gstreamer/gst-sdk/tutorials/android-tutorial-5/jni/tutorial-5.c

572 lines
23 KiB
C
Executable file

#include <string.h>
#include <jni.h>
#include <android/log.h>
#include <android/native_window.h>
#include <android/native_window_jni.h>
#include <gst/gst.h>
#include <gst/interfaces/xoverlay.h>
#include <gst/video/video.h>
#include <pthread.h>
GST_DEBUG_CATEGORY_STATIC (debug_category);
#define GST_CAT_DEFAULT debug_category
/*
* These macros provide a way to store the native pointer to CustomData, which might be 32 or 64 bits, into
* a jlong, which is always 64 bits, without warnings.
*/
#if GLIB_SIZEOF_VOID_P == 8
# define GET_CUSTOM_DATA(env, thiz, fieldID) (CustomData *)(*env)->GetLongField (env, thiz, fieldID)
# define SET_CUSTOM_DATA(env, thiz, fieldID, data) (*env)->SetLongField (env, thiz, fieldID, (jlong)data)
#else
# define GET_CUSTOM_DATA(env, thiz, fieldID) (CustomData *)(jint)(*env)->GetLongField (env, thiz, fieldID)
# define SET_CUSTOM_DATA(env, thiz, fieldID, data) (*env)->SetLongField (env, thiz, fieldID, (jlong)(jint)data)
#endif
/* Do not allow seeks to be performed closer than this distance. It is visually useless, and will probably
* confuse some demuxers. */
#define SEEK_MIN_DELAY (500 * GST_MSECOND)
/* Structure to contain all our information, so we can pass it to callbacks */
typedef struct _CustomData {
jobject app; /* Application instance, used to call its methods. A global reference is kept. */
GstElement *pipeline; /* The running pipeline */
GMainContext *context; /* GLib context used to run the main loop */
GMainLoop *main_loop; /* GLib main loop */
gboolean initialized; /* To avoid informing the UI multiple times about the initialization */
ANativeWindow *native_window; /* The Android native window where video will be rendered */
GstState state; /* Current pipeline state */
GstState target_state; /* Desired pipeline state, to be set once buffering is complete */
gint64 duration; /* Cached clip duration */
gint64 desired_position; /* Position to seek to, once the pipeline is running */
GstClockTime last_seek_time; /* For seeking overflow prevention (throttling) */
gboolean is_live; /* Live streams do not use buffering */
} CustomData;
/* playbin2 flags */
typedef enum {
GST_PLAY_FLAG_TEXT = (1 << 2) /* We want subtitle output */
} GstPlayFlags;
/* These global variables cache values which are not changing during execution */
static pthread_t gst_app_thread;
static pthread_key_t current_jni_env;
static JavaVM *java_vm;
static jfieldID custom_data_field_id;
static jmethodID set_message_method_id;
static jmethodID set_current_position_method_id;
static jmethodID on_gstreamer_initialized_method_id;
static jmethodID on_media_size_changed_method_id;
/*
* Private methods
*/
/* Register this thread with the VM */
static JNIEnv *attach_current_thread (void) {
JNIEnv *env;
JavaVMAttachArgs args;
GST_DEBUG ("Attaching thread %p", g_thread_self ());
args.version = JNI_VERSION_1_4;
args.name = NULL;
args.group = NULL;
if ((*java_vm)->AttachCurrentThread (java_vm, &env, &args) < 0) {
GST_ERROR ("Failed to attach current thread");
return NULL;
}
return env;
}
/* Unregister this thread from the VM */
static void detach_current_thread (void *env) {
GST_DEBUG ("Detaching thread %p", g_thread_self ());
(*java_vm)->DetachCurrentThread (java_vm);
}
/* Retrieve the JNI environment for this thread */
static JNIEnv *get_jni_env (void) {
JNIEnv *env;
if ((env = pthread_getspecific (current_jni_env)) == NULL) {
env = attach_current_thread ();
pthread_setspecific (current_jni_env, env);
}
return env;
}
/* Change the content of the UI's TextView */
static void set_ui_message (const gchar *message, CustomData *data) {
JNIEnv *env = get_jni_env ();
GST_DEBUG ("Setting message to: %s", message);
jstring jmessage = (*env)->NewStringUTF(env, message);
(*env)->CallVoidMethod (env, data->app, set_message_method_id, jmessage);
if ((*env)->ExceptionCheck (env)) {
