video_output.c

/******************************************************************************
 * video_output.c : video output thread
 * (c)2000 VideoLAN
 ******************************************************************************
 * This module describes the programming interface for video output threads.
 * It includes functions allowing to open a new thread, send pictures to a
 * thread, and destroy a previously oppenned video output thread.
 ******************************************************************************/

/******************************************************************************
 * Preamble
 ******************************************************************************/
#include <errno.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>

#include "common.h"
#include "config.h"
#include "mtime.h"
#include "vlc_thread.h"
#include "video.h"
#include "video_output.h"
#include "video_text.h"
#include "video_sys.h"
#include "video_yuv.h"
#include "intf_msg.h"
#include "main.h"

/******************************************************************************
 * Local prototypes
 ******************************************************************************/
static int      InitThread              ( vout_thread_t *p_vout );
static void     RunThread               ( vout_thread_t *p_vout );
static void     ErrorThread             ( vout_thread_t *p_vout );
static void     EndThread               ( vout_thread_t *p_vout );
static void     DestroyThread           ( vout_thread_t *p_vout, int i_status );
static void     Print                   ( vout_thread_t *p_vout, int i_x, int i_y, int i_halign, int i_valign, unsigned char *psz_text );

static void     SetBufferArea           ( vout_thread_t *p_vout, int i_x, int i_y, int i_w, int i_h );
static void     SetBufferPicture        ( vout_thread_t *p_vout, picture_t *p_pic );
static void     RenderPicture           ( vout_thread_t *p_vout, picture_t *p_pic );
static void     RenderPictureInfo       ( vout_thread_t *p_vout, picture_t *p_pic );
static void     RenderSubPictureUnit    ( vout_thread_t *p_vout, spu_t *p_spu );
static void     RenderInterface         ( vout_thread_t *p_vout );
static void     RenderIdle              ( vout_thread_t *p_vout );
static void     RenderInfo              ( vout_thread_t *p_vout );
static int      Manage                  ( vout_thread_t *p_vout );

/******************************************************************************
 * vout_CreateThread: creates a new video output thread
 ******************************************************************************
 * This function creates a new video output thread, and returns a pointer
 * to its description. On error, it returns NULL.
 * If pi_status is NULL, then the function will block until the thread is ready.
 * If not, it will be updated using one of the THREAD_* constants.
 ******************************************************************************/
vout_thread_t * vout_CreateThread               ( char *psz_display, int i_root_window, 
                                                  int i_width, int i_height, int *pi_status )
{
    vout_thread_t * p_vout;                              /* thread descriptor */
    int             i_status;                                /* thread status */
    int             i_index;                /* index for array initialization */    

    /* Allocate descriptor */
    intf_DbgMsg("\n");    
    p_vout = (vout_thread_t *) malloc( sizeof(vout_thread_t) );
    if( p_vout == NULL )
    {
        intf_ErrMsg("error: %s\n", strerror(ENOMEM));        
        return( NULL );
    }

    /* Initialize thread properties - thread id and locks will be initialized 
     * later */
    p_vout->b_die               = 0;
    p_vout->b_error             = 0;    
    p_vout->b_active            = 0;
    p_vout->pi_status           = (pi_status != NULL) ? pi_status : &i_status;
    *p_vout->pi_status          = THREAD_CREATE;    

    /* Initialize some fields used by the system-dependant method - these fields will
     * probably be modified by the method, and are only preferences */
    p_vout->i_width             = i_width;
    p_vout->i_height            = i_height;
    p_vout->i_bytes_per_line    = i_width * 2;    
    p_vout->i_screen_depth      = 15;
    p_vout->i_bytes_per_pixel   = 2;
    p_vout->f_gamma             = VOUT_GAMMA;    

    p_vout->b_grayscale         = main_GetIntVariable( VOUT_GRAYSCALE_VAR, 
                                                       VOUT_GRAYSCALE_DEFAULT );
    p_vout->b_info              = 0;    
    p_vout->b_interface         = 0;
    p_vout->b_scale             = 0;
    
    intf_DbgMsg("wished configuration: %dx%d,%d (%d bytes/pixel, %d bytes/line)\n",
                p_vout->i_width, p_vout->i_height, p_vout->i_screen_depth,
                p_vout->i_bytes_per_pixel, p_vout->i_bytes_per_line );

