media/jni/android_media_MediaPlayer.cpp

/* //device/libs/android_runtime/android_media_MediaPlayer.cpp
**
** Copyright 2007, The Android Open Source Project
**
** Licensed under the Apache License, Version 2.0 (the "License");
** you may not use this file except in compliance with the License.
** You may obtain a copy of the License at
**
**     http://www.apache.org/licenses/LICENSE-2.0
**
** Unless required by applicable law or agreed to in writing, software
** distributed under the License is distributed on an "AS IS" BASIS,
** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
** See the License for the specific language governing permissions and
** limitations under the License.
*/

//#define LOG_NDEBUG 0
#define LOG_TAG "MediaPlayer-JNI"
#include "utils/Log.h"

#include <media/mediaplayer.h>
#include <stdio.h>
#include <assert.h>
#include <limits.h>
#include <unistd.h>
#include <fcntl.h>
#include <utils/threads.h>
#include "jni.h"
#include "JNIHelp.h"
#include "android_runtime/AndroidRuntime.h"


// ----------------------------------------------------------------------------

using namespace android;

// ----------------------------------------------------------------------------

struct fields_t {
    jfieldID    context;
    jfieldID    surface;
    /* actually in android.view.Surface XXX */
    jfieldID    surface_native;

    jmethodID   post_event;
};
static fields_t fields;

static Mutex sLock;

// ----------------------------------------------------------------------------
// ref-counted object for callbacks
class JNIMediaPlayerListener: public MediaPlayerListener
{
public:
    JNIMediaPlayerListener(JNIEnv* env, jobject thiz, jobject weak_thiz);
    ~JNIMediaPlayerListener();
    void notify(int msg, int ext1, int ext2);
private:
    JNIMediaPlayerListener();
    jclass      mClass;     // Reference to MediaPlayer class
    jobject     mObject;    // Weak ref to MediaPlayer Java object to call on
};

JNIMediaPlayerListener::JNIMediaPlayerListener(JNIEnv* env, jobject thiz, jobject weak_thiz)
{

    // Hold onto the MediaPlayer class for use in calling the static method
    // that posts events to the application thread.
    jclass clazz = env->GetObjectClass(thiz);
    if (clazz == NULL) {
        LOGE("Can't find android/media/MediaPlayer");
        jniThrowException(env, "java/lang/Exception", NULL);
        return;
    }
    mClass = (jclass)env->NewGlobalRef(clazz);

    // We use a weak reference so the MediaPlayer object can be garbage collected.
    // The reference is only used as a proxy for callbacks.
    mObject  = env->NewGlobalRef(weak_thiz);
}

JNIMediaPlayerListener::~JNIMediaPlayerListener()
{
    // remove global references
    JNIEnv *env = AndroidRuntime::getJNIEnv();
    env->DeleteGlobalRef(mObject);
    env->DeleteGlobalRef(mClass);
}

void JNIMediaPlayerListener::notify(int msg, int ext1, int ext2)
{
    JNIEnv *env = AndroidRuntime::getJNIEnv();
    env->CallStaticVoidMethod(mClass, fields.post_event, mObject, msg, ext1, ext2, 0);
}

// ----------------------------------------------------------------------------

static sp<Surface> get_surface(JNIEnv* env, jobject clazz)
{
    Surface* const p = (Surface*)env->GetIntField(clazz, fields.surface_native);
    return sp<Surface>(p);
}

static sp<MediaPlayer> getMediaPlayer(JNIEnv* env, jobject thiz)
{
    Mutex::Autolock l(sLock);
    MediaPlayer* const p = (MediaPlayer*)env->GetIntField(thiz, fields.context);
    return sp<MediaPlayer>(p);
}

static sp<MediaPlayer> setMediaPlayer(JNIEnv* env, jobject thiz, const sp<MediaPlayer>& player)
{
    Mutex::Autolock l(sLock);
    sp<MediaPlayer> old = (MediaPlayer*)env->GetIntField(thiz, fields.context);
    if (player.get()) {
        player->incStrong(thiz);
    }
    if (old != 0) {
        old->decStrong(thiz);
    }
    env->SetIntField(thiz, fields.context, (int)player.get());
    return old;
}