GST_ERROR ("Failed to call Java method");
(*env)->ExceptionClear (env);
}
(*env)->DeleteLocalRef (env, jmessage);
}
/* Tell the application what is the current position and clip duration */
static void set_current_ui_position (gint position, gint duration, CustomData *data) {
JNIEnv *env = get_jni_env ();
(*env)->CallVoidMethod (env, data->app, set_current_position_method_id, position, duration);
if ((*env)->ExceptionCheck (env)) {
GST_ERROR ("Failed to call Java method");
(*env)->ExceptionClear (env);
}
}
/* If we have pipeline and it is running, query the current position and clip duration and inform
* the application */
static gboolean refresh_ui (CustomData *data) {
GstFormat fmt = GST_FORMAT_TIME;
gint64 current = -1;
gint64 position;
/* We do not want to update anything unless we have a working pipeline in the PAUSED or PLAYING state */
if (!data || !data->pipeline || data->state < GST_STATE_PAUSED)
return TRUE;
/* If we didn't know it yet, query the stream duration */
if (!GST_CLOCK_TIME_IS_VALID (data->duration)) {
if (!gst_element_query_duration (data->pipeline, &fmt, &data->duration)) {
GST_WARNING ("Could not query current duration (normal for still pictures)");
data->duration = 0;
}
}
if (!gst_element_query_position (data->pipeline, &fmt, &position)) {
GST_WARNING ("Could not query current position (normal for still pictures)");
position = 0;
}
/* Java expects these values in milliseconds, and GStreamer provides nanoseconds */
set_current_ui_position (position / GST_MSECOND, data->duration / GST_MSECOND, data);
return TRUE;
}
/* Forward declaration for the delayed seek callback */
static gboolean delayed_seek_cb (CustomData *data);
/* Perform seek, if we are not too close to the previous seek. Otherwise, schedule the seek for
* some time in the future. */
static void execute_seek (gint64 desired_position, CustomData *data) {
gint64 diff;
if (desired_position == GST_CLOCK_TIME_NONE)
return;
diff = gst_util_get_timestamp () - data->last_seek_time;
if (GST_CLOCK_TIME_IS_VALID (data->last_seek_time) && diff < SEEK_MIN_DELAY) {
/* The previous seek was too close, delay this one */
GSource *timeout_source;
if (data->desired_position == GST_CLOCK_TIME_NONE) {
/* There was no previous seek scheduled. Setup a timer for some time in the future */
timeout_source = g_timeout_source_new ((SEEK_MIN_DELAY - diff) / GST_MSECOND);
g_source_set_callback (timeout_source, (GSourceFunc)delayed_seek_cb, data, NULL);
g_source_attach (timeout_source, data->context);
g_source_unref (timeout_source);
}
/* Update the desired seek position. If multiple petitions are received before it is time
* to perform a seek, only the last one is remembered. */
data->desired_position = desired_position;
GST_DEBUG ("Throttling seek to %" GST_TIME_FORMAT ", will be in %" GST_TIME_FORMAT,
GST_TIME_ARGS (desired_position), GST_TIME_ARGS (SEEK_MIN_DELAY - diff));
} else {
/* Perform the seek now */
GST_DEBUG ("Seeking to %" GST_TIME_FORMAT, GST_TIME_ARGS (desired_position));
data->last_seek_time = gst_util_get_timestamp ();
gst_element_seek_simple (data->pipeline, GST_FORMAT_TIME, GST_SEEK_FLAG_FLUSH | GST_SEEK_FLAG_KEY_UNIT, desired_position);
data->desired_position = GST_CLOCK_TIME_NONE;
}
}
/* Delayed seek callback. This gets called by the timer setup in the above function. */
static gboolean delayed_seek_cb (CustomData *data) {
GST_DEBUG ("Doing delayed seek to %" GST_TIME_FORMAT, GST_TIME_ARGS (data->desired_position));
execute_seek (data->desired_position, data);
return FALSE;
}
/* Retrieve errors from the bus and show them on the UI */
static void error_cb (GstBus *bus, GstMessage *msg, CustomData *data) {
GError *err;
gchar *debug_info;
gchar *message_string;
gst_message_parse_error (msg, &err, &debug_info);
message_string = g_strdup_printf ("Error received from element %s: %s", GST_OBJECT_NAME (msg->src), err->message);
g_clear_error (&err);
g_free (debug_info);
set_ui_message (message_string, data);