#ifdef STATS
    /* Initialize statistics fields */
    p_vout->render_time         = 0;    
    p_vout->c_fps_samples       = 0;    
#endif      

    /* Initialize running properties */
    p_vout->i_changes           = 0;
    p_vout->last_picture_date   = 0;
    p_vout->last_display_date   = 0;

    /* Initialize buffer index */
    p_vout->i_buffer_index      = 0;

    /* Initialize pictures and spus - translation tables and functions
     * will be initialized later in InitThread */    
    for( i_index = 0; i_index < VOUT_MAX_PICTURES; i_index++)
    {
        p_vout->p_picture[i_index].i_type   = EMPTY_PICTURE;
        p_vout->p_picture[i_index].i_status = FREE_PICTURE;
        p_vout->p_spu[i_index].i_type  = EMPTY_SPU;
        p_vout->p_spu[i_index].i_status= FREE_SPU;
    }
   
    /* Create and initialize system-dependant method - this function issues its
     * own error messages */
    if( vout_SysCreate( p_vout, psz_display, i_root_window ) )
    {
      free( p_vout );
      return( NULL );
    }
    intf_DbgMsg("actual configuration: %dx%d,%d (%d bytes/pixel, %d bytes/line)\n",
                p_vout->i_width, p_vout->i_height, p_vout->i_screen_depth,
                p_vout->i_bytes_per_pixel, p_vout->i_bytes_per_line );

    /* Load fonts - fonts must be initialized after the systme method since
     * they may be dependant of screen depth and other thread properties */
    p_vout->p_default_font      = vout_LoadFont( VOUT_DEFAULT_FONT );    
    if( p_vout->p_default_font == NULL )
    {
        vout_SysDestroy( p_vout );        
        free( p_vout );        
        return( NULL );        
    }    
    p_vout->p_large_font        = vout_LoadFont( VOUT_LARGE_FONT );        
    if( p_vout->p_large_font == NULL )
    {
        vout_UnloadFont( p_vout->p_default_font );        
        vout_SysDestroy( p_vout );        
        free( p_vout );        
        return( NULL );        
    }     

    /* Create thread and set locks */
    vlc_mutex_init( &p_vout->picture_lock );
    vlc_mutex_init( &p_vout->spu_lock );    
    vlc_mutex_init( &p_vout->change_lock );    
    vlc_mutex_lock( &p_vout->change_lock );    
    if( vlc_thread_create( &p_vout->thread_id, "video output", (void *) RunThread, (void *) p_vout) )
    {
        intf_ErrMsg("error: %s\n", strerror(ENOMEM));
        vout_UnloadFont( p_vout->p_default_font );
        vout_UnloadFont( p_vout->p_large_font );        
	vout_SysDestroy( p_vout );
        free( p_vout );
        return( NULL );
    }   

    intf_Msg("Video display initialized (%dx%d, %d bpp)\n", 
             p_vout->i_width, p_vout->i_height, p_vout->i_screen_depth );    

    /* If status is NULL, wait until the thread is created */
    if( pi_status == NULL )
    {
        do
        {            
            msleep( THREAD_SLEEP );
        }while( (i_status != THREAD_READY) && (i_status != THREAD_ERROR) 
                && (i_status != THREAD_FATAL) );
        if( i_status != THREAD_READY )
        {
            return( NULL );            
        }        
    }
    return( p_vout );
}

/******************************************************************************
 * vout_DestroyThread: destroys a previously created thread
 ******************************************************************************
 * Destroy a terminated thread. 
 * The function will request a destruction of the specified thread. If pi_error
 * is NULL, it will return once the thread is destroyed. Else, it will be 
 * update using one of the THREAD_* constants.
 ******************************************************************************/
void vout_DestroyThread( vout_thread_t *p_vout, int *pi_status )
{  
    int     i_status;                                        /* thread status */

