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<<<<   3411   >>>>

Topic: What mp3 quality do you want?

Message 1 / 15
Clitheroe KidJul 22, 2009
 

 
The only way I have yet found of editing mp4 files without re-encoding them
is a Windows program called mp4Box.

It's a command-line only program, so is very cumbersome to use.

And in order to edit .aac files you must first "mux" them to mp4. This
doesn't involve any re-encoding, but just adds frame headers to the raw
data. FFMPEG will do this conversion.

I find that decompressing from MP4 to WAV (using my old copy of Cool Edit
Pro) and editing the resulting WAV file (and, optionally, normalizing it),
then re-encoding to MP4 at the file's original bitrate, is a more workable
solution, and doesn't seem to introduce any audible effects.

----- Original Message -----
From: "charles_454545" <charles@...>
To: <just-a-minute@...>
Sent: Wednesday, July 22, 2009 6:17 PM
Subject: [just-a-minute] Re: What mp3 quality do you want?


> --- In just-a-minute@..., "eriatarkae@..." <eriatarka1@...>
wrote:
>
> >> If you edit get_iplayer in a text editor to add "-V 2" to the lameopts
argument, the output should be pretty close to ideal as far as mp3 files go.
>
> > Definitely sounds like the right thing to do, but unfortunately I can't
work out how to. Any ideas what to edit to achieve this?
>
> get_iplayer is a perl script, so you can edit it in any plain old
> text editor. After googling around on hydrogen audio for about
> half an hour yesterday, I decided to upgrade to lame 3.98.2 (for
> its improved vbr) and use these arguments: "-q 0 -Y -v".
> So, I edited get_iplayer to replace this line:
>
> $binopts->{lame} = '-f';
>
> with this line:
>
> $binopts->{lame} = '-q 0 -Y -v';
>
> new versions of get_iplayer come out =constantly= so I wish
> there was a way to store these options somewhere :)
>
>
> >> The next question -- since most media players support .aac --
> >> is why not just keep the raw, original .aac files and avoiding
> >> the aac->mp3 transcode step. If we can find a utility to trim
> >> the extra six minutes off the ends, IMO that would be the
> >> Right Thing.
>
> > 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.
>
> Well, I'll keep uploading mp3s... it's going to be the
> lingua franca of the audio world for some time to come.
> (My Cowon D2+ doesn't support aac, and my personal
> preference would be ogg... ;)
>
>
> > 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.
>
> Does trimming the ends and saving as mp4 cause a re-encode?
> Because if it doesn't re-encode, and if the results play
> nicely with iTunes/iPods/etc, that would be very nice indeed...
>
>
>
> ------------------------------------
>
> Yahoo! Groups Links
>
>
>
>

 
<<<<   3412   >>>>

Topic: Re: What mp3 quality do you want?

Message 2 / 15
charles_454545Jul 22, 2009
 

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

> Someone else is *very* interested in this thread - me!
>
> I think you will find that flvstreamer is capable on its own of
> capturing the flv stream (which is actually an aac file inside
> an flv wrapper), without any involvement of get_iplayer.

Right. get_iplayer is a perl "glue" script that uses other
tools like lame, mplayer, and flvstreamer, and ffmpeg to do
the heavy lifting.

> It's get_iplayer that's converting your aac file to mp3.
> If you cut get_iplayer out of the picture you will simply
> get the flv stream, with an aac file wrapped up inside it.
>
> And there are lots of programs which can extract an aac
> file from the flv wrapper, e.g. ffmpeg.

Right again. This is exactly what get_iplayer is doing --
it pulls down the flv with flvstreamer, then runs it through
ffmpeg to output an aac.

What I'm planning to do for the mp3s is what you describe,
then faad2 to decompress the aac into a wav,
then audacity to trim off the adverts and off-topic continuity,
then lame to re-encode as an mp3.

Hopefully we can also trim those source aac files with QT Pro,
as Robert suggests, and put that online as well. It's got a
shorter lineage, is half the filesize, and should play on
people's iPods/iTouches/etc.

I'm positive this is overkill for a show that will
only have possibly a dozen episodes broadcast per year,
but it's perversely fun to talk through the process :)

> Please tell me: what Operating System are you using?
> This makes a *big* difference to how get_iplayer and
> flvstreamer work!

Fedora 11, which is a version of Linux.

cheers,
Charles

 
<<<<   3413   >>>>

Topic: What mp3 quality do you want?

Message 3 / 15
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
>
>
>
>------------------------------------
>
>Yahoo! Groups Links
>
>
>

 
<<<<   3414   >>>>

Topic: Re: What mp3 quality do you want?

Message 4 / 15
berlinirvingJul 22, 2009
 

 
This topic clearly has legs and has generated lots of useful discussion.

I'm only here for a moment to say that it's clear from the early posts that the general preference is to have as good a quality as possible, and lesser quality versions can be made if someone wants them. While I can't fix those which I have recorded up till now that are only 56 bit rate, I shall make future mp3s to equal the source.

This leaves me with a question of the quality of the ABC RN source, as streamed on the web. What mp3 bit rate would equal the web stream?

It's clear that some of you are making better quality recordings than anything I produce, as I only record the stream using Sound Force, edit the front and end, lift the volume a bit, save it as a wav and convert it to a 56k bit rate mp3.

When I upload my files to Mediafire it might be best if I state in the titles the bit rates; this might be useful info to some people.

 
<<<<   3416   >>>>

Topic: What mp3 quality do you want?

