SMP/HT fixes

[melted] / src / modules / sdl / consumer_sdl.c

/*
 * consumer_sdl.c -- A Simple DirectMedia Layer consumer
 * Copyright (C) 2003-2004 Ushodaya Enterprises Limited
 * Author: Dan Dennedy <dan@dennedy.org>
 *
 * 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 2 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 */

#include "consumer_sdl.h"
#include <framework/mlt_frame.h>
#include <framework/mlt_deque.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <pthread.h>
#include <SDL/SDL.h>
#include <SDL/SDL_syswm.h>
#include <sys/time.h>

/** This classes definition.
*/

typedef struct consumer_sdl_s *consumer_sdl;

struct consumer_sdl_s
{
        struct mlt_consumer_s parent;
        mlt_properties properties;
        mlt_deque queue;
        pthread_t thread;
        int joined;
        int running;
        uint8_t audio_buffer[ 4096 * 10 ];
        int audio_avail;
        pthread_mutex_t audio_mutex;
        pthread_cond_t audio_cond;
        pthread_mutex_t video_mutex;
        pthread_cond_t video_cond;
        int window_width;
        int window_height;
        float aspect_ratio;
        float display_aspect;
        double last_frame_aspect;
        int width;
        int height;
        int playing;
        int sdl_flags;
        SDL_Surface *sdl_screen;
        SDL_Overlay *sdl_overlay;
        SDL_Rect rect;
        uint8_t *buffer;
        int bpp;
};

/** Forward references to static functions.
*/

static int consumer_start( mlt_consumer parent );
static int consumer_stop( mlt_consumer parent );
static int consumer_is_stopped( mlt_consumer parent );
static void consumer_close( mlt_consumer parent );
static void *consumer_thread( void * );
static int consumer_get_dimensions( int *width, int *height );
static void consumer_sdl_event( mlt_listener listener, mlt_properties owner, mlt_service this, void **args );

/** This is what will be called by the factory - anything can be passed in
        via the argument, but keep it simple.
*/

mlt_consumer consumer_sdl_init( char *arg )
{
        // Create the consumer object
        consumer_sdl this = calloc( sizeof( struct consumer_sdl_s ), 1 );

        // If no malloc'd and consumer init ok
        if ( this != NULL && mlt_consumer_init( &this->parent, this ) == 0 )
        {
                // Create the queue
                this->queue = mlt_deque_init( );

                // Get the parent consumer object
                mlt_consumer parent = &this->parent;

                // We have stuff to clean up, so override the close method
                parent->close = consumer_close;

                // get a handle on properties
                mlt_service service = MLT_CONSUMER_SERVICE( parent );
                this->properties = MLT_SERVICE_PROPERTIES( service );

                // Set the default volume
                mlt_properties_set_double( this->properties, "volume", 1.0 );

                // This is the initialisation of the consumer
                pthread_mutex_init( &this->audio_mutex, NULL );
                pthread_cond_init( &this->audio_cond, NULL);
                pthread_mutex_init( &this->video_mutex, NULL );
                pthread_cond_init( &this->video_cond, NULL);
                
                // Default scaler (for now we'll use nearest)
                mlt_properties_set( this->properties, "rescale", "nearest" );

                // Default buffer for low latency
                mlt_properties_set_int( this->properties, "buffer", 1 );

                // Default progressive true
                mlt_properties_set_int( this->properties, "progressive", 0 );

                // Default audio buffer
                mlt_properties_set_int( this->properties, "audio_buffer", 512 );

                // Get sample aspect ratio
                this->aspect_ratio = mlt_properties_get_double( this->properties, "aspect_ratio" );

                // Ensure we don't join on a non-running object
                this->joined = 1;
                
                // Default display aspect ratio
                this->display_aspect = 4.0 / 3.0;
                
                // process actual param
                if ( arg == NULL || sscanf( arg, "%dx%d", &this->width, &this->height ) != 2 )
                {
                        this->width = mlt_properties_get_int( this->properties, "width" );
                        this->height = mlt_properties_get_int( this->properties, "height" );
                }

                // Default window size
                this->window_width = ( float )this->height * this->display_aspect;
                this->window_height = this->height;

                // Set the sdl flags
                this->sdl_flags = SDL_HWSURFACE | SDL_ASYNCBLIT | SDL_HWACCEL | SDL_RESIZABLE | SDL_DOUBLEBUF;