    /* Set status */
    intf_DbgMsg("\n");
    p_vout->pi_status = (pi_status != NULL) ? pi_status : &i_status;
    *p_vout->pi_status = THREAD_DESTROY;    
     
    /* Request thread destruction */
    p_vout->b_die = 1;

    /* If status is NULL, wait until thread has been destroyed */
    if( pi_status == NULL )
    {
        do
        {
            msleep( THREAD_SLEEP );
        }while( (i_status != THREAD_OVER) && (i_status != THREAD_ERROR) 
                && (i_status != THREAD_FATAL) );   
    }
}

/******************************************************************************
 * vout_DisplaySubPictureUnit: display a sub picture unit
 ******************************************************************************
 * Remove the reservation flag of an spu, which will cause it to be ready for
 * display. The picture does not need to be locked, since it is ignored by
 * the output thread if is reserved.
 ******************************************************************************/
void  vout_DisplaySubPictureUnit( vout_thread_t *p_vout, spu_t *p_spu )
{
#ifdef DEBUG_VIDEO
    char        psz_begin_date[MSTRTIME_MAX_SIZE];  /* buffer for date string */
    char        psz_end_date[MSTRTIME_MAX_SIZE];    /* buffer for date string */
#endif

#ifdef DEBUG
    /* Check if status is valid */
    if( p_spu->i_status != RESERVED_SPU )
    {
        intf_DbgMsg("error: spu %p has invalid status %d\n", p_spu, p_spu->i_status );       
    }   
#endif

    /* Remove reservation flag */
    p_spu->i_status = READY_SPU;

#ifdef DEBUG_VIDEO
    /* Send subpicture informations */
    intf_DbgMsg("spu %p: type=%d, begin date=%s, end date=%s\n", p_spu, p_spu->i_type, 
                mstrtime( psz_begin_date, p_spu->begin_date ), 
                mstrtime( psz_end_date, p_spu->end_date ) );    
#endif
}

/******************************************************************************
 * vout_CreateSubPictureUnit: allocate an spu in the video output heap.
 ******************************************************************************
 * This function create a reserved spu in the video output heap. 
 * A null pointer is returned if the function fails. This method provides an
 * already allocated zone of memory in the spu data fields. It needs locking
 * since several pictures can be created by several producers threads. 
 ******************************************************************************/
spu_t *vout_CreateSubPictureUnit( vout_thread_t *p_vout, int i_type, 
                                 int i_size )
{
    //??
}

/******************************************************************************
 * vout_DestroySubPictureUnit: remove a permanent or reserved spu from the heap
 ******************************************************************************
 * This function frees a previously reserved spu.
 * It is meant to be used when the construction of a picture aborted.
 * This function does not need locking since reserved spus are ignored by
 * the output thread.
 ******************************************************************************/
void vout_DestroySubPictureUnit( vout_thread_t *p_vout, spu_t *p_spu )
{
#ifdef DEBUG
   /* Check if spu status is valid */
   if( p_spu->i_status != RESERVED_SPU )
   {
       intf_DbgMsg("error: spu %p has invalid status %d\n", p_spu, p_spu->i_status );       
   }   
#endif

    p_spu->i_status = DESTROYED_SPU;

#ifdef DEBUG_VIDEO
    intf_DbgMsg("spu %p\n", p_spu);    
#endif
}

/******************************************************************************
 * vout_DisplayPicture: display a picture
 ******************************************************************************
 * Remove the reservation flag of a picture, which will cause it to be ready for
 * display. The picture won't be displayed until vout_DatePicture has been 
 * called.
 ******************************************************************************/
void  vout_DisplayPicture( vout_thread_t *p_vout, picture_t *p_pic )
{
    vlc_mutex_lock( &p_vout->picture_lock );
    switch( p_pic->i_status )
    {
    case RESERVED_PICTURE:        
        p_pic->i_status = RESERVED_DISP_PICTURE;
        break;        
    case RESERVED_DATED_PICTURE:
        p_pic->i_status = READY_PICTURE;
        break;        
#ifdef DEBUG
    default:        
        intf_DbgMsg("error: picture %p has invalid status %d\n", p_pic, p_pic->i_status );    
        break;        
#endif
    }

