On Sun, 20 Jul 2014 09:34:21 +0100, Jim Lesurf wrote:

So info on those points would be welcome. Failing that I may try
something like xfce Mint sometime. But its a bit of a faff as a
temporary measure if someone can tell me in advance that won't do the
job and point me at a better choice. (I'm asking at the BBC about this
as well.)

Speaking as a dyed-in-the-wool RedHat guy, I was pretty impressed with
vanilla Mint when I installed it last Xmas for my sister. The install was
easy and I like the Cinnamon desktop. Vanilla Mint runs at an acceptable
speed on her somewhat underpowered HP laptop.

My sister likes Mint too: the reason for this install was that the then-
latest Ubuntu version had really ****ed her off by not only screwing with
the desktop, but also taking away a number of small GUI tools she found
very useful. She's a power user rather than a tekkie, which is why I did
the install.

-----

Personal BBC comment: I really wish that the NRDC surround sound format
would be reinstated even if only as an Internet audio format. You
probably remember it: it used a tetrahedral mic assembly for recording
and was transmitted as four channnels: mono + left-right, front-rear and
ceiling-floor difference signals. I remember hearing it at an internal
BBC sound equipment exhibition in 1980 and being totally blown away with
it on both speakers and headphones. About the same time I went to the
Sony shop on Regent St and hearing one of their surround sound demos,
also using four speakers, and being distinctly underwhelmed by it.

For me a big plus of the NRDC system was that you could pick your point
in the audience by tweaking the preamp - forward gave a brighter
orchestral sound and minimal audience noise while rearward gave a
mellower orchestral sound and brought up the audience: you could localise
coughs and foot stomping all around yourself. This was from a demo
recording they'd made during the Proms by hanging a single tetrahedral
mice from the middle of the Albert Hall's domed roof.

Never mind all that browser ********: I'd happily install a freestanding
Winamp equivalent application if did the same job as that NRDC preamp and
could feed the result to my headhones or my external sound system via an
external sound card. If it could be installed on a RaspberryPi and look
like another physical preamp, so much the better!


--
martin@ | Martin Gregorie
gregorie. | Essex, UK
org |

In article , Andy
Furniss spam@spam wrote:
Jim Lesurf wrote:
In article , Andy
Furniss spam@spam wrote:


snip Agree.

Below is probably flawed/outdated - just first impressions from a bit of
random searching.

However AIUI at present the engineers are really at the stage of
testing and seeing how well their 4.0 streams may work. They hope the
new streams will be good. Their main focus will be on that. From their
POV a limit on browser choice probably isn't their concern *at
present* since it isn't a standard service. Mine at present would be
on assessing sound quality *if* I can manage to capture a stream!

As I see it the browser is the player here and chrome is closed and
using it's own licensed AAC dec (maybe fdkaac which is available in
source form). The open version of chrome by default at least will only
play open codecs to avoid IP issues. I also don't know if it will do
DASH - maybe, as it's javascript that the the BBC use - as stated in the
link Rupert gave it's a version of an open reference implementation.

Also the link says the stream is 320kbit fixed rate and the DASH is only
used for chunking.

http://www.bbc.co.uk/rd/blog/2014/03...rce-extensions

So currently I don't think you will be able to cap the stream as easily
as using wget or mplayer on the R3 HD stream.

My assumption is that is so. However I'm hoping I could capture the
*decoded* audio LPCM on its way to the 'DAC' by using ALSA. (cf below)
That would do for my purposes as I want "the results you get using the BBC
recommended setup" to find out what users can expect to get.

FWIW The BBC would probably let me have some examples of what they are
sending for comparison purposes if I succeed. They've done that in past
years when I was checking their now-standard 320k stereo streams. But no
point in my asking them for this if I have nothing from the 'output end of
the standard pipe' to compare it with. I have no doubt the producers and
engineers will be producing good results that are 'all right leaving here'.
:-) The question is how much this may be affected by passing though the
pipe!

For capping decoded PCM - I guess you can already do that - follow the
sursound thread for others experience and some ready made samples.

