Re: Dynamic Range plugin
Reply #86 – 2024-05-21 00:49:11
IMHO completely unnecessary now we have True Peak, LUFS-I and PLR available natively in Foobar. Hi Mr. “darkflame,” The BS.1770 metrics to which you refer, True Peak and LRA (as expressed in LUFS-I; LUFS is a unit of measure) were never designed to represent subjective or perceived loudness. In a digital broadcast environment, LRA is a standardized dynamic range measurement, but it is tailored specifically for a particular purpose; the algorithmic control of playback gain to provide uniform subjective loudness across all broadcast program content. That standardized measurement is LRA or Loudness Range, and is part of the ITU-R BS.1770 family of recommendations ( as recommended by the ploud expert group) used by content providers, distributors, and hardware manufacturers to automatically reproduce all broadcast audio content at a similarly perceived loudness. LRA was designed to reflect the deviation of loudness events primarily for broadcast applications. Unfortunately, LRA isn’t ideal for evaluating the subjective loudness of pop and other styles of music since most of recorded music happens in a range of amplitude which is explicitly ignored by the mandated LRA algorithm. LRA is a “weighted” or purposefully skewed measurement, designed to force “interstitials” or short duration content, usually advertisements, into a similar perceived loudness as that to the “program” or long–form content that surrounds them. For good or ill, BS.1770 has come to be thought of as The Path to subjective loudness control of all audio, even of music, even though it was designed to crush television commercials that were too loud. As to Crest Factor and PLR, there is no standard measurement method. So, different manufacturer’s meters and algorithms display varying results, with each showing its own interpretation of the same audio source. As an example, many use RMS instead of Short–term LU or Loudness Units. The difference between PLR and DRi (integrated DR Dynamic Range) is simple: PLR is the difference between peak and average, and is not standardized, while DRi is always, repeatably DR. The i in DRi stands for integrated in the same way that the I in LUFS–I also stands for integrated. That is, integrated or “windowed” over time; a rolling integration. Also, DRi ignores low amplitude information, so called “background loudness,” for the sake of a more predictable measurement result. That is the opposite of LRA, which ignores the highest amplitude information. Plus, the DR algorithm incorporates additional processing for meaningful measurement of the dynamic integrity and dynamic density of popular music. Lastly, for easy understanding and comparison, official DRi is always an integer value. Note that the Foobar plug–in does not perform either an LRA nor a DRi measurement. BTW, neither does Roon! P.S. — True Peak or “TP” has absolute nothing to do with perceived loudness in the human perception sense, or Loudness in the 1770 sense. The human ear cannot detect True Peaks! TP was designed to prevent, by way of accurate measurement, DAC overloads and subsequent distortion due to inter–sample peaks. As with 1770 as a whole, TP is about machine behavior, not human hearing.