#ifdef DEBUG_VIDEO
    intf_DbgMsg("picture %p\n", p_pic );
#endif

    vlc_mutex_unlock( &p_vout->picture_lock );
}

/******************************************************************************
 * vout_DatePicture: date a picture
 ******************************************************************************
 * Remove the reservation flag of a picture, which will cause it to be ready for
 * display. The picture won't be displayed until vout_DisplayPicture has been 
 * called.
 ******************************************************************************/
void  vout_DatePicture( vout_thread_t *p_vout, picture_t *p_pic, mtime_t date )
{
    vlc_mutex_lock( &p_vout->picture_lock );
    p_pic->date = date;    
    switch( p_pic->i_status )
    {
    case RESERVED_PICTURE:        
        p_pic->i_status = RESERVED_DATED_PICTURE;
        break;        
    case RESERVED_DISP_PICTURE:
        p_pic->i_status = READY_PICTURE;
        break;        
#ifdef DEBUG
    default:        
        intf_DbgMsg("error: picture %p has invalid status %d\n", p_pic, p_pic->i_status );    
        break;        
#endif
    }

#ifdef DEBUG_VIDEO
    intf_DbgMsg("picture %p\n", p_pic);
#endif

    vlc_mutex_unlock( &p_vout->picture_lock );
}

/******************************************************************************
 * vout_CreatePicture: allocate a picture in the video output heap.
 ******************************************************************************
 * This function create a reserved image in the video output heap. 
 * A null pointer is returned if the function fails. This method provides an
 * already allocated zone of memory in the picture data fields. It needs locking
 * since several pictures can be created by several producers threads. 
 ******************************************************************************/
picture_t *vout_CreatePicture( vout_thread_t *p_vout, int i_type, 
			       int i_width, int i_height )
{
    int         i_picture;                                   /* picture index */
    int         i_chroma_width = 0;                           /* chroma width */    
    picture_t * p_free_picture = NULL;                  /* first free picture */    
    picture_t * p_destroyed_picture = NULL;        /* first destroyed picture */    

    /* Get lock */
    vlc_mutex_lock( &p_vout->picture_lock );

    /* 
     * Look for an empty place 
     */
    for( i_picture = 0; 
         i_picture < VOUT_MAX_PICTURES; 
         i_picture++ )
    {
	if( p_vout->p_picture[i_picture].i_status == DESTROYED_PICTURE )
	{
	    /* Picture is marked for destruction, but is still allocated - note
             * that if width and type are the same for two pictures, chroma_width 
             * should also be the same */
	    if( (p_vout->p_picture[i_picture].i_type           == i_type)   &&
		(p_vout->p_picture[i_picture].i_height         == i_height) &&
		(p_vout->p_picture[i_picture].i_width          == i_width) )
	    {
		/* Memory size do match : memory will not be reallocated, and function
                 * can end immediately - this is the best possible case, since no
                 * memory allocation needs to be done */
		p_vout->p_picture[i_picture].i_status = RESERVED_PICTURE;
#ifdef DEBUG_VIDEO
                intf_DbgMsg("picture %p (in destroyed picture slot)\n", 
                            &p_vout->p_picture[i_picture] );                
#endif
		vlc_mutex_unlock( &p_vout->picture_lock );
		return( &p_vout->p_picture[i_picture] );
	    }
	    else if( p_destroyed_picture == NULL )
	    {
		/* Memory size do not match, but picture index will be kept in
		 * case no other place are left */
		p_destroyed_picture = &p_vout->p_picture[i_picture];                
	    }	    
	}
        else if( (p_free_picture == NULL) && 
                 (p_vout->p_picture[i_picture].i_status == FREE_PICTURE ))
        {
	    /* Picture is empty and ready for allocation */
            p_free_picture = &p_vout->p_picture[i_picture];            
        }
    }

