Want to reduce bitrate for dts audio file ??

[claypillar]

I've a dts 5.1 audio file ripped from a DVD. The file size is 778MB. I want to reduce the size of this dts audio file by changing the audio bitrate. I tried this with BeLight, but BeLight or BeSweet don't output dts audio. Although the file is opening in these softwares, it couldn't be re-saved as dts. I was able to save the file as ac3 with 192 Kbps audio bitrate as 5.1 ch sound, but I want it as 5.1 ch dts sound with 192Kbps bitrate. I bitrate of the original dts audio is around 784Kbps.

I've very little knowledge about the dts audio format. I've a question abt it:

I found the dts 5.1 audio much louder than the ac3 5.1 audio, but ac3 5.1 much sharper(every channel is clearly heard although the LFE is not as boosting as dts) than the dts 5.1 while watching the DVD. Can anyone tell me the technical difference between these two audio formats, and which one is better, and why??

[guns1inger]

192 for 5.1 DTS will sound horrible., as it will for 192 AC3. There simply isn't enough space for 6 channels in that bitrate.

DTS compresses less than AC3, hence the higher bitrates and larger file sizes. If you reduce the bitrate you destroy any advantage that this brings. It is rare that a movie will have only a DTS soundtrack. If is has AC3 and size if your issue, use that instead.

As a guide, most movies have AC3 5.1 at 384 or 448, and 2 channel at 192 or 224. What you are doing is like squeezing CD audio into 64kbps mp3. It will be small, but it will sound like crap.

As to which is better, it varies from disk to disk. Some disks use the same basic channel masters for both, in which case there is almost no dofference. Yes, DTS punches up the bass and little, and has slightly better clarity due to it's higher bitrates, but most players require a seperate DTS decoding amplifier to make use of it. AC3 is smaller (around 60% of the size for the same movie), and the DVD spec says a player must be able to downsample AC3 to 2 channels for analogue output.

The only time you notice a real difference is when the audio is specifically mixed for DTS, in which case it is superior to AC3 (imo), however the difference, even with a good amp and speakers, is not orders of magnitude better than AC3. Of course, all this is moot if you reduce the bitrate of 5.1 down to 192Kbps, as you have destroyed any clarity or vallue the sound track has.

[claypillar]

I'm much satisfied with the dts audio than the ac3 audio track. So, I want to convert dts into ac3. I referred to one of the guides. Following the procedure, I seperated the dts file into 6 mono waves(16-bit wave) using Tranzcode, and used BeLight 0.22 Beta6 to make the .mux file from the 6 mono waves. The .mux file on opening with notepad looks like this:

F:\BHD\Tranzcode_6monowaves\DTS_Audio_0xBD_0x8A_Delay_-67ms_1-FL.wav
F:\BHD\Tranzcode_6monowaves\DTS_Audio_0xBD_0x8A_Delay_-67ms_1-C.wav
F:\BHD\Tranzcode_6monowaves\DTS_Audio_0xBD_0x8A_Delay_-67ms_1-FR.wav
F:\BHD\Tranzcode_6monowaves\DTS_Audio_0xBD_0x8A_Delay_-67ms_1-SL.wav
F:\BHD\Tranzcode_6monowaves\DTS_Audio_0xBD_0x8A_Delay_-67ms_1-SR.wav
F:\BHD\Tranzcode_6monowaves\DTS_Audio_0xBD_0x8A_Delay_-67ms_1-LFE.wav

I opened this .mux file in BeSweetGUI v0.7 b8 and set the output to .ac3. After pressing the MUX to AC3 button, a notepad file opened containing the following information:

Error 59: Failed to sync to payload's start position : "f:\BHD\Tranzcode_6monowaves\sample.mux"BeSweet v1.4 by DSPguru.                          
--------------------------
Using hip.dll v1.13 by Myers Carpenter <myers@users.sf.net>
Using AC3enc.dll v0.2 by Gerard Lantau & Dg (http://ffmpeg.org).

