5.1 on stereo

[richarddd]

Will a 2 channel soundtrack play any better than a 5.1 channel soundtrack on a stereo (i.e., 2 channel player)?

In other words, if you're backing up a DVD that has both 5.1 and 2 channel sound, and the result may be played either on a multi-speaker home theater or a 2 speaker player, is there any reason to retain the 2 channel soundtrack?

[gircobain]

See the General Audio FAQ (http://forum.doom9.org/showthread.php?s=&threadid=68300#post424063), Q12

In the end though I guess it's a matter of personal taste which one sounds better

[richarddd]

If it's a matter of taste, the better backup strategy would be to only keep the 5.1 sound so that you have more bits for the video stream.

Do you agree?

[gircobain]

Sure, as I play my backups on a dvd player hooked to my home theater system, I always keep only the 5.1 track

[richarddd]

Yes, but the issue is what to do when the disc might be played back on either a mutli-channel home theater or a two channel stereo.

[ObiKenobi]

If it's gonna be played back on strictly a 2 channel setup I would say keep the 2.0, but if you will be watching on a surround setup then you will definitely want the 5.1 mix as an upmixed stereo track just isn't going to sound as good.

[richarddd]

Originally posted by ObiKenobi
If it's gonna be played back on strictly a 2 channel setup I would say keep the 2.0, but if you will be watching on a surround setup then you will definitely want the 5.1 mix as an upmixed stereo track just isn't going to sound as good.

Yes, but the issue is what to do when the disc might be played back on either a mutli-channel home theater or a two channel stereo.

[ObiKenobi]

Originally posted by richarddd
Yes, but the issue is what to do when the disc might be played back on either a mutli-channel home theater or a two channel stereo.


Then like I said above, if it is going to ever be played on a surround system you will want to keep the 5.1 track over the stereo track.

[Mug Funky]

i tend to keep all audio except for DTS tracks (which are huge and actually don't give any better quality than a 448kbps 5.1 or a 224 2.0 in ac3.

although for something like a hollywood movie with several different language tracks, well, i'd only keep the english and the subs (though i don't really need the subs either).

for anime, i keep both tracks, because there's time you'll want either one.

bear in mind you're not backing these discs up for distributing to other people (i hope), so only consider YOUR playback equipment, bearing in mind future upgrades, of course.

[richarddd]

Originally posted by Mug Funky
consider YOUR playback equipment, bearing in mind future upgrades, of course.

I currently have only 2 channel playback, but will likely get 5.1 at some point. 5.1 usually sounds fine on 2 channel, but sometimes it seems dialog is a bit muffled on 5.1. Doing comparative listening to both soundtracks is a hassle, so I'm trying to come up with a general rule. Also some movies would seem to benefit more from 5.1 than others (compare recent action/adventure to older movies which were not recorded multi-channel).

[ursamtl]

One point to consider here is that a 5.1 AC3 track contains information that allows it to be properly downmixed when played through an older Dolby Surround system. So if space is limited and the choice is between 5.1 AC3 or 2.0 AC3, I would go for the 5.1 track.

As for DTS, it will not play at all on a system that doesn't have a DTS decoder. Therefore, it should never be kept as the only audio track.

[BigDid]

Originally posted by richarddd
I currently have only 2 channel playback, but will likely get 5.1 at some point. 5.1 usually sounds fine on 2 channel, but sometimes it seems dialog is a bit muffled on 5.1. Doing comparative listening to both soundtracks is a hassle, so I'm trying to come up with a general rule. Also some movies would seem to benefit more from 5.1 than others (compare recent action/adventure to older movies which were not recorded multi-channel).
Hi Richarddd, happy new year, :)

I am actually discussing on a french forum a matter near this one (Low bitrate audio for SAP), it seems things are not always straightforward as they appear, at least when ac3 transcoding is involved... :scared:
If things get more clear, I will come back here to give some infos.

Did

[richarddd]

Originally posted by ursamtl
One point to consider here is that a 5.1 AC3 track contains information that allows it to be properly downmixed when played through an older Dolby Surround system. So if space is limited and the choice is between 5.1 AC3 or 2.0 AC3, I would go for the 5.1 track.

That's interesting. Why would there ever be a need to include both 2.0 and 5.1?

Space is always limited :) Most of my encoding is to DVDR using CCE and I'd rather have more bits for video (for xvid encoding I always downmix to 2 channel).

