Manuals / ViewCast / Computer Equipment / Network Card

ViewCast Understanding Vertical Blanking Interval and Its Capture with Osprey Models

Models: Osprey-450e Osprey-240e

1 98
Download 98 pages 30.24 Kb
Page 78
Image 78

AVStream Driver Reference Information

application. This capability requires custom programming. Refer to the Osprey AVStream SDK Users’ Guide. A sample SDK applet named TCApp illustrates the interface.

Figure 61. Timecode Video Marking

Timecode stamping must be enabled in the driver before it can be used, and the field and line number correctly set. To access the controls, go to the Device property tab and click Extras…

It is recommended that timecode marking be disabled when not in use, especially the auto search feature – on a slow machine it uses several percent of CPU bandwidth – especially if timecodes are not present.

Note: VITC and LTC – Longitudinal Timecode – are two distinct encoding systems, and this driver supports only VITC.

A suggested reference on timecode is Timecode: a user’s guide – 3rd ed., John Ratcliff, Focal Press, 1999.

Vertical Blanking Interval (VBI) capture

The Osprey AVStream driver provides DirectShow-compatible VBI pins. VBI data includes Vertical Interval Timecode (VITC) in both the NTSC and PAL worlds. In NTSC, line 21 Closed Captioning (although it is part of the video interval rather than true VBI data), is commonly treated as VBI data. In PAL, World Standard Teletext (WST) is encoded in the VBI data region.

The driver delivers VBI data as raw waveforms, which are then decoded by external DirectShow filters. DirectShow provides three filters under the classification “WDM Streaming VBI Codecs” that will decode data from VBI pins:

∙CC Decoder

∙NABTS/FEC VBI Codec

∙WST Codec

With the Osprey AVStream driver, either the CC pin or the VBI pin can be used to obtain closed caption data. If the VBI pin is used, an extra filter is required to turn the raw waveform into CC character pairs.

When SimulStream is not installed, the driver supports two VBI pin instances. In practice, a DirectShow Smart Tee Filter can be inserted into the graph to make any number of VBI pins. When SimulStream is installed, multiple VBI pins are allowed.

72

ViewCast

Page 77 Page 79
Page 78
Image 78
ViewCast Osprey-450e, Osprey-240e manual Vertical Blanking Interval VBI capture, Timecode Video Marking
Page 77 Page 79

Osprey-450e, Osprey-240e specifications

The ViewCast Osprey series, particularly the Osprey-240e and Osprey-450e, represents a significant advancement in the field of video capture and encoding technology. These high-performance video capture cards are designed to meet the growing demands of professional broadcast environments, video production, and live streaming applications.

The Osprey-240e offers a compact design while delivering excellent performance. It is equipped with dual channel input capabilities, allowing users to capture multiple streams simultaneously. This feature is particularly beneficial for broadcasters and content creators looking to streamline their workflows. The Osprey-240e supports a variety of input formats including SDI and HDMI, ensuring compatibility with a wide range of video sources. Its robust encoding capabilities allow for real-time video streaming in HD resolution, making it suitable for live events, webinars, and other digital content delivery applications.

On the other hand, the Osprey-450e takes video capture to the next level with enhanced capabilities. It supports up to four channels of video input, making it an ideal solution for multi-camera setups. The Osprey-450e also boasts advanced encoding technologies that facilitate high-quality video compression without sacrificing performance. This model is particularly well-suited for enterprise-level applications where high-definition video quality is paramount. Users can experience lower latency and improved encoding efficiency, resulting in smoother viewing experiences for end-users.

Both models feature powerful drivers and software support that integrate seamlessly with a variety of video production and streaming applications. The Osprey series is designed with user-friendly interfaces, making it accessible for both seasoned professionals and newcomers alike. The cards are also compatible with many of the industry-standard software solutions, enabling users to harness the full potential of their video content.

These capture cards also prioritize reliability and durability, ensuring long operational life even under demanding conditions. Their efficient thermal management systems keep components cool during extended use, thereby enhancing performance consistency.

In summary, the ViewCast Osprey-240e and Osprey-450e deliver impressive features tailored for a range of video applications. Their support for multiple input channels, advanced encoding technologies, and strong software compatibility make them invaluable tools in the modern digital media landscape, solidifying their reputation among content creators and broadcasters alike.