mirror of
https://gitlab.freedesktop.org/gstreamer/gstreamer.git
synced 2024-12-11 19:06:33 +00:00
386 lines
14 KiB
Objective-C
386 lines
14 KiB
Objective-C
#import "GStreamerBackend.h"
|
|
|
|
#include <gst/gst.h>
|
|
#include <gst/video/video.h>
|
|
|
|
GST_DEBUG_CATEGORY_STATIC (debug_category);
|
|
#define GST_CAT_DEFAULT debug_category
|
|
|
|
/* 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)
|
|
|
|
@interface GStreamerBackend()
|
|
-(void)setUIMessage:(gchar*) message;
|
|
-(void)app_function;
|
|
-(void)check_initialization_complete;
|
|
@end
|
|
|
|
@implementation GStreamerBackend {
|
|
id ui_delegate; /* Class that we use to interact with the user interface */
|
|
GstElement *pipeline; /* The running pipeline */
|
|
GstElement *video_sink; /* The video sink element which receives XOverlay commands */
|
|
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 */
|
|
UIView *ui_video_view; /* UIView that holds the video */
|
|
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 */
|
|
}
|
|
|
|
/*
|
|
* Interface methods
|
|
*/
|
|
|
|
-(id) init:(id) uiDelegate videoView:(UIView *)video_view
|
|
{
|
|
if (self = [super init])
|
|
{
|
|
self->ui_delegate = uiDelegate;
|
|
self->ui_video_view = video_view;
|
|
self->duration = GST_CLOCK_TIME_NONE;
|
|
|
|
GST_DEBUG_CATEGORY_INIT (debug_category, "tutorial-4", 0, "iOS tutorial 4");
|
|
gst_debug_set_threshold_for_name("tutorial-4", GST_LEVEL_DEBUG);
|
|
|
|
/* Start the bus monitoring task */
|
|
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
|
|
[self app_function];
|
|
});
|
|
}
|
|
|
|
return self;
|
|
}
|
|
|
|
-(void) deinit
|
|
{
|
|
if (main_loop) {
|
|
g_main_loop_quit(main_loop);
|
|
}
|
|
}
|
|
|
|
-(void) play
|
|
{
|
|
target_state = GST_STATE_PLAYING;
|
|
is_live = (gst_element_set_state (pipeline, GST_STATE_PLAYING) == GST_STATE_CHANGE_NO_PREROLL);
|
|
}
|
|
|
|
-(void) pause
|
|
{
|
|
target_state = GST_STATE_PAUSED;
|
|
is_live = (gst_element_set_state (pipeline, GST_STATE_PAUSED) == GST_STATE_CHANGE_NO_PREROLL);
|
|
}
|
|
|
|
-(void) setUri:(NSString*)uri
|
|
{
|
|
const char *char_uri = [uri UTF8String];
|
|
g_object_set(pipeline, "uri", char_uri, NULL);
|
|
GST_DEBUG ("URI set to %s", char_uri);
|
|
}
|
|
|
|
-(void) setPosition:(NSInteger)milliseconds
|
|
{
|
|
gint64 position = (gint64)(milliseconds * GST_MSECOND);
|
|
if (state >= GST_STATE_PAUSED) {
|
|
execute_seek(position, self);
|
|
} else {
|
|
GST_DEBUG ("Scheduling seek to %" GST_TIME_FORMAT " for later", GST_TIME_ARGS (position));
|
|
self->desired_position = position;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Private methods
|
|
*/
|
|
|
|
/* Change the message on the UI through the UI delegate */
|
|
-(void)setUIMessage:(gchar*) message
|
|
{
|
|
NSString *string = [NSString stringWithUTF8String:message];
|
|
if(ui_delegate && [ui_delegate respondsToSelector:@selector(gstreamerSetUIMessage:)])
|
|
{
|
|
[ui_delegate gstreamerSetUIMessage:string];
|
|
}
|
|
}
|
|
|
|
/* Tell the application what is the current position and clip duration */
|
|
-(void) setCurrentUIPosition:(gint)pos duration:(gint)dur
