Difference between revisions of "Support:AJAVideo/ImplementationDetail"

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(Created page with "= AJA Video Implementation = __TOC__ This section describes the AJA Video implementation in more detail. {{M-Note|Note that "DVIO" refers to the ''Digital Vision Video Libr...")
 
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The Kona 3G supports 4K video (3840/4096x2160) over SDI but not HDMI. HDMI output is disabled while a 4K video format is selected, resulting in a green display on the attached HDMI receiver. Normal HDMI display will resume when a non-4K video format is selected.
 
The Kona 3G supports 4K video (3840/4096x2160) over SDI but not HDMI. HDMI output is disabled while a 4K video format is selected, resulting in a green display on the attached HDMI receiver. Normal HDMI display will resume when a non-4K video format is selected.
  
−
== Changes to I/O Mode Behaviour ==
+
== I/O Mode Behaviour ==
  
−
The DVIO AJA component handles incompatibilities between video formats and the I/O mode configured by the user via the preferences.
+
=== Video IO/Monitoring Preferences / VTR Layoff / VTR Capture UI ===
  
−
The AJA component attempts to set up the desired video format and may adjust the requested I/O mode if necessary in order to achieve this. In such cases, it takes the I/O mode as specifying ''absolutely'' the available hardware connectivity and receiver functionality (i.e. dual-link connection and 3G support), while treating provision of RGB444 colour as ''desired'' rather than obligatory.  
+
... video refs tab
  
−
There are still cases where incompatibility can result in card set-up failure but fall-back options will be used wherever possible.
+
In the Video IO/Monitoring preferences page, VTR Layoff UI and VTR Capture UI :
  
−
The following limitations and fall-back behaviours apply :
+
* '''Phys Links''' - The number of physical links (i.e. cables) connecting outputs or inputs (as relevant to use case) of the video I/O card to the remote SDI device. The user must set this to reflect the connections they have made to a monitor or VTR.
 +
* '''Max Data Rate''' - The maximum data rate that the remote SDI device can receive or will send and, if 3G, which levels of 3G are supported. The user must set this to reflect the capabilities of the remote device when performing video output or the output expected from the remote device when performing video input.
 +
* '''SDI Colour''' - The colour encoding that the user would like sent over SDI. While our application will deliver this colour encoding whenever possible, it cannot be guaranteed to be delivered in all cases and the application may choose to fall back to a colour encoding compatible with the other parameters and the video format in use.
  
−
RGB444 is not supported for 720p, NTSC and PAL video formats and they never need more than 1.5 Gbit/s bandwidth.
+
=== Stereo ===
  
−
* Fall back to YUV422, single link, no 3G for these formats.
+
When monitoring a stereo project, the application will deliver stereo video whenever possible. However, it cannot be guaranteed to be delivered in all cases and the application may choose to fall back to '''mono'''.
  
−
When YUV422 is requested, this is taken to indicate that only '''one''' physical link is present (or ''four'' if a 4K format is desired), without 3G support.  
+
{{M-Note|If only one of the desired settings ''colour encoding'' and ''stereo'' can be achieved, the colour encoding will be preferred and output will fall back to mono.}}
  
−
* High frame rate (see below) 1080p or 4x1080p video formats can not be set as sufficient bandwidth is not available.
+
=== UI Notification ===
  
−
When RGB444 via dual-link is requested, this is taken to indicate that '''two''' physical links are present (or ''four'' if a 4K format is desired), without 3G support.  
+
The application informs the user of the actual SDI configuration in use. For VTR Layoff and Capture, this is displayed in the relevant UI. For monitoring, it is displayed in the main project editor display.  
  
−
* High frame rate 4x1080p video formats can not be set as sufficient bandwidth is not available (eight physical links would be required just for YUV422).
+
Coloured text is used to indicate general status :
−
* High frame rate 1080p video formats and normal frame rate 4x1080p video formats are supported but fall back to YUV422. Otherwise, RGB444 is provided.
 
  
−
When RGB444 via ''3G level A'' is requested, this is taken to indicate that only '''one''' physical link is present (or ''four'' if a 4K format is desired), with 3G support.  
+
* <span style="color: red; background-color: black">Red</span> indicates that the required video format is not supported at all with the current number of physical links and maximum data rate.
 +
* <span style="color: yellow; background-color: black">Yellow</span> indicates that the required video format is supported but with a fall-back colour encoding or, for stereo monitoring only, fall-back to mono output.
 +
* <span style="color: white; background-color: black">White</span> indicates that the video format is fully supported.
  
−
* It is assumed that 3G-supporting devices will support ''both'' levels A and B. It seems that the AJA cards support 3G level A only for high frame rate 1080p and 4x1080p video formats; we provide 3G level A for these formats but fall back to YUV422. For all other video formats, we fall back to 3G level B.
+
The Video IO/Monitoring Preference page has a new button "...View SDI Format Support".  
  
