This guide helps you diagnose and fix stuttering during live stream playback on ApsaraVideo Live.
Stuttering can affect a single viewer or all viewers depending on where in the pipeline the problem originates. Use the following categories to narrow down the root cause before diving into specific fixes.
All viewers affected: The issue likely originates at the ingest client, network upstream, or server side.
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Single viewer affected: The issue likely originates at the viewer's local network or playback client.
Ingest client
Insufficient frame rate
For the human eye to perceive video as smooth, the frame rate must be at least 15 frames per second (FPS). Below 10 FPS, stuttering becomes noticeable. Set the frame rate to at least 15 FPS unless your use case requires otherwise.
Frame rates above 30 FPS are generally imperceptible to the human eye and increase bandwidth consumption. Balance visual quality against bandwidth cost when configuring your video capture settings.
Encoding overload
If the bitrate, frame rate, or codec profile exceeds your hardware capacity, encoding slows down and the stream cannot reach the frame rate required for smooth playback.
To fix this:
Lower the bitrate, frame rate, or codec profile settings.
If performance improves, upgrade the ingest client hardware.
CPU saturation on mobile devices
Streaming is CPU-intensive. On low-end mobile devices, CPU usage above 80% during ingestion degrades video capture, causing stuttering and screen tearing for viewers.
Close unnecessary applications on the ingest device to free up CPU resources.
Insufficient upstream bandwidth
Insufficient upstream bandwidth or network jitter reduces the data transmission rate, preventing the stream from reaching the frame rate required for smooth playback.
Check your upstream bandwidth with a tool like Speedtest.
Network
Network conditions are the most common cause of stuttering. Check the following factors.
Insufficient bandwidth capacity
Verify that your internet service provider's plan provides enough bandwidth for live streaming.
Downstream bandwidth consumption
Other network activities, such as large file downloads or uploads, can consume available bandwidth and cause stuttering. Pause or limit concurrent bandwidth-heavy tasks during the stream.
System resource contention
Background applications can compete for CPU, memory, or network resources. Close unnecessary programs before starting the stream to free up system resources.
Server side
The server caches approximately 4 seconds of data by default to speed up video startup and reduce stuttering. This cache duration fluctuates depending on the keyframe interval, also known as Group of Pictures (GOP) size. Adjust the cache time to minimize stuttering.
Set the latency configuration to High. For detailed instructions, see Configure the live streaming latency.
The actual latency depends on two factors: the latency configuration and GOP. For example, if the latency configuration for a Real-Time Messaging Protocol (RTMP) stream is set to Medium and the GOP is 2s, the actual latency is between 2s and 6s. High latency causes the ingest and playback clients to go out of sync. Choose a latency level that suits your business requirements.
Playback client
Most players use a receive buffer and decode video only after the buffer fills. A larger buffer reduces stuttering caused by brief network interruptions but increases playback latency. A smaller buffer reduces latency but makes the player more sensitive to network fluctuations.
If your player supports buffer configuration, reduce the buffer size to minimize latency while still smoothing out short network interruptions. If stuttering persists, check whether the player version is up to date and whether the playback device has sufficient CPU and memory resources.