video_output.c

/*****************************************************************************
 * video_output.c : video output thread
 * 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 oppened video output thread.
 *****************************************************************************
 * Copyright (C) 2000 VideoLAN
 *
 * Authors:
 *
 * 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, USA.
 *****************************************************************************/

/*****************************************************************************
 * Preamble
 *****************************************************************************/
#include "defs.h"

#include <errno.h>                                                 /* ENOMEM */
#include <stdlib.h>                                                /* free() */
#include <stdio.h>                                              /* sprintf() */
#include <string.h>                                            /* strerror() */

#include "config.h"
#include "common.h"
#include "threads.h"
#include "mtime.h"
#include "plugins.h"
#include "video.h"
#include "video_output.h"
#include "video_text.h"
#include "video_spu.h"
#include "video_yuv.h"

#include "intf_msg.h"
#include "main.h"

/*****************************************************************************
 * Local prototypes
 *****************************************************************************/
static int      BinaryLog         ( u32 i );
static void     MaskToShift       ( int *pi_left, int *pi_right, u32 i_mask );
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_h_align, int i_v_align,
                                    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     RenderSubPicture  ( vout_thread_t *p_vout,
                                    subpicture_t *p_subpic );
static void     RenderInterface   ( vout_thread_t *p_vout );
static int      RenderIdle        ( vout_thread_t *p_vout );
static void     RenderInfo        ( vout_thread_t *p_vout );
static void     Synchronize       ( vout_thread_t *p_vout, s64 i_delay );
static int      Manage            ( vout_thread_t *p_vout );
static int      Align             ( vout_thread_t *p_vout, int *pi_x,
                                    int *pi_y, int i_width, int i_height,
                                    int i_h_align, int i_v_align );
static void     SetPalette        ( p_vout_thread_t p_vout, u16 *red,
                                    u16 *green, u16 *blue, u16 *transp );

/*****************************************************************************
 * 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,
                          int i_method, void *p_data )
{
    vout_thread_t * p_vout;                             /* thread descriptor */
    typedef void    ( vout_getplugin_t ) ( vout_thread_t * p_vout );
    int             i_status;                               /* thread status */
    int             i_index;               /* index for array initialization */
    int             i_best_index = 0, i_best_score = 0;

    /* 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 );
    }

    p_vout->p_set_palette       = SetPalette;

    /* Get a suitable video plugin */
    for( i_index = 0 ; i_index < p_main->p_bank->i_plugin_count ; i_index++ )
    {
        /* If there's a plugin in p_info ... */
        if( p_main->p_bank->p_info[ i_index ] != NULL )
        {
            /* ... and if this plugin provides the functions we want ... */
            if( p_main->p_bank->p_info[ i_index ]->vout_GetPlugin != NULL )
            {
                /* ... and if this plugin has a good score ... */
                if( p_main->p_bank->p_info[ i_index ]->i_score > i_best_score )
                {
                    /* ... then take it */
                    i_best_score = p_main->p_bank->p_info[ i_index ]->i_score;
                    i_best_index = i_index;
                }
            }
        }
    }

    if( i_best_score == 0 )
    {
        free( p_vout );
        return( NULL );
    }

    /* Get the plugin functions */
    ( (vout_getplugin_t *)
      p_main->p_bank->p_info[ i_best_index ]->vout_GetPlugin )( p_vout );

    /* 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_changes           = 0;
    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 bpp (%d Bpl)\n",
                 p_vout->i_width, p_vout->i_height, p_vout->i_screen_depth,
                 p_vout->i_bytes_per_pixel * 8, p_vout->i_bytes_per_line );

    /* Initialize idle screen */
    p_vout->last_display_date   = mdate();
    p_vout->last_display_date   = 0;
    p_vout->last_idle_date      = 0;

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

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

    /* Initialize pictures and subpictures - 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;
    }
    for( i_index = 0; i_index < VOUT_MAX_SUBPICTURES; i_index++)
    {
        p_vout->p_subpicture[i_index].i_type  = EMPTY_SUBPICTURE;
        p_vout->p_subpicture[i_index].i_status= FREE_SUBPICTURE;
    }
    p_vout->i_pictures = 0;

    /* Initialize synchronization informations */
    p_vout->i_synchro_level     = VOUT_SYNCHRO_LEVEL_START;

