AudioRecord> lpRecorder = getAudioRecord(env, thiz);
499    uint32_t markerPos = 0;
500
501    if (lpRecorder == NULL) {
502        jniThrowException(env, "java/lang/IllegalStateException",
503            "Unable to retrieve AudioRecord pointer for getMarkerPosition()");
504        return (jint)AUDIO_JAVA_ERROR;
505    }
506    lpRecorder->getMarkerPosition(&markerPos);
507    return (jint)markerPos;
508}
509
510
511// ----------------------------------------------------------------------------
512static jint android_media_AudioRecord_set_pos_update_period(JNIEnv *env,  jobject thiz,
513        jint period) {
514
515    sp<AudioRecord> lpRecorder = getAudioRecord(env, thiz);
516
517    if (lpRecorder == NULL) {
518        jniThrowException(env, "java/lang/IllegalStateException",
519            "Unable to retrieve AudioRecord pointer for setPositionUpdatePeriod()");
520        return (jint)AUDIO_JAVA_ERROR;
521    }
522    return nativeToJavaStatus( lpRecorder->setPositionUpdatePeriod(period) );
523}
524
525
526// ----------------------------------------------------------------------------
527static jint android_media_AudioRecord_get_pos_update_period(JNIEnv *env,  jobject thiz) {
528
529    sp<AudioRecord> lpRecorder = getAudioRecord(env, thiz);
530    uint32_t period = 0;
531
532    if (lpRecorder == NULL) {
533        jniThrowException(env, "java/lang/IllegalStateException",
534            "Unable to retrieve AudioRecord pointer for getPositionUpdatePeriod()");
535        return (jint)AUDIO_JAVA_ERROR;
536    }
537    lpRecorder->getPositionUpdatePeriod(&period);
538    return (jint)period;
539}
540
541
542// ----------------------------------------------------------------------------
543// returns the minimum required size for the successful creation of an AudioRecord instance.
544// returns 0 if the parameter combination is not supported.
545// return -1 if there was an error querying the buffer size.
546static jint android_media_AudioRecord_get_min_buff_size(JNIEnv *env,  jobject thiz,
547    jint sampleRateInHertz, jint channelCount, jint audioFormat) {
548
549    ALOGV(">> android_media_AudioRecord_get_min_buff_size(%d, %d, %d)",
550          sampleRateInHertz, channelCount, audioFormat);
551
552    size_t frameCount = 0;
553    audio_format_t format = audioFormatToNative(audioFormat);
554    status_t result = AudioRecord::getMinFrameCount(&frameCount,
555            sampleRateInHertz,
556            format,
557            audio_channel_in_mask_from_count(channelCount));
558
559    if (result == BAD_VALUE) {
560        return 0;
561    }
562    if (result != NO_ERROR) {
563        return -1;
564    }
565    return frameCount * channelCount * audio_bytes_per_sample(format);
566}
567
568
569// ----------------------------------------------------------------------------
570// ----------------------------------------------------------------------------
571static JNINativeMethod gMethods[] = {
572    // name,               signature,  funcPtr
573    {"native_start",         "(II)I",    (void *)android_media_AudioRecord_start},
574    {"native_stop",          "()V",    (void *)android_media_AudioRecord_stop},
575    {"native_setup",         "(Ljava/lang/Object;Ljava/lang/Object;IIII[I)I",
576                                       (void *)android_media_AudioRecord_setup},
577    {"native_finalize",      "()V",    (void *)android_media_AudioRecord_finalize},
578    {"native_release",       "()V",    (void *)android_media_AudioRecord_release},
579    {"native_read_in_byte_array",
580                             "([BII)I", (void *)android_media_AudioRecord_readInByteArray},
581    {"native_read_in_short_array",
582                             "([SII)I", (void *)android_media_AudioRecord_readInShortArray},
583    {"native_read_in_direct_buffer","(Ljava/lang/Object;I)I",
584                                       (void *)android_media_AudioRecord_readInDirectBuffer},
