-----DVD Shrink audio question --------------

[firebirdude]

After DVD Shrink does the initial analysis and then brings up menu, it often shows several different audio tracks on the DVD. Sometimes in different languages. I always uncheck those to increase output quality....however the DVD often has several English tracks. Example:
AC3 2.1-channel English
AC3 5.1-channel English
DTS 5.1-channel English
What does AC3 and DTS stand for? Also, while playing the backup DVD in my player, how do I switch between audio types? I mean, what if I only keep the DTS 5.1 and don't play it on a 5.1 audio system? Or only keep the 2.1 and play it on a 5.1 system? Why would anyone keep the 2.1 if the 5.1 works on everything?

Basically, I've been keeping all the English tracks because I don't know any better. But if I can just keep the 5.1 and increase the video quality output, that would be great.

[MOVIEGEEK]

AC3=Dolby Digital,all DVD players support this compressed format.
DTS=A high quality compressed format,some DVD players can decode this format but most can only output via coaxial or optical.
All DVD players downsample 5.1 to 2ch when outputting to analog composite(red&white connectors).If you have a surround system then use 5.1 AC3 or DTS,if not use 2.0 AC3*.
*Most 2.0 AC3 tracks are commentary so use the preview feature in DVDShrink or PowerDVD to make sure.

[dvdguy4]

AC3 is the norm on a dvd.
DTS---DTS (Digital Theater Systems) Digital Surround is an optional multi-channel digital audio format, using lossy compression from PCM at 48 kHz at up to 24 bits. The data rate is from 64 kbps to 1536 kbps, with typical rates of 754.5 and 1509.25 for 5.1 channels and 377 or 754 for 2 channels. (The DTS Coherent Acoustics format supports up to 4096 kbps variable data rate for lossless compression, but this isn't supported by DVD. DVD also does not allow DTS sampling rates other than 48 kHz.). Channel combinations are (front/surround): 1/0, 2/0, 3/0, 2/1, 2/2, 3/2. The LFE channel is optional with all combinations. DTS ES support 6.1 channels in two ways: 1) a Dolby Surround EX compatible matrixed rear center channel, 2) a discrete 7th channel. DTS also has a 7.1-channel mode (8 discrete channels), but no DVDs have used it yet. The 7-channel and 8-channel modes require a new decoder. The DVD standard includes an audio stream format reserved for DTS, but many older players ignore it. The DTS format used on DVDs is different from the one used in theaters

AC3----Audio Codec 3. This was the original and more technical name for Dolby Digital. Replaced by marketing mavens when they realized that Dolby's name was not in the title. Some RF modulated, 5.1-encoded laser discs were labeled as AC3. Later versions were labeled as Dolby Digital.


If you have a amp that has both dolby digital and dts encoders then the choice is yours, however the dts track is alot larger than the DD track or tracks. DTS I think has a much richer sound design than the Dolby track but thats also up to the end user. The bass is terrific while the Dolbys bass is average. When I back up my dvds with both I go with the Dolby soundtrack cause of the size and I want to keep as much quality as I possibly can. Like I said its up to you.

[yoda313]

I don't think it was mentioned so I'll bring it up. If you do a DTS only movie backup you will ONLY be able to hear it through a surround system with a DTS decoder (and of course a dvd player that plays back dts - most seem to these days). If you play it back just over the tv you won't hear anything. That's why its generally better to backup just the dolby 5.1 track to save space and improve the picture quality.

If its a short movie, say an hour and a half or so, you could probably get away with a dolby 5.1 and dts 5.1 track and still have a decent picture. Though if you're using a hdtv you might want to think about going with only one audio track to preserve as much of the video as possible.

EDIT

Why would anyone keep the 2.1 if the 5.1 works on everything

Well actually it would be 2.0 stereo. Sometimes you might try doing just the stereo track to preserve as much of the video quality as possible at the expense of the audio features. And technically there won't be any difference between the 2.0 and 5.1 on a regular tv even if its a stereo tv since the dvd player would automatically downscale the 5.1 to plain stereo for the regular tv.

[firebirdude]

Thank you for all your replies. They helped a lot

Like I said, I have been keeping all audio versions so far. So the DTS version is the only one that I MIGHT have trouble with? (if my player doesn't have a DTS decoder) So if I remove the DTS 5.1 and AC3 2.1....and just leave the AC3 5.1 (Dolby, correct?), I should be good on any player and any audio system I play the backup on? Or does the AC3 5.1 need a decoder as well?

I will be keeping these for sometime. I want them to be playable no matter what audio/video system I upgrade to in the years of future ahead.

[yoda313]

You'll be a-ok with just a dolby 5.1 track. Many professional hollywood movies only come with a single dolby 5.1 track.

[firebirdude]

Cool. So I'll just keep the AC3 5.1 on all my DVD backups from now on. Then I can maximize video/audio quality, but still be able to play them on any home theater.

[redwudz]

I only keep the AC3 5.1 and it's worked fine for me. Usually the first 5.1 audio is the right one for me, but it can vary. The AC3 5.1 audio will play as stereo on most players or audio amps that don't have a 5.1 decoder, so it is usually the best choice for your only audio and should be fine for the future, AC3 decoder or not.

[firebirdude]

Thank you for all your replies. But I have since noticed on many DVDs that the AC3 2.1 audio is large. Maybe 150k. And the AC3 5.1 is very very small. Like maybe only 1k. I find it hard to believe that the "higher quality" audio is only 1k. And if I was to exclude to 2.1 audio everything would play fine off that 1k. Know what I mean?

[garryheather]

Also, while playing the backup DVD in my player, how do I switch between audio types?

You should have a button on your remote labeled as Audio or Language - something like that. Pressing that button should cycle between all the available audio tracks.