|
|
{
|
|
if(ui_delegate && [ui_delegate respondsToSelector:@selector(setCurrentPosition:duration:)])
|
|
{
|
|
[ui_delegate setCurrentPosition:pos duration:dur];
|
|
}
|
|
}
|
|
|
|
/* If we have pipeline and it is running, query the current position and clip duration and inform
|
|
* the application */
|
|
static gboolean refresh_ui (GStreamerBackend *self) {
|
|
gint64 position;
|
|
|
|
/* We do not want to update anything unless we have a working pipeline in the PAUSED or PLAYING state */
|
|
if (!self || !self->pipeline || self->state < GST_STATE_PAUSED)
|
|
return TRUE;
|
|
|
|
/* If we didn't know it yet, query the stream duration */
|
|
if (!GST_CLOCK_TIME_IS_VALID (self->duration)) {
|
|
gst_element_query_duration (self->pipeline, GST_FORMAT_TIME, &self->duration);
|
|
}
|
|
|
|
if (gst_element_query_position (self->pipeline, GST_FORMAT_TIME, &position)) {
|
|
/* The UI expects these values in milliseconds, and GStreamer provides nanoseconds */
|
|
[self setCurrentUIPosition:position / GST_MSECOND duration:self->duration / GST_MSECOND];
|
|
}
|
|
return TRUE;
|
|
}
|
|
|
|
/* Forward declaration for the delayed seek callback */
|
|
static gboolean delayed_seek_cb (GStreamerBackend *self);
|
|
|
|
/* 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 position, GStreamerBackend *self) {
|
|
gint64 diff;
|
|
|
|
if (position == GST_CLOCK_TIME_NONE)
|
|
return;
|
|
|
|
diff = gst_util_get_timestamp () - self->last_seek_time;
|
|
|
|
if (GST_CLOCK_TIME_IS_VALID (self->last_seek_time) && diff < SEEK_MIN_DELAY) {
|
|
/* The previous seek was too close, delay this one */
|
|
GSource *timeout_source;
|
|
|
|
if (self->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, (__bridge void *)self, NULL);
|
|
g_source_attach (timeout_source, self->context);
|
|
g_source_unref (timeout_source);
|
|
}
|
|
/* Update the desired seek position. If multiple requests are received before it is time
|
|
* to perform a seek, only the last one is remembered. */
|
|
self->desired_position = position;
|
|
GST_DEBUG ("Throttling seek to %" GST_TIME_FORMAT ", will be in %" GST_TIME_FORMAT,
|
|
GST_TIME_ARGS (position), GST_TIME_ARGS (SEEK_MIN_DELAY - diff));
|
|
} else {
|
|
/* Perform the seek now */
|
|
GST_DEBUG ("Seeking to %" GST_TIME_FORMAT, GST_TIME_ARGS (position));
|
|
self->last_seek_time = gst_util_get_timestamp ();
|
|
gst_element_seek_simple (self->pipeline, GST_FORMAT_TIME, GST_SEEK_FLAG_FLUSH | GST_SEEK_FLAG_KEY_UNIT, position);
|
|
self->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 (GStreamerBackend *self) {
|
|
GST_DEBUG ("Doing delayed seek to %" GST_TIME_FORMAT, GST_TIME_ARGS (self->desired_position));
|
|
execute_seek (self->desired_position, self);
|
|
return FALSE;
|
|
}
|
|
|
|
/* Retrieve errors from the bus and show them on the UI */
|
|
static void error_cb (GstBus *bus, GstMessage *msg, GStreamerBackend *self)
|
|
{
|
|
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);
|
|
[self setUIMessage:message_string];
|
|
g_free (message_string);
|
|
gst_element_set_state (self->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, GStreamerBackend *self) {
