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AC3 5.1 to AAC 5.1 Suitable Mode/Profile/Bitrate?
Makaveli7184
post Jun 21 2012, 15:25
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I have a large number of 5.1 AC3 audio file encoded at CBR 384 kbps that i want to transcode to AAC. Channel mapping is not a problem. Bytes are scarce, so my goal is to minimize bitrate while preserving audio transparency.
Now i've read in various online posts that AAC standards recommend around 260 kbps for 5.1 audio. I'm using a certain application (i'm not interested in suggestions of using another one or another encoder for that matter) that uses up-to-date AAC codecs. This application gives me the option of encoding in CBR AAC (bitrate ranging from 4 to 448 kbps in increments of 4, and profiles HE2/HE/LC are completely user selected) and VBR AAC (where i can choose a quality preset from 1 to 5, 5 being highest quality and largest filesize and where profile is strictly automatic, HE-AAC 2 kicks in when using Q1, HE-AAC when using Q2, and from Q3 to Q5, format profile is LC).

Giving all the above, and knowing that audio transparency and quality is usually subjective, what would be a good option?
My initial preference is using VBR Q3/LC which gives me 5.1 audio files encoded at around 250 ~ 300 kbps. Do i need to go higher?? Can i go lower without losing perceptive quality?? Should i consider lower CBR with HE profile??

Waiting for some suggestions. Thank you.
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Makaveli7184
post Jun 25 2012, 20:29
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Well, let's say that i wanted to convert an original AC3 to another AC3 file (audio unedited), would there have been any need to go higher then the original 384 kbps of the original AC3??
I ask because various listening tests have proven (albeit many of them indirectly) that AAC 5.1 @ vbr 256 kbps is almost always "equal" to AC3 5.1 @ cbr 384 kbps. Now i'm sure that factoring in that the original AC3s are lossy might affect the result of the mentioned tests, but how much?
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Posts in this topic
- Makaveli7184   AC3 5.1 to AAC 5.1 Suitable Mode/Profile/Bitrate?   Jun 21 2012, 15:25
- - probedb   Do some tests and find out. You're going from ...   Jun 21 2012, 16:02
- - Makaveli7184   Well, i appreciate your input, but that's not ...   Jun 21 2012, 16:39
- - onkl   5.1 AC3 with only 384 kbps is already quite low. I...   Jun 21 2012, 22:00
- - Makaveli7184   Well, let's say that i wanted to convert an or...   Jun 25 2012, 20:29
|- - saratoga   QUOTE (Makaveli7184 @ Jun 25 2012, 15:29)...   Jun 26 2012, 02:44
|- - Makaveli7184   QUOTE (saratoga @ Jun 26 2012, 01:44) QUO...   Jun 26 2012, 03:05
|- - probedb   QUOTE (Makaveli7184 @ Jun 26 2012, 03:05)...   Jun 26 2012, 08:03
- - saratoga   If you're just doing it for fun, might as well...   Jun 26 2012, 04:05
- - Makaveli7184   Wow... The hostility on this forum is crazy.. Seco...   Jun 26 2012, 15:55
- - onkl   Lossy to lossy is ugly and not so advanced formats...   Jun 26 2012, 16:14
|- - jetpower   QUOTE (onkl @ Jun 26 2012, 17:14) Simple ...   Jun 26 2012, 17:30
|- - john33   QUOTE (jetpower @ Jun 26 2012, 17:30) QUO...   Jun 26 2012, 17:40
- - john33   When decoding a lossy audio file, the content that...   Jun 26 2012, 17:34
|- - Makaveli7184   QUOTE (onkl @ Jun 26 2012, 15:14) Lossy t...   Jun 26 2012, 18:35
- - Makaveli7184   Also, is there a decent "DelayCut" equiv...   Jun 26 2012, 18:39
- - onkl   MP3directcut which can also do fading, so somethin...   Jun 26 2012, 18:45
|- - Makaveli7184   QUOTE (onkl @ Jun 26 2012, 17:45) MP3dire...   Jun 26 2012, 19:04
|- - Dynamic   QUOTE (Makaveli7184 @ Jun 26 2012, 18:04)...   Jun 28 2012, 07:03
- - Makaveli7184   Thanks for everyone who contributed in this thread...   Jul 10 2012, 20:03


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