UxPlay/renderers/video_renderer_gstreamer.c

/**
 * RPiPlay - An open-source AirPlay mirroring server for Raspberry Pi
 * Copyright (C) 2019 Florian Draschbacher
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301  USA
 */

#include "video_renderer.h"
#include <assert.h>
#include <gst/gst.h>
#include <gst/app/gstappsrc.h>
#include <X11/Xlib.h>
#include <X11/Xutil.h>
#include <stdio.h>

Display* display;
Window root, my_window;

struct video_renderer_s {
    logger_t *logger;
    GstElement *appsrc, *pipeline, *sink;
};

static gboolean check_plugins (void)
{
    int i;
    gboolean ret;
    GstRegistry *registry;
    const gchar *needed[] = { "app", "libav", "playback", "autodetect", NULL};

    registry = gst_registry_get ();
    ret = TRUE;
    for (i = 0; i < g_strv_length ((gchar **) needed); i++) {
        GstPlugin *plugin;
        plugin = gst_registry_find_plugin (registry, needed[i]);
        if (!plugin) {
            g_print ("Required gstreamer plugin '%s' not found\n", needed[i]);
            ret = FALSE;
            continue;
        }
        gst_object_unref (plugin);
    }
    return ret;
}

Window enum_windows(Display* display, Window window, int depth) {
    int i;

    XTextProperty text;
    XGetWMName(display, window, &text);
    char* name;
    XFetchName(display, window, &name);

    if (name != 0 &&  strcmp((const char*) g_get_application_name(), name) == 0) {
        return window;
      }

    Window _root, parent;
    Window* children;
    unsigned int n;
    XQueryTree(display, window, &_root, &parent, &children, &n);
    if (children != NULL) {
      for (i = 0; i < n; i++) {
            Window w = enum_windows(display, children[i], depth + 1);
            if (w) return w;
        }
        XFree(children);
    }

    return (Window) NULL;
}

video_renderer_t *video_renderer_init(logger_t *logger, const char *server_name) {
    display = XOpenDisplay(NULL);
    root = XDefaultRootWindow(display);  

    video_renderer_t *renderer;
    GError *error = NULL;

    renderer = calloc(1, sizeof(video_renderer_t));
    assert(renderer);

    gst_init(NULL, NULL);
    g_set_application_name(server_name);
 
    renderer->logger = logger;
     
    assert(check_plugins ());

    renderer->pipeline = gst_parse_launch("appsrc name=video_source stream-type=0 format=GST_FORMAT_TIME is-live=true !"
    "queue ! decodebin ! videoconvert ! autovideosink name=video_sink sync=false", &error);
    g_assert (renderer->pipeline);

    renderer->appsrc = gst_bin_get_by_name (GST_BIN (renderer->pipeline), "video_source");
    renderer->sink = gst_bin_get_by_name (GST_BIN (renderer->pipeline), "video_sink");

    return renderer;
}

void video_renderer_start(video_renderer_t *renderer) {
    //g_signal_connect( renderer->pipeline, "deep-notify", G_CALLBACK(gst_object_default_deep_notify ), NULL );
    gst_element_set_state (renderer->pipeline, GST_STATE_PLAYING);
}

void video_renderer_render_buffer(video_renderer_t *renderer, raop_ntp_t *ntp, unsigned char* data, int data_len, uint64_t pts, int type) {
    GstBuffer *buffer;

    assert(data_len != 0);

    buffer = gst_buffer_new_and_alloc(data_len);
    assert(buffer != NULL);
    GST_BUFFER_DTS(buffer) = (GstClockTime)pts;
    gst_buffer_fill(buffer, 0, data, data_len);
    gst_app_src_push_buffer (GST_APP_SRC(renderer->appsrc), buffer);

    if (!my_window) {
        my_window = enum_windows(display, root, 0);
        if (my_window) {
	    const char* str = g_get_application_name();
            Atom _NET_WM_NAME = XInternAtom(display, "_NET_WM_NAME", 0);
            Atom UTF8_STRING = XInternAtom(display, "UTF8_STRING",0);
            XChangeProperty(display, my_window, _NET_WM_NAME, UTF8_STRING, 8, 0, (const unsigned char *) str, strlen(str));
            XSync(display, False);
        }
    }
}

void video_renderer_flush(video_renderer_t *renderer) {

}

void video_renderer_destroy(video_renderer_t *renderer) {
    gst_app_src_end_of_stream (GST_APP_SRC(renderer->appsrc));
    gst_element_set_state (renderer->pipeline, GST_STATE_NULL);
    gst_object_unref (renderer->pipeline);
    if (renderer) {
        free(renderer);
    }
}

/* not implemented for gstreamer */
void video_renderer_update_background(video_renderer_t *renderer, int type) {
}