Introduction
Real-Time Messaging Protocol or RTMP, is a live streaming protocol that provides high-performance transmission of video, audio, and data between encoder and server across the internet. RTMP is an essential part of live streaming and it is supported by most streaming providers, encoders, and platforms.
RTMP Syntax
Videolinq accepts RTMP streams originating from hardware or software encoders. When creating a channel and selecting RTMP as a video source, we present you with the RTMP path that uses by default TCP port 1935 in a path, followed by a stream key. Here is an example of a generic RTMP path and stream key. These values can be copied and used by most streaming encoders:
rtmp://go-xx.videolinq.net:1935/ingest?user=tgwpFv9sOp@pKmKNTwe:dyBNIlZa4N
cC9jY42w@pKmKNTwe
Some encoders do not support the insertion of a separated RTMP path and stream key. Simply add the stream key at the end of the RTMP path like this:
rtmp://go-xx.videolinq.net:1935/ingest?user=tgwpFv9sOp@pKmKNTwe:dyBNIlZa4N/cC9jY42w@pKmKNTwe
Some encoders or platforms will require a username and password:
RTMP: rtmp://go-xx.videolinq.net:1935/ingest/
Stream key: cC9jY42w@pKmKNTwe
Username: tgwpFv9sOp
Password: dyBNIlZa4N
Customers who want to secure the stream sent to Videolinq use the RTMP path and stream key provided, and change rtmp to rtmps and 1935 to 443:
rtmps://go-xx.videolinq.net:443/ingest?user=tgwpFv9sOp@pKmKNTwe:dyBNIlZa4N
cC9jY42w@pKmKNTwe
Bitrate and Resolution
RTMP can be generated by software encoders, hardware encoders, or 3rd party streaming service providers and media platforms. Regardless of what your RTMP source is, for proper capture and signal re-distribution, the RTMP stream must meet the following requirements:
Resolution between 720p to 1080p.
Video bitrate between 2 to 8 MBps (8 MBps maximum).
Audio bitrate between 60 to 128 KBps.
Video encoded with H.264 Baseline, Main, or High profile.
Video frame rate up to 60 frames per second.
Insert a keyframe (GOP) every 1 or 2 seconds.
Use Constant Bitrate (CBR) and not Variable Bitrate (VBR).
Adaptive Bitrate (ABR) is not supported.
To satisfy output to most social media platforms we recommend the following configuration: CBR Video of 1920x1080 resolution at 6 MBps using H.264 Main profile, 25-30 frames-per-second with a keyframe every 2 seconds. Audio at 128 Kbps Stereo using the AAC codec.
RTMP streams that are losing packets on the way, will be rejected by Videolinq after a few minutes of transmission.
Signal Monitoring
The channel preview player provides a good indication of the incoming RTMP stream. The stream you see in the preview player was received by Videolinq and distributed to the Videolinq content delivery network (CDN). The stream is then pulled back into the preview player providing a simulation of what quality you can expect to see when you point to the stream with a player or distribute the feed to social media or 3rd party platforms. Remember to insert 1 keyframe every 2 seconds to start playback faster.
If you have questions about this article contact technical support.