gstreamer/tests/examples/sdl/sdlshare.c

/*
 * GStreamer
 * Copyright (C) 2009 Julien Isorce <julien.isorce@gmail.com>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library 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
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public
 * License along with this library; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 */

#include <gst/gst.h>

#ifdef WIN32
#define WIN32_LEAN_AND_MEAN
#include <windows.h>
#endif
#if defined(__APPLE__) && defined(__MACH__)
#include <OpenGL/gl.h>	// Header File For The OpenGL32 Library
#include <OpenGL/glu.h>	// Header File For The GLu32 Library
#else
#include <GL/gl.h>	// Header File For The OpenGL32 Library
#include <GL/glu.h>	// Header File For The GLu32 Library
#endif
#include "SDL.h"
#include "SDL_opengl.h"

/* hack */
typedef struct _GstGLBuffer GstGLBuffer;
struct _GstGLBuffer
{
  GstBuffer buffer;

  GObject *obj;

  gint width;
  gint height;
  GLuint texture;
};

/* rotation angle for the triangle. */
float rtri = 0.0f;

/* rotation angle for the quadrilateral. */
float rquad = 0.0f;

/* A general OpenGL initialization function.  Sets all of the initial parameters. */
void InitGL(int Width, int Height)	        // We call this right after our OpenGL window is created.
{
  glViewport(0, 0, Width, Height);
  glClearColor(0.0f, 0.0f, 0.0f, 0.0f);		// This Will Clear The Background Color To Black
  glClearDepth(1.0);				// Enables Clearing Of The Depth Buffer
  glDepthFunc(GL_LESS);				// The Type Of Depth Test To Do
  glEnable(GL_DEPTH_TEST);			// Enables Depth Testing
  glShadeModel(GL_SMOOTH);			// Enables Smooth Color Shading

  glMatrixMode(GL_PROJECTION);
  glLoadIdentity();				// Reset The Projection Matrix

  gluPerspective(45.0f,(GLfloat)Width/(GLfloat)Height,0.1f,100.0f);	// Calculate The Aspect Ratio Of The Window

  glMatrixMode(GL_MODELVIEW);
}

/* The main drawing function. */
void DrawGLScene(GstGLBuffer *gst_gl_buf)
{
  GLuint texture = gst_gl_buf->texture;
  GLfloat width = (GLfloat) gst_gl_buf->width;
  GLfloat height = (GLfloat) gst_gl_buf->height;
  
  glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);		// Clear The Screen And The Depth Buffer
  glLoadIdentity();				// Reset The View

  glTranslatef(-1.5f,0.0f,-6.0f);		// Move Left 1.5 Units And Into The Screen 6.0
	
  glRotatef(rtri,0.0f,1.0f,0.0f);		// Rotate The Triangle On The Y axis 
  // draw a triangle (in smooth coloring mode)
  glBegin(GL_POLYGON);				// start drawing a polygon
  glColor3f(1.0f,0.0f,0.0f);			// Set The Color To Red
  glVertex3f( 0.0f, 1.0f, 0.0f);		// Top
  glColor3f(0.0f,1.0f,0.0f);			// Set The Color To Green
  glVertex3f( 1.0f,-1.0f, 0.0f);		// Bottom Right
  glColor3f(0.0f,0.0f,1.0f);			// Set The Color To Blue
  glVertex3f(-1.0f,-1.0f, 0.0f);		// Bottom Left	
  glEnd();					// we're done with the polygon (smooth color interpolation)

  glEnable (GL_TEXTURE_RECTANGLE_ARB);
  glBindTexture (GL_TEXTURE_RECTANGLE_ARB, texture);
  glTexParameteri (GL_TEXTURE_RECTANGLE_ARB, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
  glTexParameteri (GL_TEXTURE_RECTANGLE_ARB, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
  glTexParameteri (GL_TEXTURE_RECTANGLE_ARB, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
  glTexParameteri (GL_TEXTURE_RECTANGLE_ARB, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
  glTexEnvi (GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_REPLACE);

  glLoadIdentity();				// make sure we're no longer rotated.
  glTranslatef(1.5f,0.0f,-6.0f);		// Move Right 3 Units, and back into the screen 6.0
	
  glRotatef(rquad,1.0f,0.0f,0.0f);		// Rotate The Quad On The X axis 
  // draw a square (quadrilateral)
  glColor3f(0.5f,0.5f,1.0f);			// set color to a blue shade.
  glBegin(GL_QUADS);				// start drawing a polygon (4 sided)
  glTexCoord3f (0.0f, height, 0.0f);
  glVertex3f(-1.0f, 1.0f, 0.0f);		// Top Left
  glTexCoord3f (width, height, 0.0f);
  glVertex3f( 1.0f, 1.0f, 0.0f);		// Top Right
  glTexCoord3f (width, 0.0f, 0.0f);
  glVertex3f( 1.0f,-1.0f, 0.0f);		// Bottom Right
  glTexCoord3f (0.0f, 0.0f, 0.0f);
  glVertex3f(-1.0f,-1.0f, 0.0f);		// Bottom Left	
  glEnd();					// done with the polygon

  glBindTexture (GL_TEXTURE_RECTANGLE_ARB, 0);

  rtri+=1.0f;					// Increase The Rotation Variable For The Triangle
  rquad-=1.0f;					// Decrease The Rotation Variable For The Quad 

