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Topic: Converting AC3 to other lossy format (Read 3068 times) previous topic - next topic

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  • GregDunn
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Converting AC3 to other lossy format
I have a couple of legally owned DVDs with separate high quality AC3 music-only soundtracks which I'd like to listen to on my iPod.  Is there any easy way to tell what the bit rate is on these tracks (just for the heck of it)?

Also, does it make any kind of sense to re-encode in a usable lossy format for listening or should I just bite the bullet and extract them into a lossless format, accepting the size increase?  If no one has practical experience with doing this on an AC3 track, I may run some DB tests later - but it won't be for a while.

Converting AC3 to other lossy format
Reply #1
Quote from: GregDunn link=msg=0 date=
Is there any easy way to tell what the bit rate is on these tracks (just for the heck of it)?

You can check that out with MediaInfo (it's also available as a feature when installing K-Lite Mega Codec Pack).
Most AC-3 audio tracks are 192kbps. For 5.1 Surround, 448kbps is definitely the most common, sometimes 384.
Quote from: GregDunn link=msg=0 date=
Also, does it make any kind of sense to re-encode in a usable lossy format for listening or should I just bite the bullet and extract them into a lossless format, accepting the size increase?  If no one has practical experience with doing this on an AC3 track, I may run some DB tests later - but it won't be for a while.

First, it depends where it's 5.1 or stereo (different quality). Second, what lossy format are talking about? MP3, AAC, OGG?

  • botface
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Converting AC3 to other lossy format
Reply #2
I've transcoded AC3 to .ogg quite often. I often record music programmes from TV on a DVD recorder. It records the sound as stereo 256kbps AC3. I transcode to .ogg at Q5 or 6.

However, if it's something I really want to keep long term I use Lossywav/FLAC or Wavpack lossy and aim at a bitrate around 400kbps to be fairly confident that I'm not introducing any artefacts in the conversion process

  • GregDunn
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Converting AC3 to other lossy format
Reply #3
Ah, that looks like Windows-only.  Sorry, should have specified I'm on a Mac.  I didn't see anything relating to bitrate in Audacity when I imported it, but perhaps I'm looking in the wrong place...

I will probably encode as AAC or Apple's lossless just for convenience; this won't get played on anything but my iPod and maybe the AppleTV.

  • Nessuno
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Converting AC3 to other lossy format
Reply #4
I will probably encode as AAC or Apple's lossless just for convenience; this won't get played on anything but my iPod and maybe the AppleTV.


On OSX there are a lot of transcoders from/to nearly every known codec. Go Google for XLD, xACT, Max...
... I live by long distance.

  • DVDdoug
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Converting AC3 to other lossy format
Reply #5
Quote
I didn't see anything relating to bitrate in Audacity when I imported it, but perhaps I'm looking in the wrong place...
Since the bitrate is the number of bits per second, you can convert bits to bytes and seconds to minutes, and the (approximate average) bitrate is:

Bitrate in kbps = (File Size in MB x 140) /Playing Time in minutes
  • Last Edit: 02 April, 2012, 02:01:43 PM by DVDdoug