Logging start : 10/03/05 , 06:19:28.

g:\Downloads\Directware\Audio Video Editors\Set1\BeSweetCommanLine\BeSweet.exe -core( -input f:\BHD\Tranzcode_6monowaves\sample.mux -output f:\BHD\Tranzcode_6monowaves\sample.ac3 -logfilea G:\Downloads\Directware\Audio Video Editors\Set2\besweet_gui\BeSweet.log ) -ac3enc( -b 384 ) -profile( ~~~~~ Default Profile ~~~~~ ) 

[00:00:00:000] +------- BeSweet -----                          
[00:00:00:000] |  Input : f:\BHD\Tranzcode_6monowaves\sample.mux
[00:00:00:000] |  Output: f:\BHD\Tranzcode_6monowaves\sample.ac3
[00:00:00:000] |  Floating-Point Process: No
[00:00:00:000] |  Source Sample-Rate: 48.0KHz
[00:00:00:000] +------- AC3ENC ------
[00:00:00:000] |  Bitrate method  : CBR
[00:00:00:000] |  AC3 bitrate     : 384
[00:00:00:000] |  Channels Mode   : 2.0
[00:00:00:000] |  Error Protection: Yes
[00:00:00:000] +---------------------
Error 32: No input-data was found (wrong substream?)
Quiting...
[00:00:00:000] Conversion Completed !                                    
Logging ends : 10/03/05 , 06:19:28.

I don't know what's wrong. Pls suggest a method to convert these 6 monowaves into Dolby ac3 5.1 Surround. I even used Sony Vegas 6.0. But, after Rendering As 'ac3', the file is not saved. The 'Render As' window stays still without any activity. I don't exactly know how to work with Sony Vegas 6.0. So, please explain the procedure to convert 6 mono waves into ac3 5.1 using Sony Vegas 6.0 too.

[guns1inger]

I haven't used besweet, so this is just guessing, but the first things I would check are

is the .mux file called sample.mux ?
is it found in the folder f:\BHD\Tranzcode_6monowaves\ ?

do you have everything configured correctly, as the output indicates that had it been successful, you would have ended up with 2 channel output, not 5.1 ?

[claypillar]

is the .mux file called sample.mux ?
is it found in the folder f:\BHD\Tranzcode_6monowaves\ ?

yes, the .mux is called sample.mux. The sample.mux file is saved in Tranzcode_6monowaves folder(the same folder contains all 6 mono waves).

Whatever is the number of channels, the other configurations are correct for sure. So, according to the fact that all 6 mono wave files are present in the Tranzcode_6monowaves folder along with sample.mux file, there should not be any problem in recognizing the .wav files and .mux file...however, the error mssg as shown above tells that there is no input-data, which simply seems ridiculous, and is confusing me a lot.

So, I decided to go for the Foobar2000 software - it converts the dts file into wav file, (which is practically not easy in BeSweet, maybe, b'coz dts codec's are not as efficient as the other audio format codecs). I got the 6ch wav equivalent of dts audio. Now, I converted this wav audio into ac3 with the desired bitrate using HeadAC3he. The only aspect I'm worried about is the 'bitrate compromise issue'. Practically, I don't think reducing bitrate of ac3(converted from dts) will not give the digital surround experience.

[guns1inger]

The bitrate doesn't affect the surround experience, as this is contained inthe positioning of the mono wav files. All the bitrate will influence is the quality of the actual audio in the finished file. As a 448Kbps AC3 is, quality wise, within a few % of a 768Kbps DTS (in most cases), you are unlikely to notice any difference unless you are using high end audio reference kit.

[claypillar]

I noticed that fact. I played the new ac3 file(encoded from dts) and found it quite promising. However, I've a small problem. It goes like this:

Due to the FAT32 File System on my PC, I actually split the dts file into three parts(using DVD Audio Splitter) such that the corresponding wav files(after conversion) donot occupy size greater than 4GB. So, the result was that I got three seperate wav files from the split up dts files, and consequently(as I encoded the wav into ac3), I got three ac3 files finally. Now, I want to join these three 3 ac3 files into a single ac3 file. I didn't find any tool to do this. Pls suggest one.

[guns1inger]

you are sol. I do not know of any tool that can do this, and pretty much every post regarding trying to join audio tracks end up with 'how do I fix my sync problems ?'.

You probably should have mentioned this earlier - it would have saved you a lot of wasted time.