|
|
self->target_state = GST_STATE_PAUSED;
|
|
self->is_live = (gst_element_set_state (self->pipeline, GST_STATE_PAUSED) == GST_STATE_CHANGE_NO_PREROLL);
|
|
execute_seek (0, self);
|
|
}
|
|
|
|
/* 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, GStreamerBackend *self) {
|
|
self->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, GStreamerBackend *self) {
|
|
gint percent;
|
|
|
|
if (self->is_live)
|
|
return;
|
|
|
|
gst_message_parse_buffering (msg, &percent);
|
|
if (percent < 100 && self->target_state >= GST_STATE_PAUSED) {
|
|
gchar * message_string = g_strdup_printf ("Buffering %d%%", percent);
|
|
gst_element_set_state (self->pipeline, GST_STATE_PAUSED);
|
|
[self setUIMessage:message_string];
|
|
g_free (message_string);
|
|
} else if (self->target_state >= GST_STATE_PLAYING) {
|
|
gst_element_set_state (self->pipeline, GST_STATE_PLAYING);
|
|
} else if (self->target_state >= GST_STATE_PAUSED) {
|
|
[self setUIMessage:"Buffering complete"];
|
|
}
|
|
}
|
|
|
|
/* Called when the clock is lost */
|
|
static void clock_lost_cb (GstBus *bus, GstMessage *msg, GStreamerBackend *self) {
|
|
if (self->target_state >= GST_STATE_PLAYING) {
|
|
gst_element_set_state (self->pipeline, GST_STATE_PAUSED);
|
|
gst_element_set_state (self->pipeline, GST_STATE_PLAYING);
|
|
}
|
|
}
|
|
|
|
/* Retrieve the video sink's Caps and tell the application about the media size */
|
|
static void check_media_size (GStreamerBackend *self) {
|
|
GstElement *video_sink;
|
|
GstPad *video_sink_pad;
|
|
GstCaps *caps;
|
|
GstVideoInfo info;
|
|
|
|
/* Retrieve the Caps at the entrance of the video sink */
|
|
g_object_get (self->pipeline, "video-sink", &video_sink, NULL);
|
|
|
|
/* Do nothing if there is no video sink (this might be an audio-only clip */
|
|
if (!video_sink) return;
|
|
|
|
video_sink_pad = gst_element_get_static_pad (video_sink, "sink");
|
|
caps = gst_pad_get_current_caps (video_sink_pad);
|
|
|
|
if (gst_video_info_from_caps (&info, caps)) {
|
|
info.width = info.width * info.par_n / info.par_d;
|
|
GST_DEBUG ("Media size is %dx%d, notifying application", info.width, info.height);
|
|
|
|
if (self->ui_delegate && [self->ui_delegate respondsToSelector:@selector(mediaSizeChanged:height:)])
|
|
{
|
|
[self->ui_delegate mediaSizeChanged:info.width height:info.height];
|
|
}
|
|
}
|
|
|
|
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, GStreamerBackend *self)
|
|
{
|
|
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 (self->pipeline)) {
|
|
self->state = new_state;
|
|
gchar *message = g_strdup_printf("State changed to %s", gst_element_state_get_name(new_state));
|
|
[self setUIMessage:message];
|
|
g_free (message);
|
|
|
|
if (old_state == GST_STATE_READY && new_state == GST_STATE_PAUSED)
|
|
{
|
|
check_media_size(self);
|
|
|
|
/* If there was a scheduled seek, perform it now that we have moved to the Paused state */
|
|
if (GST_CLOCK_TIME_IS_VALID (self->desired_position))
|
|
execute_seek (self->desired_position, self);
|
|
}
|
|
}
|
|
}
|
|
|
|
/* Check if all conditions are met to report GStreamer as initialized.
