crop.c

video linux conference

    ADD_PARENT_CALLBACKS( SendEventsToChild );

    return VLC_SUCCESS;
}

/*****************************************************************************
 * End: terminate Crop video thread output method
 *****************************************************************************/
static void End( vout_thread_t *p_vout )
{
    int i_index;

    /* Free the fake output buffers we allocated */
    for( i_index = I_OUTPUTPICTURES ; i_index ; )
    {
        i_index--;
        free( PP_OUTPUTPICTURE[ i_index ]->p_data_orig );
    }
}

/*****************************************************************************
 * Destroy: destroy Crop video thread output method
 *****************************************************************************
 * Terminate an output method created by CropCreateOutputMethod
 *****************************************************************************/
static void Destroy( vlc_object_t *p_this )
{
    vout_thread_t *p_vout = (vout_thread_t *)p_this;

    if( p_vout->p_sys->p_vout )
    {
        DEL_CALLBACKS( p_vout->p_sys->p_vout, SendEvents );
        vlc_object_detach( p_vout->p_sys->p_vout );
        vout_Destroy( p_vout->p_sys->p_vout );
    }

    DEL_PARENT_CALLBACKS( SendEventsToChild );

    free( p_vout->p_sys );
}

/*****************************************************************************
 * Manage: handle Crop events
 *****************************************************************************
 * This function should be called regularly by video output thread. It manages
 * console events. It returns a non null value on error.
 *****************************************************************************/
static int Manage( vout_thread_t *p_vout )
{
    video_format_t fmt = {0};

    if( !p_vout->p_sys->b_changed )
    {
        return VLC_SUCCESS;
    }

    vout_Destroy( p_vout->p_sys->p_vout );

    fmt.i_width = fmt.i_visible_width = p_vout->p_sys->i_width;
    fmt.i_height = fmt.i_visible_height = p_vout->p_sys->i_height;
    fmt.i_x_offset = fmt.i_y_offset = 0;
    fmt.i_chroma = p_vout->render.i_chroma;
    fmt.i_aspect = p_vout->p_sys->i_aspect;
    fmt.i_sar_num = p_vout->p_sys->i_aspect * fmt.i_height / fmt.i_width;
    fmt.i_sar_den = VOUT_ASPECT_FACTOR;

    p_vout->p_sys->p_vout = vout_Create( p_vout, &fmt );
    if( p_vout->p_sys->p_vout == NULL )
    {
        msg_Err( p_vout, "failed to create vout" );
        return VLC_EGENERIC;
    }

    p_vout->p_sys->b_changed = VLC_FALSE;
    p_vout->p_sys->i_lastchange = 0;

    return VLC_SUCCESS;
}

/*****************************************************************************
 * Render: display previously rendered output
 *****************************************************************************
 * This function sends the currently rendered image to Crop image, waits
 * until it is displayed and switches the two rendering buffers, preparing next
 * frame.
 *****************************************************************************/
static void Render( vout_thread_t *p_vout, picture_t *p_pic )
{
    picture_t *p_outpic = NULL;
    int i_plane;

    if( p_vout->p_sys->b_changed )
    {
        return;
    }

    while( ( p_outpic =
                 vout_CreatePicture( p_vout->p_sys->p_vout, 0, 0, 0 )
           ) == NULL )
    {
        if( p_vout->b_die || p_vout->b_error )
        {
            vout_DestroyPicture( p_vout->p_sys->p_vout, p_outpic );
            return;
        }

        msleep( VOUT_OUTMEM_SLEEP );
    }

    vout_DatePicture( p_vout->p_sys->p_vout, p_outpic, p_pic->date );
    vout_LinkPicture( p_vout->p_sys->p_vout, p_outpic );

    for( i_plane = 0 ; i_plane < p_pic->i_planes ; i_plane++ )
    {
        uint8_t *p_in, *p_out, *p_out_end;
        int i_in_pitch = p_pic->p[i_plane].i_pitch;
        const int i_out_pitch = p_outpic->p[i_plane].i_pitch;
        const int i_copy_pitch = p_outpic->p[i_plane].i_visible_pitch;

        p_in = p_pic->p[i_plane].p_pixels
                /* Skip the right amount of lines */
                + i_in_pitch * ( p_pic->p[i_plane].i_visible_lines *
                                 p_vout->p_sys->i_y / p_vout->output.i_height )
                /* Skip the right amount of columns */
                + i_in_pitch * p_vout->p_sys->i_x / p_vout->output.i_width;

        p_out = p_outpic->p[i_plane].p_pixels;
        p_out_end = p_out + i_out_pitch * p_outpic->p[i_plane].i_visible_lines;

        while( p_out < p_out_end )
        {
            p_vout->p_vlc->pf_memcpy( p_out, p_in, i_copy_pitch );
            p_in += i_in_pitch;
            p_out += i_out_pitch;
        }
    }

    vout_UnlinkPicture( p_vout->p_sys->p_vout, p_outpic );
    vout_DisplayPicture( p_vout->p_sys->p_vout, p_outpic );