Why, in god's name, do you still have fat32 ?

[claypillar]

you are sol. --> what does that mean ??

I got a tool which can join ac3 files. It's the same tool which splits and merges dts files - DVD Audio Files Splitter. This tool has an option to join ac3 or dts files together.

Now, that I got the complete ac3 audio track from a complete dts audio track, I still am inclined towards the thought --> "If only I could reduce the bitrate of dts....", b'coz, if I could've really reduced the bitrate of dts audio track, I need not do all these conversions i.e., from dts to wav then to ac3 etc.. to save the file size. If any one of you knows the method to encode a dts with lesser bitrates, pls tell me, coz, finally that is what i want.

[guns1inger]

how big are the files ? 4gb is a per file limitation, and none of these should be that big, so maybe you don't have to split them.

[BJ_M]

why not just use the ac3 file which is on the dvd ?

all dts dvd's have ac3 also ...

[claypillar]

4gb is a per file limitation, and none of these should be that big

What do u mean, none of these ??? You're forgetting the fact that in the process of converting from dts to ac3, I first need to convert the dts audio track into wav format (using Foobar2000 audio tool), and then using Headac3he, I've convert this wav file into ac3 format. I hope you now understood at which point of the conversion process I faced the FAT32 problem - it is during the dts to wav conversion. the wav files are exceeding 4GB size. So, I had to split he dts files, such that the corresponding wav files(from dts conversion) will not occupy more than 4GB.

why not just use the ac3 file which is on the dvd ?

You're right. Even my DVD has an ac3 audio. But, I found the dts audio much powerful, exciting and good to hear while watching the movie. So, I thoght, if at all I backup this DVD, I should definitely have one dts audio track. However, when I demuxed the dts and ac3 audio tracks from the DVD, I found that the dts track occupies insanely large size compared to the ac3 audio track, coz, the bitrate with which it was encoded was relatively higher than the ac3 audio bitrate(ac3 - 448Kbps, dts- 768 Kbps). So, since I developed certain attachment to the dts sound effects, and since I didn't find any tool to drop the bitrate of a dts audio track, and since some of you guys suggested that conversion from dts into ac3 with reduced bitrate doesn't result in much quality loss relative to the original dts track(as shown in the below quote),

The bitrate doesn't affect the surround experience, as this is contained inthe positioning of the mono wav files. All the bitrate will influence is the quality of the actual audio in the finished file. As a 448Kbps AC3 is, quality wise, within a few % of a 768Kbps DTS (in most cases), you are unlikely to notice any difference unless you are using high end audio reference kit.

I decided to convert the dts into ac3(with 448Kbps or lesser bitrate), so that

1.) I can experience atleast a part of the dts effects in the converted ac3 audio.
2.) I can have a small size audio file compared to the large dts file.

This is the actual reason for converting the dts audio into ac3. It is not that there is no ac3 audio track on the DVD. It is due to sheer curiosity of experincing dts effects on a CD(containing the DVD backup), that I resorted to the 'dts to ac3' conversion.

[guns1inger]

If you drop the bitrate of the DTS audio down to that level you will loose all that you liked about it in the first place, and it will sound worse than the AC3 audio track.

I still find it hard to believe that any of the single, mono wav files (representing each track) could be larger than 4 GBs, however a multi-channel wav file could easily be that big.

[Jester700]

You're right. Even my DVD has an ac3 audio. But, I found the dts audio much powerful, exciting and good to hear while watching the movie. So, I thoght, if at all I backup this DVD, I should definitely have one dts audio track. However, when I demuxed the dts and ac3 audio tracks from the DVD, I found that the dts track occupies insanely large size compared to the ac3 audio track, coz, the bitrate with which it was encoded was relatively higher than the ac3 audio bitrate(ac3 - 448Kbps, dts- 768 Kbps). So, since I developed certain attachment to the dts sound effects, and since I didn't find any tool to drop the bitrate of a dts audio track, and since some of you guys suggested that conversion from dts into ac3 with reduced bitrate doesn't result in much quality loss relative to the original dts track(as shown in the below quote),

The original AC3 was encoded from non-compressed files. IMO you are mistaken if you think re-encoding a DTS track as AC3 will sound better than the existing AC3. I mean, have fun & try it if you can, but don't expect miracles.