|
|
* These conditions will change depending on the application */
|
|
-(void) check_initialization_complete
|
|
{
|
|
if (!initialized && main_loop) {
|
|
GST_DEBUG ("Initialization complete, notifying application.");
|
|
if (ui_delegate && [ui_delegate respondsToSelector:@selector(gstreamerInitialized)])
|
|
{
|
|
[ui_delegate gstreamerInitialized];
|
|
}
|
|
initialized = TRUE;
|
|
}
|
|
}
|
|
|
|
/* Main method for the bus monitoring code */
|
|
-(void) app_function
|
|
{
|
|
GstBus *bus;
|
|
GSource *timeout_source;
|
|
GSource *bus_source;
|
|
GError *error = NULL;
|
|
|
|
GST_DEBUG ("Creating pipeline");
|
|
|
|
/* Create our own GLib Main Context and make it the default one */
|
|
context = g_main_context_new ();
|
|
g_main_context_push_thread_default(context);
|
|
|
|
/* Build pipeline */
|
|
pipeline = gst_parse_launch("playbin", &error);
|
|
if (error) {
|
|
gchar *message = g_strdup_printf("Unable to build pipeline: %s", error->message);
|
|
g_clear_error (&error);
|
|
[self setUIMessage:message];
|
|
g_free (message);
|
|
return;
|
|
}
|
|
|
|
/* Set the pipeline to READY, so it can already accept a window handle */
|
|
gst_element_set_state(pipeline, GST_STATE_READY);
|
|
|
|
video_sink = gst_bin_get_by_interface(GST_BIN(pipeline), GST_TYPE_VIDEO_OVERLAY);
|
|
if (!video_sink) {
|
|
GST_ERROR ("Could not retrieve video sink");
|
|
return;
|
|
}
|
|
gst_video_overlay_set_window_handle(GST_VIDEO_OVERLAY(video_sink), (guintptr) (id) ui_video_view);
|
|
|
|
/* Instruct the bus to emit signals for each received message, and connect to the interesting signals */
|
|
bus = gst_element_get_bus (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, context);
|
|
g_source_unref (bus_source);
|
|
g_signal_connect (G_OBJECT (bus), "message::error", (GCallback)error_cb, (__bridge void *)self);
|
|
g_signal_connect (G_OBJECT (bus), "message::eos", (GCallback)eos_cb, (__bridge void *)self);
|
|
g_signal_connect (G_OBJECT (bus), "message::state-changed", (GCallback)state_changed_cb, (__bridge void *)self);
|
|
g_signal_connect (G_OBJECT (bus), "message::duration", (GCallback)duration_cb, (__bridge void *)self);
|
|
g_signal_connect (G_OBJECT (bus), "message::buffering", (GCallback)buffering_cb, (__bridge void *)self);
|
|
g_signal_connect (G_OBJECT (bus), "message::clock-lost", (GCallback)clock_lost_cb, (__bridge void *)self);
|
|
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, (__bridge void *)self, NULL);
|
|
g_source_attach (timeout_source, context);
|
|
g_source_unref (timeout_source);
|
|
|
|
/* Create a GLib Main Loop and set it to run */
|
|
GST_DEBUG ("Entering main loop...");
|
|
main_loop = g_main_loop_new (context, FALSE);
|
|
[self check_initialization_complete];
|
|
g_main_loop_run (main_loop);
|
|
GST_DEBUG ("Exited main loop");
|
|
g_main_loop_unref (main_loop);
|
|
main_loop = NULL;
|
|
|
|
/* Free resources */
|
|
g_main_context_pop_thread_default(context);
|
|
g_main_context_unref (context);
|
|
gst_element_set_state (pipeline, GST_STATE_NULL);
|
|
gst_object_unref (pipeline);
|
|
pipeline = NULL;
|
|
|
|
ui_delegate = NULL;
|
|
ui_video_view = NULL;
|
|
|
|
return;
|
|
}
|
|
|
|
@end
|