Re: Radio File Format Questions

2013-12-01 Thread Vangelis forthnet

On Sun Dec 1 23:01:15 GMT 2013, Budgie wrote:


Hi Vangelis,
Top posting just to say thanks.


You are most welcome...

You have given me much to consider: 
More than I dared hope.


Since this is a public mailing list, I tend to think there's 
some chance others may (or may not) benefit from what 
I write...



If I get stuck, will start a new thread.


If you stumble upon FFmpeg specific issues, please do 
consider that FFmpeg may be a helper utility used by get_iplayer, 
but this is the get_iplayer mailing list and it could be disputed by other 
list members (or its maintainer) that FFmpeg usage queries are outside 
the scope of this list - FWIW, there's ample documentation on the net 
on FFmpeg  and a very active mailing list (that I frequented in the past) 
here:


http://ffmpeg.org/pipermail/ffmpeg-user/


On 01/12/13 05:22, Vangelis forthnet wrote:

On Sat Nov 30 23:14:55 GMT 2013, Budgie wrote:
(gigantic snip)
get_iplayer at lists.infradead.org
http://lists.infradead.org/mailman/listinfo/get_iplayer


(Please read this as a "do not repeat in future"  friendly advice, 
not a reprimand:)
You shouldn't have quoted the entirety of my long reply in your  
"just to say thanks" message; this was in direct disrespect of  
the list netiquette, found here:


http://david.woodhou.se/email.html

I have kept a copy of my mail in my "Sent Items" folder, 
the other list members have a copy of it in their "Inboxes" 
and those who are reading the list archives are just one click 
away from it if currently reading your latest reply!
This type of  behaviour will (if it hasn't already) get you on 
a "blacklist" by the maintainer of the list, Mr Woodhouse...


Most Kind Regards,
Vangelis

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Re: Radio File Format Questions

2013-12-01 Thread Budgie

Hi Vangelis,
Top posting just to say thanks.  You have given me much to consider: 
More than I dared hope.  Will pursue over the next few days.  If I get 
stuck will start a new thread.


I have now proved to my satisfaction that my problem is due to issues at 
the BBC end.


My reference to flac was an aberration on my part.

Budgie.


On 01/12/13 05:22, Vangelis forthnet wrote:

On Sat Nov 30 23:14:55 GMT 2013, Budgie wrote:


Hi Vangelis,
I have been working on other stuff and only now return to sort out my
problem files.  Would you have time to help some more please?


Hello there Budgie :-) ; I was surprised, to say the least, that a 4.5
month old
thread was bumped... I'll try to do my best, but do keep in mind that I
have NO
knowledge of Open Source OSs, just the WindowsVista x86 I am running in
this aging laptop; I only hope you can extrapolate what I say to your
setup, else
the majority of the list members are savvy enough and can help you
further...


I do have ffprobe but do not see any mention of HE-AACv2 or
AAC-LC when I run it on a problem file.  What I do see is :-

[Stream #0:0(und): Audio: aac (mp4a / 0x6134706D), 44100 Hz, stereo,
fltp, 48 kb/s (default).


You may want to further investigate the capabilities of ffprobe by
printing its help
content::

ffprobe -h > "FFprobe Help.txt" (this for Win).

What you'd need in your case is the more verbose command "-show_streams".
Sacrificing the brevity of my reply, I've opted to illustrate this with
an example:

Running the following command (from a UK IP),
get_iplayer --type=radio --pid=b03j5fxd --modes=flashaacstd --force -w
--file-prefix="aacla[b03fbbbt]" --tag-podcast-radio

will get you what you've labeled as "higher quality radio option"; this
in fact is an MP4 container with the Apple
implemented .m4a extention (for Ipod compatible audio-only content),
which "contains" a AAC-LC audio stream @128kbpsABR.

ffprobe -show_streams "aaclc[b03fbbbt].m4a"

will produce a list of info; I'd have expected that ffprobe under
"profile=" would say
"aac_low', but instead it says "unknown".
However, you should pay attention to the following set of info:

codec_time_base=1/44100
sample_rate=44100
channels=2
time_base=1/44100
bit_rate=127999