    /* If no free picture is available, use a destroyed picture */
    if( (p_free_picture == NULL) && (p_destroyed_picture != NULL ) )
    { 
	/* No free picture or matching destroyed picture has been found, but
	 * a destroyed picture is still avalaible */
        free( p_destroyed_picture->p_data );        
        p_free_picture = p_destroyed_picture;        
    }

    /*
     * Prepare picture
     */
    if( p_free_picture != NULL )
    {
        /* Allocate memory */
        switch( i_type )
        {
        case YUV_420_PICTURE:          /* YUV 420: 1,1/4,1/4 samples per pixel */
            i_chroma_width = i_width / 2;            
            p_free_picture->p_data = malloc( i_height * i_chroma_width * 3 * sizeof( yuv_data_t ) );
            p_free_picture->p_y = (yuv_data_t *)p_free_picture->p_data;
            p_free_picture->p_u = (yuv_data_t *)p_free_picture->p_data +i_height*i_chroma_width*4/2;
            p_free_picture->p_v = (yuv_data_t *)p_free_picture->p_data +i_height*i_chroma_width*5/2;
            break;
        case YUV_422_PICTURE:          /* YUV 422: 1,1/2,1/2 samples per pixel */
            i_chroma_width = i_width / 2;            
            p_free_picture->p_data = malloc( i_height * i_chroma_width * 4 * sizeof( yuv_data_t ) );
            p_free_picture->p_y = (yuv_data_t *)p_free_picture->p_data;
            p_free_picture->p_u = (yuv_data_t *)p_free_picture->p_data +i_height*i_chroma_width*2;
            p_free_picture->p_v = (yuv_data_t *)p_free_picture->p_data +i_height*i_chroma_width*3;
            break;
        case YUV_444_PICTURE:              /* YUV 444: 1,1,1 samples per pixel */
            i_chroma_width = i_width;            
            p_free_picture->p_data = malloc( i_height * i_chroma_width * 3 * sizeof( yuv_data_t ) );
            p_free_picture->p_y = (yuv_data_t *)p_free_picture->p_data;
            p_free_picture->p_u = (yuv_data_t *)p_free_picture->p_data +i_height*i_chroma_width;
            p_free_picture->p_v = (yuv_data_t *)p_free_picture->p_data +i_height*i_chroma_width*2;
            break;                
#ifdef DEBUG
        default:
            intf_DbgMsg("error: unknown picture type %d\n", i_type );
            p_free_picture->p_data   =  NULL;            
            break;            
#endif    
        }

        if( p_free_picture->p_data != NULL )
        {        
            /* Copy picture informations, set some default values */
            p_free_picture->i_type                      = i_type;
            p_free_picture->i_status                    = RESERVED_PICTURE;
            p_free_picture->i_matrix_coefficients       = 1; 
            p_free_picture->i_width                     = i_width;
            p_free_picture->i_height                    = i_height;
            p_free_picture->i_chroma_width              = i_chroma_width;            
            p_free_picture->i_display_horizontal_offset = 0;
            p_free_picture->i_display_vertical_offset   = 0;            
            p_free_picture->i_display_width             = i_width;
            p_free_picture->i_display_height            = i_height;
            p_free_picture->i_aspect_ratio              = AR_SQUARE_PICTURE;            
            p_free_picture->i_refcount                  = 0;            
        }
        else
        {
            /* Memory allocation failed : set picture as empty */
            p_free_picture->i_type   =  EMPTY_PICTURE;            
            p_free_picture->i_status =  FREE_PICTURE;            
            p_free_picture =            NULL;            
            intf_ErrMsg("warning: %s\n", strerror( ENOMEM ) );            
        }
        
#ifdef DEBUG_VIDEO
        intf_DbgMsg("picture %p (in free picture slot)\n", p_free_picture );        
#endif
        vlc_mutex_unlock( &p_vout->picture_lock );
        return( p_free_picture );
    }
    