  // swap buffers to display, since we're double buffered.
  SDL_GL_SwapBuffers();
}

gboolean update_sdl_scene (GstElement *fakesink)
{
  GMainLoop *loop = g_object_get_data (G_OBJECT (fakesink), "loop");
  GAsyncQueue *queue_input_buf = g_object_get_data (G_OBJECT (fakesink), "queue_input_buf");
  GAsyncQueue *queue_output_buf = g_object_get_data (G_OBJECT (fakesink), "queue_output_buf");
  GstGLBuffer *gst_gl_buf = g_async_queue_pop (queue_input_buf);
  
  SDL_Event event;
  while ( SDL_PollEvent(&event) ) {
    if ( event.type == SDL_QUIT ) {
      g_main_loop_quit(loop);
    }
    if ( event.type == SDL_KEYDOWN ) {
      if ( event.key.keysym.sym == SDLK_ESCAPE ) {
        g_main_loop_quit(loop);
      }
    }
  }

  DrawGLScene(gst_gl_buf);

  /* push buffer so it can be unref later */
  g_async_queue_push (queue_output_buf, gst_gl_buf);

  return FALSE;
}

/* fakesink handoff callback */
void
on_gst_buffer (GstElement *fakesink, GstBuffer *buf, GstPad *pad, gpointer data)
{
  GAsyncQueue *queue_input_buf = NULL;
  GAsyncQueue *queue_output_buf = NULL;

  /* ref then push buffer to use it in sdl */
  gst_buffer_ref (buf);
  queue_input_buf = g_object_get_data (G_OBJECT (fakesink), "queue_input_buf");
  g_async_queue_push (queue_input_buf, buf);
  if (g_async_queue_length (queue_input_buf) > 3)
    g_idle_add (update_sdl_scene, fakesink);

  /* pop then unref buffer we have finished to use in sdl */
  queue_output_buf = g_object_get_data (G_OBJECT (fakesink), "queue_output_buf");
  if (g_async_queue_length (queue_output_buf) > 3) {
    GstBuffer *buf_old = g_async_queue_pop (queue_output_buf);
    gst_buffer_unref (buf_old);
  }
}

/* gst bus signal watch callback */
void
end_stream_cb (GstBus *bus, GstMessage *msg, GMainLoop *loop)
{
  switch (GST_MESSAGE_TYPE (msg)) {

    case GST_MESSAGE_EOS:
      g_print ("End-of-stream\n");
      g_print ("For more information, try to run: GST_DEBUG=gldisplay:2 ./sdlshare\n");
      break;

    case GST_MESSAGE_ERROR:
    {
      gchar *debug = NULL;
      GError *err = NULL;

      gst_message_parse_error (msg, &err, &debug);

      g_print ("Error: %s\n", err->message);
      g_error_free (err);

      if (debug) {
        g_print ("Debug deails: %s\n", debug);
        g_free (debug);
      }

      break;
    }

    default:
      break;
  }

  g_main_loop_quit (loop);
}

int main(int argc, char **argv) 
{

#ifdef WIN32
  HGLRC sdl_gl_context = 0;
  HDC sdl_dc = 0;
#else
  SDL_SysWMinfo info;
  Display *sdl_display = NULL;
  Window sdl_win = 0;
  GLXContext sdl_gl_context = NULL;
#endif

  GMainLoop *loop = NULL;
  GstPipeline *pipeline = NULL;
  GstBus *bus = NULL;
  GstElement *glupload = NULL;
  GstElement *fakesink = NULL;
  GstState state = 0;
  GAsyncQueue *queue_input_buf = NULL;
  GAsyncQueue *queue_output_buf = NULL;

  /* Initialize SDL for video output */
  if ( SDL_Init(SDL_INIT_VIDEO) < 0 ) {
    fprintf(stderr, "Unable to initialize SDL: %s\n", SDL_GetError());
    return -1;
  }

  /* Create a 640x480 OpenGL screen */
  if ( SDL_SetVideoMode(640, 480, 0, SDL_OPENGL) == NULL ) {
    fprintf(stderr, "Unable to create OpenGL screen: %s\n", SDL_GetError());
    SDL_Quit();
    return -1;
  }