    /* The source image may still be in the cache ... parse it! */
    if( p_vout->p_sys->b_autocrop )
    {
        UpdateStats( p_vout, p_pic );
    }
}

static void UpdateStats( vout_thread_t *p_vout, picture_t *p_pic )
{
    uint8_t *p_in = p_pic->p[0].p_pixels;
    int i_pitch = p_pic->p[0].i_pitch;
    int i_visible_pitch = p_pic->p[0].i_visible_pitch;
    int i_lines = p_pic->p[0].i_visible_lines;
    int i_firstwhite = -1, i_lastwhite = -1, i;

    /* Determine where black borders are */
    switch( p_vout->output.i_chroma )
    {
    case VLC_FOURCC('I','4','2','0'):
        /* XXX: Do not laugh ! I know this is very naive. But it's just a
         *      proof of concept code snippet... */
        for( i = i_lines ; i-- ; )
        {
            const int i_col = i * i_pitch / i_lines;

            if( p_in[i_col/2] > 40
                 && p_in[i_visible_pitch/2] > 40
                 && p_in[i_visible_pitch/2 + i_col/2] > 40 )
            {
                if( i_lastwhite == -1 )
                {
                    i_lastwhite = i;
                }
                i_firstwhite = i;
            }
            p_in += i_pitch;
        }
        break;

    default:
        break;
    }

    /* Decide whether it's worth changing the size */
    if( i_lastwhite == -1 )
    {
        p_vout->p_sys->i_lastchange = 0;
        return;
    }

    if( (unsigned int)(i_lastwhite - i_firstwhite)
                                           < p_vout->p_sys->i_height / 2 )
    {
        p_vout->p_sys->i_lastchange = 0;
        return;
    }

    if( (unsigned int)(i_lastwhite - i_firstwhite)
                                          < p_vout->p_sys->i_height + 16
         && (unsigned int)(i_lastwhite - i_firstwhite + 16)
                                                > p_vout->p_sys->i_height )
    {
        p_vout->p_sys->i_lastchange = 0;
        return;
    }

    /* We need at least 25 images to make up our mind */
    p_vout->p_sys->i_lastchange++;
    if( p_vout->p_sys->i_lastchange < 25 )
    {
        return;
    }

    /* Tune a few values */
    if( i_firstwhite & 1 )
    {
        i_firstwhite--;
    }

    if( !(i_lastwhite & 1) )
    {
        i_lastwhite++;
    }

    /* Change size */
    p_vout->p_sys->i_y = i_firstwhite;
    p_vout->p_sys->i_height = i_lastwhite - i_firstwhite + 1;

    p_vout->p_sys->i_aspect = p_vout->output.i_aspect
                            * p_vout->output.i_height / p_vout->p_sys->i_height
                            * p_vout->p_sys->i_width / p_vout->output.i_width;

    p_vout->p_sys->b_changed = VLC_TRUE;
}

/*****************************************************************************
 * SendEvents: forward mouse and keyboard events to the parent p_vout
 *****************************************************************************/
static int SendEvents( vlc_object_t *p_this, char const *psz_var,
                       vlc_value_t oldval, vlc_value_t newval, void *_p_vout )
{
    vout_thread_t *p_vout = (vout_thread_t *)_p_vout;
    vlc_value_t sentval = newval;

    /* Translate the mouse coordinates */
    if( !strcmp( psz_var, "mouse-x" ) )
    {
        sentval.i_int += p_vout->p_sys->i_x;
    }
    else if( !strcmp( psz_var, "mouse-y" ) )
    {
        sentval.i_int += p_vout->p_sys->i_y;
    }

    var_Set( p_vout, psz_var, sentval );

    return VLC_SUCCESS;
}

/*****************************************************************************
 * SendEventsToChild: forward events to the child/children vout
 *****************************************************************************/
static int SendEventsToChild( vlc_object_t *p_this, char const *psz_var,
                       vlc_value_t oldval, vlc_value_t newval, void *p_data )
{
    vout_thread_t *p_vout = (vout_thread_t *)p_this;
    var_Set( p_vout->p_sys->p_vout, psz_var, newval );
    return VLC_SUCCESS;
}