    // No free or destroyed picture could be found
    intf_DbgMsg( "warning: heap is full\n" );
    vlc_mutex_unlock( &p_vout->picture_lock );
    return( NULL );
}

/******************************************************************************
 * vout_DestroyPicture: remove a permanent or reserved picture from the heap
 ******************************************************************************
 * This function frees a previously reserved picture or a permanent
 * picture. It is meant to be used when the construction of a picture aborted.
 * Note that the picture will be destroyed even if it is linked !
 * This function does not need locking since reserved pictures are ignored by
 * the output thread.
 ******************************************************************************/
void vout_DestroyPicture( vout_thread_t *p_vout, picture_t *p_pic )
{
#ifdef DEBUG
   /* Check if picture status is valid */
   if( (p_pic->i_status != RESERVED_PICTURE) && 
       (p_pic->i_status != RESERVED_DATED_PICTURE) &&
       (p_pic->i_status != RESERVED_DISP_PICTURE) )
   {
       intf_DbgMsg("error: picture %p has invalid status %d\n", p_pic, p_pic->i_status );       
   }   
#endif

    p_pic->i_status = DESTROYED_PICTURE;

#ifdef DEBUG_VIDEO
    intf_DbgMsg("picture %p\n", p_pic);    
#endif
}

/******************************************************************************
 * vout_LinkPicture: increment reference counter of a picture
 ******************************************************************************
 * This function increment the reference counter of a picture in the video
 * heap. It needs a lock since several producer threads can access the picture.
 ******************************************************************************/
void vout_LinkPicture( vout_thread_t *p_vout, picture_t *p_pic )
{
    vlc_mutex_lock( &p_vout->picture_lock );
    p_pic->i_refcount++;

#ifdef DEBUG_VIDEO
    intf_DbgMsg("picture %p refcount=%d\n", p_pic, p_pic->i_refcount );    
#endif

    vlc_mutex_unlock( &p_vout->picture_lock );
}

/******************************************************************************
 * vout_UnlinkPicture: decrement reference counter of a picture
 ******************************************************************************
 * This function decrement the reference counter of a picture in the video heap.
 ******************************************************************************/
void vout_UnlinkPicture( vout_thread_t *p_vout, picture_t *p_pic )
{
    vlc_mutex_lock( &p_vout->picture_lock );
    p_pic->i_refcount--;

#ifdef DEBUG_VIDEO
    if( p_pic->i_refcount < 0 )
    {
        intf_DbgMsg("error: refcount < 0\n");
        p_pic->i_refcount = 0;        
    }    
#endif

    if( (p_pic->i_refcount == 0) && (p_pic->i_status == DISPLAYED_PICTURE) )
    {
	p_pic->i_status = DESTROYED_PICTURE;
    }

#ifdef DEBUG_VIDEO
    intf_DbgMsg("picture %p refcount=%d\n", p_pic, p_pic->i_refcount );    
#endif

    vlc_mutex_unlock( &p_vout->picture_lock );
}

/******************************************************************************
 * vout_ClearBuffer: clear a whole buffer
 ******************************************************************************
 * This function is called when a buffer is initialized. It clears the whole
 * buffer.
 ******************************************************************************/
void vout_ClearBuffer( vout_thread_t *p_vout, vout_buffer_t *p_buffer )
{
    /* No picture previously */
    p_buffer->i_pic_x =         0;
    p_buffer->i_pic_y =         0;
    p_buffer->i_pic_width =     0;
    p_buffer->i_pic_height =    0;

    /* The first area covers all the screen */
    p_buffer->i_areas =                 1;
    p_buffer->pi_area_begin[0] =        0;
    p_buffer->pi_area_end[0] =          p_vout->i_height - 1;
}

/* following functions are local */

/******************************************************************************
 * InitThread: initialize video output thread
 ******************************************************************************
 * This function is called from RunThread and performs the second step of the
 * initialization. It returns 0 on success. Note that the thread's flag are not
 * modified inside this function.
 ******************************************************************************/
static int InitThread( vout_thread_t *p_vout )
{
    /* Update status */
    intf_DbgMsg("\n");
    *p_vout->pi_status = THREAD_START;    

