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Does HD-Radio's HDC Codec Utilize "Parametric Stereo"?

Wolfie770

Wolfie770

Like the HE-AAC V2/eAAC+ .m4a Profile uses Parametric Stereo by default, is PS also used, or something like it, within the HDC Codec of HD Radio?

It is known, HDC, to be based, partially, on the HE-AAC V1/AAC+ standard, but did it borrow that stereo trick, or something like it, for "Parametric Stereo"?

If so, does it help or harm sound quality, in a general sense?
Is the Stereo generally pretty convincing for normal listening enviornments (not ABX, normal)?
 
https://en.wikipedia.org/wiki/High-Definition_Coding says "in June 2017, the format was reverse engineered and determined to be a variant of HE-AACv1." Parametric stereo was introduced in HE-AAC v2, and the reverse engineering technical analysis of HDC makes no mention of parametric stereo functionality within it. So it would appear that the answer is no.

web.archive.org

Receiving NRSC-5

NRSC-5-C is the standard for digital terrestial radio in the United States. The physical layer and protocols are well documented on the NRSC's website. The audio compression details are conspicuously absent considering that the goal of the standard is digital audio.
web.archive.org web.archive.org
 
Yes, HDC does use PS. Its a modified version from your standard Parametric stereo that you see in a regular aac or m4a file.

Ps is used only on subchannels at low bitrates. 48kbps or lower for example.

Nrsc5's code currently uses faad2's drm ps decoding with a few changes.

Whether or not it sounds good is up to your interpretation.
 
TheDaChicken said:
Yes, HDC does use PS. Its a modified version from your standard Parametric stereo that you see in a regular aac or m4a file.

Ps is used only on subchannels at low bitrates. 48kbps or lower for example.
Click to expand...
Glad I was careful enough to say "appear." Because I see that you would know. :)

So I'm seeing some of the backported parametric L/R panning logic for HDC starting around line 381 here, then?

Nrsc5's code currently uses faad2's drm ps decoding with a few changes.
Click to expand...
By NRSC-5's code, do you mean Ibiquity's official codecs' code incorporates actual code from the open source FAAD2 project? That seems so unusual to me. I'm accustomed to these giant commercial interests only licensing closed source codecs.
 


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