Is it still DTS audio if its at 448kb/s on a dvd?

[yoda313]

So I was wondering something. Say you were to take a dts audio track on a dvd and somehow reduce it to 448kbs instead of 700 something or the max 1500 something. Would it still technically be dts even though you have now compressed it down to the max bitrate for dolby digital on dvd?

I'm just curious. The headers would stay the same and your amp would read it as dts instead of dolby digital I would imagine. But would there be any point besides saving space on a dvd? This is an interesting question I just thought of. Is it still dts if its compressed to the size of an ac3 file?


Edit - I guess what I am asking is would the resulting compressed dts file contain more audio information at the same bitrate of the same track in ac3 format? (both being at 448kbs that is?).

[minidv2dvd]

maybe, but dts encoders won't encode to anything other than 1536 or 768.

i don't think the dts decoder in the amp would play anything else either.

if you some how managed both to encode and decode at a lower bitrate i don't think it would sound any better than a 6ch ac-3 at the same bitrate. they are both lossy formats, dts on dvd sounds better than ac-3 at because it has almost twice the bitrate at 768 and four times the bitrate at 1536.

[yoda313]

but dts encoders won't encode to anything other than 1536 or 768.

i don't think the dts decoder in the amp would play anything else either.

I guess I wasn't thinking of that side of the equation. That would put a clincher on this theory. I was thinking dts would be technically better at the same bitrate but if decoders won't recognize it than it would be more pointless than it already was.

[rallymax]

here is a good summary of the (consumer) use of DTS vs Dolby Digital. - to summarize the sumamry - it mostly seems to be opinion rather than hard facts when comparing the two encoder algorithms at the same data rate.

http://en.wikipedia.org/wiki/DTS_(sound_system)#History

In the consumer (home theater) market, AC-3 and DTS are close in terms of audio performance. When the DTS audio track is encoded at its highest legal bitrate (1,536 kbit/s), technical experts rank DTS as perceptually transparent for most audio program material (i.e., indistinguishable to the uncoded source in a double blind test). Dolby claims its competing AC-3 codec achieves similar transparency at its highest coded bitrate (640 kbit/s). However, in program material available to home consumers (DVD, broadcast, and subscription digital TV), neither AC-3 nor DTS run at their highest allowed bitrate. DVD and broadcast (ATSC) HDTV cap AC-3 bitrate at 448 kbit/s. But even at that rate, consumer audio gear already enjoys better audio performance than theatrical (35 mm movie) installations, which are limited to even lower bitrates. When DTS audio was introduced to the DVD specification, studios authored DVD movies at DTS' full bitrate (1,536 kbit/s). Later, movie titles were almost always encoded at a reduced bitrate of 768 kbit/s, ostensibly to increase the number of audio tracks on the movie disc. At this reduced rate (768 kbit/s), DTS no longer retains audio transparency.

AC-3 and DTS are sometimes judged by their encoded bitrates. DTS proponents claim that the extra bits give higher fidelity and more dynamic range, providing a richer and more lifelike sound. But no conclusion can be drawn from their respective bitrates, as each codec relies on different coding tools and syntax to compress audio.

[rzainaddin]

Hi,

Did you find a way to reduce the size of DTS files, When I try to encode it, then the size will be so large either for 1536Kbit/s or 768, both will give same size approx 1.2 GB for 120 M Movie. when you go to DTS movie like Bourun Supremacy and demux DTS files, then the size will be reasonable Approx. 600 MB and half size of my encoded files,,,,
Is thier any diffirent between Hardware and available software (Like surcode) encoding

Pls Help

[minidv2dvd]

Hi,

Did you find a way to reduce the size of DTS files, When I try to encode it, then the size will be so large either for 1536Kbit/s or 768, both will give same size approx 1.2 GB for 120 M Movie. when you go to DTS movie like Bourun Supremacy and demux DTS files, then the size will be reasonable Approx. 600 MB and half size of my encoded files,,,,
Is thier any diffirent between Hardware and available software (Like surcode) encoding

Pls Help

the same size thing for both 768kbps and 1536kbps doesn't make any sense at all. one is half the size of the other no matter what program encodes it.

[raquete]

all posts and explanations from minidv2dvd are corrects.(others users posted good explanations too)
if you want to gain space go to AC3 640K(or 448K) that sounds better than DTS 768k and give you short size.

[yoda313]

if you want to gain space go to AC3 640K(or 448K) that sounds better than DTS 768k and give you short size.

Actually this question wasn't for any conversion needs. It was just more of a "what if" question.

And technically I believe 448khz is the max for dolby digital ac3 on the dvd side of things. Of course it can go higher for dolby true hd on hd-dvd and bluray.

[raquete]

no, you can go to AC3 640K, works in lots of standalones, in my 2 players and have in P.Floyd-Pulse dvd too(448k and 640k).
you only need to encode a short sample to test in your standalone player.
if works in your player(and i can bet), go ahead.

cheers!