This is indicative of the flashaacstd radio mode.

get_iplayer --type=radio --pid=b03j5fxd --modes=flashaaclow --force -w
--file-prefix="aache2[b03fbbbt]" --tag-podcast-radio

will fetch the "lower quality radio option", the one that IS NOT
SUPPORTED by your hardware player.

ffprobe -show_streams "aache2[b03fbbbt].m4a"

this time produces the next set of info:

codec_time_base=1/22050
sample_rate=44100
channels=1
time_base=1/44100
bit_rate=47999

which is indicative of the flashaaclow radiomode.
(codec_time_base=1/22050 signifies the presence of SBR, while
channels=1 may mean either a monaural stream, or, as is the case here,
the presence of Parametric Stereo [=PS]; AAC+SBR+PS= HE-AACv2 !
Please read further at
http://en.wikipedia.org/wiki/AAC%2B )

Of course, with MediaInfo installed (on Windows), all is much simpler.
The programme injects a right-click context menu entry, which, when
selected, shows this info:

"aaclc[b03fbbbt].m4a"

Audio
ID   : 1
Format   : AAC
Format/Info  : Advanced Audio Codec
Format profile   : LC
Codec ID : 40
Duration : 30mn 0s
Bit rate mode: Variable
Bit rate : 128 Kbps
Maximum bit rate : 192 Kbps
Channel(s)   : 2 channels
Channel positions: Front: L R
Sampling rate: 44.1 KHz

"aache2[b03fbbbt].m4a"

Audio
ID   : 1
Format   : AAC
Format/Info  : Advanced Audio Codec
Format profile   : HE-AACv2 / HE-AAC / LC
Codec ID : 40
Duration : 30mn 0s
Bit rate mode: Constant
Bit rate : 48.0 Kbps
Channel(s)   : 2 channels / 1 channel / 1 channel
Channel positions: Front: L R / Front: C / Front: C
Sampling rate: 44.1 KHz / 44.1 KHz / 22.05 KHz

I would urge you to install MediaInfo for your distro, if you
haven't done already, because it is way more practical in examining
media files than the CLI ffprobe - please ask for further help, if needed,
about installing it on your OS, as I am clueless in this field... :-{

I interpret this to mean that I have downloaded the flashaaclow
version which from your advice I interpret to be the HE-AACv2 encoded
version.  Is that correct?Judging only by the declared bitrate (= 48
kb/s), then YES - but if you had the patience to

read through my elaboration above, then you'd have figured this out
already :-)


Since I have no idea why I get these files from time to time


I can safely say tha

Re: Radio File Format Questions

2013-11-30 Thread Vangelis forthnet

On Sat Nov 30 23:14:55 GMT 2013, Budgie wrote:


Hi Vangelis,
I have been working on other stuff and only now return to sort out my
problem files.  Would you have time to help some more please?


Hello there Budgie :-) ; I was surprised, to say the least, that a 4.5 month 
old
thread was bumped... I'll try to do my best, but do keep in mind that I have 
NO

knowledge of Open Source OSs, just the WindowsVista x86 I am running in
this aging laptop; I only hope you can extrapolate what I say to your setup, 
else
the majority of the list members are savvy enough and can help you 
further...



I do have ffprobe but do not see any mention of HE-AACv2 or
AAC-LC when I run it on a problem file.  What I do see is :-

[Stream #0:0(und): Audio: aac (mp4a / 0x6134706D), 44100 Hz, stereo,
fltp, 48 kb/s (default).


You may want to further investigate the capabilities of ffprobe by printing 
its help

content::

ffprobe -h > "FFprobe Help.txt" (this for Win).