g_free (message_string);
data->target_state = GST_STATE_NULL;
gst_element_set_state (data->pipeline, GST_STATE_NULL);
}
/* Called when the End Of the Stream is reached. Just move to the beginning of the media and pause. */
static void eos_cb (GstBus *bus, GstMessage *msg, CustomData *data) {
data->target_state = GST_STATE_PAUSED;
data->is_live = (gst_element_set_state (data->pipeline, GST_STATE_PAUSED) == GST_STATE_CHANGE_NO_PREROLL);
execute_seek (0, data);
}
/* Called when the duration of the media changes. Just mark it as unknown, so we re-query it in the next UI refresh. */
static void duration_cb (GstBus *bus, GstMessage *msg, CustomData *data) {
data->duration = GST_CLOCK_TIME_NONE;
}
/* Called when buffering messages are received. We inform the UI about the current buffering level and
* keep the pipeline paused until 100% buffering is reached. At that point, set the desired state. */
static void buffering_cb (GstBus *bus, GstMessage *msg, CustomData *data) {
gint percent;
if (data->is_live)
return;
gst_message_parse_buffering (msg, &percent);
if (percent < 100 && data->target_state >= GST_STATE_PAUSED) {
gchar * message_string = g_strdup_printf ("Buffering %d%%", percent);
gst_element_set_state (data->pipeline, GST_STATE_PAUSED);
set_ui_message (message_string, data);
g_free (message_string);
} else if (data->target_state >= GST_STATE_PLAYING) {
gst_element_set_state (data->pipeline, GST_STATE_PLAYING);
} else if (data->target_state >= GST_STATE_PAUSED) {
set_ui_message ("Buffering complete", data);
}
}
/* Called when the clock is lost */
static void clock_lost_cb (GstBus *bus, GstMessage *msg, CustomData *data) {
if (data->target_state >= GST_STATE_PLAYING) {
gst_element_set_state (data->pipeline, GST_STATE_PAUSED);
gst_element_set_state (data->pipeline, GST_STATE_PLAYING);
}
}
/* Retrieve the video sink's Caps and tell the application about the media size */
static void check_media_size (CustomData *data) {
JNIEnv *env = get_jni_env ();
GstElement *video_sink;
GstPad *video_sink_pad;
GstCaps *caps;
GstVideoFormat fmt;
int width;
int height;
/* Retrieve the Caps at the entrance of the video sink */
g_object_get (data->pipeline, "video-sink", &video_sink, NULL);
video_sink_pad = gst_element_get_static_pad (video_sink, "sink");
caps = gst_pad_get_negotiated_caps (video_sink_pad);
if (gst_video_format_parse_caps(caps, &fmt, &width, &height)) {
int par_n, par_d;
if (gst_video_parse_caps_pixel_aspect_ratio (caps, &par_n, &par_d)) {
width = width * par_n / par_d;
}
GST_DEBUG ("Media size is %dx%d, notifying application", width, height);
(*env)->CallVoidMethod (env, data->app, on_media_size_changed_method_id, (jint)width, (jint)height);
if ((*env)->ExceptionCheck (env)) {
GST_ERROR ("Failed to call Java method");
(*env)->ExceptionClear (env);
}
}
gst_caps_unref(caps);
gst_object_unref (video_sink_pad);
gst_object_unref(video_sink);
}
/* Notify UI about pipeline state changes */
static void state_changed_cb (GstBus *bus, GstMessage *msg, CustomData *data) {
GstState old_state, new_state, pending_state;
gst_message_parse_state_changed (msg, &old_state, &new_state, &pending_state);
/* Only pay attention to messages coming from the pipeline, not its children */
if (GST_MESSAGE_SRC (msg) == GST_OBJECT (data->pipeline)) {
data->state = new_state;
gchar *message = g_strdup_printf("State changed to %s", gst_element_state_get_name(new_state));
set_ui_message(message, data);
g_free (message);
/* The Ready to Paused state change is particularly interesting: */
if (old_state == GST_STATE_READY && new_state == GST_STATE_PAUSED) {
/* By now the sink already knows the media size */
check_media_size(data);
/* If there was a scheduled seek, perform it now that we have moved to the Paused state */
if (GST_CLOCK_TIME_IS_VALID (data->desired_position))
execute_seek (data->desired_position, data);
}
}
}
/* Check if all conditions are met to report GStreamer as initialized.