−
When RGB444 via 3G level B is requested, this is taken to indicate that only '''one''' physical link is present (or ''four'' if a 4K format is desired), with 3G support.  
+
... View SDI Format button
  
−
* It is assumed that 3G-supporting devices will support both levels A and B. High frame rate 4x1080p video formats can't be implemented using 3G level B due to the way the card needs to be configured for high frame rates with 3G level B, so we fall back to 3G level A YUV422 for these formats.  
+
This opens a dialog that displays, for the current Phys Links, Max Data Rate and SDI Colour settings and each video format available:
−
* High frame rate 1080p video formats are supported but fall back to YUV422. Otherwise, RGB444 is provided.
+
 
 +
* Whether the format is supported at all and, if not, why.
 +
* What kind of SDI link will be used for this format.
 +
* What colour encoding will be used for this format and, if it is not the one desired by the user, why.
 +
* Whether stereo will be available for this format and, if not, why.
 +
 
 +
This should help gauge SDI output support for the selected settings and enable experimentation.
 +
 
 +
=== 12 Bit Mode ===
 +
 
 +
For application version 2015.2 and later, RGB444 12-bit colour can now be sent via 3G SDI and is no longer limited to dual-link 1.5G.
 +
 
 +
This enables 12 bit in stereo and Quad-SDI scenarios as well as mono over a single cable.
 +
 
 +
== Limitations ==
 +
 
 +
SD and 720p standards are taken as supporting only '''YUV422 10-bit colour'''.
 +
 
 +
{{M-Note|AJA Video hardware only supports YUV422 10-bit colour for SD and 720p modes.}}
  
−
{{M-Note|Note :
 
  
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* 12 bit/component I/O modes are not supported for AJA cards at this time.
 
−
* By "high frame rate", we mean > 30fps, i.e. 50, 59.94 and 60 fps. "Normal frame rate" means 30 fps or less.
 
−
}}
 
  
 
[[Category:Support]]
 
[[Category:Support]]

Revision as of 16:07, 23 June 2016

AJA Video Implementation

This section describes the AJA Video implementation in more detail.

Note that "DVIO" refers to the Digital Vision Video Library used by Nucoda and Phoenix to interface to video I/O boards like AJA and DVS.

Mapping of Signals to SDI Ports

The SDI I/O is mapped as labelled on the Kona 3G, Kona 4, AJA Breakout Box and cables.

  • 4K or UHDTV modes will map all four links as output, starting with SDI 1 to 4.

HDMI Support

If the AJA video I/O card supports HDMI output using the selected format, video will automatically be output over HDMI in addition to SDI.

The DVIO AJA component will detect the capabilities of the downstream receiver attached to the HDMI port and configure the output accordingly, updating if the receiver changes while running. Specifically :

  • HDMI output will be set to 10 bits/component if the receiver supports that, otherwise 8 bits/component.
  • The protocol sent via the HDMI port will be switched between HDMI and DVI to match the receiver's expectations.

The HDMI output is always set to RGB, which all HDMI implementations are required to support (regardless of the receiver's support for YUV).

No option is provided to enable YUV over HDMI.

The Kona 3G supports 4K video (3840/4096x2160) over SDI but not HDMI. HDMI output is disabled while a 4K video format is selected, resulting in a green display on the attached HDMI receiver. Normal HDMI display will resume when a non-4K video format is selected.

I/O Mode Behaviour

Video IO/Monitoring Preferences / VTR Layoff / VTR Capture UI

... video refs tab

In the Video IO/Monitoring preferences page, VTR Layoff UI and VTR Capture UI :

  • Phys Links - The number of physical links (i.e. cables) connecting outputs or inputs (as relevant to use case) of the video I/O card to the remote SDI device. The user must set this to reflect the connections they have made to a monitor or VTR.
  • Max Data Rate - The maximum data rate that the remote SDI device can receive or will send and, if 3G, which levels of 3G are supported. The user must set this to reflect the capabilities of the remote device when performing video output or the output expected from the remote device when performing video input.
  • SDI Colour - The colour encoding that the user would like sent over SDI. While our application will deliver this colour encoding whenever possible, it cannot be guaranteed to be delivered in all cases and the application may choose to fall back to a colour encoding compatible with the other parameters and the video format in use.

Stereo

When monitoring a stereo project, the application will deliver stereo video whenever possible. However, it cannot be guaranteed to be delivered in all cases and the application may choose to fall back to mono.

If only one of the desired settings colour encoding and stereo can be achieved, the colour encoding will be preferred and output will fall back to mono.

UI Notification

The application informs the user of the actual SDI configuration in use. For VTR Layoff and Capture, this is displayed in the relevant UI. For monitoring, it is displayed in the main project editor display.

Coloured text is used to indicate general status :

  • Red indicates that the required video format is not supported at all with the current number of physical links and maximum data rate.
  • Yellow indicates that the required video format is supported but with a fall-back colour encoding or, for stereo monitoring only, fall-back to mono output.
  • White indicates that the video format is fully supported.

The Video IO/Monitoring Preference page has a new button "...View SDI Format Support".

... View SDI Format button

This opens a dialog that displays, for the current Phys Links, Max Data Rate and SDI Colour settings and each video format available:

  • Whether the format is supported at all and, if not, why.
  • What kind of SDI link will be used for this format.
  • What colour encoding will be used for this format and, if it is not the one desired by the user, why.
  • Whether stereo will be available for this format and, if not, why.

This should help gauge SDI output support for the selected settings and enable experimentation.

12 Bit Mode

For application version 2015.2 and later, RGB444 12-bit colour can now be sent via 3G SDI and is no longer limited to dual-link 1.5G.

This enables 12 bit in stereo and Quad-SDI scenarios as well as mono over a single cable.

Limitations

SD and 720p standards are taken as supporting only YUV422 10-bit colour.

AJA Video hardware only supports YUV422 10-bit colour for SD and 720p modes.

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