Hi all,

Is there any software freely available that lets you convert LPCM 5.1 to DTS? I can't find any using google (although DTS themselves talk about such software here), and it looks like other than DTS themselves, this is the place to ask. The reason I want to is because some HDDVD discs have LPCM 5.1 and DD tracks but no full bit-rate DTS, and I only have hardware support for DTS.

Thanks,
Pete

As far as I know, there is no free DTS encoder available.

That PDF talks about encoding software, but in no way make reference to them being free.
There are no free DTS encoders, and what the DTS company refers to as "not expensive" is relative to.
Is not expensive for with a U$S 50.000 budget to buy DVD authoring equipment, as software DTS encoders are about U$S 1.000 worth and hardware encoders are a little pricier, but it is expensive for a someone who has 1 PC and a bugdet not big enough to get a Coke from a vending machine.
It also strikes me as odd that you say your hardware only supports DTS decoding.
Dolby Digital is a mandatory standard on all DVD decoding software/hardware. If it says it plays DVD-Video, it MUST be able to play a DD track.

Later, man

Thanks for the replies guys. Note that I didn't necessarily ask about a free encoder, only a freely (readily) available one

I admit I wasn't entirely accurate in saying I only have DTS hardware support, sure I have Dolby too, but full bit-rate DTS sounds so much better to me than ~448K AC3. It just seems a real shame to have to listen to the Dolby track when there's also 4608Kbps LPCM available.

Can someone advise me on either of the two options I have left:

1) Converting the LPCM to the highest bit-rate AC3 possible, 640 kbit/s, and hoping it sounds as good as full bit-rate DTS at 1,536 kbit/s (IMHO and AFAIK only the Star Wars rerererelease manages this).

2) Find a new soundcard that has 5.1 analogue outputs, buy a couple of extra quality RCA cables and hook the computer up to the 6 channel analogue input on my hardware decoder.

Which would be easiest/sound best?

Thanks,
Pete

I'd like to know if this statement can be backed up by ABX tests. So far I've been happily throwing away DTS duplicates of movie soundtracks. But there are quite many people claiming DTS is better. What is the general consensus among audio experts about DTS vs A/52?

I'd prefer analogue outputs from the computer to have complete control over speakers and without the trouble of setting up realtime encoding of every signal.

As far as I know, the general consensus is that you can't compare them with movie soundtracks because Dolby and DTS tracks have different pre-processing before encoding. Theatrical releases of movies use different muxing for each format, so the comparison can't be done on a "same source" basis. That's why they sound different, not better or worse, just different.
If you can obtain an original uncompressed source (like the LPCM), decode it and recompress it to both formats, you won't notice the difference between the resulting AC3 and DTS files.

There's one thing I like to say when referring to DTS: considering that it uses 768 to 1536 kbps for encoding, why is anybody saying that is better than Dolby?
If I were to say that I like to use 1536kbps when compressing to MP3 or AAC, I would be inmediately committed to an insane asylum (sorry, mental health facility ).

And I too prefer using my PC for decoding. But if the soundcard is a cheapo one, then I would just use PC -> digital out -> hardware decoding.

Later

That is the bitrate for 5.1 or even 6 or 7.1 channels though, so not totally insane compared to the
2 for MP3 :-) Anyway: DTS' claim has always been that DTS sound is better because of the higher
bitrate (among other claims, though).
Personally, I haven't heard any difference on DVDs with soundtracks in AC3 and DTS...
I still own some DTS-CDs though and like them (like Steely Dans Gaucho) for the sound quality, but
this is largely due to the master, I think...

This is mainly because the DTS soundtracks commonly found on DVDs are at half bit-rate, at which it sounds very similar to AC3. This is why I'm excited about utilizing the LPCM tracks on HDDVDs...


That's a bold statement, have you actually done this? What bit-rates did you use?


