Picture-in-Picture plugin

Plugin BPP_PiP allows to organize picture-in-picture (simultaneous preview of two or more independent channels) if you have more than one tuner installed.

PiP device can be any tuner or video capture device installed to the system. Due to some limitations the exclusion is videocapture devices integrated with video adapters (video inputs of VGA adapters).

You need to clearly realize that when PiP is active, main window will display channel received by main tuner, and the PiP window will display picture from PiP tuner.

So, when you exchange the contents of windows, then not the window size and position is adjusted, but full retuning of both tuners to the proper channels. If one device is set to display from composite or S-Video input, then exchanging is impossible, because the software of main tuner is not able to get the picture from video inputs of PiP device, and vice versa.

BPP_PiP plugin works with any device through WDM-driver and this imposes definite restrictions to the control over device. For exampe, it is impossible to set the automatic detection of video standard (see below), to set modes of frame and line synchronization and other options available in main program.

Because of difference between capture devices and between driver settings, the same channel may look different in main window and PiP window.

PiP device

For work in «picture-in-picture» mode you need to select the so called "PiP device". By PiP-device it is meant the set of driver components that is responsible for work of the video input physical device. Each component is responsible to control definite functions of that device.

TV-tuner – driver component, that is responsible to control the RF module of tuner and channel selection. For some input devices without RF modules this component is just formal and you may omit the selection. But if the PiP device is TV-tuner and this component is not selected, then channel swithcing in PiP window will be impossible, and the PiP device will automatically be set to work with composite or S-Video input.

TV-audio – driver component responsible for switching between audio-modes of TV program sound.

Crossbar – component responsible for switching between every inputs and outputs that are, available to the capture device (TV, Composite, S-Video, etc.)

Capture device – driver component, responsible for control over video decoding, transformation and digitizing video and audio data.

For PiP to work you need to select at least Crossbar and Capture device.

All selected driver components must belong to the same device. It is sometimes difficult to determine which component from this list belongs to which device. Many tuner manufacturers as a rule designate by their name only the main capture device component. At the same time other components may have names given by reference driver manufacturer and may not reflect the belonging to the particular device. The sample is shown at the picture.

If the system has two identical tuners, then the device list will contain the couples of identical lines. In that case it is recommended to keep the order of device selection. I.e., if you selected the first of two devices in the list «TV tuner», then for other components you must select the first component of two identical.

If the PiP device is selected improperly, then on saving the settings (button «Save PiP device parameters») will be shown warning or the message about impossibility of it's launch.

In the case you chosen the main tuner as a PiP device there will no be warnings or errors. Nevertheless, because main tuner is busy by the Behold TV application, then there will no be picture either in PiP window or in the main window.

There is a button that opens a dialog window of driver settings against every line with PiP device component. These settings are provided by the driver manufacturer and allow to tune such picture parameters as brightness, contrast, saturation, etc. Beholder driver in addition allows to set the AGC of Philips/NXP chipset and more fine regulate it's audio settings, but that is not important for the work of PiP device.

Format of video stream – the list of video data formats simultaneously supported by plugin and PiP device. The list is filled after the choosing and saving the settings of PiP device. If the PiP device supports none of YUY, UYVY or RGB24 formats, then the list will contain the choice "Default". As a rule this means that the device has it's own data format on the driver output and needs special converter that will connect automatically.

Size of video stream – the size of picture in pixels, that is requested from the PiP device. To reduce the load on system and exclude the necessity of deinterlace filters the size of stream is limited by the size of one field (384*288 or less). However, drivers of some devices don't allow to change the size of video stream and ignore this setting. In this case the size of stream is set by driver and the PiP window may contain interlace artefacts.

PiP window

This group of settings allows to set such PiP window parameters as it's size, position, transparency and frame attributes. The parameter «Picture size» sets the size of picture inside the PiP window. Size and position of PiP window is set in percents relative to the size of main window. The color of PiP window frame is recommended to select from desaturated colors, because pure colors of small picture details in YUY2 format (overlay surface) are shown with distortions.

PiP video standard

On channel switch plugin has to set definite video standard for PiP channel. The type of video standard is read by plugin from channel settings in the channel setings in main tuner application. Nevertheless, it is impossible to set automatic detection of video standard, that may be set for some channels, by means of WDM driver. Also, WDM driver of PiP device may in principle support either manual or automatic detection of TV standard. Also some WDM drivers may work in autodetect mode only to the first setting to fixed standard and it is impossible to revert them to autodetect mode after that. The setting «PiP video standard» partially allows to solve these issues.

If the mode «Auto» is selected in the «PiP video standard» list, then plugin will not try to set video standard on channel switch. In this case the driver will apply it's default settings.

If any other TV system is selected in «PiP video standard» list, then this standard will be forced for every channel which has «Autodetect» mode in main application.

If the Beholder tuner is used as a PiP device, then the «PiP video standard» setting become inactual. Behold TV driver always work in autodetect mode and ignores all tries to force to set it.

Control

The control of PiP is performed with the help of plugin menu, mouse or keyboard. Mouse allows to drag the PiP window within the main window and exchange the contents of windows by double click.

On manual change of overlay scale in the video adapter settings, in the 16:9 PanScan mode, and on saving of screen proportions in Full Screen mode, mouse cursor may not fall into the visible size of PiP window.

Part of PiP control function is layed on keyboard, for that every control command has it's own hotkey combination.

Hotkeys

Hotkeys are used to control the PiP from keyboard.

To set the new hotkey combination you need to select the line with command and by double clicking or pressing Enter open the hotkey editing window. To accept the entered hotkey combination press Enter, to cancel – Esc, to clear – Delete.

Hotkeys assigned to control PiP, must not be used in main program. Otherwise both actions will be performed simultaneously.

Performance

When the BPP_PiP plugin is attached, two video capture devices are initialized simultaneously at the application startup. The launch and shutdown time will increase. If you don't use PiP, remove it from the list of plugins.

BPP_PiP plugin doesn't process the received picture, doesn't use system resources to output the video to the screen and directly works only with driver of PiP device. The system load with the plugin consists of work of plugin itself (2-10% depending on the chosen size and format of the video stream) and the work of PiP device. The system load by drivers of some devices may gain 15-20% and higher. In contrast, the Beholder driver spends less than 1% of system resources (CPU P IV 2.4 GHz).

WDM-drivers of some devices has pecularity of very long initialization time, switching time between channels and, especially, between different inputs. Swithing time sometimes achieves 5 and more seconds. At that time the system load may rise to 100%, which causes temporary system hang on and shuttering the video in the main tuner window.

Addition

Starting with version 1.20 BPP_PiP plugin supports any number of tuners in system. To attach 2 or more tuners as PiP devices you need to do the following:

1. Create several instances of BPP_PiP plugin in ..\Plugins folder by copying and renaming the original plugin file, for example so:
   
   BPP_PiP_1.dll
   BPP_PiP_2.dll
   BPP_PiP_3.dll
   ………………
   
2. Then select each created plugin sample to the list of active plugins for preview and recording.
3. After that you may set up each plugin instance to it's tuner and set individual hotkey settings.

List of changes

• First release.

• Added possibility to work with two or more tuners as PiP devices.

• Added saving settings in Windows 7.

• Added support of Behold TV instances.

Link to the plugin: BPP_PiP_v122.zip (50.4 kb)

01.03.11