To date the approach that has been taken for contribution or distribution of Ultra HD has typically been to divide the picture into 4 quadrants and use 4 x H.264 HD encoders. Typical bitrates have had to remain high, over 100 Mbit/s, to allow for extra bandwidth to be used to try to mask the picture joins. This approach has been fraught with difficulties as the quadrants fall out of sync and the joins in the middle of the picture are hard to eradicate completely even with high bit rates. The approach is also costly as gangs of 4 encoders and 4 decoders are required, as well as extra synchronisation equipment.
With the availability of real time HEVC encoders and professional HEVC decoders it is now possible to turn to HEVC for live event contribution. The HEVC approach delivers significant bit rate savings versus the 4 by HD H.264 approach, bit rates are typically halved for the same picture quality without the risk of picture joins destroying the image. Using a hardware based encoder also delivers low latency, an essential feature for any contribution solution.
The Excel 4000 now with 4:2:2, 12-bit support, is ideally suited for the contribution application as it is based on Xylostream’s compression engine - a set of innovative, proprietary HEVC algorithms - running on an FPGA-accelerated High Performance Computer. As such the hardware accelerated platform provides very low latency encoding. In addition, the Excel 4000 is capable of sustaining bit rates up to 80Mbit/s allowing for the highest quality contribution feeds.
Compressed video contribution feeds need to be decoded and then presented to the playout chain over 4x3G-SDI. The XD4000 provides the final link in the contribution chain allowing the contributed video to be presented over standard interfaces. As the XD4000 uses a unique hardware decoder latency is also minimised. The unit also supports up to 12-bit colour depth and bit rates up to 80Mbit/s as a match for the Xylostream Excel 4000 encoder.
Follow the link to Download the Datasheet for the Excel 4000
Follow the link to download the XD4000 Datasheet