    /* Create and initialize system-dependant method - this function issues its
     * own error messages */
    if( p_vout->p_sys_create( p_vout, psz_display, i_root_window, p_data ) )
    {
        free( p_vout );
        return( NULL );
    }
    intf_DbgMsg( "actual configuration: %dx%d, %d/%d bpp (%d Bpl), "
                 "masks: 0x%x/0x%x/0x%x\n",
                 p_vout->i_width, p_vout->i_height, p_vout->i_screen_depth,
                 p_vout->i_bytes_per_pixel * 8, p_vout->i_bytes_per_line,
                 p_vout->i_red_mask, p_vout->i_green_mask,
                 p_vout->i_blue_mask );

    /* Calculate shifts from system-updated masks */
    MaskToShift( &p_vout->i_red_lshift, &p_vout->i_red_rshift,
                 p_vout->i_red_mask );
    MaskToShift( &p_vout->i_green_lshift, &p_vout->i_green_rshift,
                 p_vout->i_green_mask );
    MaskToShift( &p_vout->i_blue_lshift, &p_vout->i_blue_rshift,
                 p_vout->i_blue_mask );

    /* Set some useful colors */
    p_vout->i_white_pixel = RGB2PIXEL( p_vout, 255, 255, 255 );
    p_vout->i_black_pixel = RGB2PIXEL( p_vout, 0, 0, 0 );
    p_vout->i_gray_pixel  = RGB2PIXEL( p_vout, 128, 128, 128 );
    p_vout->i_blue_pixel  = RGB2PIXEL( p_vout, 0, 0, 50 );

    /* Load fonts - fonts must be initialized after the system method since
     * they may be dependant on screen depth and other thread properties */
    p_vout->p_default_font = vout_LoadFont( DATA_PATH "/" VOUT_DEFAULT_FONT );
    if( p_vout->p_default_font == NULL )
    {
        p_vout->p_default_font = vout_LoadFont( "share/" VOUT_DEFAULT_FONT );
    }
    if( p_vout->p_default_font == NULL )
    {
        intf_ErrMsg( "vout error: could not load default font\n" );
        p_vout->p_sys_destroy( p_vout );
        free( p_vout );
        return( NULL );
    }
    p_vout->p_large_font = vout_LoadFont( DATA_PATH "/" VOUT_LARGE_FONT );
    if( p_vout->p_large_font == NULL )
    {
        p_vout->p_large_font = vout_LoadFont( "share/" VOUT_LARGE_FONT );
    }
    if( p_vout->p_large_font == NULL )
    {
        intf_ErrMsg( "vout error: could not load large font\n" );
        vout_UnloadFont( p_vout->p_default_font );
        p_vout->p_sys_destroy( p_vout );
        free( p_vout );
        return( NULL );
    }

    /* Create thread and set locks */
    vlc_mutex_init( &p_vout->picture_lock );
    vlc_mutex_init( &p_vout->subpicture_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 );
        p_vout->p_sys_destroy( p_vout );
        free( p_vout );
        return( NULL );
    }

    intf_Msg( "Video display initialized (%dx%d, %d/%d bpp)\n", p_vout->i_width,
              p_vout->i_height, p_vout->i_screen_depth,
              p_vout->i_bytes_per_pixel * 8 );

    /* 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_DisplaySubPicture: display a subpicture unit
 *****************************************************************************
 * Remove the reservation flag of an subpicture, 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_DisplaySubPicture( vout_thread_t *p_vout, subpicture_t *p_subpic )
{
#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_subpic->i_status != RESERVED_SUBPICTURE )
    {
        intf_DbgMsg("error: subpicture %p has invalid status %d\n", p_subpic,
                    p_subpic->i_status );
    }
#endif

    /* Remove reservation flag */
    p_subpic->i_status = READY_SUBPICTURE;

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

/*****************************************************************************
 * vout_CreateSubPicture: allocate an subpicture in the video output heap.
 *****************************************************************************
 * This function create a reserved subpicture 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.
 *****************************************************************************/
subpicture_t *vout_CreateSubPicture( vout_thread_t *p_vout, int i_type,
                                     int i_size )
{
    int                 i_subpic;                        /* subpicture index */
    subpicture_t *      p_free_subpic = NULL;       /* first free subpicture */
    subpicture_t *      p_destroyed_subpic = NULL; /* first destroyed subpic */