What you'd need in your case is the more verbose command "-show_streams".
Sacrificing the brevity of my reply, I've opted to illustrate this with an 
example:


Running the following command (from a UK IP),
get_iplayer --type=radio --pid=b03j5fxd --modes=flashaacstd --force -w --file-prefix="aacla[b03fbbbt]" 
--tag-podcast-radio


will get you what you've labeled as "higher quality radio option"; this in 
fact is an MP4 container with the Apple
implemented .m4a extention (for Ipod compatible audio-only content), which 
"contains" a AAC-LC audio stream @128kbpsABR.


ffprobe -show_streams "aaclc[b03fbbbt].m4a"

will produce a list of info; I'd have expected that ffprobe under "profile=" 
would say

"aac_low', but instead it says "unknown".
However, you should pay attention to the following set of info:

codec_time_base=1/44100
sample_rate=44100
channels=2
time_base=1/44100
bit_rate=127999

This is indicative of the flashaacstd radio mode.

get_iplayer --type=radio --pid=b03j5fxd --modes=flashaaclow --force -w --file-prefix="aache2[b03fbbbt]" 
--tag-podcast-radio


will fetch the "lower quality radio option", the one that IS NOT SUPPORTED 
by your hardware player.


ffprobe -show_streams "aache2[b03fbbbt].m4a"

this time produces the next set of info:

codec_time_base=1/22050
sample_rate=44100
channels=1
time_base=1/44100
bit_rate=47999

which is indicative of the flashaaclow radiomode.
(codec_time_base=1/22050 signifies the presence of SBR, while
channels=1 may mean either a monaural stream, or, as is the case here,
the presence of Parametric Stereo [=PS]; AAC+SBR+PS= HE-AACv2 !
Please read further at
http://en.wikipedia.org/wiki/AAC%2B )

Of course, with MediaInfo installed (on Windows), all is much simpler.
The programme injects a right-click context menu entry, which, when
selected, shows this info:

"aaclc[b03fbbbt].m4a"

Audio
ID   : 1
Format   : AAC
Format/Info  : Advanced Audio Codec
Format profile   : LC
Codec ID : 40
Duration : 30mn 0s
Bit rate mode: Variable
Bit rate : 128 Kbps
Maximum bit rate : 192 Kbps
Channel(s)   : 2 channels
Channel positions: Front: L R
Sampling rate: 44.1 KHz

"aache2[b03fbbbt].m4a"

Audio
ID   : 1
Format   : AAC
Format/Info  : Advanced Audio Codec
Format profile   : HE-AACv2 / HE-AAC / LC
Codec ID : 40
Duration : 30mn 0s
Bit rate mode: Constant
Bit rate : 48.0 Kbps
Channel(s)   : 2 channels / 1 channel / 1 channel
Channel positions: Front: L R / Front: C / Front: C
Sampling rate: 44.1 KHz / 44.1 KHz / 22.05 KHz

I would urge you to install MediaInfo for your distro, if you
haven't done already, because it is way more practical in examining
media files than the CLI ffprobe - please ask for further help, if needed,
about installing it on your OS, as I am clueless in this field... :-{

I interpret this to mean that I have downloaded the flashaaclow
version which from your advice I interpret to be the HE-AACv2 encoded
version.  Is that correct?Judging only by the declared bitrate (= 48 kb/s), 
then YES - but if you had the patience to
read through my elaboration above, then you'd have figured this out already 
:-)



Since I have no idea why I get these files from time to time


I can safely say that most probably it's something on the Beeb's side - in 
the latest
month I came across 4 or 5 instances where a radio show was unavailable in 
the
flashaacstd mode for no apparent reason; the radio shows preceding & 
succeeding it
might've been, not the specific one in between I was after. And the 
situation remained
so for the whole duration of the 7day avai

Re: Radio File Format Questions

2013-11-30 Thread Jeremy Nicoll - ml get_iplayer
Budgie  wrote:

>Since I have no idea why I get these files from time to time I assume I 
>do not have get_iplayer set up correctly so that is cannot download in 
>this format.  First request then is what should I put in my options file 
>to ensure I only get the higher quality radio options?

I think you need to set --modes= to a list of the modes you're willing to
download.  Suppose that the default is something like:

  flashaachigh,flashaacstd,flashaaclow,wma

but that at the time that your fetch is attempted only the lower quality
files are actually working properly from the content provider... then GiP
has probably tried the high quality ones, they've failed and the lower
quality one has been fetched.  If you code for example

  --modes=flashaachigh,flashaacstd

then I think only those quality levels would be attempted.

-- 
Jeremy Nicoll - my opinions are my own.

