Six Encoder Problems and How to Solve ThemOctober 29, 2019
Professional live streaming involves a lot of moving parts, and there’s one part of the workflow that brings the most trouble: encoding. The process of compressing video data from a baseband signal for high-quality delivery to a broad global audience is complicated. While encoding itself is a complex task, the encoder algorithms aren’t always to blame. Rather, a myriad of other variables can introduce issues to the workflow.
In this blog, we’ll examine the six most common challenges when encoding and how they can be avoided.
Six Common Encoder Problems:
- Encoder Configuration Mishaps
- Identifying Pre-Event Issues
- Limited On-Site Expertise
- Sharing Equipment Across a Team
- Limited Bandwidth
- Network Path Issues
1. Encoder Configuration Mishaps
It’s important to understand what you’re trying to deliver when configuring a live stream. The right encoding settings depend entirely on your use case. We often see broadcasters using the wrong settings by either relying on static encoder settings or mismanaging encoding presets when re-tuning for another broadcast.
Relying on Static Encoder Settings
Content distributors may be tempted to take a one-size-fits-all approach to video encoding by sticking with a tried-and-true setting for their encoder — regardless of where they’re trying to stream to. This leads to issues when the settings fail to align with workflow requirements, as the right encoder settings for one broadcast may be ill-suited for another.
Mismanaging Encoding Presets
Other broadcasters who choose to tune the encoder for each broadcast may struggle to manage presets across an array of inputs and outputs, eventually resulting in failure due to an oversight. For example, a broadcaster may forget to decrease bitrate or frame rate, thereby misaligning with the expected settings at the destination.
Choosing the right encoding settings for a given workflow is vital. While most encoders expose configuration settings, it often feels like you need to be a streaming engineer to properly set them.
In addition to providing built-in encoding presets for popular destinations, the Wowza ClearCaster provides a cloud-based manager that streamlines encoder configuration. The ClearCaster Manager gives administrators the control to not only customize templates but also the user interfaces. That way, advanced users can have full access to change encoder settings — while less technical users can work within limited control templates. This advanced control prevents encoder mishaps by enabling custom-fit workflows for each team’s needs.
2. Identifying Pre-Event Issues
It’s important to test your workflow before going live. But even then, most broadcasters lack confidence that everything will work seamlessly during an event. A major reason for this anxiety is that encoder health and first-mile performance has historically been a black box. The limited data and control has broadcasters flying blind and hoping for the best.
Seventy-two percent of event producers surveyed by Wowza said they were unsatisfied with their ability to detect a problem before broadcasting a live stream.
We designed the ClearCaster to take the guesswork out of first-mile performance. The ClearCaster Manager improves broadcasters’ ability to identify issues by providing 100-plus health metrics in real time. Content distributors can use this data to immediately pinpoint the cause of problems for their events and gain confidence to go live.
3. Limited On-Site Expertise
Most folks in live event production aren’t experts in video encoding. And while streaming engineers used to be on site for every event, that’s no longer possible in our content-flooded landscape.
It’s easy to teach someone how to press a Go Live button, but it’s challenging to build a workflow that truly empowers less technical team members to do so with confidence.
The ClearCaster empowers streaming engineers to scale their operations with powerful cloud-based control and monitoring tools. Remote engineers can build broadcasts in advance and instruct less technical users to simply click a button to take events live. Additionally, remote monitoring capabilities allow remote engineers to confirm stream health, identify issues, and solve problems on the fly.
4. Sharing Equipment Across a Team
Large production teams need to share equipment, but different events have different requirements — which means that each user is required to configure new encoding settings. Most encoders have archaic menus with tons of knobs and hidden settings. Worse yet, once configured, it’s not always apparent how the last user set the machine. When working in groups, these hidden settings and limited visibility can cause serious problems.
The root cause of all this is that encoders weren’t designed for teams. Rather, they were built for users who never change their workflow.
The ClearCaster Manager’s broadcast and fleet management capabilities offer the ability to quickly configure broadcasts without getting tripped up by the last event’s encoding settings. While typical encoders carry state, meaning that each user inherits the settings of whomever used the appliance before them, the ClearCaster does not. Instead, it listens to the cloud-based manager to know what it should do and the encoders takes on 100% of the configuration in real time.
5. Limited Bandwidth
Bandwidth is often taken for granted until adverse network conditions strike. Being able to power through unexpected fluctuations can make or break a broadcast.
A sudden dip in bandwidth, even just a 3-second hiccup, causes catastrophic issues for typical encoders. Oftentimes encoders will either (a) fall behind in getting video frames out, causing viewer buffering and potentially crashing the encoding from the load, or (b) start dropping frames in an effort to meet bandwidth limitations, resulting in jittery video playback. Neither makes for a good viewer experience.
It helps to have an encoder that can adapt based on network conditions. With adaptive network encoding, the ClearCaster sets a target bitrate that it then adjusts in real-time based on network performance.
As bandwidth drops, the ClearCaster will immediately throttle down bitrate so as to not fall behind. And as bandwidth recovers, the ClearCaster will throttle the bitrate back up. This automated bandwidth recovery via adaptive network encoding leads to significant increases in stream reliability and quality.
6. Network Path Issues
Sometimes the network path is to blame for bandwidth limitations. To get to any point on the internet, streaming data must travel across a series of servers at points of presence (PoPs). This path to the designated ingest point can become congested, and sometimes service providers will send users to a PoP that is far away due to incorrect DNS mapping.
The nearest ingest point isn’t always best, but sending streams to an ingest point that is too far away (e.g., New York City to Singapore) also has its problems. What’s most important is quickly identifying any network problems so they can be resolved immediately.
The ClearCaster collects a dozen low-level network metrics, and it exposes useful information to users via the live monitoring tab. Specifically, users can use the roundtrip time (rtt) to understand if they are having a sudden network issue or if they are being routed to an ingest point that’s too far away.
Once a network path issue is identified, broadcasters can work with their network team or ISP to improve the pathing. If distance is the issue, we’d suggest finding another ingest point that’s closer. Content distributors can also try to go down a different path by using a cloud service between the source and the ingest point.