                // Allow thread to be started/stopped
                parent->start = consumer_start;
                parent->stop = consumer_stop;
                parent->is_stopped = consumer_is_stopped;

                // Register specific events
                mlt_events_register( this->properties, "consumer-sdl-event", ( mlt_transmitter )consumer_sdl_event );

                // Return the consumer produced
                return parent;
        }

        // malloc or consumer init failed
        free( this );

        // Indicate failure
        return NULL;
}

static void consumer_sdl_event( mlt_listener listener, mlt_properties owner, mlt_service this, void **args )
{
        if ( listener != NULL )
                listener( owner, this, ( SDL_Event * )args[ 0 ] );
}

int consumer_start( mlt_consumer parent )
{
        consumer_sdl this = parent->child;

        if ( !this->running )
        {
                pthread_attr_t thread_attributes;
                
                consumer_stop( parent );

                this->running = 1;
                this->joined = 0;

                // Allow the user to force resizing to window size
                if ( mlt_properties_get_int( this->properties, "resize" ) )
                {
                        mlt_properties_set_int( this->properties, "width", this->width );
                        mlt_properties_set_int( this->properties, "height", this->height );
                }

                // Inherit the scheduling priority
                pthread_attr_init( &thread_attributes );
                pthread_attr_setinheritsched( &thread_attributes, PTHREAD_INHERIT_SCHED );

                pthread_create( &this->thread, &thread_attributes, consumer_thread, this );
        }

        return 0;
}

int consumer_stop( mlt_consumer parent )
{
        // Get the actual object
        consumer_sdl this = parent->child;

        if ( this->joined == 0 )
        {
                // Kill the thread and clean up
                this->joined = 1;
                this->running = 0;
                pthread_join( this->thread, NULL );
        }

        return 0;
}

int consumer_is_stopped( mlt_consumer parent )
{
        consumer_sdl this = parent->child;
        return !this->running;
}

static int sdl_lock_display( )
{
        SDL_Surface *screen = SDL_GetVideoSurface( );
        return screen != NULL && ( !SDL_MUSTLOCK( screen ) || SDL_LockSurface( screen ) >= 0 );
}

static void sdl_unlock_display( )
{
        SDL_Surface *screen = SDL_GetVideoSurface( );
        if ( screen != NULL && SDL_MUSTLOCK( screen ) )
                SDL_UnlockSurface( screen );
}

static void sdl_fill_audio( void *udata, uint8_t *stream, int len )
{
        consumer_sdl this = udata;

        // Get the volume
        float volume = mlt_properties_get_double( this->properties, "volume" );

        pthread_mutex_lock( &this->audio_mutex );

        // Block until audio received
        while ( this->running && len > this->audio_avail )
                pthread_cond_wait( &this->audio_cond, &this->audio_mutex );

        if ( this->audio_avail >= len )
        {
                // Place in the audio buffer
                memcpy( stream, this->audio_buffer, len );

                // Remove len from the audio available
                this->audio_avail -= len;

                // Remove the samples
                memmove( this->audio_buffer, this->audio_buffer + len, this->audio_avail );
        }
        else
        {
                // Just to be safe, wipe the stream first
                memset( stream, 0, len );

                // Copy what we have into the stream
                memcpy( stream, this->audio_buffer, this->audio_avail );

                // Mix the audio 
                SDL_MixAudio( stream, stream, len, ( int )( ( float )SDL_MIX_MAXVOLUME * volume ) );

                // No audio left
                this->audio_avail = 0;
        }

        // We're definitely playing now
        this->playing = 1;

        pthread_cond_broadcast( &this->audio_cond );
        pthread_mutex_unlock( &this->audio_mutex );
}

static int consumer_play_audio( consumer_sdl this, mlt_frame frame, int init_audio, int *duration )
{
        // Get the properties of this consumer
        mlt_properties properties = this->properties;
        mlt_audio_format afmt = mlt_audio_pcm;

        // Set the preferred params of the test card signal
        int channels = mlt_properties_get_int( properties, "channels" );
        int frequency = mlt_properties_get_int( properties, "frequency" );
        static int counter = 0;

        int samples = mlt_sample_calculator( mlt_properties_get_double( this->properties, "fps" ), frequency, counter++ );
        
        int16_t *pcm;
        int bytes;

        mlt_frame_get_audio( frame, &pcm, &afmt, &frequency, &channels, &samples );
        *duration = ( ( samples * 1000 ) / frequency );

        if ( mlt_properties_get_int( properties, "audio_off" ) )
        {
                this->playing = 1;
                init_audio = 1;
                return init_audio;
        }

        if ( init_audio == 1 )
        {
                SDL_AudioSpec request;
                SDL_AudioSpec got;

                int audio_buffer = mlt_properties_get_int( properties, "audio_buffer" );