[claypillar]

do you mean to say, ac3 remains ac3 always, whether it is the original audio track from DVD or whether it is converted from dts ??

is that what u meant??

what does IMO mean ??

[manono]

IMO=In My Opinion

SOL=S**t Out of Luck

This whole thread baffles me anyway. First you want to reduce DTS to a DTS 5.1 with a bitrate of 192? What on earth were you thinking? Then after you find out you can't reencode DTS to a lower bitrate, you still insist on reencoding it to AC3? If there's already a DD 5.1 AC3 track, then why would you even think about reencoding the DTS?

I have myself reencoded full bitrate DTS to DD 5.1 448 AC3 when there was only a DD 2.0 on the DVD. Otherwise, I just don't see the point. As mentioned several times, the quality will be worse than the existing DD 5.1 track.

Also as mentioned, DTS 784 audio is only marginally better than DD 5.1 448. There's a bit better bass, but you'll need a pretty high end audio system to tell the difference. Mainly DTS is just louder, and for some reason people equate volume with quality.

Also, converting DTS to AC3 is pretty tricky, as you don't get the same channels as when you decode DD 5.1 AC3 into 6 channel WAV. The channels are mislabeled, are switched, and I had a helluva time getting them corrected. BeSweet messed it up. Don't know about other programs.

[whitejremiah]

yea, i'd personally only mess around with it if its got ONLY a mono or stereo audio then the DTS...that way provided you convert it all correctly at least you can have a 5.1 track of sorts....but yes, definately use the 5.1 track if its present.....DTS is slightly clearer, but if you start downsampling it, compressing it, ect, it will DEFINATELY end up sounding worse than the ac3....what we have been trying to say is that normally the ac3 and the DTS are sourced from the same non compressed source, and the only real differance is that the DTS is slightly enchanced because of the higher bitrates. Honestly, just hanging onto the ac3 is by far the best choice....

[claypillar]

Also as mentioned, DTS 784 audio is only marginally better than DD 5.1 448. There's a bit better bass, but you'll need a pretty high end audio system to tell the difference. Mainly DTS is just louder, and for some reason people equate volume with quality.

I liked the above explanation. It really clarified a lot about the long fight between Dolby 5.1ch and dts audio tracks. I have to believe what manono said - dts is much louder than Dolby, that's it. I arrived at the conclusion that there's no difference between Dolby 5.1 ch and dts except the higher volume or bass(which is attributed to higher bitrates of dts).

However, my struggle to get the dts audio quality(or volume whatever you call it) at a much lower bitrates may be possible if I encode dts into aac at much lower bitrates. I'll try it myself.

The reason for my new idea(to encode dts into aac) and the procedure I'll will follow next are given below. Pls have a look:

REASON:
I encoded the MPEG-2 DVD video into AVI using x264 codec, as it is the best quality codec I found on earth(compared to the regular XviD, DivX codecs). I'm informed of the fact that MP4 is a better container for x264 encoded videos rather than AVI or MKV by celtric_druid(refer to my posts in video section). Since MP4 can accept only aac audio, I'm making a trial attempt to see if AAC audio can reach the standards of dts.

PROCEDURE:
1.) I'll convert the dts into wav using Foobar2000
2.) Convert wav into AAC at desired bitrate(will decide upon testing) using HeadAC3he.
3.) Encode MPEG2 into AVI using x264 codec in VirtualDubMod
4.) Extract .264 video file from the above AVI and mux it with previously obtained AAC audio using YAMB+MP4Box.

If any of you guys feel that my attempt to convert dts into AAC(expecting equivalent quality) is waste, please let me know.

For a while, I'm keeping aside the MKV container. If I feel, MP4 is not the right idea, I'll try MKV next.

[guns1inger]

to convert dts into AAC(expecting equivalent quality) is waste

Re-phrase this as 'acceptable quality' and I won't tell you that you are wasting your time. To expect equivelent quality is a fool's dream.

Either this has been an ever evolving project, or the fact that you are going from DVD to mp4 is yet another vital piece of information you neglected to mention at any previous point.