    /* Initialize output method - this function issues its own error messages */
    if( vout_SysInit( p_vout ) )
    {
        return( 1 );
    } 

    /* Initialize convertion tables and functions */
    if( vout_InitTables( p_vout ) )
    {
        intf_ErrMsg("error: can't allocate translation tables\n");
        return( 1 );                
    }
    
    /* Mark thread as running and return */
    p_vout->b_active =          1;    
    *p_vout->pi_status =        THREAD_READY;    
    intf_DbgMsg("thread ready\n");    
    return( 0 );    
}

/******************************************************************************
 * RunThread: video output thread
 ******************************************************************************
 * Video output thread. This function does only returns when the thread is
 * terminated. It handles the pictures arriving in the video heap and the
 * display device events.
 ******************************************************************************/
static void RunThread( vout_thread_t *p_vout)
{
    int             i_index;                                 /* index in heap */
    mtime_t         current_date;                             /* current date */
    mtime_t         display_date;                             /* display date */    
    boolean_t       b_display;                                /* display flag */    
    picture_t *     p_pic;                                 /* picture pointer */
    spu_t *         p_spu;                              /* subpicture pointer */    
     
    /* 
     * Initialize thread
     */
    p_vout->b_error = InitThread( p_vout );
    if( p_vout->b_error )
    {
        DestroyThread( p_vout, THREAD_ERROR );
        return;        
    }    
    intf_DbgMsg("\n");

    /*
     * Main loop - it is not executed if an error occured during
     * initialization
     */
    while( (!p_vout->b_die) && (!p_vout->b_error) )
    {
        /* Initialize loop variables */
        p_pic =         NULL;
        p_spu =         NULL;
        display_date =  0;        
        current_date =  mdate();

        /* 
	 * Find the picture to display - this operation does not need lock,
         * since only READY_PICTUREs are handled 
         */
        for( i_index = 0; i_index < VOUT_MAX_PICTURES; i_index++ )
	{
	    if( (p_vout->p_picture[i_index].i_status == READY_PICTURE) &&
		( (p_pic == NULL) || 
		  (p_vout->p_picture[i_index].date < display_date) ) )
	    {
                p_pic = &p_vout->p_picture[i_index];
                display_date = p_pic->date;                
	    }
	}
 
        if( p_pic )
        {
#ifdef STATS
            /* Computes FPS rate */
            p_vout->p_fps_sample[ p_vout->c_fps_samples++ % VOUT_FPS_SAMPLES ] = display_date;
#endif	    
	    if( display_date < current_date )
	    {
		/* Picture is late: it will be destroyed and the thread will sleep and
                 * go to next picture */
                vlc_mutex_lock( &p_vout->picture_lock );
                p_pic->i_status = p_pic->i_refcount ? DISPLAYED_PICTURE : DESTROYED_PICTURE;
		intf_DbgMsg( "warning: late picture %p skipped refcount=%d\n", p_pic, p_pic->i_refcount );
                vlc_mutex_unlock( &p_vout->picture_lock );
                p_pic =         NULL;                
                display_date =  0;                
	    }
	    else if( display_date > current_date + VOUT_DISPLAY_DELAY )
	    {
		/* A picture is ready to be rendered, but its rendering date is
		 * far from the current one so the thread will perform an empty loop
		 * as if no picture were found. The picture state is unchanged */
                p_pic =         NULL;                
                display_date =  0;                
	    }
        }

        /*
         * Find the subpicture to display - this operation does not need lock, since
         * only READY_SPUs are handled. If no picture has been selected,
         * display_date will depend on the spu
         */
        //??