* These conditions will change depending on the application */
static void check_initialization_complete (CustomData *data) {
JNIEnv *env = get_jni_env ();
if (!data->initialized && data->native_window && data->main_loop) {
GST_DEBUG ("Initialization complete, notifying application. native_window:%p main_loop:%p", data->native_window, data->main_loop);
/* The main loop is running and we received a native window, inform the sink about it */
gst_x_overlay_set_window_handle (GST_X_OVERLAY (data->pipeline), (guintptr)data->native_window);
(*env)->CallVoidMethod (env, data->app, on_gstreamer_initialized_method_id);
if ((*env)->ExceptionCheck (env)) {
GST_ERROR ("Failed to call Java method");
(*env)->ExceptionClear (env);
}
data->initialized = TRUE;
}
}
/* Main method for the native code. This is executed on its own thread. */
static void *app_function (void *userdata) {
JavaVMAttachArgs args;
GstBus *bus;
CustomData *data = (CustomData *)userdata;
GSource *timeout_source;
GSource *bus_source;
GError *error = NULL;
guint flags;
GST_DEBUG ("Creating pipeline in CustomData at %p", data);
/* Create our own GLib Main Context and make it the default one */
data->context = g_main_context_new ();
g_main_context_push_thread_default(data->context);
/* Build pipeline */
data->pipeline = gst_parse_launch("playbin2", &error);
if (error) {
gchar *message = g_strdup_printf("Unable to build pipeline: %s", error->message);
g_clear_error (&error);
set_ui_message(message, data);
g_free (message);
return NULL;
}
/* Disable subtitles */
g_object_get (data->pipeline, "flags", &flags, NULL);
flags &= ~GST_PLAY_FLAG_TEXT;
g_object_set (data->pipeline, "flags", flags, NULL);
/* Set the pipeline to READY, so it can already accept a window handle, if we have one */
data->target_state = GST_STATE_READY;
gst_element_set_state(data->pipeline, GST_STATE_READY);
/* Instruct the bus to emit signals for each received message, and connect to the interesting signals */
bus = gst_element_get_bus (data->pipeline);
bus_source = gst_bus_create_watch (bus);
g_source_set_callback (bus_source, (GSourceFunc) gst_bus_async_signal_func, NULL, NULL);
g_source_attach (bus_source, data->context);
g_source_unref (bus_source);
g_signal_connect (G_OBJECT (bus), "message::error", (GCallback)error_cb, data);
g_signal_connect (G_OBJECT (bus), "message::eos", (GCallback)eos_cb, data);
g_signal_connect (G_OBJECT (bus), "message::state-changed", (GCallback)state_changed_cb, data);
g_signal_connect (G_OBJECT (bus), "message::duration", (GCallback)duration_cb, data);
g_signal_connect (G_OBJECT (bus), "message::buffering", (GCallback)buffering_cb, data);
g_signal_connect (G_OBJECT (bus), "message::clock-lost", (GCallback)clock_lost_cb, data);
gst_object_unref (bus);
/* Register a function that GLib will call 4 times per second */
timeout_source = g_timeout_source_new (250);
g_source_set_callback (timeout_source, (GSourceFunc)refresh_ui, data, NULL);
g_source_attach (timeout_source, data->context);
g_source_unref (timeout_source);
/* Create a GLib Main Loop and set it to run */
GST_DEBUG ("Entering main loop... (CustomData:%p)", data);
data->main_loop = g_main_loop_new (data->context, FALSE);
check_initialization_complete (data);
g_main_loop_run (data->main_loop);
GST_DEBUG ("Exited main loop");
g_main_loop_unref (data->main_loop);
data->main_loop = NULL;
/* Free resources */
g_main_context_pop_thread_default(data->context);
g_main_context_unref (data->context);
data->target_state = GST_STATE_NULL;
gst_element_set_state (data->pipeline, GST_STATE_NULL);
gst_object_unref (data->pipeline);
return NULL;
}
/*
* Java Bindings
*/
/* Instruct the native code to create its internal data structure, pipeline and thread */
static void gst_native_init (JNIEnv* env, jobject thiz) {
CustomData *data = g_new0 (CustomData, 1);
data->desired_position = GST_CLOCK_TIME_NONE;
data->last_seek_time = GST_CLOCK_TIME_NONE;