                // specify audio format
                memset( &request, 0, sizeof( SDL_AudioSpec ) );
                this->playing = 0;
                request.freq = frequency;
                request.format = AUDIO_S16;
                request.channels = channels;
                request.samples = audio_buffer;
                request.callback = sdl_fill_audio;
                request.userdata = (void *)this;
                if ( SDL_OpenAudio( &request, &got ) != 0 )
                {
                        fprintf( stderr, "SDL failed to open audio: %s\n", SDL_GetError() );
                        init_audio = 2;
                }
                else if ( got.size != 0 )
                {
                        SDL_PauseAudio( 0 );
                        init_audio = 0;
                }
        }

        if ( init_audio == 0 )
        {
                mlt_properties properties = MLT_FRAME_PROPERTIES( frame );
                bytes = ( samples * channels * 2 );
                pthread_mutex_lock( &this->audio_mutex );
                while ( this->running && bytes > ( sizeof( this->audio_buffer) - this->audio_avail ) )
                        pthread_cond_wait( &this->audio_cond, &this->audio_mutex );
                if ( this->running )
                {
                        if ( mlt_properties_get_double( properties, "_speed" ) == 1 )
                                memcpy( &this->audio_buffer[ this->audio_avail ], pcm, bytes );
                        else
                                memset( &this->audio_buffer[ this->audio_avail ], 0, bytes );
                        this->audio_avail += bytes;
                }
                pthread_cond_broadcast( &this->audio_cond );
                pthread_mutex_unlock( &this->audio_mutex );
        }
        else
        {
                this->playing = 1;
        }

        return init_audio;
}

static int consumer_play_video( consumer_sdl this, mlt_frame frame )
{
        // Get the properties of this consumer
        mlt_properties properties = this->properties;

        mlt_image_format vfmt = mlt_image_yuv422;
        int width = this->width, height = this->height;
        uint8_t *image;
        int changed = 0;

        if ( this->running && mlt_properties_get_int( properties, "video_off" ) == 0 )
        {
                // Get the image, width and height
                mlt_events_fire( properties, "consumer-frame-show", frame, NULL );
                mlt_frame_get_image( frame, &image, &vfmt, &width, &height, 0 );
                
                // Handle events
                if ( this->sdl_screen != NULL )
                {
                        SDL_Event event;
        
                        changed = consumer_get_dimensions( &this->window_width, &this->window_height );

                        while ( SDL_PollEvent( &event ) )
                        {
                                mlt_events_fire( this->properties, "consumer-sdl-event", &event, NULL );

                                switch( event.type )
                                {
                                        case SDL_VIDEORESIZE:
                                                this->window_width = event.resize.w;
                                                this->window_height = event.resize.h;
                                                changed = 1;
                                                break;
                                        case SDL_QUIT:
                                                this->running = 0;
                                                break;
                                        case SDL_KEYDOWN:
                                                {
                                                        mlt_producer producer = mlt_properties_get_data( properties, "transport_producer", NULL );
                                                        char keyboard[ 2 ] = " ";
                                                        void (*callback)( mlt_producer, char * ) = mlt_properties_get_data( properties, "transport_callback", NULL );
                                                        if ( callback != NULL && producer != NULL && event.key.keysym.unicode < 0x80 && event.key.keysym.unicode > 0 )
                                                        {
                                                                keyboard[ 0 ] = ( char )event.key.keysym.unicode;
                                                                callback( producer, keyboard );
                                                        }
                                                }
                                                break;
                                }
                        }
                }
        
                if ( width != this->width || height != this->height )
                {
                        if ( this->sdl_overlay != NULL )
                                SDL_FreeYUVOverlay( this->sdl_overlay );
                        this->sdl_overlay = NULL;
                }

                if ( this->running && ( this->sdl_screen == NULL || changed ) )
                {
                        // Force an overlay recreation
                        if ( this->sdl_overlay != NULL )
                                SDL_FreeYUVOverlay( this->sdl_overlay );
                        this->sdl_overlay = NULL;

