handbrake sound question

[lazydays]

When using handbrake to convert a dvd I normally use the "universal" preset which sets the audio to 160kbps. I am ripping a musical dvd right now and so I manually cranked that number up to 320kbps but I'm wondering if I am wasting disc space or not. What bitrate is audio normally recorded onto a dvd, or does it vary? Thanks.

[rich in distress]

It depends on the format of the audio, pcm, dts, mpg, etc.
video will occupy much more than that, so I guess it's ok... I do hear degradation at 160 when I get picky.

[Lew Zealand]

Many DVDs of older or TV-based productions are just 192 kbps AC3 2.0 (ie: stereo only AC3). Listening quality comparisons have generally set similar sound quality for 192 AC3, 160 MP3 and 128 AAC.

Converting to 160 AAC will result in minimal loss of quality though as always there is a slight reduction in quality as a result of recompressing the data. I try to recompress the video only and keep the audio in it's original AC3 for computer playback, though you need to convert to AAC for iThing playback.

For more recentl releases, there are encodes which use 256-384 AC3 stereo or 448 5.1 surround. 256-384 AC3 is higher quality and if you see that, use a similar bitrate for AAC to realize the incremental improvement in quality. 448 5.1 is about the same as 160 kbps stereo as it contains 5.1 channels, but if you are doing a stereo (or analog Dolby surround) mixdown, I use ~256 kbps.

Handbrake will tell you the bitrate of the original, use that as your guide.

[deckeda]

Be careful in cranking up the audio bit rate of that transcode to 320kbps. Once you do that, your "universal file" will be incompatible with all iPods/iPhones/AppleTV.

And if you don't intend to play the file on an iPod, you're giving up picture quality on more capable devices such as iPhone4/iPad/AppleTV, ---those can play the "AppleTV" and "AppleTV 2" preset files.

The best sound you can get from a DVD is either the original AC-3 Dolby soundtrack, DTS if present or PCM stereo. Only the latter isn't compressed, but isn't surround either. Handbrake will let you select for example AC-3 passthrough on one of the Apple presets for the second audio choice.

The result will be that if you play it on an AppleTV or iDevice, the regular 160kbps AAC audio plays and the AC-3 track gets ignored, and if you connect to a surround sound receiver, it'll pick out the unfettered AC-3 soundtrack and sound as good as the original DVD! Pretty slick, although it makes your file a little larger.

[guitarist]

Deckeda, that's an informed answer. Sounds like you've done some homework.

I've just upgraded our home's Home Theater set up, with a more advanced 2011 Yamaha Receiver and 5.1 surround upstairs in our living room, for our best sound, and in my office downstairs, our older (2007) Onkyo receiver, and 7.1 sound (I like collecting and testing speakers) and now that I have more reason to care about movie sound, I'm reexamining all my Apple TV Handbrake encodes.

I am grateful for Handbrake's presets and its handling of surround sound, preserving AC-3 Dolby, when present. And am paying attention to how to better encode movies in the future. Including boosting bitrates when appropriate. For movies with good sound design, and action movies. I love sound design in motion pictures, it's as interesting as and as fun as good cinematography.