Frame grabbers or capture cards find many applications in industrial, broadcast, infrastructure, surveillance and medical markets. Taking input from SD/HD cameras over HDMI®, 3G-SDI or analog interfaces, these cards provide audio and video data to the host system/PC to which it’s plugged in. PCIe is a popularly used interface between the card and the host. Applications on host use the audio and video inputs over PCIe to realize use cases like video conferencing, editing, recording, preview or content sharing.
Sounds simple enough. So, where’s the catch?
Well, the challenge most such cards face are in providing a true plug-n-play experience. In particular what stands out is:
- Ability of the capture card driver to work on any host PC configuration (ex: PCIe lane configuration, operating system such as Windows & Linux, flavors/revisions of these operating systems, etc.).
- Seamlessness of operation with standard commercial applications running on host PC (Ex: VLC for streaming, Skype/Facebook for video conferencing, Media Players for preview, Windows Movie Maker for editing etc.)
So, how does one achieve this?
The key is to architect by making some smart choices.
- Distribute your capture card with auto-install drivers (ex: Debian packages for Ubuntu, .rpm packages for Red Hat Linux or click-wrap installation for Windows)
- These drivers follow standard rules and methods that users are familiar with.
- Use standard driver API frameworks like V4L2 and ALSA for Linux, DirectShow/AVStream for Windows
- Most commercial applications respect and work with these API frameworks.
- This helps when migrating across versions of the OS.
- Have a common driver architecture across all operating systems, limiting the OS-specific changes to the API layer. That way, the time to port to a new OS or API standard will be quick!
- Use a wide pool of commercial applications for validation
- Each application may configure the driver differently, and validating this way will increase the plug-n-play compatibility and the probability of other applications to work straight away as well.
Check out Ittiam’s PCIdash Capture Card – a compact high-performance card architected based on these principles. PCI dash enables single and multi-channel audio video capture & video encode while ensuring seamless operation with applications like Skype, VLC, Facebook, YouTube and many more!