// If exception is NULL and opStatus is not OK, this method sends an error
// event to the client application; otherwise, if exception is not NULL and
// opStatus is not OK, this method throws the given exception to the client
// application.
static void process_media_player_call(JNIEnv *env, jobject thiz, status_t opStatus, const char* exception, const char *message)
{
    if (exception == NULL) {  // Don't throw exception. Instead, send an event.
        if (opStatus != (status_t) OK) {
            sp<MediaPlayer> mp = getMediaPlayer(env, thiz);
            if (mp != 0) mp->notify(MEDIA_ERROR, opStatus, 0);
        }
    } else {  // Throw exception!
        if ( opStatus == (status_t) INVALID_OPERATION ) {
            jniThrowException(env, "java/lang/IllegalStateException", NULL);
        } else if ( opStatus != (status_t) OK ) {
            if (strlen(message) > 230) {
               // if the message is too long, don't bother displaying the status code
               jniThrowException( env, exception, message);
            } else {
               char msg[256];
                // append the status code to the message
               sprintf(msg, "%s: status=0x%X", message, opStatus);
               jniThrowException( env, exception, msg);
            }
        }
    }
}

static void
android_media_MediaPlayer_setDataSource(JNIEnv *env, jobject thiz, jstring path)
{
    sp<MediaPlayer> mp = getMediaPlayer(env, thiz);
    if (mp == NULL ) {
        jniThrowException(env, "java/lang/IllegalStateException", NULL);
        return;
    }

    if (path == NULL) {
        jniThrowException(env, "java/lang/IllegalArgumentException", NULL);
        return;
    }

    const char *pathStr = env->GetStringUTFChars(path, NULL);
    if (pathStr == NULL) {  // Out of memory
        jniThrowException(env, "java/lang/RuntimeException", "Out of memory");
        return;
    }
    status_t opStatus = mp->setDataSource(pathStr);

    // Make sure that local ref is released before a potential exception
    env->ReleaseStringUTFChars(path, pathStr);
    process_media_player_call( env, thiz, opStatus, "java/io/IOException", "setDataSource failed." );
}

static void
android_media_MediaPlayer_setDataSourceFD(JNIEnv *env, jobject thiz, jobject fileDescriptor, jlong offset, jlong length)
{
    sp<MediaPlayer> mp = getMediaPlayer(env, thiz);
    if (mp == NULL ) {
        jniThrowException(env, "java/lang/IllegalStateException", NULL);
        return;
    }

    if (fileDescriptor == NULL) {
        jniThrowException(env, "java/lang/IllegalArgumentException", NULL);
        return;
    }
    int fd = getParcelFileDescriptorFD(env, fileDescriptor);
    process_media_player_call( env, thiz, mp->setDataSource(fd, offset, length), "java/io/IOException", "setDataSourceFD failed." );
}


static void
android_media_MediaPlayer_prepare(JNIEnv *env, jobject thiz)
{
    sp<MediaPlayer> mp = getMediaPlayer(env, thiz);
    if (mp == NULL ) {
        jniThrowException(env, "java/lang/IllegalStateException", NULL);
        return;
    }
    jobject surface = env->GetObjectField(thiz, fields.surface);
    if (surface != NULL) {
        const sp<Surface>& native_surface = get_surface(env, surface);
        //LOGI("prepare: surface=%p (id=%d)",
        //        native_surface.get(), native_surface->ID());
        mp->setVideoSurface(native_surface);
    }
    process_media_player_call( env, thiz, mp->prepare(), "java/io/IOException", "Prepare failed." );
}

static void
android_media_MediaPlayer_prepareAsync(JNIEnv *env, jobject thiz)
{
    sp<MediaPlayer> mp = getMediaPlayer(env, thiz);
    if (mp == NULL ) {
        jniThrowException(env, "java/lang/IllegalStateException", NULL);
        return;
    }
    jobject surface = env->GetObjectField(thiz, fields.surface);
    if (surface != NULL) {
        const sp<Surface>& native_surface = get_surface(env, surface);
        LOGI("prepareAsync: surface=%p (id=%d)",
                native_surface.get(), native_surface->ID());
        mp->setVideoSurface(native_surface);
    }
    process_media_player_call( env, thiz, mp->prepareAsync(), "java/io/IOException", "Prepare Async failed." );
}

