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<<<<   3430   >>>>

Topic: What mp3 quality do you want?

Message 1 / 4
Clitheroe KidJul 23, 2009
 

 
The BBC were originally using 128kbps mp3 (throughout 2008) on the iPlayer.

The page you mention deals only with some tests they conducted last
February, at a point when they were considering using a reduced bitrate of
96kbps, bolstered by AAC+ to offset the bitrate reduction.

Since then they've migrated to 128kbps AAC. The software I use (Winamp 5,
Media Player Classic, and RTMPdump) reports that they're now using AAC-LC.

----- Original Message -----
From: "Greg Linden" <gmlinden@...>
To: <just-a-minute@...>
Sent: Thursday, July 23, 2009 12:00 AM
Subject: [just-a-minute] Re: What mp3 quality do you want?


> Look at this table from February:
>
http://www.digitalradiotech.co.uk/2009/02/bbc_test_aac+_streams_overtake_dab_quality.php
> = http://tinyurl.com/dmakzp
> The on-demand stream for Radio 4 is listed as 96k AAC+. It also
> mentions that the Flash window will report simple AAC (not AAC+)
> regardless of which type it is.
> Greg
>
> At 10:07 PM +0100 7/22/09, Clitheroe Kid wrote:
> >You've suggested that the BBC's audio iPlayer files are using HE AAC
(a.k.a.
> >AAC+). However, according to the BBC website, the BBC uses LC-AAC, not
> >AAC-HE.
> >
> >
> >----- Original Message -----
> >From: "Greg Linden" <gmlinden@...>
> >To: <just-a-minute@...>
> >Sent: Wednesday, July 22, 2009 6:48 PM
> >Subject: [just-a-minute] Re: What mp3 quality do you want?
> >
> >
> >> 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
> >> >
> >> >
> >> >
> >> >------------------------------------
> >> >
> >> >Yahoo! Groups Links
> >> >
> >> >
> >> >
> >>
> >>
> >> ------------------------------------
> >>
> >> Yahoo! Groups Links
> >>
> >>
> >>
> >>
> >
> >
> >
> >------------------------------------
> >
> >Yahoo! Groups Links
> >
> >
> >
>
>
> ------------------------------------
>
> Yahoo! Groups Links
>
>
>
>

 
<<<<   3431   >>>>

Topic: What mp3 quality do you want?

Message 2 / 4
Clitheroe KidJul 23, 2009
 

 
How do you configure get_iplayer to download flashacc?

----- Original Message -----
From: "eriatarkae@..." <eriatarka1@...>
To: <just-a-minute@...>
Sent: Thursday, July 23, 2009 4:42 PM
Subject: [just-a-minute] Re: What mp3 quality do you want?


> Well, I'm slightly nervous (and rather thrilled) to see so many responses,
just when I was afraid it had become a duologue.
>
> So, I think as far as clarifying anything goes, here's the conclusions I
reached for the optimal way to go about this. Feel free (as you will) to
chip in. This is taking in everything from the posts you've made since my
last.
>
> Firstly, I think we should definitely upload (for BBC streams) an .m4a.
This is the native audio format for iTunes. It can be brought about without
any destructive processes like so:
>
> Configure get_iplayer to download flashaac. Use QuicktimePro to top and
tail, then to save as an .m4a - upload.
>
> As I have QuicktimePro (it's really quite useful for movie editing etc),
and the required programmes already set up to do all of this, I will put
myself forward to carry this out.
>
> This would provide the best quality version there is, and should be used
at least for archival purposes.
>
> Secondly, I think that mp3s should be uploaded. Charles (who usually
bears this burden) has much of the setup already, if not all.
>
> Configure get_iplayer to download flashaac. Import to a sound editor, top
and tail, convert to lame V2. Upload.
>
> The other alternative for mp3s just has a different step - I prefer it, as
it definitely has no destructive steps, but it may be fiddly.
>
> Configure get_iplayer so that it downloads the best quality stream and
converts it to lame V2 mp3. Then use mp3DirectCut (freeware) to top and tail
non-destructively. Upload.
>
> I'm not sure there are refinements to be made really. If anyone can spot
it, that would be great.
>
> I may well trial the .m4a version for this coming series. It should play
on most computers with iTunes or VLC - including Fedora - is technically
better quality, and smaller file size.
>
> If anyone has anything to add, again, feel free - I don't want to feel
imposing.
>
> Robert
>
>
>
> ------------------------------------
>
> Yahoo! Groups Links
>
>
>
>

 
<<<<   3432   >>>>

Topic: What mp3 quality do you want?