Yes, I'm hoping that will be OK. Although I've never done anything like
this with ALSA for surround and I have no way of listening to it. That
means I may do a simply divert so no sound emerges, it all gets sent to a
file for later analysis.

What would be particularly interesting is if I can catch a Prom that gives
me surround via HDTV FreeView *and* the new stream.

Alas, I haven't been able to check the FAQ or do anything today as the BBC
iplayer seems 'occupied' every time I've tried it.

I'm hoping FF developers can and will realise this issue needs
addressing. It probably won't go away.

From reading their tracker threads they are addressing it - but of
course their are (were?) potential IP/licence issues that come when
anything with MPEG in the name is is involved, so both DASH and the
browser being the player could be/have been tricky.

It will be handy if they do manage - open source = can cap the raw
stream, I am not so sure content providers will be as pleased.

I have my doubts that most home users will want to capture the stream in
its encoded form. Indeed, I've never bothered as my focus is on the above.
I judge by the outcome as compared with what the BBC shovel in their end of
the pipe.

Seems to be just chrome currently, as for distro - no idea.

As things stand I'll try Mint + Chrome when I get around to this. Unless
someone can advise otherwise. Still not been able to check the FAQ because
I can't get reliable BBC pages at present, but I may email someone to ask.

Wonder if the BBC iplayer site problems occurring now is a co-incidence...

Jim

--
Please use the address on the audiomisc page if you wish to email me.
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html
Audio Misc http://www.audiomisc.co.uk/index.html

In article , Martin Gregorie
wrote:
On Sun, 20 Jul 2014 09:34:21 +0100, Jim Lesurf wrote:

So info on those points would be welcome. Failing that I may try
something like xfce Mint sometime. But its a bit of a faff as a
temporary measure if someone can tell me in advance that won't do the
job and point me at a better choice. (I'm asking at the BBC about this
as well.)

Speaking as a dyed-in-the-wool RedHat guy, I was pretty impressed with
vanilla Mint when I installed it last Xmas for my sister. The install
was easy and I like the Cinnamon desktop. Vanilla Mint runs at an
acceptable speed on her somewhat underpowered HP laptop.

OK. Noted. I tend to prefer xfce for the desktop. Not sure how that relates
to cinnamon/mate/whatever. No doubt I'll find out by making a mistake, i.e.
the usual way. :-)

Personal BBC comment: I really wish that the NRDC surround sound format
would be reinstated even if only as an Internet audio format.

Agreed. Yes I recall it. The new 22+ channel hyper vector systems seem to
be rather over-re-inventing it!



Never mind all that browser ********: I'd happily install a
freestanding Winamp equivalent application if did the same job as that
NRDC preamp and could feed the result to my headhones or my external
sound system via an external sound card. If it could be installed on a
RaspberryPi and look like another physical preamp, so much the better!


That raises the question of iplayer on the RPi. Will Chrome run on the RPi
distros? It would be hard for the BBC to ignore RPi given how many are in
use now.

Jim

--
Please use the address on the audiomisc page if you wish to email me.
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html
Audio Misc http://www.audiomisc.co.uk/index.html

Martin Gregorie wrote:

Personal BBC comment: I really wish that the NRDC surround sound
format would be reinstated even if only as an Internet audio format.
You probably remember it: it used a tetrahedral mic assembly for
recording and was transmitted as four channnels: mono + left-right,
front-rear and ceiling-floor difference signals. I remember hearing
it at an internal BBC sound equipment exhibition in 1980 and being
totally blown away with it on both speakers and headphones. About the
same time I went to the Sony shop on Regent St and hearing one of
their surround sound demos, also using four speakers, and being
distinctly underwhelmed by it.

For me a big plus of the NRDC system was that you could pick your
point in the audience by tweaking the preamp - forward gave a
brighter orchestral sound and minimal audience noise while rearward
gave a mellower orchestral sound and brought up the audience: you
could localise coughs and foot stomping all around yourself. This was
from a demo recording they'd made during the Proms by hanging a
single tetrahedral mice from the middle of the Albert Hall's domed
roof.

Never mind all that browser ********: I'd happily install a
freestanding Winamp equivalent application if did the same job as
that NRDC preamp and could feed the result to my headhones or my
external sound system via an external sound card. If it could be
installed on a RaspberryPi and look like another physical preamp, so
much the better!