static void
android_media_MediaPlayer_start(JNIEnv *env, jobject thiz)
{
    sp<MediaPlayer> mp = getMediaPlayer(env, thiz);
    if (mp == NULL ) {
        jniThrowException(env, "java/lang/IllegalStateException", NULL);
        return;
    }
    process_media_player_call( env, thiz, mp->start(), NULL, NULL );
}

static void
android_media_MediaPlayer_stop(JNIEnv *env, jobject thiz)
{
    sp<MediaPlayer> mp = getMediaPlayer(env, thiz);
    if (mp == NULL ) {
        jniThrowException(env, "java/lang/IllegalStateException", NULL);
        return;
    }
    process_media_player_call( env, thiz, mp->stop(), NULL, NULL );
}

static void
android_media_MediaPlayer_pause(JNIEnv *env, jobject thiz)
{
    sp<MediaPlayer> mp = getMediaPlayer(env, thiz);
    if (mp == NULL ) {
        jniThrowException(env, "java/lang/IllegalStateException", NULL);
        return;
    }
    process_media_player_call( env, thiz, mp->pause(), NULL, NULL );
}

static jboolean
android_media_MediaPlayer_isPlaying(JNIEnv *env, jobject thiz)
{
    sp<MediaPlayer> mp = getMediaPlayer(env, thiz);
    if (mp == NULL ) {
        jniThrowException(env, "java/lang/IllegalStateException", NULL);
        return false;
    }
    return mp->isPlaying();
}

static void
android_media_MediaPlayer_seekTo(JNIEnv *env, jobject thiz, int msec)
{
    sp<MediaPlayer> mp = getMediaPlayer(env, thiz);
    if (mp == NULL ) {
        jniThrowException(env, "java/lang/IllegalStateException", NULL);
        return;
    }
    process_media_player_call( env, thiz, mp->seekTo(msec), NULL, NULL );
}

static int
android_media_MediaPlayer_getVideoWidth(JNIEnv *env, jobject thiz)
{
    sp<MediaPlayer> mp = getMediaPlayer(env, thiz);
    if (mp == NULL ) {
        jniThrowException(env, "java/lang/IllegalStateException", NULL);
        return 0;
    }
    int w;
    if (0 == mp->getVideoWidth(&w))
        return w;
    return 0;
}

static int
android_media_MediaPlayer_getVideoHeight(JNIEnv *env, jobject thiz)
{
    sp<MediaPlayer> mp = getMediaPlayer(env, thiz);
    if (mp == NULL ) {
        jniThrowException(env, "java/lang/IllegalStateException", NULL);
        return 0;
    }
    int h;
    if (0 == mp->getVideoHeight(&h))
        return h;
    return 0;
}


static int
android_media_MediaPlayer_getCurrentPosition(JNIEnv *env, jobject thiz)
{
    sp<MediaPlayer> mp = getMediaPlayer(env, thiz);
    if (mp == NULL ) {
        jniThrowException(env, "java/lang/IllegalStateException", NULL);
        return 0;
    }
    int msec;
    process_media_player_call( env, thiz, mp->getCurrentPosition(&msec), NULL, NULL );
    return msec;
}

static int
android_media_MediaPlayer_getDuration(JNIEnv *env, jobject thiz)
{
    sp<MediaPlayer> mp = getMediaPlayer(env, thiz);
    if (mp == NULL ) {
        jniThrowException(env, "java/lang/IllegalStateException", NULL);
        return 0;
    }
    int msec;
    process_media_player_call( env, thiz, mp->getDuration(&msec), NULL, NULL );
    return msec;
}

static void
android_media_MediaPlayer_reset(JNIEnv *env, jobject thiz)
{
    sp<MediaPlayer> mp = getMediaPlayer(env, thiz);
    if (mp == NULL ) {
        jniThrowException(env, "java/lang/IllegalStateException", NULL);
        return;
    }
    process_media_player_call( env, thiz, mp->reset(), NULL, NULL );
}