        /*
         * Perform rendering, sleep and display rendered picture
         */
        if( p_pic )                            /* picture and perhaps spu */
        {
            b_display = p_vout->b_active;            

            if( b_display )
            {                
                /* Set picture dimensions and clear buffer */
                SetBufferPicture( p_vout, p_pic );

                /* Render picture and informations */
                RenderPicture( p_vout, p_pic );             
                if( p_vout->b_info )
                {
                    RenderPictureInfo( p_vout, p_pic );
                    RenderInfo( p_vout );                
                }
            }
            
            /* Remove picture from heap */
            vlc_mutex_lock( &p_vout->picture_lock );
            p_pic->i_status = p_pic->i_refcount ? DISPLAYED_PICTURE : DESTROYED_PICTURE;
            vlc_mutex_unlock( &p_vout->picture_lock );                          

            /* Render interface and spus */
            if( b_display && p_vout->b_interface )
            {
                RenderInterface( p_vout );                
            }
            if( p_spu )
            {
                if( b_display )
                {                    
                    RenderSubPictureUnit( p_vout, p_spu );
                }                

                /* Remove spu from heap */
                vlc_mutex_lock( &p_vout->spu_lock );
                p_spu->i_status = DESTROYED_SPU;
                vlc_mutex_unlock( &p_vout->spu_lock );                          
            }

        }
        else if( p_spu )                                     /* spu alone */
        {
            b_display = p_vout->b_active;

            if( b_display )
            {                
                /* Clear buffer */
                SetBufferPicture( p_vout, NULL );

                /* Render informations, interface and spu */
                if( p_vout->b_info )
                {
                    RenderInfo( p_vout );
                }
                if( p_vout->b_interface )
                {
                    RenderInterface( p_vout );
                }
                RenderSubPictureUnit( p_vout, p_spu );            
            }            

            /* Remove spu from heap */
            vlc_mutex_lock( &p_vout->spu_lock );
            p_spu->i_status = DESTROYED_SPU;
            vlc_mutex_unlock( &p_vout->spu_lock );                          
        }
        else                                              /* idle screen alone */
        {            
            //??? render on idle screen or interface change
            b_display = 0;             //???
        }

        /*
         * Sleep, wake up and display rendered picture
         */

#ifdef STATS
        /* Store render time */
        p_vout->render_time = mdate() - current_date;
#endif

        /* Give back change lock */
        vlc_mutex_unlock( &p_vout->change_lock );        

        /* Sleep a while or until a given date */
        if( display_date != 0 )
        {
            mwait( display_date );
        }
        else
        {
            msleep( VOUT_IDLE_SLEEP );                
        }            

        /* On awakening, take back lock and send immediately picture to display, 
         * then swap buffers */
        vlc_mutex_lock( &p_vout->change_lock );        
#ifdef DEBUG_VIDEO
        intf_DbgMsg( "picture %p, spu %p\n", p_pic, p_spu );        
#endif            
        if( b_display && !(p_vout->i_changes & VOUT_NODISPLAY_CHANGE) )
        {
            vout_SysDisplay( p_vout );
            p_vout->i_buffer_index = ++p_vout->i_buffer_index & 1;
        }

        /*
         * Check events and manage thread
	 */
        if( vout_SysManage( p_vout ) | Manage( p_vout ) )
	{
	    /* A fatal error occured, and the thread must terminate immediately,
	     * without displaying anything - setting b_error to 1 cause the
	     * immediate end of the main while() loop. */
	    p_vout->b_error = 1;
	}  
    } 

    /*
     * Error loop - wait until the thread destruction is requested
     */
    if( p_vout->b_error )
    {
        ErrorThread( p_vout );        
    }

    /* End of thread */
    EndThread( p_vout );
    DestroyThread( p_vout, THREAD_OVER ); 
    intf_DbgMsg( "thread end\n" );
}

/******************************************************************************
 * ErrorThread: RunThread() error loop
 ******************************************************************************
 * This function is called when an error occured during thread main's loop. The
 * thread can still receive feed, but must be ready to terminate as soon as
 * possible.
 ******************************************************************************/
static void ErrorThread( vout_thread_t *p_vout )
{
    /* Wait until a `die' order */
    intf_DbgMsg("\n");