I prefer using my hardware decoder/surround amplifier for decoding, that way it's just one digital connection between PC and decoder. The problem with LPCM at the bit-rates found on HDDVDs is that it exceeds the bandwidth of a single S/PDIF connection. That's why instead of having to buy a new soundcard and several quality cables I'd rather reencode the LPCM to full bit-rate DTS (not necessarily real-time BTW, unless that is also possible)...

What I mean, is that at that rate, 1536 kbps for 6 channels is roughly, 256 kbps per channel.
If it were an MP3 2-ch, it would be a 512 kbps file.
If DTS uses distributes the bitrate similar to Dolby (kbps/channel x 5.33333) it's about 288 per channel. Which makes it 576 kbps for a 2ch file.
* I took that 1/3 bitrate for the LFE from somewhere, don't remember where, but it was so long ago that I might be totally wrong, so don't take it as set in stone. The maths give you 448= 84x5 + 28x1 (LFE 1/3), 384=72x5 + 24x1
That's what I'm talking about.
It's like saying that an MP3 or AAC file should be encoded at 512 kbps to sound well, when it's more likely that you won't be able to hear any difference above the 224-256kbps.


Later





I've used 448 and 640 kbps AC3 and 768 and 1536 kbps DTS encodes from MLP sources.

If you can hear a difference, then yay for you, man, your ears are way better than average.
As macbear said, just ABX it and you'll find out if it's just a feeling or you can actually tell the difference between both.

Later

What playback hardware (decoder, cables and speakers) did you use for your tests? Also were they ABX?

I used my PC with an Audigy 2 ZS in 6 channel mode analog out to a set of 3 pairs of speakers (one amplifier per pair). I use DD-EX or DTS-ES hardware decoding so I have 3 sets of equal speakers and an extra subwoofer for the LFE (for 6.1). But in this case, didn't use the LFE or the 6th speaker (CS or BC channel).
The sources were MLP songs. For that, I acknowledge it can be biased as not also tested with movie tracks but didn't have an uncompressed or losslessly compressed source for that. I think it was like a year and a half o 2 years ago, don't remember. I found no difference so I just stopped worrying about which format was better.
I don't think the cables were bad quality ones as a f***** hate cheap crap, the didn't cost U$S 0.35 cents nor 50 bucks (I'm not in USA, man, but Argentina).
PC-> Audigy 2 Zs analogue jack out -> amplifier jack in ->

The thing is the ABX, man.
If you can hear the difference and objectively see that thru ABX, then it doesn't matter what anybody else might think.

Later, man

And remember, if you do ABX you must use ReplayGain because DTS will always be louder than AC3. They exploit the fact that AC3 cleverly has a low reference level.

Minnetonka Audio has an promotion action till the end of the month, you will get Surcode DVD-DTS for 250 bucks (half the regular price). The CD-only (=44.1 kHz only) version costs 100$ regularly. Surcode DVD-DTS is a fully-licensed DTS encoder for 48 and 44.1 kHz.

Just to give you some price figures and product names (to further investigate on)...

This piece of software has been the only somehow "available" DTS encoder for many years, until a Nuendo plugin came out a while ago and DTS finally released its own software, as well as publicly available information on licensing encoder libraries (they kept everything under there own control for many years and only sold there hardware encoder).

Best, G.W.

250 bucks now?
Well, I guess it sounds alright now that DDPlus/HD and DTS-HD are becomeing the new standards every day that passes.

Later, dudes

"Standard" is a neat word... it just indicates which market demand they wanna create.

Yeap, hopefully, one day we'll be able to have hardware than can be soft/firmware upgraded to recognize and decode any format we want.
Wouldn't that be something?
"Wanna play AAC? Just insert this card with the AAC-decoding-plugin to upgrade your firmware/software".

Later

Those kinds of ideas are always unthoroughly thought, because your proposal would require an infinite amount of processing power and memory, in order to be able to cope with *any* codec - no matter how complex.

Best, G.W.

