Ripping audio from DVD..Why are there two identical audio streams ?
Posted: Tue Nov 02, 2021 2:02 am
One question I never figured out. Many commercial DVD's I come across, when I try to rip the audio there are two identical audio streams, both will be AC3 (48khz 2 channel). They will be under separate titles. For example, I'm ripping a DVD that has 3 episodes of a show. So Title 1 will be the introduction to the dvd. Title 2 + 3 will be for episode 1, title 4 + 5 for episode 2, and title 6 + 7 for episode 3. Title 2 + 3 will have identical audio, and both will be AC3 (48khz 2 channel). I don't understand why. I get it if you have a 2 channel stream and a 6 channel stream, but why the identical streams ? I'm trying to listen for some kind of difference, but I can't tell. I'm psyching myself out thinking one is a little better than the other, but audio tools show me no difference. Thanks.
Okay, I just checked the DVD out with DVD Shrink, and it's not just two separate audio streams per episode. Each episode is on the DVD twice. These sets came out 10-20 years ago and are dual layered dvd's. DVD Shrink has Titles 2+3 being the same, 4+5 the same, and 6+7 the same. I can extract each one separately. So I copied Title 3 into a folder, and Title 4 into a folder. They both play back the same. All audio and video attributes were the same during playback. So I don't get it. It's not just with this DVD. It's something I noticed on a lot of commercial DVD's. There's got to be a difference somehow, but I'm not seeing it. More experienced people who have dug into this stuff further over the years hopefully would know.
Okay, I just checked the DVD out with DVD Shrink, and it's not just two separate audio streams per episode. Each episode is on the DVD twice. These sets came out 10-20 years ago and are dual layered dvd's. DVD Shrink has Titles 2+3 being the same, 4+5 the same, and 6+7 the same. I can extract each one separately. So I copied Title 3 into a folder, and Title 4 into a folder. They both play back the same. All audio and video attributes were the same during playback. So I don't get it. It's not just with this DVD. It's something I noticed on a lot of commercial DVD's. There's got to be a difference somehow, but I'm not seeing it. More experienced people who have dug into this stuff further over the years hopefully would know.