Sample Rates - Revision history

Admin at 21:57, 9 May 2026

2026-05-09T21:57:35Z

Admin at 21:56, 9 May 2026

2026-05-09T21:56:23Z

← Older revision		Revision as of 16:56, 9 May 2026
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	Sample ~~rates~~		For the Rivendell Radio Automation System, the most common and recommended sample rates are:

			44.1 kHz — traditional music/CD workflow
			48 kHz — broadcast/video standard and generally preferred for modern radio

			Rivendell itself supports multiple PCM sample rates, but the important thing is that the entire chain matches:

			audio interface
			JACK/PipeWire
			Rivendell audio store
			GlassCoder & GlassGUI/BUTT/DarkIce/Liquidsoap
			Stereo Tool
			streaming encoder

			The System Sample Rate should be chosen before importing audio and should not be changed later on an active system.

			Recommended setups

			Modern FM / streaming station

			Use:

			48 kHz
			16-bit or 24-bit PCM

			Why:

			Native rate for most broadcast hardware
			Matches AAC, Opus, and most streaming pipelines
			Avoids resampling when using JACK/PipeWire and modern processors
			Better interoperability with video/social content

			Legacy music library/CD-focused workflow

			Use:

			44.1 kHz
			Mainly if your source material is overwhelmingly CD rips

			This avoids resampling imported audio, but modern broadcast chains generally benefit more from 48 kHz consistency.

			What NOT to use

			Avoid:

			96 kHz
			192 kHz

			They dramatically increase:

			CPU usage
			JACK/PipeWire overhead
			storage
			network bandwidth

			...with essentially no listener benefit for radio broadcast or streaming.

			Best practice for Rivendell systems

			A very stable modern chain is:

			Rivendell audio store - 48 kHz
			JACK/PipeWire - 48 kHz
			Stereo Tool - 48 kHz
			Liquidsoap internal - 48 kHz
			Streaming encoder - 48 kHz input
			Final MP3/AAC stream - 44.1 or 48 kHz

			For most setups, keeping everything at 48 kHz end-to-end will minimize:

			xruns
			resampler artifacts
			clock drift
			unnecessary ffmpeg processing

imported>ImportBot: Imported from scrape

2026-05-09T15:18:54Z

Imported from scrape

← Older revision		Revision as of 10:18, 9 May 2026
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	= Sample ~~Rates in Rivendell =~~		Sample rates

	~~This page documents how audio sample~~ rates ~~are handled in the '''Rivendell Radio Automation System''', including supported rates, configuration considerations, and best practices for production and ingestion.~~

	~~== Overview ==~~

	Rivendell supports a '''fixed system‑wide sample rate'''. All audio stored in the Rivendell audio store must match the system's configured rate to ensure correct playback, timing accuracy, and log integrity.

	~~Unlike some modern media systems, Rivendell does not transparently mix or resample audio files with differing sample rates at runtime.~~

	~~== Supported Sample Rates ==~~

	~~Rivendell supports the following PCM audio sample rates:~~

	* '''44,100 Hz (44.1 kHz)'''
	* '''48,000 Hz (48 kHz)'''

	~~Only one sample rate may be used per Rivendell system at a time, and all audio files must match the configured rate.~~

	~~''Important:'' The chosen sample rate is a '''system‑level configuration decision'''. Mixing 44.1 kHz and 48 kHz audio in the same Rivendell system is not supported.~~

	~~== Choosing a Sample Rate ==~~

	~~=== 44.1 kHz ===~~

	~~44.1 kHz has historically been the most common Rivendell configuration.~~

	~~Advantages:~~
	* Compatible with legacy CD‑based and broadcast workflows
	* Widely used in existing Rivendell installations
	* Proven stability

	~~=== 48 kHz ===~~

	~~48 kHz is commonly used in modern broadcast and video‑adjacent workflows.~~

	~~Advantages:~~
	* Industry standard for video and many modern broadcast chains
	* Reduces the need for external sample‑rate conversion when interfacing with video systems
	* Supported by Rivendell when configured consistently

	~~''Note:'' Switching an existing system from 44.1 kHz to 48 kHz requires re‑importing or converting all stored audio.~~

	~~== Bit Depth ==~~

	~~While this page focuses on sample rates, bit depth is also relevant.~~

	* '''16‑bit''' linear PCM is the standard and recommended format.
	* Some workflows may allow import of higher bit‑depth material, but audio is typically stored and processed as 16‑bit PCM.

	~~== Channel Configuration ==~~

	~~Rivendell supports both mono and stereo audio at either supported sample rate.~~

	* Mono: Single channel PCM
	* Stereo: Left / Right PCM

	~~The configured system sample rate (44.1 kHz or 48 kHz) applies equally to mono and stereo files.~~

	~~== Importing Audio ==~~

	~~When importing audio into Rivendell using:~~
	* '''rdimport'''
	* Rivendell GUI import tools
	* Automated ingest workflows

	~~Ensure that all source files meet the system requirements:~~

	* Sample Rate: '''Matches the system configuration (44.1 kHz or 48 kHz)'''
	* Encoding: Linear PCM (WAV)
	* Bit Depth: 16‑bit recommended
	* Channels: Mono or Stereo

	~~Files with mismatched sample rates must be converted before import.~~

	~~== Sample Rate Conversion ==~~

	~~Common source sample rates that may require conversion include:~~

	* 44.1 kHz (if the system is configured for 48 kHz)
	* 48 kHz (if the system is configured for 44.1 kHz)
	* 96 kHz or higher (high‑resolution recording)

