Bitrates & Resolutions
Recommended Bitrates & Resolutions:
Video quality depends on allocated bandwidth per stream which must fit in the limits of the connection upload speed for broadcaster and download speed for watcher.
Higher resolution requires more bandwidth to show a clear picture without much pixelation. More pixels require more bandwidth.
Higher video bandwidth setting will reduce required compression level and pixelation on movements but will require users to have higher connection or will cause massive frame loss, interruptions, big latency.
Recommended video bitrates in Mbps (b/s)
|Format||Pixels||Bitrate (Mbps)||Transfer (b/s)|
Bitrate is usually in bits (8 data bits = 1 byte space). Obtain generated transfer by diving bitrate to 8 bits/byte.
Ex. 8Mbitsps generates 1Mbyte/s transfer (1000000b/s) and file size when recording.
Client Connection Requirements
When broadcasting, total stream size should be less than maximum broadcaster upload speed.
Do a speed test from broadcaster computer to a location near your streaming (rtmp) server using a tool like SpeedTest.net . Drag and zoom to a server in contry/state where you host (Ex: North America if you host on LOS) and select it. The upload speed is the maximum data you’ll be able to broadcast.
To obtain kb/s from kbps divide by 8. In example 400kbps is 50kb/s (50 000 b/s). This is required when configuring streaming applications in b/s.
Number of streams consumed for each user connected to server depends on communication logic.
For 1 way broadcasts each user consumes 1 stream.
If there are 2 way private video chat rooms where each user sees 1 other video and transmits 1 video, 2 streams per user will be required.
If there are video conference rooms where each user transmits 1 video and sees other 3 videos, 4 streams per user will be required.
To host hundreds or thousands of streams simultaneously, servers with 1000Mbps connection are required.
It’s important to have the server in a reputable data center with high connectivity so all your users can connect to the server at good speed, from their different networks and providers.
To evaluate server and network capacity when choosing a server, consider monthly transfer available.
In example, LOS Servers are setup to allow 100Tb/month data traffic which means around 308Mbps average continuous transfer.
A provider selling servers with 10Tb/month is ready to handle around 30Mbps average transfer and if server allows only 5Tb/month your project should not require more than 15Mbps average transfer.
On high traffic events, servers could handle spikes up to double or more of this average bandwidth only if network load is low at that moment. Reliable services should be planned based on provider network capacity.
Codec profile – base
Codec level – 3
Rate control – CBR
Slice count – 0
GOP length – 100
B-frames count – 0
IDR interval – 0
Reference frames number – 1
NAL HRD Conformance – Enabled
HRD Buffer Length – 0
HRD Initial Delay – 0
Look Ahead – Disabled
Look Ahead Depth – 0
Aspect Ratio – static pixel aspect ratio from first source IDR
Deinterlace Algorithm – BOB
Deinterlace – Enabled
Hardware acceleration – Enabled