DScaler -- Still

| Still

DScaler is now able to produce a video stream from a still file. This type of source is not interlaced, so the deinterlace mode is irrelevant for this type of source, but you can use all the available filters as you do for all other video sources.

They are three different still sources in DScaler, and a virtual playlist (a playlist is not necessarily attached to a file) is associated to each of them :

- Still : contains all the still files opened by the user
- Patterns : contains all the pre-defined test patterns
- Snapshots : contains all the stills taken during the current DScaler session

Each time the current DScaler source is one of these still sources, the menu "Playlist" is available in the menubar.

Displaying a still

DScaler can be used to display stills directly in the graphic card overlay. DScaler supports most of JPEG and TIFF files.

A DScaler new file format has been created too. It is used to describe test patterns. The test pattern is generated in the graphic card overlay according to its description when this file is opened in DScaler.

To open a new still file, select the item "Open file..." in the menu "Sources". The selected file, if supported by DScaler, will be added to the virtual playlist associated to the "Still" source and will be displayed.

Taking a still

DScaler can be used to take a still of what is currently displayed by DScaler.

To take a still, select the item "Take One Still Picture" in the menu "Actions", or use the "L" shortcut.
You can use a particular mode to take stills periodically, that is every <n> seconds. The time to wait between each still is defined in the still settings. To launch the process, select the item "Take Periodic Still Pictures" in the menu "Actions"; to stop the process, select it again.
Finally, there is another mode that allows you to take <n> consecutive stills. The number of stills to take is defined in the still settings. With this mode, the stills are stored in memory and are not saved directly in a file. That is necessary to avoid dropped fields and to have really the consecutive pictures of a video stream. To do that, select the item "Take Consecutive Still Pictures" in the the menu "Actions".

When you take a still, depending on a setting you can adjust, either the still is stored in memory and you can save it in a file later, or a file is automatically created in the DScaler main directory or in the directory you specified in your settings. The following rule is applied to define the file name :
TV<yyyy><mm><dd><hh><mi><ss><cc>.<ext> where :
<yyyy> is the current year, <mm> is the current month, <dd> is the current day
<hh> is the current hour, <mi> is the current minute, <ss> is the current second
<cc> is a counter between 00 and 99 allowing 100 captures in the same second
<ext> is tif or jpg
The same rule is applied when saving a still that is currently only stored in memory (the date and time used will be those when the still was taken and not those when you save the file).
A particular setting allows you to use a different file naming, and always override the same file when taking stills : TV.<ext> where <ext> is tif or jpg.

You have a direct access to all the stills taken during the current DScaler session as they are all grouped in a virtual playlist. Select the "Snapshots" source in the menu "Sources" to have a direct access to these stills.

You can choose between different file formats when taking a still :

- TIFF with RGB colourspace : a conversion from YCbCr colourspace to RGB colourspace is applied but no compression
- TIFF with YCbCr colourspace : no colorspace conversion neither compression is applied
- JPEG : a JPEG compression is applied

Warning: in one side, the format TIFF YCbCr is the best as it takes a perfect copy of what is in the overlay and you can restore exactly the same content later; in another side, this format is not supported by lots of graphic software. So this format has to be avoided if you want to share this file with other people.

When a still taken by DScaler is displayed in DScaler, you can use the keyboard key "i" to have information about the DScaler context when this still was taken. These information are displayed using OSD.

The following settings can be adjusted; they are all defined in the section "Still" of the ini file.

