Avi-DTS guide

[Wilbert]

Some of you know that since about a week it is possible to encode a dvd to DivX/Xvid containing a dts stream, and to play those files. I wrote a small guide which described this. It is a first draft, so it contains typos, misses colors. Of course other comments are welcome. I hope you will enjoy it.

The guide can be found here (http://www.geocities.com/wilbertdijkhof/).

[gabest]

Just read it through, good job :)

[The Belgain]

Does this mean that we can now save a DTS track as a wav file (which means we could use this rather than the ac3 for re-encoding giving better results)?

Are there any plans to incorporate DTS input into BeSweet now that there is a plabck filter DSPGuru?

[Wilbert]

@The Belgain,

Does this mean that we can now save a DTS track as a wav file (which means we could use this rather than the ac3 for re-encoding giving better results)?
Yes, can either put a wav header on it (with Besplit) or save it to uncompressed wav. I _think_ that Besweet can downmix 6 channel (uncompressed) wav to mp3, but I'm not sure.

@gabest,

Is there any reason why you didn't include iviaudio.ax and dtssource.ax in the test.rar package at Doom9's download site?

Of course, also I'm very curious to The Belgain second question (transcoding dts to a lower bitrate would be nice for a start).

[gabest]

Originally posted by Wilbert
Is there any reason why you didn't include iviaudio.ax and dtssource.ax in the test.rar package at Doom9's download site?It is still in my test.rar, no idea about the one in the download section.Of course, also I'm very curious to The Belgain second question (transcoding dts to a lower bitrate would be nice for a start). I don't know about any dts encoder. The basic idea behind the whole "project" was to enable multiplexed dts sound in avi.

[The Belgain]

By "transcoding to a lower bitrate" I meant a lower bitrate mp3, ogg, etc, not a lower bitrate DTS.

I don't think it's really very useful to be able to mux DTS into avi until DVD-writers become widespread because I don't think the improvement in sound quality is worth an extra CD.

Using a better quality source for transcoding would be nice though. It would also be nice to use DTS as source for making audio CDs too.

[Wilbert]

It is still in my test.rar, no idea about the one in the download section.
Oh, I didn't look right. Only iviaudio.ax (4.5) is not included.

A question, I was reading this thread "http://www.everwicked.com/forums/showthread.php?s=&threadid=1588". Is that similar/the same as putting a wav header on a dts file with Besplit?

[gabest]

No, dts-wav is a bit different. In such a file data is stored like how the 8 bit characters are converted to 7 or 6 bit in email. Every 16 bit is regroupped and stored as a 14 bit word leaving the upper 2 bits empty. But of course it is also possible to store the original dts data in wav, but then you will need the avi<->ac3/dts filter to play it back with iviaudio.

[DSPguru]

dts input support is certainly a goal.

[The Belgain]

That's nice to hear DSPguru. Presumably at the moment we can already to it manually by producing the 6-channel wav and feeding that to BeSweet (it accepts 6-channel wavs, right?).

[DSPguru]

multichannel waves are supported (only 16bit waves, though), but downmix to 2ch is only possible by using the downmix plugin.

[The Belgain]

Oh right, so azid can only downmix ac3 streams then?

[DJ Bobo]

DTS support so we can transcode it is good.

Muxing DTS with AVI is senseless. DTS has just too high a bitrate. Anyone that will be muxing DTS with AVI is just crazy.

[ookzDVD]

Originally posted by DJ Bobo
DTS support so we can transcode it is good.

Muxing DTS with AVI is senseless. DTS has just too high a bitrate. Anyone that will be muxing DTS with AVI is just crazy.

In this case I AGREE with you :)

[Wilbert]

Muxing DTS with AVI is senseless. DTS has just too high a bitrate. Anyone that will be muxing DTS with AVI is just crazy.
Fine, if that's your opinion. I disagree. People also use three CD's for svcd, is that also senseless ?

[OvERaCiD23]

Anyone that will be muxing DTS with AVI is just crazy.

For what you gain, it is senseless. If one wants a DTS track badly enough, watch the DVD itself. AC3 already takes up a substantial portion of our CDs (.5-.75 of a CD). It's nice that it can be done now, but is not practical for the majority of us ripping. (I'm a quality freak ~~> 2 CDs, AC3 on nearly all movies; and I don't even want to consider DTS as an option).

[Hiro2k]

Well if we could transcode the DTS stream to a lower bitrate then I would consider muxing it into my movies. A DTS at 448 and an AC3 at 448 will not sound the same since the DTS stream was created from a cleaner source at a higher bitrate. But I would never place the original DTS in my movie for the same reasons listed above.

[The Belgain]

Um, if you had an original ac3 at 448 and a DTS you'd transcoded down to 448 from another DTS file, the ac3 would have higher quality (both because it had a cleaner source - uncompressed in the studios - and because ac3 is designed to perform well at low bitrates, whereas DTS is aimed at high bitrates).

So there's no point transcoding the DTS to a lower bitrate, you'd be better off using the ac3 (assuming there is a 5.1 ac3 track on the DVD).

[MaTTeR]

Originally posted by The Belgain
Presumably at the moment we can already to it manually by producing the 6-channel wav and feeding that to BeSweet (it accepts 6-channel wavs, right?). How to produce the 6ch WAV file from DTS though? Everything I've got out of GraphEdit so far is a 2ch file.

@all
It's all well and good to hear about the _theory_ of quality for a transcoded DTS file to a lower bitrate. Has anyone truly attempted to compare yet though? I'd give one of my teeth to transcode a full bitrate DTS track down to a 256Kbps AC3 file for certain movies! LOL I suppose that would be senseless and crazy too?

@DJ Bobo
Crazy to mux DTS in an AVI file?!?! Well I guess I've been called worse :D Somehow I'm starting to read your mind before you even post in certain audio threads these days.

BTW- I just encoded all 10 episodes of "Band Of Brothers" with the full bitrate DTS 768Kbps track. I ended up with each 60min episode on an 80min CD with an average XviD quantizer around 2.9 using Qpel, GMC and B-Frames 1/150/100:D Video and audio quality are outstanding compared to the source! If it were legal I'd happily send you a copy and then beg for your opinion:)

[Wilbert]

For those who are interested. I updated my guide. Mainly added the use of "Avi-Mux prerelease" instead of 1.11 because of that "muxing resulting in multiple files" problem.

[ookzDVD]

@Wilbert,

Thank you,
Now .OGM is support muxing the .dts with latest Cyrius' Ogmuxer. :)

[Wilbert]

I got your hint :) I will add it next time.

[Wilbert]

Updated my guide. I added ogm+dts muxing using OGMuxer.

I hope ookzDVD approves it :)

[ookzDVD]

Originally posted by Wilbert
Updated my guide. I added ogm+dts muxing using OGMuxer.

I hope ookzDVD approves it :)

:)
Thank you for updating the guide,
now it's perfect imho :)

PS. The .PDF size is 1MB :(

[Wilbert]

Thanks! We will see what I can do about the filesize ...