[claypillar]

Re-phrase this as 'acceptable quality'.....equivelent quality is a fool's dream

Point noted. Yes, what I mean is 'acceptable quality'. I totally agree that equal quality is a fool's dream. I've to process the dts audio yet. I'll tell you the result soon.

[claypillar]

Firstly, Everything mentioned below relates only to 6ch audio tracks:

I've tried all kinds of bitrates ranging from 224Kbps to as much as 448Kbps while encoding wav(obtained from dts using Foobar2000) into aac(using Headac3he), but none of the aac files is able to beat the dts quality. Leave about dts, aac is not even as good as ac3 audio(having same or even less bitrate). So, I decided to stick with ac3 audio. Since, I wanted two audio tracks to be present in the resulting container(I'm using MKV here with H.264 encoded AVI as video), I used a simple technique which can give me the dts cum Dolby experience. Before, discussing this technique, let me mention one assumption that I made.

The assumption is

Since ac3 or dts audio tracks are made from Uncompressed PCM 6 mono wav tracks, and since dts sounds louder due to larger bitrate, and ac3 sounds lighter owing to relatively smaller bitrates, it can be assumed that both ac3 and dts audio tracks are content-wise the same i.e., both can sound louder if larger bitrates are used. However, since ac3 uses higher compression techniques than dts, encoding the wav into ac3 by reducing the bitrate of ac3(ranging from 160Kbps to 224Kbps and ensuring that channel gains are reduced) can result in the so called "Dolby 5.1 ch Experience", and encoding the same wav into ac3 with higher bitrates(ranging from 224Kbps to 448Kbps and ensuring that channel gains are increased or atleast not changed) can give the so called "DTS 5.1 ch Experience". Although both are ac3 Dolby Tracks, the higher bitrate track will sound louder than the lower birate track resulting in clear domination of one of the tracks, and these tracks can be used on CDs owing to their lesser size compared to the original dts tracks.

Technique that I used(to get small size audio files)
Let me call these audio tracks created using this technique(for the sole purpose of fitting onto CDs) as Virtual Tracks i.e., Virtual Dolby & Virtual dts

1.) To create Virtual Dolby for CDs

-->Took the original AC3 audio track(448Kbps) from DVD and reduced it's bitrate to aprrox. 40% of original in Headac3he options menu(i.e., 192Kbps)
-->Decreased the L/R/SL/SR input channel gains and Output Center channel gain by 3dB
-->Encoded ac3 again as ac3 with 192Kbps.

2.) To create Virtual dts for CDs

-->Took the original dts track from the DVD
(Remember: The channels of this track are a bit different from the channels of original ac3 track)
-->Converted it into multichannel wav using Foobar2000
-->Opened wav in Headac3he and setup the Global Gain to 8dB, Booster Level to 4
-->Increased the input gains of L/R/SL/SR channels and Output Center channel gain by 3dB
-->Encoded the wav into ac3 with 256Kbps bitrate.

Now, I muxed the above tracks with AVI(containing H.264 encoded video) into MKV container and played it in Media Player Classic with it's in-built ac3 decoder. The difference was quite sharp. I can tell with total guarantee that people who hear these tracks can call them as Dolby and dts tracks seperately.

Where did I find the difference and how ?

-->First - the Virtual Dolby is encoded from original Dolby with less bitrate and channel gains are dropped. So, although all channels are heard with clarity, the amplification is less.
-->Second - the Virtual dts is encoded from original dts(through intermediate wav conversion) with higher bitrate. Since original dts has different channel mixing than the original Dolby, I can note the swapping of L/R/SL/SR channels when changing from Virtual Dolby to Virtual dts(same thing happens when tracks are changed on original DVD). Moreover, I increased the channel gains by 3dB, increased the Booster level 4 times, and also the Global Gain is made 8dB. So, the amplification is quite higher than the Virtual Dolby track.

If you observe closely, on an overall basis, I kept the combined size of both audio tracks equal to the size of the original ac3 track, b'coz, the Virtual Dolby has a bitrate of 192kbps, Virtual dts has 256Kbps. So, combining both gives us 448Kbps which is the standard ac3 bitrate of original Dolby tracks!! This is the major aspect to be considered to ensure no increase in file size.

