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Configuration

Environment variables​

LIVE_COMPOSITOR_API_PORT​

API port. Defaults to 8081.

LIVE_COMPOSITOR_INSTANCE_ID​

ID that will be returned in GET /status request. Can be used to identify if we are connecting to the correct compositor instance.

LIVE_COMPOSITOR_OUTPUT_FRAMERATE​

Output framerate for all output streams. This value can be a number or string in the NUM/DEN format, where both NUM and DEN are unsigned integers. Defaults to 30

LIVE_COMPOSITOR_OUTPUT_SAMPLE_RATE​

Output sample rate for all output streams. This value has to be a number or string representing supported sample rate. Defaults to 48000.

Supported sample rates are: 8000, 12000, 16000, 24000, 48000

LIVE_COMPOSITOR_FORCE_GPU​

If enabled, GPU will be required for rendering. If only CPU based adapters will be found then process will exit with an error. Defaults to false.

LIVE_COMPOSITOR_STREAM_FALLBACK_TIMEOUT_MS​

A timeout that defines when the compositor should switch to fallback on the input stream that stopped sending frames. Defaults to 500.

LIVE_COMPOSITOR_LOGGER_LEVEL​

Logger level. Value can be defined as error/warn/info/debug/trace.

This value also supports syntax for more detailed configuration. See tracing-subscriber crate documentation for more info.

Defaults to info,wgpu_hal=warn,wgpu_core=warn.

LIVE_COMPOSITOR_LOGGER_FORMAT​

Logger format. Supported options:

  • json
  • compact
  • pretty
warning

This option does not apply to logs produced by FFmpeg or the embedded Chromium instance used for web rendering. Defaults to json.

LIVE_COMPOSITOR_FFMPEG_LOGGER_LEVEL​

Minimal log level that should be logged. Supported options:

  • error - equivalent to FFmpeg's error, 16
  • warn - equivalent to FFmpeg's warning, 24
  • info - equivalent to FFmpeg's info, 32
  • debug - equivalent to FFmpeg's debug, 48

See -loglevel option in FFmpeg documentation. Defaults to warn.

LIVE_COMPOSITOR_DOWNLOAD_DIR​

A path to a directory in which downloaded files will be stored. Uses the location provided by the OS if not set.

In this directory, an instance of the compositor will create a subdirectory named live-compositor-<random number>. Downloaded temporary files will be stored there.

LIVE_COMPOSITOR_WEB_RENDERER_ENABLE​

Enable web rendering capabilities. With this option disabled, you can not use WebView components or register WebRenderer instances.

Defaults to false. Valid values: true, false, 1, 0.

LIVE_COMPOSITOR_WEB_RENDERER_GPU_ENABLE​

Enable GPU support inside the embedded Chromium instance.

Defaults to true. Valid values: true, false, 1, 0.

LIVE_COMPOSITOR_OFFLINE_PROCESSING_ENABLE​

If enabled, sets LIVE_COMPOSITOR_AHEAD_OF_TIME_PROCESSING_ENABLE and LIVE_COMPOSITOR_NEVER_DROP_OUTPUT_FRAMES options to true. If those values are also defined then they take priority over this value.

Defaults to false. Valid values: true, false, 1, 0.

LIVE_COMPOSITOR_AHEAD_OF_TIME_PROCESSING_ENABLE​

If enabled, the LiveCompositor server will try to generate output frames/samples ahead of time if all inputs are available.

When to enable this option:

  • If you want to process input streams faster than in real time.

Defaults to false. Valid values: true, false, 1, 0.

LIVE_COMPOSITOR_NEVER_DROP_OUTPUT_FRAMES​

If enabled, the LiveCompositor server will not drop frames/samples from output stream even if rendering or encoding is not fast enough to process it in real time.

Defaults to false. Valid values: true, false, 1, 0.

LIVE_COMPOSITOR_RUN_LATE_SCHEDULED_EVENTS​

Parts of the compositor API support a schedule_time_ms field to apply certain actions at a specific time. If enabled, the event will still be executed, even if it was scheduled too late. Otherwise, it will be discarded.

Defaults to false. Valid values: true, false, 1, 0.

LIVE_COMPOSITOR_REQUIRED_WGPU_FEATURES​

Comma separated list of WebGPU features that need to be enabled. See https://docs.rs/wgpu/22.1.0/wgpu/struct.Features.html for a list of available options.

Defaults to UNIFORM_BUFFER_AND_STORAGE_TEXTURE_ARRAY_NON_UNIFORM_INDEXING,SAMPLED_TEXTURE_AND_STORAGE_BUFFER_ARRAY_NON_UNIFORM_INDEXING.

Additionally, TEXTURE_BINDING_ARRAY and PUSH_CONSTANTS are also required, but this requirement can not be overwritten by changing this environment variable.

LIVE_COMPOSITOR_INPUT_BUFFER_DURATION_MS​

Duration of an input buffer in milliseconds. New stream will not be processed until this buffer is filled, so this value controls the trade-off between latency and resilience to stream delays.

This value can be safely set to 0 if either:

  • All input streams are required
  • All input streams are started with a specific offset_ms and you are delivering them early enough for decoding to finish.
warning

Increasing this value always increases the latency of the stream by the same amount.

Defaults to 80ms (about 5 frames in 60 fps).