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Re: Radio File Format Questions

2013-11-30 Thread Budgie

On 14/07/13 13:37, Vangelis forthnet wrote:

On Sat Jul 13 15:52:02 BST 2013, Budgie wrote:


As usual, a couple of questions.

Is the file format HE-AAC v2 the normal output for a low bit rate
download or is it another, to me, anomaly?


Hello.
Yes, 'flashaaclow' radiomode yields an audio file packaged in an MP4
container
(whose format profile is "Apple audio with iTunes info", hence the .m4a
extention),
which in it contains a raw ADTS (audio data transport stream) .aac file
encoded in
HE-AACv2 as you correctly state; HE-AAC is AAC+SBR, v2 indicates the use of
PS (parametric stereo). The encode uses a VBR with a mean value of 48kbps.
NB that if you come from a non-UK IP, this is the only audio quality
available to you
for National Stations.
If in the UK, the default high quality mode (= flashaac/flashaacstd) is
again an
.m4a file, but the audio stream contained therein is encoded in AAC LC
(no SBR, no PS)
@ 128kbps (320kbps for Radio 3) ABR, that's why it is more compatible
with software/
hardware players.
Depending on the player used, the PS part may be skipped (audio plays in
mono), or both
PS+SBR skipped, in which case audio plays in mono and in very low
quality, since only
half the sampling rate is used.
In my Windows setup I haven't come across a software player that does
not play at least
the AAC part of a HE-AACv2 encode. But hardware players (like your
network player here:

http://www.linn.co.uk/all-products/network-music-players/sneaky-ds

) behave differently; the features list of yours only mentions a
"generic AAC" decoding support,
so it may be expected that it does not support HE-AAC (try a World
Service download) or
HE-AACv2, as you have found out.

On your laptop, any ffmpeg based software player (FFplay, + the ones you
mentioned)
can play fully HE-AACv2 audio streams.


What programme can I use to find out the detailed information of what is
in each .m4a file?


As a generic multimedia file "investigator", you can use the CLI FFprobe,

http://ffmpeg.org/ffprobe.html

which, together with FFplay, is part of the FFmpeg package - if it isn't
available
for your OS, maybe its fork "avprobe" is:

http://libav.org/avprobe.html

As a personal choice though, I'd recommend MediaInfo - it comes both as
a GUI & CLI
and is available for a plethora of OSes, including yours (openSUSE 12.2)
here:

http://mediaarea.net/el/MediaInfo/Download/openSUSE


what would you recommend I run to change
the format of the sound file and to what format?


dinkypumpkin in your answer to you has kindly suggested a recode from
HE-AACv2 -> AAC-LC through FFmpeg (or avconv). If your FFmpeg
is built with support for one of the non-free AAC encoders (libfaac or the
far better libfdk_aac), then I guess it'd be fine,
but the native encoder (-c:a aac -strict -2)
lacks in performance, especially in music parts -
for speech is fine.

If I can humbly share my opinion, I have found that a transcode from
HE-AACv2 @48kbps -> LAME MP3 @ 96kbps (for spoken content) /
112 (or even 128) kbps (for music content) is more than adequate and I
would
propose that, since your SneakyDS does play MP3 files.

Regards.

Vangelis


Hi Vangelis,
I have been working on other stuff and only now return to sort out my 
problem files.  Would you have time to help some more please?


First question concerns diagnosis of the files which do not play on Linn 
device.  I do have ffprobe but do not see any mention of HE-AACv2 or 
AAC-LC when I run it on a problem file.  What I do see is :-


[CODE]
Stream #0:0(und): Audio: aac (mp4a / 0x6134706D), 44100 Hz, stereo, 
fltp, 48 kb/s (default).

[CODE]

I interpret this to mean that I have the downloaded the flashaaclow 
version which from your advice I interpret to be the HE-AACv2 encoded 
version.  Is that correct?


Since I have no idea why I get these files from time to time I assume I 
do not have get_iplayer set up correctly so that is cannot download in 
this format.  First request then is what should I put in my options file 
to ensure I only get the higher quality radio options?


Second question is please could you help with ffmpeg command line to 
convert these files to files that will play as suggested previously by 
dinkypumpkin.  I regret my knowledge is not up to doing it without more 
help with command options.


