Why do some DVD videos have faint sound?

[tashirosgt]

The extent of my DVD watching consists of 20 minutes per day while I ride an exercise machine, but I have watched quite a variety of DVDs, playing them on a portable with VLC under FC 12. There are some DVDs where the sound track is faint. (example: Chemistry part 1,2,3 by "The Standard Deviants").

I don't understand why this should happen. This shouldn't be a analog problem with the physical DVD disk itself, correct? The sound is in a digital format, so it must be a problem with how the whole sound track was recorded. Or can an error in one or two bits on the disk set the playboack volume wrong?

[Dutchy]

Some videos have garbled sound for me with VLC on F16.
In my case this is a VLC problem rather than an actual problem on the video's side (in Totem it works perfect).
You might be seeing this also but in some other incarnation.

As for you question, it is next to impossible that a few flipped bits cause the volume to change significantly during encoding or decoding time (a short blip or hick may occur or playback may completely stop, but that affects the picture as well).
It's more likely to be intentional or a bug.
What happens when you use some other player than VLC?

[ryptyde]

I have had the same experience with DVD sound on the Play Station 3 console using commercially made discs. I think it most likely attributable to poor quality control in the manufacturing process.

phil

[CronoCloud]

Originally Posted by ryptyde

I have had the same experience with DVD sound on the Play Station 3 console using commercially made discs. I think it most likely attributable to poor quality control in the manufacturing process.

phil

Ditto! and with regular non-PS2/PS3 DVD/Blu-Ray players as well. It can also depend on which soundtrack you use. If you have only a stereo setup, if the disc uses a 5.1 surround it can sometimes be unusually quiet, though not always.


CronoCloud

[Penguinclaw]

Interestinly I've noticed that music dvds are much louder than film/movie dvds and tv dvds are in between. I think it might be due to the mixing process and what the sound engineer is trying to achieve in a limited bit space. I wonder if the same is true of blue-rays with there much higher storage capacity?

Of course I could be barking up the wrong tree!

[RupertPupkin]

Originally Posted by tashirosgt

There are some DVDs where the sound track is faint.

Don't worry, the problem may not be with VLC or the DVD. It could just be that you're going deaf.

[bonedome]

Rupert could you write in bold capitals please I can't hear you properly

When audio is compressed the sound spectrum becomes limited, this isn't a problem if the sound volume never reaches this limit, if it does the encoder has to either distort the sound or clip it, thus a loss of quality (for anything
very loud), to retain the quality you/the dvd makers can reduce the encoded volume, the drawback being having to turn the volume up.
Can I just point out it's not the encoder that reduces the volume, the input file has its volume decreased

By the way, anyone know why cannabis enhances your hearing