Introduction to Aspect Ratios
The aspect ratio of a video is the relation between the height and the width of a video. If the aspect ratio is wrong,
the image may appear stretched or squashed. One of the problems with Media Player is that it didn't support aspect ratio
at all, which meant that you could only play a video using its original aspect ratio. The disadvantage to this is that
it limited you from playing certain videos correctly.
Toward that end, Zoom Player supports 7 distinct aspect ratio modes:
Fit to Window
This basically disables all aspect ratio and allows you to resize the video window to any size and aspect ratio.
This setting most suited TV based playback as it allows you to exactly fit the video area to the dimensions of the
screen.
Source Aspect Ratio
This setting forces a 1:1 source aspect ratio.
Derived Aspect Ratio
The derived aspect ratio is the aspect ratio derived from data within the file itself.
Fullscreen 4:3
This is a forced aspect ratio which forces any content to appear as fullscreen on 4:3 Monitors/TVs.
Widescreen 16:9
This is a forced aspect ratio which forces any content to appear as fullscreen on 16:9 Monitors/TVs.
Anamorphic
This mode stretch the source vertically by 33.333% so that it can work with Anamorphic devices (Anamorphic Lens Projectors for example).
The percentage stretched can be relative to the derived aspect ratio or to the current video dimension.
Custom
Custom can be any pre-defined Aspect Ratio. By default it's 2.35:1, but can be easily changed
by editing the Custom AR fields.
Anamorphic Aspect Ratio is Relative to
When using the Anamorphic aspect ratio mode, you can have it stretch the video relative to its source
aspect ratio or against the currently defined video dimension.
Pixel Aspect Ratio - Relative Stretch Calculator
The calculator tool helps you enter the corrent values for "Source Relative Stretch". Using this tool,
you can easily compensate for displays with non 1:1 PAR (non-square pixels) such as widescreen displays
with a resolution of 1024x768 (a popular resolution with older Plasma TVs).
Source Relative (Pixel Aspect Ratio) Values
Source Relative Stretch, sometimes referred to as PAR (Pixel Aspect Ratio), allows you to adjust the
video display so the aspect ratio appears correct on display devices where the pixels are not squares
(for example, a Plasma 16:9 TV with a resolution of 1024x768). You can use the Pixel Aspect Ratio
calculator (which is on the same page) to feed in the dimensions and resolution of your display
device and it will automatically fill in the correct Source Relative Stretch value for you. You can also
limit the Source Relative Stretch to a specific monitor (usually a monitor-output that is connect to a TV set).
Use Source Relative Stretch to compensate for non-square pixel displays (affects all AR's)
Enables/Disable support for Source Relative Stretch (Pixel Aspect Ratio). See "Source Relative (Pixel Aspect Ratio) Values"
for more information.
"Derived" mode Automatically Adjusts Aspect Ratio for badly encoded content
Some media content is badly encoded in a way that distorts the aspect ratio. With this setting enabled
and Zoom Player aspect ratio mode set to "Derived", Zoom Player will attempt to compenstate for badly
encoded content by trying to make it fit to 4:3 or 16:9 as long as the AR skew isn't too big.
Restrict AR Adjustments to Height in Fullscreen / Zoom mode (disable this on 16:9 displays)
Zoom Player always makes sure that the video image always fits into the specified Width and Height
as defined in the user interface (and presets). However, when playing certain kind of video content
(usually where the black bar on a widescreen video is encoded as part of the video) in the Anamorphic
aspect ratio, this will cause the width of the video to shrink in order to maintain the height
setting specified. When enabling this feature, only the video height will ever be scaled in fullscreen/zoom
mode, allowing the video to break out of the specified height value. This may not work well with
widescreen display devices that want to squeeze 4:3 content. So if that is the case, you may want
to disable this setting.
Setting window to Source Video Size compensates for Aspect Ratio
When setting the Zoom Player window to match the Source Video resolution, this setting instructs Zoom Player
to take into account the current aspect ratio mode.
Support Anamorphic Matroska Files
Matroska files can contain Aspect Ratio information. Depending on the filter (component) used to parse
matroska files, the aspect ratio can be handled by the component itself, or with this setting enabled, it can
be handled by Zoom Player. You should probably leave this setting disabled unless playing matroska files
gives you the wrong aspect ratio.
Specify a Custom Aspect Ratio
These two values allow you to set the Aspect Ratio as it is applied when the Aspect Ratio mode is set to
the "Custom" entry.
Some sample Aspect Ratios:
4:3
16:9
1.85:1
2.35:1