Finally I note I could transcode on downloading and save these files as 
mp3 files but is it also possible to transcode to flac?


Grateful for any further help when you have time.
Regards,
Budgie


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Re: Radio File Format Questions

2013-07-15 Thread dinkypumpkin

On 15/07/2013 21:10, Vangelis forthnet wrote:

ffmpeg -i foo.m4a -vn -c:a libmp3lame -ab 96k -ac 2 -ar 44.1k foo.mp3

(NB that the m4a file's metadata will be lost during the conversion)


If you have a relatively recent version of ffmpeg, a lot of the metadata 
will be preserved.  You'll lose the cover art, but the major ID3 frames 
will be populated.  openSUSE 12.3 packages ffmpeg 1.0.6, which is recent 
enough to do the job.




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Re: Radio File Format Questions

2013-07-15 Thread Vangelis forthnet

On Sun Jul 14 22:48:46 BST 2013, Budgie wrote:


Very many thanks for your instructive and helpful reply.


You are most welcome; apologies I did not get back to you sooner.
I am currently mourning the sudden loss of an external USB HDD
1TB in capacity, which was full with close to 900GB worth of files
(the majority of which are irreplaceable), accumulated in the course of
nearly 3 years. It will cost me a small fortune to buy a replacement disk
and recover about 85% of the data that can be salvaged from the
failed disk :-( :-(


This will help me investigate the
several other files which are causing me problems.


More often than not, the first "Listen Again" radiomode that is made
available online by the beeb after a radio show has finished is the
"flashaaclow" one (in GiP's terms), which they call the "Lower
Bandwidth Version". I don't know if this is by design, but it's my
personal observation. For example, after the Official Chart Show
on Radio 1 finishes at 19:00 BST on a Sunday, the "flashaaclow" mode
appears first 1,5-2 hours later, while it usually takes another 1-2 hours 
for

the "flashaacstd" mode to be made available (this depends on the load on
the encoders chain...).
If you are doing your audio downloads in an automated way via a PVR
list and you have not explicitly asked for the "flashaacstd" mode, then, 
when

your PVR list is executed, it may sometimes download the low quality
version of a programme, because at that time it was the only one available.
This is possibly why you end up with some HE-AACv2 .m4a files inside
your downloads folder...


for the spoken word I would be happy to use mp3.  This is how I
receive BBC podcasts of spoken word


FYI, these are mono files encoded @ 64kbps constant bitrate (CR); the
source used for the encode is probably a high quality master, that's why
they do sound quite good, but TBH I do not like the monaural sound,
especially when listened to through headphones.


If I wish to transcode the problem HE-AACv2 file to mp3 should I
do this with ffmpeg or another program?


Any audio conversion software capable of fully decoding HE-AACv2 and
encoding to mp3 should do the task; I have no clue what are your choices
in your platform (OpenSuSE 12.2).
FFmpeg is fine for this - I would use something like this:

ffmpeg -i foo.m4a -vn -c:a libmp3lame -ab 96k -ac 2 -ar 44.1k foo.mp3

(NB that the m4a file's metadata will be lost during the conversion)

On Mon Jul 15 18:31:47 BST 2013, Budgie wrote:


Yes I am using ffmpeg.  First try gave me twice the file
size as advised by Vangelis but I am looking at options to set lower bit
rate for output file.


You never mentioned that file size is an issue for you.
HE-AACv2 is a very efficient encoder at low bitrates (22-64kbps), that is 
why
it is now used very widely for internet radio streaming (to cut down on 
bandwidth

costs). In comparison, LAME MP3 lacks considerably in this field.
If you are prepared to compromise with some quality loss, you could 
experiment
with bitrates lower than 96kbps, or try a variable bitrate (VBR) scheme, but 
I
wouldn't try values lower than 64kbps (unless you are about to listen to the 
end

result on a mobile phone with a cheap set of earphones...)

Just my two "eurocents" ...

Vangelis.



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Re: Radio File Format Questions

2013-07-15 Thread roadcone (gmx) imap
Use ffmpeg but to make things easier, use Winff which is a gui interface 
with ffmpeg. I use it on both Windows and Linux and it works a treat.