SET_CUSTOM_DATA (env, thiz, custom_data_field_id, data);
GST_DEBUG_CATEGORY_INIT (debug_category, "tutorial-5", 0, "Android tutorial 5");
gst_debug_set_threshold_for_name("tutorial-5", GST_LEVEL_DEBUG);
GST_DEBUG ("Created CustomData at %p", data);
data->app = (*env)->NewGlobalRef (env, thiz);
GST_DEBUG ("Created GlobalRef for app object at %p", data->app);
pthread_create (&gst_app_thread, NULL, &app_function, data);
}
/* Quit the main loop, remove the native thread and free resources */
static void gst_native_finalize (JNIEnv* env, jobject thiz) {
CustomData *data = GET_CUSTOM_DATA (env, thiz, custom_data_field_id);
if (!data) return;
GST_DEBUG ("Quitting main loop...");
g_main_loop_quit (data->main_loop);
GST_DEBUG ("Waiting for thread to finish...");
pthread_join (gst_app_thread, NULL);
GST_DEBUG ("Deleting GlobalRef for app object at %p", data->app);
(*env)->DeleteGlobalRef (env, data->app);
GST_DEBUG ("Freeing CustomData at %p", data);
g_free (data);
SET_CUSTOM_DATA (env, thiz, custom_data_field_id, NULL);
GST_DEBUG ("Done finalizing");
}
/* Set playbin2's URI */
void gst_native_set_uri (JNIEnv* env, jobject thiz, jstring uri) {
CustomData *data = GET_CUSTOM_DATA (env, thiz, custom_data_field_id);
if (!data || !data->pipeline) return;
const jbyte *char_uri = (*env)->GetStringUTFChars (env, uri, NULL);
GST_DEBUG ("Setting URI to %s", char_uri);
if (data->target_state >= GST_STATE_READY)
gst_element_set_state (data->pipeline, GST_STATE_READY);
g_object_set(data->pipeline, "uri", char_uri, NULL);
(*env)->ReleaseStringUTFChars (env, uri, char_uri);
data->duration = GST_CLOCK_TIME_NONE;
data->is_live = (gst_element_set_state (data->pipeline, data->target_state) == GST_STATE_CHANGE_NO_PREROLL);
}
/* Set pipeline to PLAYING state */
static void gst_native_play (JNIEnv* env, jobject thiz) {
CustomData *data = GET_CUSTOM_DATA (env, thiz, custom_data_field_id);
if (!data) return;
GST_DEBUG ("Setting state to PLAYING");
data->target_state = GST_STATE_PLAYING;
data->is_live = (gst_element_set_state (data->pipeline, GST_STATE_PLAYING) == GST_STATE_CHANGE_NO_PREROLL);
}
/* Set pipeline to PAUSED state */
static void gst_native_pause (JNIEnv* env, jobject thiz) {
CustomData *data = GET_CUSTOM_DATA (env, thiz, custom_data_field_id);
if (!data) return;
GST_DEBUG ("Setting state to PAUSED");
data->target_state = GST_STATE_PAUSED;
data->is_live = (gst_element_set_state (data->pipeline, GST_STATE_PAUSED) == GST_STATE_CHANGE_NO_PREROLL);
}
/* Instruct the pipeline to seek to a different position */
void gst_native_set_position (JNIEnv* env, jobject thiz, int milliseconds) {
CustomData *data = GET_CUSTOM_DATA (env, thiz, custom_data_field_id);
if (!data) return;
gint64 desired_position = (gint64)(milliseconds * GST_MSECOND);
if (data->state >= GST_STATE_PAUSED) {
execute_seek(desired_position, data);
} else {
GST_DEBUG ("Scheduling seek to %" GST_TIME_FORMAT " for later", GST_TIME_ARGS (desired_position));
data->desired_position = desired_position;
}
}
/* Static class initializer: retrieve method and field IDs */
static jboolean gst_native_class_init (JNIEnv* env, jclass klass) {
custom_data_field_id = (*env)->GetFieldID (env, klass, "native_custom_data", "J");
set_message_method_id = (*env)->GetMethodID (env, klass, "setMessage", "(Ljava/lang/String;)V");
set_current_position_method_id = (*env)->GetMethodID (env, klass, "setCurrentPosition", "(II)V");
on_gstreamer_initialized_method_id = (*env)->GetMethodID (env, klass, "onGStreamerInitialized", "()V");
on_media_size_changed_method_id = (*env)->GetMethodID (env, klass, "onMediaSizeChanged", "(II)V");
if (!custom_data_field_id || !set_message_method_id || !on_gstreamer_initialized_method_id ||
!on_media_size_changed_method_id || !set_current_position_method_id) {
/* We emit this message through the Android log instead of the GStreamer log because the later
* has not been initialized yet.