Why didn't I find 192Kbps ac3 audio 'uncompromising' ?

If I encoded the 448kbps ac3 into 192kbps without making changes in the channel gains, then, definitely 192kbps ac3 audio track would have sounded like shit(I even tried it too). However, while reducing the bitrate, I even reduced the channel gains so, that voice doesn't fade away.

I know, that this procedure is entirely controversial, and may even seem meaningless to some people, but I tell you, this is the best way I found to put two audio tracks with optimum size such that they give dts and dolby Experience.

[claypillar]

can anybody suggest abt DRC - Dynamic Range Compression - what is it ?? How does it work ??

[guns1inger]

Your basic assumption regarding the reason for differences is flawed to begin with. The relative bitrates are not the reason DTS sounds louder and punchier than AC3. It is a result of the way the source is encoded by the two formats. If you basic premise is true, then if the bitrates were the same, the soudn would be the same. This is patently incorrect. In fact, this whole assumption is blown apart by the so-called 'virtual DTS' file, which is just an AC3 encoded file with increased gain. The higher bitrate is incidental, as it is the increased gain that makes it feel louder.

The true comparison, which is missing from your last post, is how do either of your manufactured audio tracks compare to the original AC3 5.1 track on the disk ?

If you are happy with what you have achieved, great. You have certainly put a lot of effort into it.

Personally, I don't believe you have actually proven anything other than you are able to take a perfectly good DTS audio track and convert it to sub-standard AC3 audio using freeware tools. I can't see that any of this effort is justified unless all you have is a DTS audio track and an AC3 decoder, and even then, the bitrates you are using here are too low to produce quality output.

[thegeeman]

You may want to check out:

http://www.discwelder.com/ and then

http://www.discwelder.com/pdfs/dvdAudioWhitepaper.pdf

That may help with alot of what is being said.

[MACCA350]

You may want to check out:

http://www.discwelder.com/ and then

http://www.discwelder.com/pdfs/dvdAudioWhitepaper.pdf

That may help with alot of what is being said.

This is DVD-Audio, different to DTS and DD/Ac3. DVD-Audio uses a lossless compression called MLP, and when decompressed it is bit for bit the same as the master(hense the extreams the studios went to with the copyprotection systems used on DVD-Audio's).

If you want some info about the differences between DTS and DD, read this article, http://www.spannerworks.net/reference/10_1a.asp

from the article:

When comparing DTS with 448kbps Dolby Digital (and even, to a lesser degree, 384kbps Dolby Digital) any difference noticeable can more likely be attributed to differences in mastering or production than coding schemes. Under identical mastering conditions the two systems should be nearly indistinguishable from one another.

Any attempt to compare the domestic versions of Dolby Digital and DTS with one another is extremely difficult due to one major technical difference. The domestic version of Dolby Digital incorporates a feature, called 'dialog normalization', designed to maintain a consistent centre-channel volume from all Dolby Digital sources. The dialog normalization system is designed to ensure that the average centre-channel volume is always between -25 and -31dBFS (decibels below digital full-scale), regardless of source. As a result, if dialogue is recorded at a higher volume, the Dolby Digital decoder automatically attenuates the volume of all channels to the level at which the centre-channel outputs dialogue at the set 'dialnorm' level (usually -31dBFS for Dolby Digital on DVD). Most movies' centre-channels are recorded at -27dBFS, which results in an overall lowering of 4dB in all channels. Movies can be recorded at anything from -23dBFS (e.g. 'Wild Things') to -31dBFS (e.g. 'Air Force One', non-SuperBit and 'Twister: SE'), resulting in nominal overall volume attenuation of up to 8dB ('Wild Things') or more. All channels maintain their correct relative balance, so no detrimental sonic effects can be attributed to the dialnorm process. But, because the result can be up to an 8dB reduction in volume, there is no easy way to compare DTS and Dolby Digital versions of a film's soundtrack. The overall volume of the DTS version may be 8dB or more higher than the Dolby Digital soundtrack, making direct comparisons nearly impossible. As dialnorm is constantly variable in 1dB increments, the exact difference in overall volume between Dolby Digital and DTS soundtracks often varies from film to film.