static void
android_media_MediaPlayer_setAudioStreamType(JNIEnv *env, jobject thiz, int streamtype)
{
    sp<MediaPlayer> mp = getMediaPlayer(env, thiz);
    if (mp == NULL ) {
        jniThrowException(env, "java/lang/IllegalStateException", NULL);
        return;
    }
    process_media_player_call( env, thiz, mp->setAudioStreamType(streamtype) , NULL, NULL );
}

static void
android_media_MediaPlayer_setLooping(JNIEnv *env, jobject thiz, jboolean looping)
{
    sp<MediaPlayer> mp = getMediaPlayer(env, thiz);
    if (mp == NULL ) {
        jniThrowException(env, "java/lang/IllegalStateException", NULL);
        return;
    }
    process_media_player_call( env, thiz, mp->setLooping(looping), NULL, NULL );
}

static jboolean
android_media_MediaPlayer_isLooping(JNIEnv *env, jobject thiz)
{
    sp<MediaPlayer> mp = getMediaPlayer(env, thiz);
    if (mp == NULL ) {
        jniThrowException(env, "java/lang/IllegalStateException", NULL);
        return false;
    }
    return mp->isLooping();
}

static void
android_media_MediaPlayer_setVolume(JNIEnv *env, jobject thiz, float leftVolume, float rightVolume)
{
    sp<MediaPlayer> mp = getMediaPlayer(env, thiz);
    if (mp == NULL ) {
        jniThrowException(env, "java/lang/IllegalStateException", NULL);
        return;
    }
    process_media_player_call( env, thiz, mp->setVolume(leftVolume, rightVolume), NULL, NULL );
}

// FIXME: deprecated
static jobject
android_media_MediaPlayer_getFrameAt(JNIEnv *env, jobject thiz, jint msec)
{
    return NULL;
}

static void
android_media_MediaPlayer_native_setup(JNIEnv *env, jobject thiz, jobject weak_this)
{
    LOGV("native_setup");
    sp<MediaPlayer> mp = new MediaPlayer();
    if (mp == NULL) {
        jniThrowException(env, "java/lang/RuntimeException", "Out of memory");
        return;
    }

    // create new listener and give it to MediaPlayer
    sp<JNIMediaPlayerListener> listener = new JNIMediaPlayerListener(env, thiz, weak_this);
    mp->setListener(listener);

    // Stow our new C++ MediaPlayer in an opaque field in the Java object.
    setMediaPlayer(env, thiz, mp);
}

static void
android_media_MediaPlayer_release(JNIEnv *env, jobject thiz)
{
    LOGV("release");
    sp<MediaPlayer> mp = setMediaPlayer(env, thiz, 0);
    if (mp != NULL) {
        // this prevents native callbacks after the object is released
        mp->setListener(0);
        mp->disconnect();
    }
}

static void
android_media_MediaPlayer_native_finalize(JNIEnv *env, jobject thiz)
{
    LOGV("native_finalize");
    android_media_MediaPlayer_release(env, thiz);
}

// ----------------------------------------------------------------------------

static JNINativeMethod gMethods[] = {
    {"setDataSource",       "(Ljava/lang/String;)V",            (void *)android_media_MediaPlayer_setDataSource},
    {"setDataSource",       "(Ljava/io/FileDescriptor;JJ)V",    (void *)android_media_MediaPlayer_setDataSourceFD},
    {"prepare",             "()V",                              (void *)android_media_MediaPlayer_prepare},
    {"prepareAsync",        "()V",                              (void *)android_media_MediaPlayer_prepareAsync},
    {"_start",              "()V",                              (void *)android_media_MediaPlayer_start},
    {"_stop",               "()V",                              (void *)android_media_MediaPlayer_stop},
    {"getVideoWidth",       "()I",                              (void *)android_media_MediaPlayer_getVideoWidth},
    {"getVideoHeight",      "()I",                              (void *)android_media_MediaPlayer_getVideoHeight},
    {"seekTo",              "(I)V",                             (void *)android_media_MediaPlayer_seekTo},
    {"_pause",              "()V",                              (void *)android_media_MediaPlayer_pause},
    {"isPlaying",           "()Z",                              (void *)android_media_MediaPlayer_isPlaying},
    {"getCurrentPosition",  "()I",                              (void *)android_media_MediaPlayer_getCurrentPosition},
    {"getDuration",         "()I",                              (void *)android_media_MediaPlayer_getDuration},
    {"_release",            "()V",                              (void *)android_media_MediaPlayer_release},
    {"_reset",              "()V",                              (void *)android_media_MediaPlayer_reset},
    {"setAudioStreamType",  "(I)V",                             (void *)android_media_MediaPlayer_setAudioStreamType},
    {"setLooping",          "(Z)V",                             (void *)android_media_MediaPlayer_setLooping},
    {"isLooping",           "()Z",                              (void *)android_media_MediaPlayer_isLooping},
    {"setVolume",           "(FF)V",                            (void *)android_media_MediaPlayer_setVolume},
    {"getFrameAt",          "(I)Landroid/graphics/Bitmap;",     (void *)android_media_MediaPlayer_getFrameAt},
    {"native_setup",        "(Ljava/lang/Object;)V",            (void *)android_media_MediaPlayer_native_setup},
    {"native_finalize",     "()V",                              (void *)android_media_MediaPlayer_native_finalize},
};

