// PTP Live View functions

// Function used to get viewport, bitmap and palette data via PTP

// Address of this function sent back to client program which then

// calls this with options to determine what to transfer

static int handle_video_transfer(ptp_data *data, int flags, int arg2)

{

    int total_size;             // Calculated total size of data to transfer to client

    // Structure containing the info for the current live view frame

    // This information may change across calls

    struct {

        int vp_xoffset;             // Viewport X offset in pixels (for cameras with variable image size)

        int vp_yoffset;             // Viewpoer Y offset in pixels (for cameras with variable image size)

        int vp_width;               // Actual viewport width in pixels (for cameras with variable image size)

        int vp_height;              // Actual viewport height in pixels (for cameras with variable image size)

        int vp_buffer_start;        // Offset in data transferred where the viewport data starts

        int vp_buffer_size;         // Size of viewport data sent (in bytes)

        int bm_buffer_start;        // Offset in data transferred where the bitmap data starts

        int bm_buffer_size;         // Size of bitmap data sent (in bytes)

        int palette_type;           // Camera palette type 

                                    // (0 = no palette, 1 = 16 x 4 byte AYUV values, 2 = 16 x 4 byte AYUV values with A = 0..3, 3 = 256 x 4 byte AYUV values with A = 0..3)

        int palette_buffer_start;   // Offset in data transferred where the palette data starts

        int palette_buffer_size;    // Size of palette data sent (in bytes)

    } vid_info;

    // Populate the above structure with the current default details

    vid_info.vp_xoffset = vid_get_viewport_xoffset_proper();

    vid_info.vp_yoffset = vid_get_viewport_yoffset_proper();

    vid_info.vp_width = vid_get_viewport_width_proper();

    vid_info.vp_height = vid_get_viewport_height_proper();

    vid_info.vp_buffer_start = 0;

    vid_info.vp_buffer_size = 0;

    vid_info.bm_buffer_start = 0;

    vid_info.bm_buffer_size = 0;

    vid_info.palette_type = vid_get_palette_type();

    vid_info.palette_buffer_start = 0;

    vid_info.palette_buffer_size = 0;

    total_size = sizeof(vid_info);

    // Add viewport details if requested

    if ( flags & 0x1 ) // live buffer

    {

        vid_info.vp_buffer_start = total_size;

        vid_info.vp_buffer_size = (vid_get_viewport_buffer_width_proper()*vid_get_viewport_max_height()*6)/4;

        total_size += vid_info.vp_buffer_size;

    }

    // Add bitmap details if requested

    if ( flags & 0x4 ) // bitmap buffer

    {

        vid_info.bm_buffer_start = total_size;

        vid_info.bm_buffer_size = camera_screen.buffer_width*camera_screen.height;

        total_size += vid_info.bm_buffer_size;

    }

    // Add palette detals if requested

    if ( flags & 0x8 ) // bitmap palette

    {

        vid_info.palette_buffer_start = total_size;

        vid_info.palette_buffer_size = vid_get_palette_size();

        total_size += vid_info.palette_buffer_size;

    }

    // Send header structure (along with total size to be sent)

    data->send_data(data->handle,(char*)&vid_info,sizeof(vid_info),total_size,0,0,0);

    // Send viewport data if requested

    if ( flags & 0x1 )

    {

        data->send_data(data->handle,vid_get_viewport_active_buffer(),vid_info.vp_buffer_size,0,0,0,0);

    }

    // Send bitmap data if requested

    if ( flags & 0x4 )

    {

        data->send_data(data->handle,vid_get_bitmap_active_buffer(),vid_info.bm_buffer_size,0,0,0,0);

    }

    // Send palette data if requested

    if ( flags & 0x8 )

    {

        data->send_data(data->handle,vid_get_bitmap_active_palette(),vid_info.palette_buffer_size,0,0,0,0);

    }

    return 0;

}

// Lua function to return base info for PTP live view, including address of above transfer function

static int luaCB_get_video_details( lua_State* L )

{

    // Structure to popualate with live view details

    // These details are static and only need to be retrieved once

    struct {

        int transfer_function;      // Address of transfer function above

        int vp_max_width;           // Maximum viewport width (in pixels)

        int vp_max_height;          // Maximum viewport height (in pixels)

        int vp_buffer_width;        // Viewport buffer width in case buffer is wider than visible viewport (in pixels)

        int bm_max_width;           // Maximum width of bitmap (in pixels)

        int bm_max_height;          // Maximum height of bitmap (in pixels)

        int bm_buffer_width;        // Bitmap buffer width in case buffer is wider than visible bitmap (in pixels)

        int lcd_aspect_ratio;       // 0 = 4:3, 1 = 16:9

    } details;

    // Populate structure info

    details.transfer_function = (int) handle_video_transfer;

    details.vp_max_width = vid_get_viewport_max_width();

    details.vp_max_height = vid_get_viewport_max_height();

    details.vp_buffer_width = vid_get_viewport_buffer_width_proper();

#if CAM_USES_ASPECT_CORRECTION

    details.bm_max_width = ASPECT_XCORRECTION(camera_screen.width);

#else

    details.bm_max_width = camera_screen.width;

#endif

    details.bm_max_height = camera_screen.height;

    details.bm_buffer_width = camera_screen.buffer_width;

    details.lcd_aspect_ratio = vid_get_aspect_ratio();

    // Send data back to client

    lua_pushlstring( L, (char *) &details, sizeof(details) );

    return 1;

}

#endif

   FUNC(get_video_details)

        ptp.num_param = 1;

        ptp.param1 = ((int (*)(ptp_data*,int,int)) param3)(data,param4,param5);