Clive


On 14/07/13 22:48, Budgie wrote:

If I wish to transcode the problem HE-AACv2 file to mp3 should I
do this with ffmpeg or another program?

Many thanks again,
Budgie

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Re: Radio File Format Questions

2013-07-14 Thread Vangelis forthnet

On Sun Jul 14 13:44:55 BST 2013, Chris Marriott wrote:


What do we get if we use the "aactomp3" flag on "get_iplayer"? That's the
way that I've always done it personally, and the results are entirely
satisfactory (to my ear) for spoken word programmes (which are all I ever
download).


Hello Chris!


From GiP's "longhelp" (get_iplayer --longhelp) I quote:


Recording Options:
--aactomp3  Transcode AAC audio to MP3 with ffmpeg (CBR 128k 
unless --mp3vbr is specified)
--mp3vbr   Set LAME VBR mode to N (0 to 9) for AAC transcoding. 0 = target 
bitrate 245 Kbit/s, 9 = target bitrate 65 Kbit/s (requires --aactomp3)


that is if you are downloading a "flashaac" radiomode (no matter if it is 
the low/std variant) and you have
specified the --aactomp3  switch, you will end up with an .mp3 audio file 
transcoded @ 128kbps

constant bitrate (CBR).
If it is the flashaaclow mode you are recording (which I find is sufficient 
for spoken word content), then
with --aactomp3 you do have the original quality preserved, but at a 2.6 
times the original file size (=128/48).
In such a case I would experiment with the --mp3vbr switch at values larger 
than 7, which will produce
smaller mp3 files - beware though that some hardware (/ portable) mp3 
players are "peaky" about VBR

files; they may report wrong duration or not play the mp3 file at all...
If it is the flashaacstd mode (default from within the UK) you are 
recording,  --aactomp3 produces a same size
(to the initial .aac source) audio file, with no noticeable loss of quality 
for spoken content. This is not the case

for Radio 3 content, please also refer to my post earlier in the month:

http://lists.infradead.org/pipermail/get_iplayer/2013-July/004425.html

And I will repeat myself, but only transcode if you really have to!

Now, as far as the OP (Budgie) is concerned, the way I understood it is that 
he has already on disk some
"flashaaclow" audio files that have presumably expired (so he cannot 
re-download them using the --aactomp3
switch) but needs to listen to them on his Network Player that does not 
support the encoding format of the files
(HE-AACv2 = AAC+SBR+PS). In order to do this, he must re-encode them to a 
format supported by his Player...

I hope I made things clearer now :-)

Vangelis. 



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Re: Radio File Format Questions

2013-07-14 Thread Chris Marriott
-Original Message- 
From: Vangelis forthnet

Sent: Sunday, July 14, 2013 1:37 PM
To: get_iplayer@lists.infradead.org
Subject: Re: Radio File Format Questions


If I can humbly share my opinion, I have found that a transcode from
HE-AACv2 @48kbps -> LAME MP3 @ 96kbps (for spoken content) /
112 (or even 128) kbps (for music content) is more than adequate and I 
would

propose that, since your SneakyDS does play MP3 files.


What do we get if we use the "aactomp3" flag on "get_iplayer"? That's the 
way that I've always done it personally, and the results are entirely 
satisfactory (to my ear) for spoken word programmes (which are all I ever 
download).


Chris


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Re: Radio File Format Questions

2013-07-14 Thread Vangelis forthnet

On Sat Jul 13 15:52:02 BST 2013, Budgie wrote:


As usual, a couple of questions.

Is the file format HE-AAC v2 the normal output for a low bit rate
download or is it another, to me, anomaly?


