Without the functionality of Forward Error Correction (FEC), you can expect pixilation…By using FEC enabled encoders will allow for a smoother broadcast feed. FEC is sometimes refereed to channel coding. It’s sole purpose is to handle the common errors of unreliable or noisy channels that frequently interfere with video, audio and data transmission.
What is often not understood is that Forward Error Correction does not involve the retransmission of packets. Rather, the packets are numbered (RTP protocol) and recognizes when packets are lost or missing. The FEC transmits blocks of data which include many check sums for the IP packets in the block. These check sums are used by the decoder’s FEC to recover the lost data in a block.
The best Encoder with FEC functionality is the VEN-3000. The FEC on this device can be configured to recover far more lost IP packet (longer burst of lost packets and even more single lost packets) than the standard SMPTE2022-1, therefore making it ideal for many applications. Our FEC can be configured to recover up to 250 consecutive lost IP packets (SMPTE 2022 can only recover up to 20 consecutive lost packets) and higher than 30% packet loss (the SMPTE2022 top at 20%).
Please keep in mind that packet recovery is all about the redundant (overhead) information transmitted, not just the method of how the packet recovery is implemented. The implementation can be used to tailor a the recovery process to burst errors or random packet recovery.