                        // open SDL window with video overlay, if possible
                        sdl_lock_display();
                        this->sdl_screen = SDL_SetVideoMode( this->window_width, this->window_height, this->bpp, this->sdl_flags );
                        sdl_unlock_display();
                        if ( consumer_get_dimensions( &this->window_width, &this->window_height ) )
                                this->sdl_screen = SDL_SetVideoMode( this->window_width, this->window_height, this->bpp, this->sdl_flags );
                        //SDL_Flip( this->sdl_screen );
                        mlt_properties_set_int( properties, "changed", 0 );
                }
                else if ( mlt_properties_get_int( properties, "changed" ) )
                {
                        sdl_lock_display();
                        this->sdl_screen = SDL_SetVideoMode( this->window_width, this->window_height, this->bpp, this->sdl_flags );
                        SDL_SetClipRect( this->sdl_screen, &this->rect );
                        sdl_unlock_display();
                        mlt_properties_set_int( properties, "changed", 0 );
                }

                if ( this->running )
                {
                        // Determine window's new display aspect ratio
                        float this_aspect = ( float )this->window_width / this->window_height;

                        // Determine frame's display aspect ratio
                        float frame_aspect = mlt_frame_get_aspect_ratio( frame ) * width / height;
                        this->width = width;
                        this->height = height;

                        // If using hardware scaler
                        if ( mlt_properties_get( properties, "rescale" ) != NULL &&
                                !strcmp( mlt_properties_get( properties, "rescale" ), "none" ) )
                        {
                                // Special case optimisation to negate odd effect of sample aspect ratio
                                // not corresponding exactly with image resolution.
                                if ( ( (int)( this_aspect * 1000 ) == (int)( this->display_aspect * 1000 ) ) && 
                                         ( (int)( mlt_frame_get_aspect_ratio( frame ) * 1000 ) == (int)( this->aspect_ratio * 1000 ) ) )
                                {
                                        this->rect.w = this->window_width;
                                        this->rect.h = this->window_height;
                                }
                                else
                                {
                                        // Use hardware scaler to normalise display aspect ratio
                                        this->rect.w = frame_aspect / this_aspect * this->window_width;
                                        this->rect.h = this->window_height;
                                        if ( this->rect.w > this->window_width )
                                        {
                                                this->rect.w = this->window_width;
                                                this->rect.h = this_aspect / frame_aspect * this->window_height;
                                        }
                                }
                        }
                        // Special case optimisation to negate odd effect of sample aspect ratio
                        // not corresponding exactly with image resolution.
                        else if ( (int)( this_aspect * 1000 ) == (int)( this->display_aspect * 1000 ) ) 
                        {
                                this->rect.w = this->window_width;
                                this->rect.h = this->window_height;
                        }
                        // Use hardware scaler to normalise sample aspect ratio
                        else if ( this->window_height * this->display_aspect > this->window_width )
                        {
                                this->rect.w = this->window_width;
                                this->rect.h = this->window_width / this->display_aspect;
                        }
                        else
                        {
                                this->rect.w = this->window_height * this->display_aspect;
                                this->rect.h = this->window_height;
                        }
                        
                        this->rect.x = ( this->window_width - this->rect.w ) / 2;
                        this->rect.y = ( this->window_height - this->rect.h ) / 2;

                        mlt_properties_set_int( this->properties, "rect_x", this->rect.x );
                        mlt_properties_set_int( this->properties, "rect_y", this->rect.y );
                        mlt_properties_set_int( this->properties, "rect_w", this->rect.w );
                        mlt_properties_set_int( this->properties, "rect_h", this->rect.h );

                        SDL_SetClipRect( this->sdl_screen, &this->rect );
                }

                if ( this->running && this->sdl_screen != NULL && this->sdl_overlay == NULL )
                {
                        SDL_SetClipRect( this->sdl_screen, &this->rect );
                        SDL_Flip( this->sdl_screen );
                        sdl_lock_display();
                        this->sdl_overlay = SDL_CreateYUVOverlay( this->width, this->height, SDL_YUY2_OVERLAY, this->sdl_screen );
                        sdl_unlock_display();
                }

                if ( this->running && this->sdl_screen != NULL && this->sdl_overlay != NULL )
                {
                        this->buffer = this->sdl_overlay->pixels[ 0 ];
                        sdl_lock_display();
                        if ( SDL_LockYUVOverlay( this->sdl_overlay ) >= 0 )
                        {
                                if ( image != NULL )
                                        memcpy( this->buffer, image, width * height * 2 );
                                SDL_UnlockYUVOverlay( this->sdl_overlay );
                                SDL_DisplayYUVOverlay( this->sdl_overlay, &this->sdl_screen->clip_rect );
                        }
                        sdl_unlock_display();
                }
        }

        return 0;
}

static void *video_thread( void *arg )
{
        // Identify the arg
        consumer_sdl this = arg;