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

    /*
     * Look for an empty place
     */
    for( i_subpic = 0; i_subpic < VOUT_MAX_SUBPICTURES; i_subpic++ )
    {
        if( p_vout->p_subpicture[i_subpic].i_status == DESTROYED_SUBPICTURE )
        {
            /* Subpicture is marked for destruction, but is still allocated */
            if( (p_vout->p_subpicture[i_subpic].i_type  == i_type)   &&
                (p_vout->p_subpicture[i_subpic].i_size  >= i_size) )
            {
                /* Memory size do match or is smaller : 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_subpicture[i_subpic].i_status = RESERVED_SUBPICTURE;
#ifdef DEBUG_VIDEO
                intf_DbgMsg("subpicture %p (in destroyed subpicture slot)\n",
                            &p_vout->p_subpicture[i_subpic] );
#endif
                vlc_mutex_unlock( &p_vout->subpicture_lock );
                return( &p_vout->p_subpicture[i_subpic] );
            }
            else if( p_destroyed_subpic == NULL )
            {
                /* Memory size do not match, but subpicture index will be kept in
                 * case no other place are left */
                p_destroyed_subpic = &p_vout->p_subpicture[i_subpic];
            }
        }
        else if( (p_free_subpic == NULL) &&
                 (p_vout->p_subpicture[i_subpic].i_status == FREE_SUBPICTURE ))
        {
            /* Subpicture is empty and ready for allocation */
            p_free_subpic = &p_vout->p_subpicture[i_subpic];
        }
    }

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

    /*
     * Prepare subpicture
     */
    if( p_free_subpic != NULL )
    {
        /* Allocate memory */
        switch( i_type )
        {
        case TEXT_SUBPICTURE:                             /* text subpicture */
            p_free_subpic->p_data = malloc( i_size + 1 );
            break;
        case DVD_SUBPICTURE:                          /* DVD subpicture unit */
            p_free_subpic->p_data = malloc( i_size );
            break;
#ifdef DEBUG
        default:
            intf_DbgMsg("error: unknown subpicture type %d\n", i_type );
            p_free_subpic->p_data   =  NULL;
            break;
#endif
        }

        if( p_free_subpic->p_data != NULL )
        {           /* Copy subpicture informations, set some default values */
            p_free_subpic->i_type                      = i_type;
            p_free_subpic->i_status                    = RESERVED_SUBPICTURE;
            p_free_subpic->i_size                      = i_size;
            p_free_subpic->i_x                         = 0;
            p_free_subpic->i_y                         = 0;
            p_free_subpic->i_width                     = 0;
            p_free_subpic->i_height                    = 0;
            p_free_subpic->i_horizontal_align          = CENTER_RALIGN;
            p_free_subpic->i_vertical_align            = CENTER_RALIGN;
        }
        else
        {
            /* Memory allocation failed : set subpicture as empty */
            p_free_subpic->i_type   =  EMPTY_SUBPICTURE;
            p_free_subpic->i_status =  FREE_SUBPICTURE;
            p_free_subpic =            NULL;
            intf_ErrMsg("warning: %s\n", strerror( ENOMEM ) );
        }

#ifdef DEBUG_VIDEO
        intf_DbgMsg("subpicture %p (in free subpicture slot)\n", p_free_subpic );
#endif
        vlc_mutex_unlock( &p_vout->subpicture_lock );
        return( p_free_subpic );
    }

    /* No free or destroyed subpicture could be found */
    intf_DbgMsg( "warning: heap is full\n" );
    vlc_mutex_unlock( &p_vout->subpicture_lock );
    return( NULL );
}

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

    p_subpic->i_status = DESTROYED_SUBPICTURE;

#ifdef DEBUG_VIDEO
    intf_DbgMsg("subpicture %p\n", p_subpic);
#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 )
{
#ifdef DEBUG_VIDEO
    char        psz_date[MSTRTIME_MAX_SIZE];                         /* date */
#endif

    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, display date: %s\n", p_pic, mstrtime( psz_date, p_pic->date) );
#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;
                p_vout->i_pictures++;
#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;
            p_vout->i_pictures++;
        }
        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 !
 *****************************************************************************/
void vout_DestroyPicture( vout_thread_t *p_vout, picture_t *p_pic )
{
   vlc_mutex_lock( &p_vout->picture_lock );

#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;
   p_vout->i_pictures--;

#ifdef DEBUG_VIDEO
   intf_DbgMsg("picture %p\n", p_pic);
#endif
   vlc_mutex_unlock( &p_vout->picture_lock );
}

/*****************************************************************************
 * 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;
        p_vout->i_pictures--;
    }

#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_SetBuffers: set buffers adresses
 *****************************************************************************
 * This function is called by system drivers to set buffers video memory
 * adresses.
 *****************************************************************************/
void vout_SetBuffers( vout_thread_t *p_vout, void *p_buf1, void *p_buf2 )
{
    /* No picture previously */
    p_vout->p_buffer[0].i_pic_x =         0;
    p_vout->p_buffer[0].i_pic_y =         0;
    p_vout->p_buffer[0].i_pic_width =     0;
    p_vout->p_buffer[0].i_pic_height =    0;
    p_vout->p_buffer[1].i_pic_x <