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What mp3 quality do you want?

Messages in this topic: 13 View All
Greg LindenJul 22, 2009
 

 
The format that get_iplayer extracts from the flashaac mode is
actually "aacPlus", which retains excellent quality in a very small
file. http://dictionary.zdnet.com/definition/aacplus.html

Unfortunately for Mac users, QuickTime still doesn't support it. On
a Mac, the only native apps I've found that play aacPlus files are
VLC and RealPlayer. I run WinAmp in Parallels to convert to wav or
high-bit m4a then iTunes to transcode to mp3.

Greg

At 6:23 PM +0100 7/22/09, Clitheroe Kid wrote:

>The extension commonly used by iTunes files is .m4a (which stands for mp4
>audio). This is simply an mp4 file which contains only an audio stream. MP4
>is a video format, so usually has both a video stream and an audio stream.
>
>The program ffmpeg has an option to save a raw .AAC file as an MP4 file
>(with the extension .mp4 or .m4a), without re-encoding the file.
>
>An audio-only MPEG-4 file can be named either .mp4 or .m4a since those types
>of file are both encoded in exactly the same way, but the latter is only
>encoding audio (instead of audio and video).
>
>AAC is a type of MPEG-4 file. But a raw AAC file won't play in iTunes merely
>by changing the file's extension from .aac to .mp4, because you have to do
>more to the file than that! It has to be "muxed" in order to become an mp4
>file. That doesn't involve re-encoding it! It has to do with creating a
>frame header for each frame, one that iTunes can read.
>
>MP4 is a video format, so it uses frames (normally 25 frames per second, the
>standard video format). Each frame has a header (a few bytes, describing the
>audio format of the data stream). FFMPEG can add those headers to the raw
>AAC data, to create a fully valid MP4 file.
>
>Almost *any* player can play an mp4 file (though iTunes might need the
>file's extension to be renamed to .m4a).
>
>Stephen
>
>
>----- Original Message -----
>From: "eriatarkae@..." <eriatarka1@...>
>To: <just-a-minute@...>
>Sent: Wednesday, July 22, 2009 1:56 PM
>Subject: [just-a-minute] Re: What mp3 quality do you want?
>
>
>> There are a few caveats to this. Firstly, the raw .aac files don't appear
>to play in iTunes (Quicktime only), and changing the extension doesn't help
>either. This is a huge problem for me, as iTunes is my central storage for
>all things JAM. Secondly, I'm fairly sure that .aac is not a suitable format
>for most people's usual use patterns - most mp3 players can't play it, and
>car stereos don't usually play it either.
>>
>> As far as utilities go, they are not freeware. There's Quicktime Pro or,
>for Macs, Fission. Quicktime Pro is useful, because if you trim to the
>selection (which is not immediately obvious, but there's a selection ruler
>across the bottom) and save as an .mp4, then that will play in iTunes.
>Fission - I have no idea, I'm on XP.
>>
>> Robert
>
>
>
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