[richarddd]

Originally posted by BigDid
Hi Richarddd, happy new year, :)

I am actually discussing on a french forum a matter near this one (Low bitrate audio for SAP), it seems things are not always straightforward as they appear, at least when ac3 transcoding is involved... :scared:
If things get more clear, I will come back here to give some infos.

Did

Hi Did, happy new year to you :)

More info would be good :D

thanks

[BigDid]

Originally posted by richarddd
Most of my encoding is to DVDR using CCE and I'd rather have more bits for video (for xvid encoding I always downmix to 2 channel).
That's one of the important point: be prepared to give (much) more space to ac3 5.1ch audio. I was not (prepared) and I had a hard time figuring it out :mad:

I have stated in another thread that I would transcode to DVD5 the DVD concert to keep the 5.1ch and the menus to select the songs. I did it but I was not satisfied by the video (using DVD shrink) compared to Xvid/AGK.
For info the 5.1 ac3/448kbps was more than 500mo and the same audio in mp3-surround2(dplII) in 128kbps would have been around 150mo!

So I will try a xvid encode on 1/2 DVD with the same source, keeping the 5.1ac3 and after +try+ to cut the resulting avi by song. I wont have the menus but I will be able to go from song to song, I hope ... :)

Did

[ursamtl]

Originally posted by richarddd
That's interesting. Why would there ever be a need to include both 2.0 and 5.1?

Space is always limited :) Most of my encoding is to DVDR using CCE and I'd rather have more bits for video (for xvid encoding I always downmix to 2 channel).

One reason I've seen mentioned for music DVDs is that some audio engineers prefer to do a separate mix for 2.0 stereo. However, this is more for artistic reasons than for any technical reason.

[richarddd]

@Did

My sense is that DVD Shrink does not do a good job at higher levels of compression (for example, below 70%). CCE seems better. xvid is better still, but has problems with bitrate spikes on some players (as we've discussed), not to mention that there are more DVD players than xvid players. Also, modern commercial movies seem to compress better than other sources.

If each song is a separate avi file, you should be able to go from song to song by hitting the "next" button, although it may take a few seconds for your player to process the avi.

[BigDid]

Originally posted by richarddd
@Did

My sense is that DVD Shrink does not do a good job at higher levels of compression (for example, below 70%). CCE seems better. xvid is better still, but has problems with bitrate spikes on some players (as we've discussed), not to mention that there are more DVD players than xvid players. Also, modern commercial movies seem to compress better than other sources.

If each song is a separate avi file, you should be able to go from song to song by hitting the "next" button, although it may take a few seconds for your player to process the avi.
Hi richarddd

Done it, first time manually, second time more automatic; using chapter extractor to get the time code, feed the time code to avi mpeg asf wmv splitter and split chapter by chapter. Maybe it could be done via VDubMod and avisynth script?
Anyway it takes time but works ok, small time difference due to the tool and or the i-frames I suppose, about 3-4 seconds, no big deal.

My test dvd is Tina Turner in Wembley, I prefer the look of the xvid file to the transcoded dvd by nero-recode (I switched to Nero because it seems having a little more quality than DVD Shrink) even if it is 74% it has some blocks or quite ugly backgrounds.

Now keeping the original 5.1 ac3 audio gives (for 1/2 dvd) me around 1.8gb for the video which seems not enough .... ;) If not that stuttering problem, I would now go for 3/5 of a dvd nearly 2.7Gb

I believe you have your infos as this thread has no more exchanges.

Bye

Did

[marioman]

Ive been using DVD2One to transcode DVDs, and it works really well, i can fit 2 movies with 5.1 AC3 in each on 1 DVD+R and you cant tell a difference on a set top player (you can a bit tho playing them on a PC but that would be expected).

Its nothing extravigant feature wise but its kinda like CCE in a way (plain jane but good at what it does do), might be worth a shot to help you get the 5.1 audio on there.

[BigDid]

Originally posted by marioman
Ive been using DVD2One to transcode DVDs, and it works really well, i can fit 2 movies with 5.1 AC3 in each on 1 DVD+R and you cant tell a difference on a set top player (you can a bit tho playing them on a PC but that would be expected).

Its nothing extravigant feature wise but its kinda like CCE in a way (plain jane but good at what it does do), might be worth a shot to help you get the 5.1 audio on there.
Thanks I'll give it a try; once cut by chapter, the small avi's (songs) plays fine, the big job is to make the cuttings :)

Did