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Topic: AC3 or AAC-5.1 for DVD backup on media server (Read 13737 times) previous topic - next topic

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  • aguy
  • [*]
AC3 or AAC-5.1 for DVD backup on media server
Hi there,

I am pretty new to this whole area.

I am planning on setting up a media server with all of my movies stored so they can be watched over network via a HTPC.

I have settled on video encoding with x264.  However I can't make up my mind about whether I should leave the audio AC3 stream as is or rencode to AAC 5.1.

I can see advantages to both.  Leave as AC3 there is no loss of quality and also will be very close to Bluray and HD-dvd spec.  However AAC 5.1 should save space and is the mp4 standard and can be muxed into mp4 container.

I am leaning towards aac 5.1 encoding with the winamp encoder (CT based) but am not sure what bitrate to aim for.  (As an idea for all my CD's I am happy with LAME at -preset standard which gives VBR about 192 kpbs).

What do people think I should do?

  • stephanV
  • [*][*][*][*]
AC3 or AAC-5.1 for DVD backup on media server
Reply #1
If you use 192 kbps for the 5.1 AAC encoding you will save about 100 MB per hour of video. I'm not sure about your encoding methods (what size you aim for, etc.) but IMO this is only worth the effort if you target 1 movie per CD... which you probably don't.
"We cannot win against obsession. They care, we don't. They win."

  • Dzamburu
  • [*][*]
  • Banned
AC3 or AAC-5.1 for DVD backup on media server
Reply #2
You can use CT @ 96-200kbs for 5.1 encoding and you shouldn't get any artifacts in sound, CT is very good with 5.1 encoding comparing to Nero 6/7 which is very terible.

  • chrizoo
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AC3 or AAC-5.1 for DVD backup on media server
Reply #3
... very good with 5.1 encoding comparing to Nero 6/7 which is very terible.

Is this true? First time that I've heard bad things about Nero AAC. What do you guys think?
  • Last Edit: 22 April, 2010, 07:07:57 AM by chrizoo

  • DVDdoug
  • [*][*][*][*][*]
AC3 or AAC-5.1 for DVD backup on media server
Reply #4
Quote
However AAC 5.1 should save space...

What's the concern with space?  Re-compressing the video can save lots of space, but re-compressing the audio is not going to make that much difference.  If you have plenty of space it's not an issue...  But, if you can't fit your movies on your hard drive without re-compressing the audio, then you will be in danger of running out of space anyway when you add a few movies.

Quote
...and is the mp4 standard and can be muxed into mp4 container.

Compatibility is a valid concern if you want to play the movies on a portable player or other computers.  For portable players, MP4/AAC is probably best.  For compatibility with varous computers its probably best to leave the whole DVD in DVD format and use DVD-player software.  This also leaves the menu intact.


  • probedb
  • [*][*][*][*][*]
AC3 or AAC-5.1 for DVD backup on media server
Reply #5
Going AC3->AAC you're also going lossy to lossy. Personally I'd just keep the AC3 track then you can just pass it to your amp to decode. If you go with AAC you're probably stuck with having to do all decoding on your PC.

AC3 or AAC-5.1 for DVD backup on media server
Reply #6
However AAC 5.1 should save space and is the mp4 standard and can be muxed into mp4 container.


With current disk prices i wouldn't bother.