  /* Set the title bar in environments that support it */
  SDL_WM_SetCaption("SDL and gst-plugins-gl", NULL);

  /* Loop, drawing and checking events */
  InitGL(640, 480);

  gst_init (&argc, &argv);
  loop = g_main_loop_new (NULL, FALSE);

  /* retrieve and turn off sdl opengl context */
#ifdef WIN32
  sdl_gl_context = wglGetCurrentContext ();
  sdl_dc = wglGetCurrentDC ();
  wglMakeCurrent (0, 0);
#else
  sdl_display = info.info.x11.display;
  sdl_win = info.info.x11.wmwindow;
  sdl_gl_context = glXGetCurrentContext ();
  glXMakeCurrent (clutter_display, None, 0);
#endif

  pipeline =
    GST_PIPELINE (gst_parse_launch
    ("videotestsrc ! video/x-raw-yuv, width=320, height=240, framerate=(fraction)30/1 ! "
       "glupload ! gleffects effect=5 ! fakesink sync=1",
       NULL));

  bus = gst_pipeline_get_bus (GST_PIPELINE (pipeline));
  gst_bus_add_signal_watch (bus);
  g_signal_connect (bus, "message::error", G_CALLBACK (end_stream_cb), loop);
  g_signal_connect (bus, "message::warning", G_CALLBACK (end_stream_cb), loop);
  g_signal_connect (bus, "message::eos", G_CALLBACK (end_stream_cb), loop);
  gst_object_unref (bus);

  /* sdl_gl_context is an external OpenGL context with which gst-plugins-gl want to share textures */
  glupload = gst_bin_get_by_name (GST_BIN (pipeline), "glupload0");
  g_object_set (G_OBJECT (glupload), "external-opengl-context", sdl_gl_context, NULL);
  g_object_unref (glupload);

  /* NULL to PAUSED state pipeline to make sure the gst opengl context is created and
   * shared with the sdl one */
  gst_element_set_state (GST_ELEMENT (pipeline), GST_STATE_PAUSED);
  state = GST_STATE_PAUSED;
  if (gst_element_get_state (GST_ELEMENT (pipeline), &state, NULL, 
        GST_CLOCK_TIME_NONE) != GST_STATE_CHANGE_SUCCESS) {
    g_debug ("failed to pause pipeline\n");
    return -1;
  }

  /* turn on back sdl opengl context */
#ifdef WIN32
  wglMakeCurrent (sdl_dc, sdl_gl_context);
#else
  glXMakeCurrent (sdl_display, sdl_win, clutter_gl_context);
#endif

  /* append a gst-gl texture to this queue when you do not need it no more */
  fakesink = gst_bin_get_by_name (GST_BIN (pipeline), "fakesink0");
  g_object_set (G_OBJECT (fakesink), "signal-handoffs", TRUE, NULL);
  g_signal_connect (fakesink, "handoff", G_CALLBACK (on_gst_buffer), NULL);
  queue_input_buf = g_async_queue_new ();
  queue_output_buf = g_async_queue_new ();
  g_object_set_data (G_OBJECT (fakesink), "queue_input_buf", queue_input_buf);
  g_object_set_data (G_OBJECT (fakesink), "queue_output_buf", queue_output_buf);
  g_object_set_data (G_OBJECT (fakesink), "loop", loop);
  g_object_unref (fakesink);

  gst_element_set_state (GST_ELEMENT (pipeline), GST_STATE_PLAYING);

  g_main_loop_run (loop);

  /* before to deinitialize the gst-gl-opengl context,
   * no shared context (here the sdl one) must be current
   */
#ifdef WIN32
  wglMakeCurrent (0, 0);
#else
  g_print ("no yet implemented if not win32\n");
  return -1;
#endif

  gst_element_set_state (GST_ELEMENT (pipeline), GST_STATE_NULL);
  g_object_unref (pipeline);

  /* turn on back sdl opengl context */
#ifdef WIN32
  wglMakeCurrent (sdl_dc, sdl_gl_context);
#else
  glXMakeCurrent (sdl_display, None, 0);
#endif

  SDL_Quit();

  /* make sure there is no pending gst gl buffer in the communication queues 
   * between sdl and gst-gl
   */
  while (g_async_queue_length (queue_input_buf) > 0) {
    GstBuffer *buf = g_async_queue_pop (queue_input_buf);
    gst_buffer_unref (buf);
  }

  while (g_async_queue_length (queue_output_buf) > 0) {
    GstBuffer *buf = g_async_queue_pop (queue_output_buf);
    gst_buffer_unref (buf);
  }

  return 0;
}