Uhhhhhhhh........
the same way any hardware decoder today needs infinite amount of processing power to decode an AC3 track or a DTS one?
Or an MP3 player or WMA player or a cellphone that plays MP4 videos....
those don't seem as supercomputers dealing with terabytes of info per second to me.

Try to decode H.264 SDTV on your 3-year-old medium-range PC. Try to playback 1080p H.264 on a current upper-class PC. etc. etc. The argument is intrinsic, I won't discuss on that anymore, it should become obvious to you.

It is not about coping with 5...15 year old standards, but with ANYTHING that might come. Period.

Actually, you can do both of those things.
I play SDTV H.264 just fine with ffdshow in my 3 year old PC (Athlon XP 2600+) and I can play 1080p in that same PC with CoreAVCDecoder, so i really don't know what you mean.
And to pretend to play a 1080p video in a cellphone or an MP4 pocket player is just... well, you get it, right?

It is *just* possible with CoreAVC, you know that, and besides, I wonder where you get 1080p footage from. I'm talking of 1080p50/60, of course. Don't stuck with 3 years, go one years further back in time, it doesn't change anything in the argument.

Excellent tips, thanks for the info, this is just what I was after...

As far as your further discussion with Skelsgard, I think that with the trend towards high bit-rate LPCM the need for decoding processing power isn't really set to grow, at least as far as DVD/films are concerned. Although LCPM is encoded in a certain sense, AFAIK it doesn't use any psycho-acoustic trickery and what not, which reduces the need for decode processing.

A simple Apple trailer in HD, man, you can get it for free and use it for testing without a problem.

I don't really understand your argument, or what is it about.

I said an upgradable hardware player that could play a format that we add to the firmware would be great, you said it was unthoroughly thought as it would require infinite processing power and memory to cope with any codec.

I said "infinite like any AC3 or DTS decoder? or MP3, WMA, or cellphone with MP4?" and you said that I should try to play A and B type of formats in a 3 year old PC and that the hardware would have to cope with any new format that will come..
and I still don't know where 1080p on a PC pops in the picture when I'm talking about MP3 players or cellphones with MP4.

But anyway, I told you I actually can play those formats in a 3 year old PC with two decoders, and you said that it's just possible with CoreAVC.
No, I already told you, I can do SDTV with ffdshow, so it's not just CoreAVC.

And if you don't want to be stuck with 3 years, than let's go 50 years in the past. Of course, as you said, that won't change the argument.


So, basically, what are you talking about?

To be honest I'm not too sure what either of you are talking about. I am sure that it has very little to do with the question/topic that I started. It's also starting to sound like an squabble, so as much as I appreciate both of your help with my question, please don't hijack my thread for it, thanks.

You are right, phusg, I apologize

No worries! Later, Pete

I'm having some trouble at the moment even getting to 6 mono wavs for input into a DTS encoder. With the help of some of Skelsgards comments here and on doom9 I've managed to:

1) Demux audio with DGIndex to a single PCM 48k 16bit 3/2lfe .pcm file.
2) Rename to a .raw and convert to wav with SoX.exe -r 48000 -s -w -c 6 file.raw file.wav
3) Split into 6 mono streams (.wavs) with WaveWizard (which needed to be set to ignore size)

WaveWizard tells me there is clipping in each file (peak conv is >2.x). The resulting .dts is mainly loud white noise. If I convert the sampling rate of the mono.wavs to 44100 then each wav individually also sounds like loud white noise, with occasional silent gaps in it (just like the .dts version)?!?

Can anybody tell me what's going on? DGIndex complains about there not being a video sequence header and the audio PID has to be set by hand to a Private Stream otherwise no demuxed .pcm file will come out...

Make sure you're working with the latest version of DGIndex. I think there were some bugfixes about LPCM.

Later

Unfortunately I already was and that isn't the problem. I checked and I had been using 1.5.0 beta 2 (part of AutoMKV). I just redid steps 1-3 starting with the latest release version DGIndex 1.4.9, but get the same result.

Any other ideas???