Thread: HD RADIO is no worse than DAB or DRM radio
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Old October 7th 07, 07:08 PM posted to rec.audio.tech,rec.audio.car,rec.radio.shortwave,ba.broadcast
SFTV_troy SFTV_troy is offline
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First recorded activity by RadioBanter: Sep 2007
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Default HD RADIO is no worse than DAB or DRM radio

Robert Orban wrote:
In article .com,
says...



Steven wrote:

HD/IBOC does not employ AAC, although an earlier
version may have IIRC. It uses something called PAC(?)


You have it backwards. It used to be PAC, derived from MP3.

Early testing showed it didn't work very well, so the codec was
switched to MPEG4 AAC+SBR.

No, it wasn't. The codec was changed to something iBiquity calls "HDC."
It is known to use the Coding Technologies' Spectral Band Replication
technology (as does MPEG HE-AAC) but its technical details are otherwise
held secret by iBiquity. This secrecy has caused considerable
controversy in the broadcast industry.



It shouldn't be too diifficult to determine - just use a little
reverse engineering. If it's using SBR, well that's all that really
matters. SBR extends the high-frequency components from ~8 to 16
kilohertz, so that even an MP3 + SBR sounds good.

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