585    {"native_set_marker_pos","(I)I",   (void *)android_media_AudioRecord_set_marker_pos},
586    {"native_get_marker_pos","()I",    (void *)android_media_AudioRecord_get_marker_pos},
587    {"native_set_pos_update_period",
588                             "(I)I",   (void *)android_media_AudioRecord_set_pos_update_period},
589    {"native_get_pos_update_period",
590                             "()I",    (void *)android_media_AudioRecord_get_pos_update_period},
591    {"native_get_min_buff_size",
592                             "(III)I",   (void *)android_media_AudioRecord_get_min_buff_size},
593};
594
595// field names found in android/media/AudioRecord.java
596#define JAVA_POSTEVENT_CALLBACK_NAME  "postEventFromNative"
597#define JAVA_NATIVERECORDERINJAVAOBJ_FIELD_NAME  "mNativeRecorderInJavaObj"
598#define JAVA_NATIVECALLBACKINFO_FIELD_NAME       "mNativeCallbackCookie"
599
600// ----------------------------------------------------------------------------
601int register_android_media_AudioRecord(JNIEnv *env)
602{
603    javaAudioRecordFields.postNativeEventInJava = NULL;
604    javaAudioRecordFields.nativeRecorderInJavaObj = NULL;
605    javaAudioRecordFields.nativeCallbackCookie = NULL;
606
607
608    // Get the AudioRecord class
609    jclass audioRecordClass = env->FindClass(kClassPathName);
610    if (audioRecordClass == NULL) {
611        ALOGE("Can't find %s", kClassPathName);
612        return -1;
613    }
614    // Get the postEvent method
615    javaAudioRecordFields.postNativeEventInJava = env->GetStaticMethodID(
616            audioRecordClass,
617            JAVA_POSTEVENT_CALLBACK_NAME, "(Ljava/lang/Object;IIILjava/lang/Object;)V");
618    if (javaAudioRecordFields.postNativeEventInJava == NULL) {
619        ALOGE("Can't find AudioRecord.%s", JAVA_POSTEVENT_CALLBACK_NAME);
620        return -1;
621    }
622
623    // Get the variables
624    //    mNativeRecorderInJavaObj
625    javaAudioRecordFields.nativeRecorderInJavaObj =
626        env->GetFieldID(audioRecordClass,
627                        JAVA_NATIVERECORDERINJAVAOBJ_FIELD_NAME, "J");
628    if (javaAudioRecordFields.nativeRecorderInJavaObj == NULL) {
629        ALOGE("Can't find AudioRecord.%s", JAVA_NATIVERECORDERINJAVAOBJ_FIELD_NAME);
630        return -1;
631    }
632    //     mNativeCallbackCookie
633    javaAudioRecordFields.nativeCallbackCookie = env->GetFieldID(
634            audioRecordClass,
635            JAVA_NATIVECALLBACKINFO_FIELD_NAME, "J");
636    if (javaAudioRecordFields.nativeCallbackCookie == NULL) {
637        ALOGE("Can't find AudioRecord.%s", JAVA_NATIVECALLBACKINFO_FIELD_NAME);
638        return -1;
639    }
640
641    // Get the AudioAttributes class and fields
642    jclass audioAttrClass = env->FindClass(kAudioAttributesClassPathName);
643    if (audioAttrClass == NULL) {
644        ALOGE("Can't find %s", kAudioAttributesClassPathName);
645        return -1;
646    }
647    jclass audioAttributesClassRef = (jclass)env->NewGlobalRef(audioAttrClass);
648    javaAudioAttrFields.fieldRecSource = env->GetFieldID(audioAttributesClassRef, "mSource", "I");
649    javaAudioAttrFields.fieldFlags = env->GetFieldID(audioAttributesClassRef, "mFlags", "I");
650    javaAudioAttrFields.fieldFormattedTags =
651            env->GetFieldID(audioAttributesClassRef, "mFormattedTags", "Ljava/lang/String;");
652    env->DeleteGlobalRef(audioAttributesClassRef);
653    if (javaAudioAttrFields.fieldRecSource == NULL
654            || javaAudioAttrFields.fieldFlags == NULL
655            || javaAudioAttrFields.fieldFormattedTags == NULL) {
656        ALOGE("Can't initialize AudioAttributes fields");
657        return -1;
658    }
659
660    return AndroidRuntime::registerNativeMethods(env,
661            kClassPathName, gMethods, NELEM(gMethods));
662}
663
664// ----------------------------------------------------------------------------
665