Debug live stream issues

Navigate to the Live Stream Input Health dashboard

The Live Stream Input Health dashboard is a real-time dashboard that provides visibility on how Mux receives your live stream from the encoder. When a sizable percentage of your viewers complain about their viewing experience or your configured Mux Data Alert fires, a good starting point for identifying the problem is understanding the live stream's health. The video below shows how to navigate to your Live Stream Input Health dashboard.

Healthy live stream

Let's first look at a healthy live stream in the dashboard.

A few key points to notice from this graph that indicate this is a healthy live stream:

• Mux is receiving consistent frames per second. Receiving inconsistent frames per second can introduce video stuttering and sometimes cause playback interruptions for all your viewers.
• Consistent non-zero audio bitrate is important for uninterrupted listening. A good encoder always creates a constant non-zero bitrate even when no person is speaking, or no music is being played. A varying audio bitrate can result in a bad listening experience and sometimes a good indicator for Audio-Video sync problems.
• Like Audio, a consistent average video bitrate is equally important for a good viewing experience. A varying video bitrate does not necessarily cause a playback problem but could result in a bad viewing experience.
  • A low variance in the video bitrate typically means optimal network bandwidth availability and encoder hardware resource utilization.
  • A high variance in the video bitrate indicates that the encoder hardware cannot keep up with the encoding load. Try reducing the video bitrate and using a constant bitrate (CBR) for a more reliable live stream input. Alternatively, you can also switch to another encoder like OBS, Wirecast, etc.
  • An unstable/unreliable network bandwidth availability results in transient video bitrate drops, which can cause playback interruptions.

Unhealthy live stream

Now let's look at a few examples of live stream issues and potential next steps for resolution.

Example 1: High video bitrate variance

Because of the constant frames per second and audio bitrate this live stream looks good, but the high variance of video bitrate and drop in the average video bitrate mid-stream can impact the viewer experience.

Example 2: Intermittent loss

Mux is receiving mostly constant frames per second and audio/video bitrate. This indicates that when the encoder is connected the stream is healthy. However the small spikes as well as intermittent loss in receiving the live stream, indicates transient network bandwidth availability issues.

Example 3: Spiky audio and video bitrate

There is a high variance in receiving audio and video bitrate in this example. Because connection never fully drops the network connection is probably not the problem in this one. More likely is that the encoder is unable to keep up at a fast enough pace to send consistent video and audio data. One cause of this is that the device running the computer might be running out of available CPU.

Example 4: Spiky frame rate

This is a good example of a very unhealthy live stream. There is high variance in the video bitrate and several instances of the frame rate dipping to nearly zero. The spiky video bitrate mid-stream indicates that the encoder is optimizing the video encoding based on the feed contents. This is not ideal for live streaming.