Whether it’s the news around the world, a corporate event, a wedding or even a funeral, live streaming has firmly found its place in modern tech. But how is it done?
The first step is the ‘acquisition’ or production of the programme. This can be a single camera in the field or an entire Multicam production which often involves production vans or trucks. The output is a final programme stream that is ready to be consumed by the audience.
But how does such a stream make its way to your internet device?
Professional Live Streaming Services use a technique called ‘bonded internet connection’. This means the incoming video signal (HDMI or SDI) is encoded into h254 or HEVC by a hardware encoder. Some of these encoders are so small that they can be mounted onto a field camera. The data stream is then divided into packets sent to a server (often thousands of miles away). Getting this data from the field to the server is essential for modern live-streaming production. The packets are not sent via a single internet connection but via multiple connections. Modern devices can simultaneously connect up to eight 4G or 5G modems. The device pushes all packets out via all available connections even if the connections don’t have equally good reception.
A server receives these data packets from all channels in a large data centre or a TV studio. If necessary, the data packets need to be reordered. Due to the unequal speed and quality of the individual connections, they will probably not arrive in the same order as they were sent. If a packet gets lost, the server sends a message to the transfer device in the field to resend the missing data packets.
This process takes place in about 2-5 seconds. This means that the live video that you might see on your device is about 5 seconds behind real-time. However, this is still acceptable, primarily if a faster alternative would involve a satellite connection and multiple times the costs.