	~~Best practices:~~
	* Perform high‑quality offline resampling
	* Avoid repeated conversion of the same audio
	* Use dithering when reducing bit depth

	~~== Clocking and Audio Hardware ==~~

	~~System‑level sample rate configuration must align with audio hardware settings.~~

	* Audio interfaces should run at the same sample rate as Rivendell
	* External word clock sources should be stable and correctly distributed
	* Hardware sample‑rate conversion should be avoided where possible

	~~Improper clocking or mismatched rates may cause:~~
	* Clicks or pops
	* Timing drift
	* Unstable playback

	~~== Timing and Logs ==~~

	~~Rivendell log timing and audio length calculations depend on a consistent sample rate.~~

	* Segue calculations
	* Event timing
	* Length metadata

Admin at 16:32, 29 January 2026

2026-01-29T16:32:26Z

Show changes

Admin at 16:27, 29 January 2026

2026-01-29T16:27:37Z

← Older revision		Revision as of 11:27, 29 January 2026
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	* Audio at other sample rates must be converted before being imported into Rivendell.		* Audio at other sample rates must be converted before being imported into Rivendell.

	~~{{Note\|~~
	Rivendell does not dynamically resample audio during playback. Files not at the correct sample rate may fail to import or play incorrectly.		Rivendell does not dynamically resample audio during playback. Files not at the correct sample rate may fail to import or play incorrectly.
	}}

	== Bit Depth ==		== Bit Depth ==
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	* Avoid on‑the‑fly sample rate conversion		* Avoid on‑the‑fly sample rate conversion
	* Document any exceptions clearly for engineering staff		* Document any exceptions clearly for engineering staff

	~~== See Also ==~~

	* [[Audio Formats in Rivendell]]
	* [[rdimport]]
	* [[Audio Hardware Configuration]]
	* [[Digital Audio Basics]]

Admin at 16:26, 29 January 2026

2026-01-29T16:26:24Z

← Older revision		Revision as of 11:26, 29 January 2026
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	Sample ~~rates~~		= Sample Rates in Rivendell =

			This page documents how audio sample rates are handled in the '''Rivendell Radio Automation System''', including supported rates, system limitations, and best practices for production and ingestion.

			== Overview ==

			Rivendell is designed primarily for broadcast radio environments and assumes a fixed digital audio sample rate throughout the system. Correct configuration and consistent audio formatting are critical to ensure reliable playback, accurate timing, and predictable audio quality.

			== Supported Sample Rates ==

			Rivendell supports '''44,100 Hz (44.1 kHz)''' PCM audio.

			* 44.1 kHz is the native and required sample rate for all audio stored in the Rivendell audio store.
			* Audio at other sample rates must be converted before being imported into Rivendell.

			{{Note\|
			Rivendell does not dynamically resample audio during playback. Files not at the correct sample rate may fail to import or play incorrectly.
			}}

			== Bit Depth ==

			While this page focuses on sample rates, bit depth is closely related and must also be considered.

			* '''16-bit''' linear PCM is the standard and most commonly used format.
			* Some workflows may support '''24-bit''' audio during import, but files are typically stored and processed as 16-bit audio internally.

			== Channel Configuration ==

			Rivendell supports both mono and stereo audio at the supported sample rate.

			* Mono: Single channel PCM
			* Stereo: Two-channel PCM (Left / Right)

			The sample rate requirement (44.1 kHz) applies equally to mono and stereo files.

			== Importing Audio ==

			When importing audio into Rivendell using tools such as:
			* '''rdimport'''
			* '''Rivendell Import GUI'''
			* External production workflows

			ensure that all source files meet the following criteria:

			* Sample Rate: '''44,100 Hz'''
			* Encoding: Linear PCM (WAV)
			* Bit Depth: 16-bit (recommended)
			* Channel Count: Mono or Stereo

			If a file does not meet these requirements, it should be converted prior to import using an external audio editor or batch processing tool.

			== Sample Rate Conversion ==

			Audio files created at common production or distribution sample rates such as:
			* 48,000 Hz (video production)
			* 96,000 Hz (high‑resolution recording)

			must be resampled to 44.1 kHz before use in Rivendell.

			Recommended practices:
			* Use high‑quality offline resampling
			* Avoid repeated resampling of the same audio
			* Apply dithering when reducing bit depth

			== Clocking and Audio Hardware ==

			Although Rivendell software assumes a 44.1 kHz internal rate, audio hardware configuration is also important.

			* Audio interfaces should be locked to a stable clock source
			* Hardware may run at 44.1 kHz or perform real‑time sample rate conversion internally
			* Mixing differing hardware clock rates without proper synchronization can cause clicks, pops, or drift

			== Timing and Logs ==

			Precise timing in Rivendell logs depends on all audio sharing the same sample rate.

			* Segue calculations
			* Event timing
			* Length metadata

			are all based on the assumption of 44.1 kHz source audio.

			Using non‑conforming files may result in:
			* Incorrect length reporting
			* Timing drift
			* Playback errors

			== Best Practices ==

			* Standardize production workflows at 44.1 kHz
			* Validate audio files before import
			* Avoid on‑the‑fly sample rate conversion
			* Document any exceptions clearly for engineering staff

			== See Also ==

			* [[Audio Formats in Rivendell]]
			* [[rdimport]]
			* [[Audio Hardware Configuration]]
			* [[Digital Audio Basics]]

imported>WaybackImport: Imported from Wayback via edit

2021-03-04T18:56:08Z

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Sample rates