        // Obtain time of thread start
        struct timeval now;
        int64_t start = 0;
        int64_t elapsed = 0;
        struct timespec tm;
        mlt_frame next = NULL;
        mlt_properties properties = NULL;
        double speed = 0;

        // Get real time flag
        int real_time = mlt_properties_get_int( this->properties, "real_time" );

        // Get the current time
        gettimeofday( &now, NULL );

        // Determine start time
        start = ( int64_t )now.tv_sec * 1000000 + now.tv_usec;

        while ( this->running )
        {
                // Pop the next frame
                pthread_mutex_lock( &this->video_mutex );
                next = mlt_deque_pop_front( this->queue );
                while ( next == NULL && this->running )
                {
                        pthread_cond_wait( &this->video_cond, &this->video_mutex );
                        next = mlt_deque_pop_front( this->queue );
                }
                pthread_mutex_unlock( &this->video_mutex );

                if ( !this->running || next == NULL ) break;

                // Get the properties
                properties =  MLT_FRAME_PROPERTIES( next );

                // Get the speed of the frame
                speed = mlt_properties_get_double( properties, "_speed" );

                // Get the current time
                gettimeofday( &now, NULL );

                // Get the elapsed time
                elapsed = ( ( int64_t )now.tv_sec * 1000000 + now.tv_usec ) - start;

                // See if we have to delay the display of the current frame
                if ( mlt_properties_get_int( properties, "rendered" ) == 1 && this->running )
                {
                        // Obtain the scheduled playout time
                        mlt_position scheduled = mlt_properties_get_position( properties, "playtime" );

                        // Determine the difference between the elapsed time and the scheduled playout time
                        mlt_position difference = scheduled - elapsed;

                        // Smooth playback a bit
                        if ( real_time && ( difference > 20000 && speed == 1.0 ) )
                        {
                                tm.tv_sec = difference / 1000000;
                                tm.tv_nsec = ( difference % 1000000 ) * 500;
                                nanosleep( &tm, NULL );
                        }

                        // Show current frame if not too old
                        if ( !real_time || ( difference > -10000 || speed != 1.0 || mlt_deque_count( this->queue ) < 2 ) )
                                consumer_play_video( this, next );

                        // If the queue is empty, recalculate start to allow build up again
                        if ( real_time && ( mlt_deque_count( this->queue ) == 0 && speed == 1.0 ) )
                        {
                                gettimeofday( &now, NULL );
                                start = ( ( int64_t )now.tv_sec * 1000000 + now.tv_usec ) - scheduled + 20000;
                        }
                }

                // This frame can now be closed
                mlt_frame_close( next );
                next = NULL;
        }

        if ( next != NULL )
                mlt_frame_close( next );

        mlt_consumer_stopped( &this->parent );

        return NULL;
}

/** Threaded wrapper for pipe.
*/

static void *consumer_thread( void *arg )
{
        // Identify the arg
        consumer_sdl this = arg;

        // Get the consumer
        mlt_consumer consumer = &this->parent;

        // Video thread
        pthread_t thread;

        // internal intialization
        int init_audio = 1;
        int init_video = 1;
        mlt_frame frame = NULL;
        mlt_properties properties = NULL;
        int duration = 0;
        int64_t playtime = 0;
        struct timespec tm = { 0, 100000 };

        this->bpp = mlt_properties_get_int( this->properties, "bpp" );

        if ( mlt_properties_get_int( MLT_CONSUMER_PROPERTIES( consumer ), "sdl_started" ) == 0 )
        {
                if ( SDL_Init( SDL_INIT_VIDEO | SDL_INIT_NOPARACHUTE ) < 0 )
                {
                        fprintf( stderr, "Failed to initialize SDL: %s\n", SDL_GetError() );
                        return NULL;
                }