*/
__android_log_print (ANDROID_LOG_ERROR, "tutorial-4", "The calling class does not implement all necessary interface methods");
return JNI_FALSE;
}
return JNI_TRUE;
}
static void gst_native_surface_init (JNIEnv *env, jobject thiz, jobject surface) {
CustomData *data = GET_CUSTOM_DATA (env, thiz, custom_data_field_id);
if (!data) return;
ANativeWindow *new_native_window = ANativeWindow_fromSurface(env, surface);
GST_DEBUG ("Received surface %p (native window %p)", surface, new_native_window);
if (data->native_window) {
ANativeWindow_release (data->native_window);
if (data->native_window == new_native_window) {
GST_DEBUG ("New native window is the same as the previous one", data->native_window);
if (data->pipeline) {
gst_x_overlay_expose(GST_X_OVERLAY (data->pipeline));
gst_x_overlay_expose(GST_X_OVERLAY (data->pipeline));
}
return;
} else {
GST_DEBUG ("Released previous native window %p", data->native_window);
data->initialized = FALSE;
}
}
data->native_window = new_native_window;
check_initialization_complete (data);
}
static void gst_native_surface_finalize (JNIEnv *env, jobject thiz) {
CustomData *data = GET_CUSTOM_DATA (env, thiz, custom_data_field_id);
if (!data) return;
GST_DEBUG ("Releasing Native Window %p", data->native_window);
if (data->pipeline) {
gst_x_overlay_set_window_handle (GST_X_OVERLAY (data->pipeline), (guintptr)NULL);
gst_element_set_state (data->pipeline, GST_STATE_READY);
}
ANativeWindow_release (data->native_window);
data->native_window = NULL;
data->initialized = FALSE;
}
/* List of implemented native methods */
static JNINativeMethod native_methods[] = {
{ "nativeInit", "()V", (void *) gst_native_init},
{ "nativeFinalize", "()V", (void *) gst_native_finalize},
{ "nativeSetUri", "(Ljava/lang/String;)V", (void *) gst_native_set_uri},
{ "nativePlay", "()V", (void *) gst_native_play},
{ "nativePause", "()V", (void *) gst_native_pause},
{ "nativeSetPosition", "(I)V", (void*) gst_native_set_position},
{ "nativeSurfaceInit", "(Ljava/lang/Object;)V", (void *) gst_native_surface_init},
{ "nativeSurfaceFinalize", "()V", (void *) gst_native_surface_finalize},
{ "nativeClassInit", "()Z", (void *) gst_native_class_init}
};
/* Library initializer */
jint JNI_OnLoad(JavaVM *vm, void *reserved) {
JNIEnv *env = NULL;
java_vm = vm;
if ((*vm)->GetEnv(vm, (void**) &env, JNI_VERSION_1_4) != JNI_OK) {
__android_log_print (ANDROID_LOG_ERROR, "tutorial-5", "Could not retrieve JNIEnv");
return 0;
}
jclass klass = (*env)->FindClass (env, "com/gst_sdk_tutorials/tutorial_5/Tutorial5");
(*env)->RegisterNatives (env, klass, native_methods, G_N_ELEMENTS(native_methods));
pthread_key_create (&current_jni_env, detach_current_thread);
return JNI_VERSION_1_4;
}