Hello.
Yes, 'flashaaclow' radiomode yields an audio file packaged in an MP4 
container
(whose format profile is "Apple audio with iTunes info", hence the .m4a 
extention),
which in it contains a raw ADTS (audio data transport stream) .aac file 
encoded in

HE-AACv2 as you correctly state; HE-AAC is AAC+SBR, v2 indicates the use of
PS (parametric stereo). The encode uses a VBR with a mean value of 48kbps.
NB that if you come from a non-UK IP, this is the only audio quality 
available to you

for National Stations.
If in the UK, the default high quality mode (= flashaac/flashaacstd) is 
again an
.m4a file, but the audio stream contained therein is encoded in AAC LC (no 
SBR, no PS)
@ 128kbps (320kbps for Radio 3) ABR, that's why it is more compatible with 
software/

hardware players.
Depending on the player used, the PS part may be skipped (audio plays in 
mono), or both
PS+SBR skipped, in which case audio plays in mono and in very low quality, 
since only

half the sampling rate is used.
In my Windows setup I haven't come across a software player that does not 
play at least
the AAC part of a HE-AACv2 encode. But hardware players (like your network 
player here:


http://www.linn.co.uk/all-products/network-music-players/sneaky-ds

) behave differently; the features list of yours only mentions a "generic 
AAC" decoding support,
so it may be expected that it does not support HE-AAC (try a World Service 
download) or

HE-AACv2, as you have found out.

On your laptop, any ffmpeg based software player (FFplay, + the ones you 
mentioned)

can play fully HE-AACv2 audio streams.


What programme can I use to find out the detailed information of what is
in each .m4a file?


As a generic multimedia file "investigator", you can use the CLI FFprobe,

http://ffmpeg.org/ffprobe.html

which, together with FFplay, is part of the FFmpeg package - if it isn't 
available

for your OS, maybe its fork "avprobe" is:

http://libav.org/avprobe.html

As a personal choice though, I'd recommend MediaInfo - it comes both as a 
GUI & CLI
and is available for a plethora of OSes, including yours (openSUSE 12.2) 
here:


http://mediaarea.net/el/MediaInfo/Download/openSUSE


what would you recommend I run to change
the format of the sound file and to what format?


dinkypumpkin in your answer to you has kindly suggested a recode from
HE-AACv2 -> AAC-LC through FFmpeg (or avconv). If your FFmpeg
is built with support for one of the non-free AAC encoders (libfaac or the
far better libfdk_aac), then I guess it'd be fine,
but the native encoder (-c:a aac -strict -2)
lacks in performance, especially in music parts -
for speech is fine.

If I can humbly share my opinion, I have found that a transcode from
HE-AACv2 @48kbps -> LAME MP3 @ 96kbps (for spoken content) /
112 (or even 128) kbps (for music content) is more than adequate and I would
propose that, since your SneakyDS does play MP3 files.

Regards.

Vangelis 



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Re: Radio File Format Questions

2013-07-13 Thread dinkypumpkin

On 13/07/2013 15:52, Budgie wrote:

Pending Linn sorting out their DS player what would you recommend I run
to change the format of the sound file and to what format?


You should be able to do an AAC->AAC transcode with ffmpeg.  The default 
settings should give you an output file with AAC-LC profile.  The AAC-HE 
profile is presumably what the Linn player can't handle.


http://ffmpeg.org/trac/ffmpeg/wiki/AACEncodingGuide

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Radio File Format Questions

2013-07-13 Thread Budgie
Further to my attempts to sort out my radio downloads, the size anomaly, 
which has been explained and non playing of some files, I found that the 
low bitrate file I mentioned earlier would not play on my Linn SneakyDS 
but the larger file did play.  Both files played well on other renderers.


I sought help on the Linn forum and this is the consequential post  from 
bubbleguuum, addressed to Linn Development Forum:-


[quote]Here's a HE-AAC v2 file that doesn't play on a DS.
It is from a BBC podcast.

It is an 48Kbps AAC SBR+PS file. foobar2000 and VLC play it.
Playing it to a DS fails silently. [quote]

As usual, a couple of questions.

Is the file format HE-AAC v2 the normal output for a low bit rate 
download or is it another, to me, anomaly?


What programme can I use to find out the detailed information of what is 
in each .m4a file?  I have used AtomicParsley to discover tagging 
metadata and then qtfaststart to sort out order of atoms where for 
whatever reason, these have been screwed up.


Pending Linn sorting out their DS player what would you recommend I run 
to change the format of the sound file and to what format?


Regards,
Budgie

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