Some nagging iTunes & iPod questions
in [Mac Systems]
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From: MartinC on 2 Aug 2010 14:27 Wayne C. Morris wrote: > Apple Lossless is not AAC (Advanced Audio Coding). Yep. Wrote AAC. Meant M4A. Sorry. :-) AAC and ALE are both variants of M4A, and not ALE a variant of AAC. However, this doesn't change the fact that lots and lots of people claim ALE is lossy, while it actually is entirely 100% and 24 carat lossless. So it does preserve a bit-copy of the source file. In the content. Not the M4A file itself. I mean, the content when it gets extracted again... Into the same format as the source file. Well, when you *open* it in an audio editor !!!!!!! (just kidding now ;-)
From: Jim Gibson on 2 Aug 2010 14:37 In article <vilain-2D9386.22564601082010(a)news.individual.net>, Michael Vilain <vilain(a)NOspamcop.net> wrote: > In article > <6d3b0733-4627-4df2-9928-39a659d5e2d3(a)l32g2000prn.googlegroups.com>, > Figaro <ponsellite(a)gmail.com> wrote: > > > Hey you Apple geniuses- > > .... > > (4) I am a hi-fi aficionado and import all my old CDs into apple > > lossless files. I am told this format is virtually indistinguishable > > from CD quality source material. My question is -- how is the > > *output* signal quality from an iPod/iPhones/etc. to my Very-High-End > > home stereo system? I hear the quality is somewhat less than CD > > quality. > > >\ > 4) To answer this question requires a subjective judgement on the > "quality" of the sound as you experience it. If you're looking for the > "best sound" why are you futzing with digital audio in the first place? > What's wrong with LPs and a tube amp? You're pretty much on your own > with this topic. Debate it ad-nauseam in the audiophile news groups > rather than here. They'll call you a clueless Apple Fanboi and plonk > you instantaneously. Ditto for the iPod. Not in <news:rec.audio.high-end> they don't. I have seen several people on that newsgroup recommend the Apple TV as a digital music server for a high-end audio system. I don't believe anybody disparages the iPod, either. Some will recommend sending the digital signal from the Apple TV to a high-end Digital-Analog-Convertor (DAC), but that recommendation is by no means unanimous. Most criticism is saved for MP3 files, or even CDs by the most anal. Not everyone there considers LPs and tube amplifiers state-of-the-art, either. It seems pretty evenly-divided between those who think digital music is the ultimate in audio reproduction, and those who prefer analog sources. -- Jim Gibson
From: nospam on 2 Aug 2010 14:55 In article <vilain-2D9386.22564601082010(a)news.individual.net>, Michael Vilain <vilain(a)NOspamcop.net> wrote: > 4) To answer this question requires a subjective judgement on the > "quality" of the sound as you experience it. If you're looking for the > "best sound" why are you futzing with digital audio in the first place? because digital audio is better than analog audio, just as digital cameras are better than film cameras. technology moves forward, not backward. > What's wrong with LPs and a tube amp? lps are primitive and sound worse than digital and tube amps can be duplicated with solid state amps far more reliably, assuming of course, you want the distortion that comes with tubes. > You're pretty much on your own > with this topic. Debate it ad-nauseam in the audiophile news groups > rather than here. They'll call you a clueless Apple Fanboi and plonk > you instantaneously. Ditto for the iPod. audiophiles a bunch of lunatics who think they can hear differences where none exist, such as different speaker cables, and come up with creative science to explain their beliefs. it's crazy what they come up with.
From: Jim Gibson on 2 Aug 2010 15:04 In article <i36qaq$5or$1(a)news.eternal-september.org>, Wes Groleau <Groleau+news(a)FreeShell.org> wrote: > On 08-02-2010 10:38, MartinC wrote: > > Wes Groleau wrote: > >>> To be precise... it is a bit-copy, as in "lossless". ;-) > >> > >> Is it really? Or is it as claimed, a different format alleged > >> to be lossless? > > > > There is so much nonsense about AAC on the net that I stopped keeping track > > a long time ago... > > I never started keeping track. :-) > > > It *is* lossless, meaning that each and every sample keeps exactly the same > > digital value that it got before. As a matter of fact, anything else would > > be incredibly stupid, because Apple Lossless files are typically some 2-3% > > larger than lossless FLAC files. > > If the two are not the same size, then at least one of them > is NOT a "bit-copy" of the CD format the other poster asked about. Advanced Audio Coding (AAC) is not lossless. It, like MP3, throws away bits of information in the audio stream to reduce the file size. Apple supports AAC and MP3 in iPods, etc. Apple Lossless Encoder (ALE) or Apple Lossless Audio Codec (ALAC) is, as the name implies, a lossless encoding, like FLAC. ALE is supported by Apple music players. Neither ALE nor FLAC produces a "bit-copy" on the media. Both use file-compression schemes to reduce file sizes. However, they use "lossless" algorithms so that a "bit-copy" audio stream can be reproduced on the fly before converting to analog. They use different algorithms that result in slightly different file sizes. ALE/ALAC was developed by Apple and is proprietary, but it has been reverse-engineered. AAC was developed by the MPEG Audio Committee and is an open standard (ISO/IEC 13818-7;1997). Free Lossless Audio Codec (FLAC) was developed by Josh Coalson as a free, open-source format. iTunes and Quick Time support for FLAC can be added using plug-ins from Xiph.org. Audio CDs do not use data compression. They do use error-correction. <http://en.wikipedia.org/wiki/Advanced_Audio_Coding> <http://en.wikipedia.org/wiki/Apple_Lossless> <http://en.wikipedia.org/wiki/Red_Book_(audio_Compact_Disc_standard)> <http://en.wikipedia.org/wiki/Free_Lossless_Audio_Codec> -- Jim Gibson
From: Wayne C. Morris on 2 Aug 2010 16:18
In article <C87CDABE.A29B2%noreply(a)nospam.invalid>, MartinC <noreply(a)nospam.invalid> wrote: > AAC and ALE are both variants of M4A, and not ALE a variant of AAC. Incorrect. They're audio encoding formats which can be stored *inside* an M4A file, but that doesn't make them variants of M4A, any more than a painted portrait and a photograph are variants of a picture frame. M4A is an unofficial filename extension for MPEG-4 Part 14, aka MP4. MP4 is a multimedia container format, like AVI and MOV. It can hold audio, video, and subtitles in various data formats; some of the audio formats supported are MP3, AAC, and Apple Lossless. M4A was introduced by Apple as a filename extension for audio-only MP4 files. Other MP4 filename extensions Apple introduced are M4P (DRM-protected audio), M4B (audio books), M4R (iPhone ringtones), and M4V (video-only MP4). M4A and M4V seem to have become de facto standards. But yes, as you say later, lossless audio compression formats preserve all the data, and the contents can be extracted to recreate a bit-for-bit copy of the original digital audio data, even though the compressed file itself isn't a bit-for-bit copy. |