Date: Sun, 28 Jun 2026 15:58:50 +0000 From: Sergio Carlavilla Delgado <carlavilla@FreeBSD.org> To: doc-committers@FreeBSD.org, dev-commits-doc-all@FreeBSD.org Cc: Marcel Weissenbach <mweissenbach-freebsd@ikaros.space> Subject: git: faed907f34 - main - Handbook-multimedia: Adding resampling audio Message-ID: <6a4144ba.3230f.710ff5d@gitrepo.freebsd.org>
index | next in thread | raw e-mail
The branch main has been updated by carlavilla: URL: https://cgit.FreeBSD.org/doc/commit/?id=faed907f34b215b8459d25dd32385226750441ad commit faed907f34b215b8459d25dd32385226750441ad Author: Marcel Weissenbach <mweissenbach-freebsd@ikaros.space> AuthorDate: 2026-06-28 15:57:37 +0000 Commit: Sergio Carlavilla Delgado <carlavilla@FreeBSD.org> CommitDate: 2026-06-28 15:57:37 +0000 Handbook-multimedia: Adding resampling audio --- .../en/books/handbook/multimedia/_index.adoc | 31 ++++++++++++++++++++++ 1 file changed, 31 insertions(+) diff --git a/documentation/content/en/books/handbook/multimedia/_index.adoc b/documentation/content/en/books/handbook/multimedia/_index.adoc index f1a56c3f13..fb6f696f35 100644 --- a/documentation/content/en/books/handbook/multimedia/_index.adoc +++ b/documentation/content/en/books/handbook/multimedia/_index.adoc @@ -237,6 +237,37 @@ Keep in mind that these values are for the example indicated above. They may vary depending on the system. ==== +[[resampling-quality]] +=== Resampling Quality + +The process of changing the sample rate of an audio stream is called resampling. + +This usually happens automatically in situations like recording audio with an DI or simply when playing back audio files with very low resolution. + +Example: DI (Digital Interface) uses 192000 kHz, application only accepts 48000 kHz (or the other way around). + +If possible, this should be adjusted outside the sound device driver, but for cases where this is not possible (Or the hardware is bad at resampling), you have influence over the quality that is used for resampling. + +Should you be unsure if you need this, for normal music listening, doing meetings and so on the default value is totally fine and most applications use 48000 kHz anyway, so resampling rarely happens. + +When making music, recording sounds otherwise where quality matters or you are an audiophile, you can increase the resampling quality. + +For the highest possible resample quality, execute the following command: + +[source,shell] +.... +# sysctl hw.snd.feeder_rate_quality=4<.> +# sysctl hw.snd.feeder_rate_round=0<.> +.... +<.> 100dB stopband, 164 taps and 97% bandwidth +<.> Large prime divisions for high accuracy + +To keep these values after reboots, they can be added to the `/etc/sysctl.conf`. + +It is important to keep in mind that adjusting the resample quality has influence on CPU usage and delay. + +More details about resampling can be read in man:sound[4] + [[troubleshooting-sound]] === Troubleshooting Soundhome | help
Want to link to this message? Use this
URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?6a4144ba.3230f.710ff5d>