Message 5 / 15
Clitheroe KidJul 22, 2009
 

 
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
>
>
>
>

 
<<<<   3417   >>>>

Topic: What mp3 quality do you want?

Message 6 / 15
Clitheroe KidJul 22, 2009
 

 
The BBC *has* already switched to AAC. If you play a file using Windows, the
BBC's iPlayer plays a flash (flv) stream containing an AAC encoded file.
(Right-clicking on the iPlayer window shows what codec is being employed).

Get_iPlayer is set to default to downloading the mp3 stream that's sent to
Apple mobile phones, by mimicking one. Which means that using the default
settings for get_iplayer gives you an mp3 file download.

But it's theoretically possible to reconfigure get_iplayer to download the
AAC stream, instead of the Apple iPhone mp3 stream.

However, on Windows 9x I've yet to figure out how to achieve this. I'm told
by Win XP users that it is possible, but FLVstreamer doesn't seem to be able
to do it under Windows ME.

----- Original Message -----
From: "charles_454545" <charles@...>
To: <just-a-minute@...>
Sent: Monday, July 20, 2009 9:42 PM
Subject: [just-a-minute] Re: What mp3 quality do you want?


> > Better yet would be to rip the stream - in other words, to download the
exact stream broadcast on iPlayer (as it is higher quality than on DAB),
which avoids the compression process altogether. The file does as a result
have the full 36 minutes broadcast on it, but with use of particular tools
you can trim the excess without loss of audio quality.
>
> That makes sense, but the JAM streams I get from both iPlayer and ABC RN
are realaudio, which for better or worse is not a very portable/common
compression format. If the BBC ever gets around to switching to AAC as
they've discussed, IMO saving the raw feed would be exactly the thing to do.

 
<<<<   3419   >>>>

Topic: What mp3 quality do you want?

Message 7 / 15
Greg LindenJul 22, 2009
 

 
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
>
>
>

 
<<<<   3425   >>>>

Topic: Re: What mp3 quality do you want?

Message 8 / 15
charles_454545Jul 22, 2009
 

 
--- In just-a-minute@..., "berlinirving" <berlinirving@...> wrote:

> I'm only here for a moment to say that it's clear from the early
> posts that the general preference is to have as good a quality as
> possible, and lesser quality versions can be made if someone wants
> them. While I can't fix those which I have recorded up till now
> that are only 56 bit rate, I shall make future mp3s to equal
> the source.
>
> This leaves me with a question of the quality of the ABC RN
> source, as streamed on the web. What mp3 bit rate would
> equal the web stream?
>
> It's clear that some of you are making better quality recordings
> than anything I produce, as I only record the stream using Sound
> Forge, edit the front and end, lift the volume a bit, save it as a
> wav and convert it to a 56k bit rate mp3.

What mp3 encoder are you using?

If "lame", I'd suggest -q 0 -V 2 as the settings.

One important step for the ABC RN sourced files is to make certain
that the .wav file passed to the mp3 encoder is only a single
channel. I think that should save space in the end product.

I agree that lightly boosting the volume (and even the bass) is
necessary on the ABC RN files. It's too bad their streams aren't
up to par with what the beeb is doing... I'd love to listen to
RN's "The Night Air" in stereo aac, but that's a different story...

cheers,
Charles

 
<<<<   3426   >>>>

Topic: Re: What mp3 quality do you want?

Message 9 / 15
charles_454545Jul 22, 2009
 

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

> The BBC *has* already switched to AAC. If you play a file
> using Windows, the BBC's iPlayer plays a flash (flv) stream
> containing an AAC encoded file. (Right-clicking on the iPlayer
> window shows what codec is being employed).

:)

Here <http://groups.yahoo.com/group/just-a-minute/message/3395>
I described why aac+ wasn't working for me... it's working now,
and definitely better than the realaudio feeds I'd been getting.

cheers,
Charles

 
<<<<   3428   >>>>

Topic: Re: What mp3 quality do you want?

Message 10 / 15
berlinirvingJul 23, 2009
 

 
When I record the wav I have sound forge set for mono so there is no second track to remove. I do have audacity but I find sound forge more user friendly.

I use audiocatalyst for converting to mp3, which I think is lame [no pun]. I'll have to go back over the posts to understand what this -q0-v2 thingy is. Thanks.

It seems to me that what we want is for the BBC to throw open their archives and let us make pristine copies from the original recordings (including all those bits they edit out from the broadcast versions).

Dal.

--- In just-a-minute@..., "charles_454545" <charles@...> wrote:
>
> What mp3 encoder are you using?
>
> If "lame", I'd suggest -q 0 -V 2 as the settings.
>
> One important step for the ABC RN sourced files is to make certain
> that the .wav file passed to the mp3 encoder is only a single
> channel. I think that should save space in the end product.
>
> I agree that lightly boosting the volume (and even the bass) is
> necessary on the ABC RN files. It's too bad their streams aren't
> up to par with what the beeb is doing... I'd love to listen to
> RN's "The Night Air" in stereo aac, but that's a different story...
>
> cheers,
> Charles
>

 
<<<<   3429   >>>>

Topic: Re: What mp3 quality do you want?

Message 11 / 15
eriatarkaeJul 23, 2009
 

 
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

 
<<<<   3430   >>>>

Topic: What mp3 quality do you want?

Message 12 / 15
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 13 / 15
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 14 / 15
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 15 / 15
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