First Blu-Ray titles not encoded with new audio codecs (1 Viewer)

[ChristopherDAC]

Question wasn't asked. Poster seemed to believe that because PCM on current formats was 44.1 kHz, PCM on Blu-Ray would be 44.1 kHz. I quoted specs for some of the existing formats, not all of them [such as DAT and VHS-PCM] but ones he might be familiar with, to show that his impression was erroneous, and that in fact only CD uses the 44.1 format. HD DVD was not mentioned.

 

[DaViD Boulet]

ChrisDac,

are you sure you weren't trying to intentionally mislead fellow HTF readers?




BTW, curious how really only CD audio (and one option for conventional DAT) uses 44.1. Someone explained to me once that it was because prior to DAT, when digital audio was first recorded into tapes used primarily for video editing for CD mastering... the 44.1 sampling rate worked well with the timing of the rotating-heads that read the tape. Ever heard of that? Just curious how since CD, virtually everything (including Minidisc) uses 48 kHz-based sampling.

 

[JeremyErwin]

My TV uses 32 KHz samples. But see

this wikipedia article for more info

 

[ChristopherDAC]

The first PCM devices available for the home, oddly enough, were VCRs. At the time, the only media with the bandwidth capacity to support digital audio were viideotape systems. Early attempts used professional videotape machines, and a whole variety of sampling frequencies, bit depths, and coding laws.

When it became clear that digital audio really did have the capability to become an important production tool, conferences among the various manufacturers started to discuss the issue of common production and interchange standards. I have a whole series of articles from the Journal of the Audio Engineering Society on this very topic.

Since videotape was being used as a storage medium, the sampling had to be related to the field-scan rate of video formats, which is nominally 60 per second for NTSC TV, and 50 for PAL. If you start looking for common multiples in the range of twice 20 000 Hz, 44 100 is one of them. Quite early on, after studies of dropout characteristics, frequency response, and so forth, Sony adopted this frequency and a 16-bit sampling word for use in their digital-audio recorder based on the 3/4-inch U-Matic videocassette, and it was subsequentlu picked up by the whole EIAJ [Japanese Electronics industry association] for use with digital audio record-playback adapters marketed for home videotape recorders, which were just coming in at that time.
Meanwhile, work on standards continued. It was felt that, because of the importance of motion-picture film audio [remember Star Wars had just come out], a common multiple with 24 frames per second was also desirable ; and this would also allow for gentler anti-aliasing filters and an overall better audio quality. There was no push for increased bit-depth, because at the time it was a challenge to make an ADC or DAC capable of making full use of all 16 bits, to say nothing of storing the resultant data! Thus 48 kHz became the professional production standard.

Since Sony's equipment was mostly 44.1, and for other reasons, they didn't really "get on board" with 48 kHz right away, and by the time things were settled the CD format was basically finalised. Sony's representative actually stated that they couldn't switch to 48 kHz because the slight increase in bitrate would push Beethoven's 9th Symphony over the capacity limit of one disc ; of course, only a few years later, the mastering parameters were changed to allow "80 minute" instead of "74 minute" [44.1/16] CDs, which could have recorded a 70 minute track [his figure] at 48/16.

Oh well!

 

[Grant H]

"IMHO - anyone touting plain DD decoding, of TruHD or DD+, as a great feature of BD-ROM is simply "sugar coating" dried elephant dung. The failure by BDA to include mandatory support for these codecs renders the whole first generation of BD players useless, as far as audio is concerned."

Not useless to anyone who doesn't want to upgrade their receiver. From my understanding, these initial titles with the multichannel PCM tracks and component video capability are a poor early-adopter's dream.

I think it's great that (had I a player) I could pop in a BD (like Terminator which seems to have the PCM tracks) after hooking it up to my receiver's 5.1 inputs (which my never-used SACD player is hooked up to now) and get uncompressed 5.1 sound and 1080i video over component.

All without upgrading the TV, without upgrading the receiver to take advantage of a new fancy codec (though I'd be getting an improved DD or DTS regardless).

Face it; you never get all the bells and whistles in the first incarnation. But this first-round compromise is nothing to sneeze at.

Will the new codecs be able to be passed by analog outputs to a receiver or be HDMI only? Just wondering if these early PCM titles will be something to cherish for those not wanting to upgrade their receivers.