In Reply to: Figure 4: Output of WMP (no Peak Extend) posted by Christine Tham on December 24, 2005 at 00:11:08:
This is what Adobe Audition reports for the digitally rip (non-decoded) wave file:
Left Right
Min Sample Value: -32425 -32418
Max Sample Value: 32399 32416
Peak Amplitude: -.09 dB -.09 dB
Possibly Clipped: 0 0
DC Offset: 0 0
Minimum RMS Power: -89.95 dB -89.84 dB
Maximum RMS Power: -4.54 dB -5.32 dB
Average RMS Power: -17 dB -17.27 dB
Total RMS Power: -15.63 dB -15.85 dB
Actual Bit Depth: 16 Bits 16 BitsUsing RMS Window of 50 ms
By contrast, this is the statistics for the WMP decoded output:
Left Right
Min Sample Value: -16212.5 -16209
Max Sample Value: 16199.5 16208
Peak Amplitude: -6.11 dB -6.11 dB
Possibly Clipped: 0 0
DC Offset: 0 0
Minimum RMS Power: -95.57 dB -95.55 dB
Maximum RMS Power: -10.56 dB -11.34 dB
Average RMS Power: -23.03 dB -23.3 dB
Total RMS Power: -21.65 dB -21.88 dB
Actual Bit Depth: 24 Bits 24 BitsUsing RMS Window of 50 ms
As you can see, even for an HDCD disc that is NOT encoded with Peak Extend, the output of WMP is not identical to the non-decoded data.
In particular, if you zoom in on both files, you will find the low level information have been subtly altered, which is consistent with what the patent describes as "low level gain manipulation".
I think this is sufficient evidence to completely destroy your theory that there is no benefit or material difference to HDCD decoding on non-Peak Extend discs.
So, bottom line is HDCD decoding does make a difference, regardless of whether the discs are flagged with Peak Extend or not.
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Follow Ups
- By the way, here are some stats on the non decoded vs decoded outputs - Christine Tham 00:28:38 12/24/05 (7)
- Thanks for posting these graphs - Charles Hansen 10:51:35 12/24/05 (6)
- Re: Thanks for posting these graphs - Christine Tham 12:12:00 12/24/05 (5)
- This is just silly - Charles Hansen 14:46:22 12/24/05 (4)
- HDCD is defined by the patent, not the implementation - Christine Tham 22:38:00 12/24/05 (3)
- Oh, that's right... - Charles Hansen 13:06:23 12/25/05 (2)
- And your point is? - Christine Tham 15:31:48 01/03/06 (1)
- Yep, yep, and yep. - Charles Hansen 19:43:56 01/03/06 (0)