Message 3 / 4
Greg LindenJul 23, 2009
 

 
That's brilliant! Thanks *so* much for setting me straight.

I can use the free version of Switch for Mac
(http://www.nch.com.au/switch/index.html) to go aac-to-mp3 (160k
seems to preserve quality). Or 4x faster is Switch for aac-to-aiff
then iTunes for aiff-to-mp3 (still using 160k).

Thanks for making my life a lot easier!

PS: In get_iplayer, adding the option "--amode=flashaac" will
retrieve the aac version.

At 6:38 PM +0100 7/23/09, Clitheroe Kid wrote:

>The BBC were originally using 128kbps mp3 (throughout 2008) on the iPlayer.
>
>The page you mention deals only with some tests they conducted last
>February, at a point when they were considering using a reduced bitrate of
>96kbps, bolstered by AAC+ to offset the bitrate reduction.
>
>Since then they've migrated to 128kbps AAC. The software I use (Winamp 5,
>Media Player Classic, and RTMPdump) reports that they're now using AAC-LC.
>
>
>----- Original Message -----
>From: "Greg Linden" <gmlinden@...>
>To: <just-a-minute@...>
>Sent: Thursday, July 23, 2009 12:00 AM
>Subject: [just-a-minute] Re: What mp3 quality do you want?
>
>
>> Look at this table from February:
>>
>http://www.digitalradiotech.co.uk/2009/02/bbc_test_aac+_streams_overtake_dab_quality.php
>> = http://tinyurl.com/dmakzp
>> The on-demand stream for Radio 4 is listed as 96k AAC+. It also
>> mentions that the Flash window will report simple AAC (not AAC+)
>> regardless of which type it is.
>> Greg
>>
>> At 10:07 PM +0100 7/22/09, Clitheroe Kid wrote:
>> >You've suggested that the BBC's audio iPlayer files are using HE AAC
>(a.k.a.
>> >AAC+). However, according to the BBC website, the BBC uses LC-AAC, not
>> >AAC-HE.
>> >
>> >
>> >----- Original Message -----
>> >From: "Greg Linden" <gmlinden@...>
>> >To: <just-a-minute@...>
>> >Sent: Wednesday, July 22, 2009 6:48 PM
> > >Subject: [just-a-minute] Re: What mp3 quality do you want?
>> >
>> >
>> >> 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
>> >> >
>> >> >
>> >> >
>> >> >------------------------------------
>> >> >
>> >> >Yahoo! Groups Links
>> >> >
>> >> >
>> >> >
>> >>
>> >>
>> >> ------------------------------------
>> >>
>> >> Yahoo! Groups Links
>> >>
>> >>
>> >>
>> >>
>> >
>> >
>> >
>> >------------------------------------
>> >
>> >Yahoo! Groups Links
>> >
>> >
>> >
>>
>>
>> ------------------------------------
>>
>> Yahoo! Groups Links
>>
>>
>>
>>
>
>
>
>------------------------------------
>
>Yahoo! Groups Links
>
>
>

 
<<<<   3433   >>>>

Topic: Re: What mp3 quality do you want?

Message 4 / 4
eriatarkaeJul 24, 2009
 

 
--- In just-a-minute@..., "Clitheroe Kid" <clitheroekid@...> wrote:

>
> How do you configure get_iplayer to download flashacc?

Well, it depends on the version you have (although possibly either will work), but it's:

1) --amode=flashaac (as in the post above)

2) --modes=flashaac

If neither of these work, you my wish to append a 1: flashaac1; sometimes it's necessary.

Then to set it as a preference:

--prefs-add [then the command above which works]

Robert