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View Full Version : NewbieQ: DVD Decoding/Encoding Basics


rstoddard
22nd October 2010, 18:57
I hope no one is offended by this, but I could really use some help understanding some basics of working with a ripped DVD file. I normally rip all of my DVD's with DVDFAB (including BDs), which creates a DVD (VOB) structure. If the DVD is good, I just copy the entire file or any chapters, and convert to MKV (or TS if its a BD). I thin play all of my files on my Popcornhour NMT.

I have been dabbling with Video/Audio editing because I find that the audio form the AC3 5.1 files really sucks in comparison to the files I have with the DTS audio. There isn't any comparison.

So, what I have been doing is trying to edit the audio (either boosting the gain on the AC3 so the volume difference between the Dolby AC3 and the DTS sound is minimized). Unfortunately, I haven't found any simple way to boost the AC3 gain. I have used Audio Converter to convert to multi-channel WMA, which works, but I suspect it is not the best approach to dealing with this. Any comments on that?

What I have been considering is trying to take the VOB file, extract the audio, convert the AC3 audio to six separate WAV channels, and either boosting the gain of the AC3 or converting it to DTS (using SurCode). My question is, is any of this worth the cost and effort? Will I produce a better DVD with DTS than by trying to tweak the AC3 to increase the gain?

Now, finally for the really stupid question (if I haven't already tried your patience!): What are the basic steps for doing this, and what application will manage it without having to use a command line app (its a little above my knowledge level!)? In a nutshell, I guess the question would be: how do you separate the video and audio (for editing) and then bring it all back together? I have so many various apps, I don't even know what they are all for or what they do. I've used/have DGIndex (DGMPGDec package), BeSweet, AVIsynth, eacto2, VirtualDub, and other apps I don't even recall.

Could someone just give me a straightforward description of the basic steps involved here and a few recommendations on apps that can perform those tasks? Even if I get the audio file the way I want, I'm a little lost on how I bring it all back together, what tool to use for that, and whether using something like DGIndex is useful in this process.

Sorry for the long post and the anal questions.... I love trying to get this stuff to work, but I'm a little lost.

Thanks for helping.

Ron

Inspector.Gadget
22nd October 2010, 20:12
Re-encoding AC3 to DTS is pointless. If 5.1 DTS on a given disc sounds better than the 5.1 AC3 track, it's probably due to the tracks being made from different mixes or an error on the studio/production house's part. AC3 is in fact a more efficient compression scheme than DTS; the perceived advantage of DTS only really (and rarely) comes out when DTS 1536 kbps is compared against AC3 448 kbps or less. In fact, starting from the same mix and given equally capable decoders for each, I think you'd be hard-pressed to determine by ABX testing the difference between high-bitrate AC3, high-bitrate DTS, and lossless mixes of the same surround track.

Besides, you can always alter audio levels on playback.