static const char* const kClassPathName = "android/media/MediaPlayer";

static int register_android_media_MediaPlayer(JNIEnv *env)
{
    jclass clazz;

    clazz = env->FindClass("android/media/MediaPlayer");
    if (clazz == NULL) {
        LOGE("Can't find android/media/MediaPlayer");
        return -1;
    }

    fields.context = env->GetFieldID(clazz, "mNativeContext", "I");
    if (fields.context == NULL) {
        LOGE("Can't find MediaPlayer.mNativeContext");
        return -1;
    }

    fields.post_event = env->GetStaticMethodID(clazz, "postEventFromNative",
                                               "(Ljava/lang/Object;IIILjava/lang/Object;)V");
    if (fields.post_event == NULL) {
        LOGE("Can't find MediaPlayer.postEventFromNative");
        return -1;
    }

    fields.surface = env->GetFieldID(clazz, "mSurface", "Landroid/view/Surface;");
    if (fields.surface == NULL) {
        LOGE("Can't find MediaPlayer.mSurface");
        return -1;
    }

    jclass surface = env->FindClass("android/view/Surface");
    if (surface == NULL) {
        LOGE("Can't find android/view/Surface");
        return -1;
    }

    fields.surface_native = env->GetFieldID(surface, "mSurface", "I");
    if (fields.surface_native == NULL) {
        LOGE("Can't find Surface fields");
        return -1;
    }

    return AndroidRuntime::registerNativeMethods(env,
                "android/media/MediaPlayer", gMethods, NELEM(gMethods));
}

extern int register_android_media_MediaRecorder(JNIEnv *env);
extern int register_android_media_MediaScanner(JNIEnv *env);
extern int register_android_media_MediaMetadataRetriever(JNIEnv *env);
extern int register_android_media_AmrInputStream(JNIEnv *env);

jint JNI_OnLoad(JavaVM* vm, void* reserved)
{
    JNIEnv* env = NULL;
    jint result = -1;

    if (vm->GetEnv((void**) &env, JNI_VERSION_1_4) != JNI_OK) {
        LOGE("ERROR: GetEnv failed\n");
        goto bail;
    }
    assert(env != NULL);

    if (register_android_media_MediaPlayer(env) < 0) {
        LOGE("ERROR: MediaPlayer native registration failed\n");
        goto bail;
    }

    if (register_android_media_MediaRecorder(env) < 0) {
        LOGE("ERROR: MediaRecorder native registration failed\n");
        goto bail;
    }

    if (register_android_media_MediaScanner(env) < 0) {
        LOGE("ERROR: MediaScanner native registration failed\n");
        goto bail;
    }

    if (register_android_media_MediaMetadataRetriever(env) < 0) {
        LOGE("ERROR: MediaMetadataRetriever native registration failed\n");
        goto bail;
    }

    if (register_android_media_AmrInputStream(env) < 0) {
        LOGE("ERROR: AmrInputStream native registration failed\n");
        goto bail;
    }

    /* success -- return valid version number */
    result = JNI_VERSION_1_4;

bail:
    return result;
}

// KTHXBYE