|
It is currently 26 Apr 2024, 15:09
|
View unsolved topics | View unanswered posts
|
|
|
|
Guest
|
Post subject: Re: Any LD's and DVD's with bit-identical AC3 soundtracks? Posted: 06 Jan 2014, 09:53 |
|
Unfortunately not, ld is 44100 and dvd is 48000 so the header (at least) for each frame will differ.
|
|
|
|
|
acuozzo
|
Post subject: Re: Any LD's and DVD's with bit-identical AC3 soundtracks? Posted: 06 Jan 2014, 21:56 |
True fan |
|
|
Joined: 08 Jan 2013, 18:13 Posts: 320 Location: United States Has thanked: 0 time Been thanked: 5 times
|
rein-o wrote: when are you coming out with a new LD player?? Now that question is a bit off-topic for this thread, don't you agree? Remember: Threads are like cable TV channels playing crummy football games... you can easily skip over 'em!
_________________ Fill my eyes with that DiscoVision!
|
|
|
|
|
happycube
|
Post subject: Re: Any LD's and DVD's with bit-identical AC3 soundtracks? Posted: 06 Jan 2014, 22:38 |
Absolute fan |
|
|
Joined: 18 Apr 2012, 18:02 Posts: 1614 Location: United States Has thanked: 71 times Been thanked: 88 times
|
The on-topic version of that is "When are you coming out with a new AC3 decoder?" It's possible using affordable components (the capture card hack I already have, or upverter + RTL-SDR) but I have no idea when it'll exist. (could use some help from the people who actually designed the encoding, as the decoding/error correction data tables aren't part of the AC3-on-LD patent. The standard AC3 spec is helpful, at least - thanks!)
_________________ Happycube Labs: Where the past is being re-made, today. [meep!]
|
|
|
|
|
Guest
|
Post subject: Re: Any LD's and DVD's with bit-identical AC3 soundtracks? Posted: 07 Jan 2014, 11:11 |
|
A capture from ld to pc via spdif (which uses the external clock signal) is at 44100, I get a 44100 2 ch wav file that when played from my pc via spdif to my avr is decoded as Ac3...
I have been concentrating on dts so my knowledge of ac3 isn't great but both ac3 and dts captures are bit perfect as they playback flawlessly from my pc via my avr.
|
|
|
|
|
substance
|
Post subject: Re: Any LD's and DVD's with bit-identical AC3 soundtracks? Posted: 07 Jan 2014, 19:53 |
Confirmed Padawan |
|
|
Joined: 16 May 2009, 18:05 Posts: 3588 Location: California, USA Has thanked: 28 times Been thanked: 323 times
|
my a/v processor shows sampling frequency of incoming digital signal.. I can try an ac-3 disc tonight and tell you what the sampling rate is. any particular title are you interested in?. I have plenty of ac-3 discs it might be best to try out the ones we both own. as for identical ac-3 tracks, we will have to hunt down early dvd pressings with 384kbps ac-3 audio. there is really few. most of the later releases(from 1998 on) are in 488kbps. I want to say the first pressing of "twister" might be one. it was the very first dvd released in the US in march 1997. it has been reprinted multiple times so I don't know if subsequent versions have different audio(I know there is a dts version). the first pressing was the hated by some hard paper cover with plastic inners that warner used on early dvds. interview with the vampire mars attacks stargate beetlejuice basic instinct these above are some other dvd releases from 1997 with ac-3 audio also exist in LD with ac-3 audio. http://www.amazon.com/Terminator-2-Judg ... ator+2+dvdthis version of terminator 2 confirmed to use the same DSS master used on this LD: Terminator 2: Judgment Day (1991) [LD68952-2DD]I cant tell for sure if they are bit perfect equal. these above titles are difficult to spot and find. Terminator 2 dvd was October 1997 release. Subsequent dvd releases used different name (extreme edition, ultimate edition etc..) and different cover so it is easier to find. The only give away for the other ones are the paper case warner used on early DvDs. hope this helps
_________________ Coming Soon Derman Labs Anything Of Substance
|
|
|
|
|
happycube
|
Post subject: Re: Any LD's and DVD's with bit-identical AC3 soundtracks? Posted: 07 Jan 2014, 22:04 |
Absolute fan |
|
|
Joined: 18 Apr 2012, 18:02 Posts: 1614 Location: United States Has thanked: 71 times Been thanked: 88 times
|
I might have that T2 LD, I'll check tonight. (From what I read in that A/52 pdf, there's a pretty good chance that I'll be able to use the CRC codes to verify decoding without having to compare against a reference, too )
_________________ Happycube Labs: Where the past is being re-made, today. [meep!]
|
|
|
|
|
Guest
|
Post subject: Re: Any LD's and DVD's with bit-identical AC3 soundtracks? Posted: 08 Jan 2014, 09:46 |
|
Yes, I capture ld ac3 to pc via pioneer rfd-1 demodulator, sorry, should've mentioned that Last night I sampled a ld ac3 audio track at 44100 and then at 48000 and both played back fine via my avr....the dolby symbol lit up .... very confused,... I'll look into it more tonight if I have time. Anyway, it not really relevant to your discussion... apologies.
|
|
|
|
|
little-endian
|
Post subject: Re: Any LD's and DVD's with bit-identical AC3 soundtracks? Posted: 29 Aug 2015, 07:08 |
Shows curiousity |
|
|
Joined: 25 Jun 2015, 01:53 Posts: 29 Has thanked: 1 time Been thanked: 1 time
|
bubski wrote: Last night I sampled a ld ac3 audio track at 44100 and then at 48000 and both played back fine via my avr....the dolby symbol lit up .... very confused,... Actually you didn't. I made the same false conclusion at first when I delt with recording S/PDIF sources. When you record analog sources, in the best case, the sample rate setting in your recording software will determine the clock rate of your sound card's ADC. In the not so great case, it will rather determine in which rate it shall be converted from a fixed sample rate ("best" sad example are many Sound Blaster cards pushing everything through the fixed 48 kHz - sample rate). When you record via S/PDIF, however, your sound card's S/PDIF receiver has to lock into the sample rate of the source, no matter of what sample rate you set in your editor. Leaving annoying stuff like resampling or volume changes aside, the sound card will forward the samples "as is" and the editor will put that into a file. Your sample rate setting here eventually only determines the sample rate header in the resulting file, which is why your AC3 file, you mistakenly recorded at 44.1 kHz, will still work. However, when you have the 44.1 kHz header set and play that back, your AC3 file should play too slow including a lower pitch respectively. Of course, a simple adjustment of the file header would do it. Furthermore, since a lot of wrong information seems to be floating around the net including the allegedly 44056 Hz for PCM of NTSC LaserDiscs, the correct sample rates are: AC3: 48000 Hz PCM (and thus DTS as well of course): 44100 Hz
|
|
|
|
|
|
|
|
|
|
|
You cannot post new topics in this forum You cannot reply to topics in this forum You cannot edit your posts in this forum You cannot delete your posts in this forum You cannot post attachments in this forum
|
|