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1
Lossless / Other Codecs / Re: DSD to PCM conversion
Last post by apastuszak -
That is true.  The assumption is that the two layers are supposed to be the same master.  But I have heard stories of the CD layer deliberately having an inferior CD layer to make the SACD more desirable.
2
Opus / Re: Opus 1.2 alpha
Last post by jmvalin -
Oh, it's interesting you say those. I thought framesize 60 improves compression a bit (while reducing transient representation as a tradeoff). Other codecs like HE-AAC and USAC seems to make a benefit from 100ms+ delay in those extreme low bitrates. I'm surprised it's not the case with Opus.
In Opus, frames of 60 ms are just a concatenation of 3 20-ms frames, except that the encoder's decisions are slightly worse (not a big deal, but it's definitely not an improvement).

CVBR was used because I'm testing for mobile broadcasting so bitrates shouldn't fluctuate too much. But hard-cbr seemed too aggressive.
FYI, Opus CVBR is the same as what other codecs call CBR. That's because what codecs like MP3 and AAC call "CBR" in in fact constrained VBR hidden behind a bit reservoir. What Opus calls CBR is hard CBR with no bit reservoir.
3
The pearl guys could weasel out all night long, it is completely irrelevant to the Fremer/Randi challenge case. You need a person to do the test, and that was Michael Fremer and you need some ridiculously priced loudspeaker cables to test against the mentioned good monster cables.
I don't think it is irrelevant at all. By pulling out, the pear guys changed the situation for everyone else.

It is to be expected that in such a challenge, which is not just about a significant amount of money, but also about the corresponding publicity, that people will play games. So if people don't weasel out at some point, realizing that their chances of winning are slim, they will want to put the blame for a fail on the other side. No surprise here.

Pear played that game right from the start, by accusing Randi of not playing fair. You can always assert that, regardless of any evidence. You just have to live with the fact that for some spectators, it will look like you are chickening out. The odds are that your believers will still believe you, maybe a bit more staunchly than before, and your sceptics will still be sceptical, maybe a bit more complacently than before. A quack who is happy with his current flock of believers will therefore tend not to engage with Randi.

I'm sure Randi is completely aware of the mechanics of this situation. It is his obvious goal to make quacks look bad. The way to do that is to tickle their self-importance and self-delusion. This will not work with a quack who knows that he's a quack, and conducts his business with full awareness of its fraudulent nature. I'm led to assume that Pear belong to this group.

The actual story is, in my opinion and from what I recall going on back then, more like this: Randi was simply unaware of the full range of nonsense that infests high end audio hardware.  He naively thought that 'cables' means cables  (insulated wires + terminals).  He was unaware , for example, that some high end cables -- speaker cables AND interconnect cables -- come with in-line 'magic boxes'  that might or might not act as crude equalizers. When he was apprised of the existence of such shenanigans (by people having much more experience with the idiocy of audiophiles), he more or less decided to wash his hands of such tiresome crapola rather than give pompous little jerks like Fremer a chance to 'win' on such a weasely technicality.

4
General Audio / Re: Lossless Podcasts
Last post by Soap -
Dude, why? The beauty of the podcasts is that they are talk audios and they can be as low as 16/24kbps.

That may be the style of podcast you prefer, but it is far from the extent of the podcast ecosystem. 

The answer most probably lies in licensing.  Streams are "harder to keep" and easier to license lossless than downloads.

5
Lossless / Other Codecs / Re: DSD to PCM conversion
Last post by krabapple -

I don't have a modified PS-3, so I can't rip the SACD to DSD sadly.  But it really doesn't matter, because the disc has a CD layer.  I just ripped that to FLAC and then AAC.

Except when it does matter.  Unfortunately there is no guarantee that the mastering of the CD layer is the same as the DSD layer, on hybrid SACD.   It cannot be assumed.

6
Like this:
Code: [Select]
sox -t s24 --endian little input.pcm -t s32 output.pcm vol 0.00390625
Depending on your file format you need to change --endian option.
7
Some basics:

- As saratoga says, 24 bits has nothing to do with frequency. It is about the maximum difference between "lowest possible positive volume" and "loudest possible volume". 24 bits is more than your ears can handle. 16 bits is enough to cover what anyone needs to listen to in an ordinary room.
- Frequency is directly related to sampling frequency. A 96 kHz file usually includes more inaudible noise. Usually only a waste of space.
- Why they sell 24-bit files even though you can't tell the difference? Because someone is willing to pay for it (and, maybe they save customer support expenses by less people nagging them about it).
- If you get two files from the same place at the same time, they are usually from the same master. If you get two files of the same recording but one was made, say, some years ago, it could be a different mastering. They could sound different because they could be, in reality, different mixes although it just says "remaster". (Mastering is more than just transferring from file to CD.)
- When comparing, you must match volume. Same file at different volumes, sound different.
8
Opus / Re: Opus 1.2 alpha
Last post by darkbyte -
Oh, it's interesting you say those. I thought framesize 60 improves compression a bit (while reducing transient representation as a tradeoff). Other codecs like HE-AAC and USAC seems to make a benefit from 100ms+ delay in those extreme low bitrates. I'm surprised it's not the case with Opus.

CVBR was used because I'm testing for mobile broadcasting so bitrates shouldn't fluctuate too much. But hard-cbr seemed too aggressive.
9
General Audio / Re: Lossless Podcasts
Last post by eahm -
Dude, why? The beauty of the podcasts is that they are talk audios and they can be as low as 16/24kbps.
10
Opus / Re: Opus 1.2 alpha
Last post by jmvalin -
I wonder which codec is being used with --bitrate 32 --framesize 60 --cvbr --downmix-mono setting right now in 1.2-alpha. Seems like a nice spot for very low bitrate generic music. It's still noticable not transparent, but artifacts are not utterly annoying (at least compared to HE-AACv1 mono at this bitrate). For me it's even listenable with headphones on. But it sounds a bit different, like it was using SILK instead of CELT. 
I could be using either SILK or CELT, depending on whether it thinks it's speech or music. Also, don't use --framesize 60 and --cvbr. They make things worse.