Setting | Default | Description
--- | --- | ---
Format of saving | 0 (TIFF RGB) | Format of saving: defines the file format used when taking stills. The possible values are 0 (TIFF RGB), 1 (TIFF YCbCr) or 2 (JPEG)..
JPEG quality compression | 95 | JPEG quality compression: defines the quality factor used when creating a JPEG file. It must be a value between 0 and 100. Higher is the value, higher is the picture quality and bigger is the file size.
Saving path for stills | DScaler directory | This string defines in which directory are saved the produced still files.
Save in the same file | OFF | Set it to 1 (ON) to bypass the normal file naming and use always the same file name when taking stills, or set it to 0 (OFF) to have the normal file naming.
Delay between stills | 60 seconds | Time in seconds to wait between each still when using the mode "take cyclic still pictures".
Number of consecutive stills | 20 | Number of stills taken when using the mode "take consecutive still pictures".
Maximum memory usage for stills | 64 Mo | Maximum quantity of memory in megaoctets used by the software to store stills.
Keep original ratio | OFF | Set it to 1 (ON) to keep the original ratio of the video source for the still, or set it to 0 (OFF) to do no resizing and take exactly what is in the video card overlay.
Stills in memory | OFF | Set it to 1 (ON) to take the stills in memory and defer the creation of the file, or set it to 0 (OFF) to immediately create the file.
OSD when taking a still | ON | Set it to 1 (ON) to have OSD information when a still is taken, or set it to 0 (OFF) to have no OSD information.

Playlists

DScaler allows to load and define playlists. A playlist is a set of still files defined in a text file with the extension ".d3u". Each line of such a file defines the path to a file which has to be a supported still file in order to be readable by DScaler.

To open a new playlist file, select the item "Open file..." in the menu "Sources". All the files contained in the selected playlist file will be added to the virtual playlist associated to the "Still" source, and the first file of the loaded playlist will be displayed.

To create and save a new playlist, you can either create manually the playlist file with a text editor, either load all the files you want to include in the new playlist and then save the current virtual playlist as a playlist file. To save the current virtual playlist as a playlist file, select the item "Save As ..." in the menu "Playlist".

The menu "Playlist" allows to navigate through the different files of the current virtual playlist : "Previous", "Next", "First" and "Last" allows to jump to the previous, the next, the first or the last file in the playlist. The sub-menu "Files" gives a direct access to all the files in the playlist. Items which are greyed in this sub-menu are files that DScaler is not able to read.

When the current still is only saved in memory and not yet saved in a file, it is possible to save it in a file using the menu item "Save". "Saved All" does the same thing but for all the files in the current virtual playlist.

The menu "Playlist" allows to change the order of files in the virtual playlist : "Up" and "Down" allows to shift up or down in the playlist the current displayed file.

To close the current displayed file and suppress it from the virtual playlist, select the item "Close" in the menu "Playlist". You can even close all the files of the virtual playlist by selecting the item "Close All" in the same menu.

Slide show

When the current virtual playlist contains several stills, it is possible to launch a slide show. You have only to select the item "Slideshow" in the menu "Playlist". A cyclic slide show will then be executed through all the files in the playlist, starting from the current displayed file. You can stop the slide show at any time by selecting again the item "Slideshow".

The following setting can be adjusted; it is defined in the section "Still" of the ini file.

Setting | Default | Description
--- | --- | ---
Slide Show Delay | 5 | Slide Show Delay: defines the duration of display of each slide. It must be a value between 1 and 60 seconds.

Test patterns

DScaler includes now a pattern generator. Each test pattern can be described in a text file with the extension ".pat". This description follows a certain syntax. When opening one of these files, DScaler automatically builds the picture corresponding to the description and display it in the graphic card overlay exactly as if it was a normal still file.

The role of this pattern generator is to create patterns which can be displayed directly in the graphic card overlay and be used by the user to adjust overlay and monitor settings. Of course, this generator cannot do everything. It is for example restricted to static pictures and to rectangular shapes.

DScaler is delivered with few pre-defined test patterns allowing to adjust contrast, brightness, color, gamma, ... You have a direct access to all these pre-defined test patterns as they are all grouped in a virtual playlist. Select the "Patterns" source in the menu "Sources" to have a direct access to these test patterns.

You can define your own test patterns. You have only to follow the right syntax and save your text in a file with an extension ".pat". When this is done, open your file in DScaler.

The size of each test pattern is not defined in the file describing the pattern but is a global DScaler setting for all the test patterns. You can adjust this setting which is defined in the section "Patternl" of the ini file.

Setting | Default | Description
--- | --- | ---
Pattern height | 576 | Pattern height: defines the height in pixels of the patterns. It must be a value betweeen 480 and 576.
Pattern width | 720 | Pattern width: defines the width in pixels of the patterns. It must be a value betweeen 240 and 768.