Overall DTS compression is not as effecient as DD and needs the higher bitrate, so you cant make a comparison just on the bitrate's. Read the article, its very interesting.

Cheers

[claypillar]

my goodness...the guide is a serious eye-opener to me. I should've read it before to avoid a lot of complexities.

[Cornucopia]

Also, it is a well documented auditory phenomenon that when people hear 2 versions of the same clip, they prefer the louder one. They say it is "brighter", has "more umph!", is "more open", "clearer", "more visceral", etc. Alot of this is due to the frequency non-linearity of the human ear (see "Fletcher-Munson Loudness Contours" for more info).

If Louder --> Better (psychoacoustically perceived)
and Higher bitrate --> Better (true),

you were thinking Louder = Higher bitrate, but that doesn't follow (notice I didn't put in "=" in the above).

*********

But I'm still confused about what you've got and about what you really want to end up with at the finish. You recently mentioned "... for CD" but that doesn't follow what you've said previously, re: DVD-Video or AVI/MKV/MP4 data.

START OVER.

Scott

[BJ_M]

You may want to check out:

http://www.discwelder.com/ and then

http://www.discwelder.com/pdfs/dvdAudioWhitepaper.pdf

That may help with alot of what is being said.

This is DVD-Audio, different to DTS and DD/Ac3. DVD-Audio uses a lossless compression called MLP, and when decompressed it is bit for bit the same as the master(hense the extreams the studios went to with the copyprotection systems used on DVD-Audio's).

If you want some info about the differences between DTS and DD, read this article, http://www.spannerworks.net/reference/10_1a.asp

from the article:

When comparing DTS with 448kbps Dolby Digital (and even, to a lesser degree, 384kbps Dolby Digital) any difference noticeable can more likely be attributed to differences in mastering or production than coding schemes. Under identical mastering conditions the two systems should be nearly indistinguishable from one another.

Any attempt to compare the domestic versions of Dolby Digital and DTS with one another is extremely difficult due to one major technical difference. The domestic version of Dolby Digital incorporates a feature, called 'dialog normalization', designed to maintain a consistent centre-channel volume from all Dolby Digital sources. The dialog normalization system is designed to ensure that the average centre-channel volume is always between -25 and -31dBFS (decibels below digital full-scale), regardless of source. As a result, if dialogue is recorded at a higher volume, the Dolby Digital decoder automatically attenuates the volume of all channels to the level at which the centre-channel outputs dialogue at the set 'dialnorm' level (usually -31dBFS for Dolby Digital on DVD). Most movies' centre-channels are recorded at -27dBFS, which results in an overall lowering of 4dB in all channels. Movies can be recorded at anything from -23dBFS (e.g. 'Wild Things') to -31dBFS (e.g. 'Air Force One', non-SuperBit and 'Twister: SE'), resulting in nominal overall volume attenuation of up to 8dB ('Wild Things') or more. All channels maintain their correct relative balance, so no detrimental sonic effects can be attributed to the dialnorm process. But, because the result can be up to an 8dB reduction in volume, there is no easy way to compare DTS and Dolby Digital versions of a film's soundtrack. The overall volume of the DTS version may be 8dB or more higher than the Dolby Digital soundtrack, making direct comparisons nearly impossible. As dialnorm is constantly variable in 1dB increments, the exact difference in overall volume between Dolby Digital and DTS soundtracks often varies from film to film.

Overall DTS compression is not as effecient as DD and needs the higher bitrate, so you cant make a comparison just on the bitrate's. Read the article, its very interesting.

Cheers

the information from your source is not totally correct in their infomation .. just so you are aware

[MACCA350]

BJ_M wrote:

the information from your source is not totally correct in their infomation .. just so you are aware

Could you be more specific, which parts are incorrect.
Have you seen the resorces he used for the article at the bottom of the page? most of the info was taken directly from DTS and DD tech papers.

The Dialogue Normalization feature is correct. If your receiver can show you, you will see it for yourself. For those with the denon 3805 while a DD track is playing press the 'on screen' button on the remote, look on your tv next to 'OFFSET' this is the amount of Dialogue Normalization in effect at that time. On 'Mighty Joe Young' it is -4

I would like to know which parts are incorrect, as I'm sure the author of the article would too.

cheers