                SDL_EnableKeyRepeat( SDL_DEFAULT_REPEAT_DELAY, SDL_DEFAULT_REPEAT_INTERVAL );
                SDL_EnableUNICODE( 1 );
        }
        else
        {
                if ( SDL_GetVideoSurface( ) != NULL )
                {
                        this->sdl_screen = SDL_GetVideoSurface( );
                        consumer_get_dimensions( &this->window_width, &this->window_height );
                        mlt_properties_set_int( this->properties, "changed", 0 );
                }
        }

        if ( !mlt_properties_get_int( MLT_CONSUMER_PROPERTIES( consumer ), "audio_off" ) )
                SDL_InitSubSystem( SDL_INIT_AUDIO );

        // Loop until told not to
        while( this->running )
        {
                // Get a frame from the attached producer
                frame = mlt_consumer_rt_frame( consumer );

                // Ensure that we have a frame
                if ( frame != NULL )
                {
                        // Get the frame properties
                        properties =  MLT_FRAME_PROPERTIES( frame );

                        // Play audio
                        init_audio = consumer_play_audio( this, frame, init_audio, &duration );

                        // Determine the start time now
                        if ( this->playing && init_video )
                        {
                                // Create the video thread
                                pthread_create( &thread, NULL, video_thread, this );

                                // Video doesn't need to be initialised any more
                                init_video = 0;
                        }

                        // Set playtime for this frame
                        mlt_properties_set_position( properties, "playtime", playtime );

                        while ( this->running && mlt_deque_count( this->queue ) > 15 )
                                nanosleep( &tm, NULL );

                        // Push this frame to the back of the queue
                        pthread_mutex_lock( &this->video_mutex );
                        mlt_deque_push_back( this->queue, frame );
                        pthread_cond_broadcast( &this->video_cond );
                        pthread_mutex_unlock( &this->video_mutex );

                        // Calculate the next playtime
                        playtime += ( duration * 1000 );
                }
        }

        // Kill the video thread
        if ( init_video == 0 )
        {
                pthread_mutex_lock( &this->video_mutex );
                pthread_cond_broadcast( &this->video_cond );
                pthread_mutex_unlock( &this->video_mutex );
                pthread_join( thread, NULL );
        }

        // internal cleanup
        if ( this->sdl_overlay != NULL )
                SDL_FreeYUVOverlay( this->sdl_overlay );

        if ( !mlt_properties_get_int( MLT_CONSUMER_PROPERTIES( consumer ), "audio_off" ) )
                SDL_QuitSubSystem( SDL_INIT_AUDIO );

        //if ( mlt_properties_get_int( MLT_CONSUMER_PROPERTIES( consumer ), "sdl_started" ) == 0 )
                //SDL_Quit( );

        while( mlt_deque_count( this->queue ) )
                mlt_frame_close( mlt_deque_pop_back( this->queue ) );

        this->sdl_screen = NULL;
        this->sdl_overlay = NULL;
        this->audio_avail = 0;

        return NULL;
}

static int consumer_get_dimensions( int *width, int *height )
{
        int changed = 0;

        // SDL windows manager structure
        SDL_SysWMinfo wm;

        // Specify the SDL Version
        SDL_VERSION( &wm.version );

        // Lock the display
        sdl_lock_display();

        // Get the wm structure
        if ( SDL_GetWMInfo( &wm ) == 1 )
        {
                // Check that we have the X11 wm
                if ( wm.subsystem == SDL_SYSWM_X11 ) 
                {
                        // Get the SDL window
                        Window window = wm.info.x11.window;

                        // Get the display session
                        Display *display = wm.info.x11.display;

                        // Get the window attributes
                        XWindowAttributes attr;
                        XGetWindowAttributes( display, window, &attr );

                        // Determine whether window has changed
                        changed = *width != attr.width || *height != attr.height;

                        // Return width and height
                        *width = attr.width;
                        *height = attr.height;
                }
        }

        // Unlock the display
        sdl_lock_display();

        return changed;
}

/** Callback to allow override of the close method.
*/

static void consumer_close( mlt_consumer parent )
{
        // Get the actual object
        consumer_sdl this = parent->child;

        // Stop the consumer
        ///mlt_consumer_stop( parent );

        // Now clean up the rest
        mlt_consumer_close( parent );

        // Close the queue
        mlt_deque_close( this->queue );

        // Destroy mutexes
        pthread_mutex_destroy( &this->audio_mutex );
        pthread_cond_destroy( &this->audio_cond );
                
        // Finally clean up this
        free( this );
}