RTMP Pass-Through

header image

What Is RTMP Pass-Through?

RTMP, or Real-Time Messaging Protocol, is a popular protocol for streaming audio, video, and data over the Internet in real time. Originally developed by Macromedia and now owned by Adobe, RTMP is widely used for live streaming because of its low latency and robust data transmission capabilities.

RTMP Pass-Through refers to the process of relaying an RTMP stream from one point to another without decoding or re-encoding the stream. In more basic terms, it’s comparable to mailing a package without examining what’s inside, preserving the content in its original state from where it began to where it’s headed.

The Role of RTMP Pass-Through in Live Streaming

Simplified Workflow

In live streaming, RTMP Pass-Through plays a crucial role by simplifying the workflow. Content creators can push their RTMP streams to servers or Content Delivery Networks (CDNs), and these entities can then relay the streams to end-users or other distribution points without modifying the original content.

Reduced Latency

One of the key benefits of RTMP Pass-Through is the reduction in latency. Since the stream is not being decoded and re-encoded at intermediary points, the time taken to process the stream is minimized. This makes sure that viewers get the live content with almost no delay, almost as if it were in real-time.

Preservation of Quality

RTMP Pass-Through helps in preserving the quality of the original stream. By avoiding multiple encoding processes, the chances of quality degradation are significantly lowered.

Scalability

RTMP Pass-Through enables scalability in live streaming. By allowing the replication and distribution of the original stream, large audiences can be served without overburdening the original streaming infrastructure.

supporting image

Advantages and Disadvantages of RTMP Pass-Through

Advantages

  • Low Latency: By avoiding unnecessary decoding and re-encoding, RTMP Pass-Through ensures low-latency streams, providing near real-time viewing experiences.
  • Quality Preservation: The original stream quality is maintained, ensuring that viewers receive the highest possible quality without degradation.
  • Simplified Workflow: Streamlining the process means fewer potential points of failure and easier management of live streams.
  • Scalability: Efficiently distribute content to larger audiences without overwhelming the original streaming setup.

Disadvantages

  • Compatibility Issues: RTMP is not universally supported across all platforms and devices, which can limit the reach of streams leveraging RTMP Pass-Through.
  • Bandwidth Requirements: Since streams are transmitted in their original form, high-quality streams can require substantial bandwidth, which may not be feasible in all scenarios.
  • Dependency on Infrastructure: Reliability depends on the robustness of the intermediate servers or CDNs used to pass through the streams. Any point of failure can affect the stream quality and delivery.
    main banner

    Wrapping Up

    RTMP Pass-Through is a valuable technique in the realm of live streaming, offering benefits such as low latency, quality preservation, and ease of scalability. However, it also comes with its own set of challenges, including compatibility issues and bandwidth requirements.

    Whether you are a content creator, a live streaming enthusiast, or a technical professional, recognizing the impact of RTMP Pass-Through can enhance your approach to live streaming and help you make the most of this powerful technology.

    Secure your digital assets and enhance your workflow with Cloudinary’s cloud solutions. Sign up for free today!

Additional Resources You May Find Useful:

QUICK TIPS
Kimberly Matenchuk
Cloudinary Logo Kimberly Matenchuk

In my experience, here are tips to optimize the use of RTMP Pass-Through in live streaming workflows:

  1. Ensure a reliable origin server
    Use robust and well-maintained origin servers for your RTMP streams. The quality of the initial stream heavily influences the success of RTMP Pass-Through, as no modifications will be made downstream.
  2. Optimize stream settings for the audience
    Since the stream isn’t re-encoded, ensure that your source settings (bitrate, resolution, and framerate) are optimized for your target audience and devices to minimize playback issues.
  3. Leverage multiple CDNs for scalability
    Use multiple CDNs with RTMP Pass-Through capabilities to ensure reliable and scalable delivery. This also provides redundancy, reducing the risk of stream interruptions during high-traffic events.
  4. Combine with adaptive bitrate (ABR) streaming
    Pair RTMP Pass-Through with an ABR-capable platform at the edge to provide viewers with multiple quality options based on their network conditions, even if the original stream remains static.
  5. Test compatibility with target platforms
    RTMP is not natively supported on all devices, such as modern browsers. Convert streams into protocols like HLS or DASH on the delivery end when needed for broader device compatibility.
Last updated: Nov 30, 2024