Octasic has brought together the key ingredients necessary to develop video algorithms for tomorrow’s video networks. Whether delivering video over wired or wireless networks to HD panels or mobile devices, Octasic’s algorithms and expertise guarantee the best possible quality. A combination of high-performance devices and fine-tuned software libraries help OEMs accelerate product development.
As DSPs go multi-core to get around the power limitations of current architectures, Octasic is ahead of the pack. With its second generation of multi-core DSPs for video, the OCT2200 Series delivers unprecedented performance in a fully-programmable DSP. Processing HD resolution video is accomplished by dividing the task across multiple cores.
Current solutions use a complicated mix of DSP processors, hardware accelerators, and general purpose CPU cores in order to achieve the performance required for high-end video systems. Octasic solutions, which are powered by the most power efficient DSP core- Opus, are much simpler to program and use only one kind of processor. This reduces the number of software tools required to create and debug code, while simplifying the system design by eliminating the need for multiple steps in a video pipeline such as managing external hardware acceleration blocks.
Octasic solutions that process video completely in software allow for very flexible implementations. One of the most important things for video conferencing equipment is compatibility and inter-operability. It is important to be able to make quick fixes to the codec in software. While H.264 is the new dominant standard, backwards compatibility with video codecs include H.261, H.263, H.263+, MPEG-4. The solution must also be future-proof to support technologies such as Scalable Video Coding (H.264 SVC).
Production Grade Codecs
Octasic offers production grade libraries for all major video codecs such as H.264, MPEG-4 and H.264. These codecs haven been deployed in many different network scenarios, leading to heavy inter-operability testing with a broad range of endpoints. These codecs have been optimized for a multi-core DSP environment, and therefore deliver excellent performance on Octasic’s DSPs.
Packet Loss Concealment
Packet loss is common on IP networks due to its fundamental “best-effort” design philosophy. When the network cannot relay a packet, it is simply discarded. The application is responsible for dealing with packet loss, either through re-transmission or concealment. When re-transmission is impractical, packet loss concealment (PLC) is the only viable approach. This most often occurs in applications that require very low delay, such as real-time communications video conferencing. Octasic’s codec libraries include algorithms that reduce the effects of packet loss. Instead of the readily-noticeable artifacts, PLC masks the loss by estimating the expected data based on previous frames.
The following video demonstrates this technology:
Video encoders rely on an algorithm called Bit-Rate Controller to control the output bit-rate of the video stream. Video streams are typically Variable Bit-Rate (VBR), meaning that the amount of bandwidth required to encode a given stream can vary depending on the complexity or movement found in the source video.
Octasic has developed patent-pending algorithms for bit-rate controllers in the video over IP space. These algorithms cover the broad spectrum of real-time to streaming video applications.
The bit-rate controller must offer the highest quality video for the bandwidth that has been allocated. The following graph demonstrates Octasic’s bit-rate controller’s performance for real-time communications where delay must be minimized.
For a given video feed, the graphs below demonstrate how Octasic is able to maintain a near-constant bit rate for a real-time video conference. By keeping the bit-rate constant, we’re able to maintain a very low delay.
In order to evaluate the effectiveness of the bit-rate controller the perceived quality must also be compared. The following graphs compare the Peak Signal-to-Noise Ratio (PSNR) of each video stream. Not only does Octasic’s solution deliver a higher PSNR on average, it also maintains a more stable level of quality. This eliminates flicker, or periods of varying crispness in the image.