Sounds like ambisonics to me, handily the patents have expired - the BBC
do still publish papers on ambisonics/binural.

If you are interested in it then sursound is the list for you - just in
the thread on this topic the posters include people who were involved in
its genesis/development, the suthor of the current decoder of choice and
those who use tetramic/soundfield in their recording work.

Binaural is also do-able, but of course you come up against issues of
whose hrtf to use/headtracking. It can be done with open source
DAWs/plugins/apps.

If you have a surround setup grab ambdec download something and enjoy
:-) Once you've worked out how to use it of course - I don't have enough
speakers as my many Genelecs idea failed with both financial and SWMBO
planning permission issues. I use headphones - sometimes with various
hrtfs but TBH I am OK with UHJ which you can easily make with jconvolver
from the wxy(z)s that are out there.

OK so there's not that much out there, Nimbus do UHJ encoded CDs which
you can buy secondhand for pennies - not quite as good as full wxyz, but
then most don't have need for height anyway.

Some recordings here -

http://ambisonic.info/index.html

The dvorak and LvB are really quite good - the latter was used in some
BBC trials IIRC.

http://ambisonics.dreamhosters.com/AMB/

Jim Lesurf wrote:

My assumption is that is so. However I'm hoping I could capture the
*decoded* audio LPCM on its way to the 'DAC' by using ALSA. (cf
below) That would do for my purposes as I want "the results you get
using the BBC recommended setup" to find out what users can expect to
get.

I've only ever capped stereo browser/flash once, some time ago. The path
of least resistance for me was to use jack + the alsa-jack plugin as
flash would only output to alsa. IIRC it was just a case of running
qjackctl then using patchbay to connect the sound to arecord. IIRC
arecord was a better choice than ffmpeg as the latter started
overwriting when the wav size limit was reached, but arecord spawned a
new file and continued.

In article , Andy
Furniss spam@spam wrote:
Jim Lesurf wrote:

My assumption is that is so. However I'm hoping I could capture the
*decoded* audio LPCM on its way to the 'DAC' by using ALSA. (cf
below) That would do for my purposes as I want "the results you get
using the BBC recommended setup" to find out what users can expect to
get.

I've only ever capped stereo browser/flash once, some time ago. The path
of least resistance for me was to use jack + the alsa-jack plugin as
flash would only output to alsa. IIRC it was just a case of running
qjackctl then using patchbay to connect the sound to arecord. IIRC
arecord was a better choice than ffmpeg as the latter started
overwriting when the wav size limit was reached, but arecord spawned a
new file and continued.

Noted. May come in handy. :-)

As yet I've managed to get ALSA to do what I want for normal playout and
recording.

However for stereo from the iplayer (FF + Flash) I use the 'simple' method
of using a USB DAC as the (alsa) default output device. Then use a DAC that
has an spdif output I connect to a recorder. This is round-the-houses in
computing terms, but works perfectly and means I really do capture what any
ordinary user would get with their default DAC. Fine for my tests.

However I have no surround sound gear at all. Not really my interest.

The good news is that, because of that, I'm happy if I can simply define
the alsa output device as actually being an alsa plug to a file. Don't care
if there is no audible output at the time. Only worry is to know if it is
working if I can't hear anything. But I've no idea if that'll work in this
case as I know nothing about Chrome in addition to not having used
surround! 8-]

The main pest with all this is having to install a distro, etc, purely to
do it. And may mean the machine isn't useful for anything else until I
finish and wipe what I did. That said, I may try a dual boot. However the
laptop only has a 60GB hard disc (SSD), so not a lot of space to play with.
It does have an SD card slot, though, which would do for the data. Wonder
how small a disc is needed for xfce Mint + Chrome and nothing much else...

Jim

--
Please use the address on the audiomisc page if you wish to email me.
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html
Audio Misc http://www.audiomisc.co.uk/index.html

What follows is something of a rant!

You may, or may not, be aware that there is a local radio
station, Radio Jackie, near where Brian Gaff lives. They have a
web page, below, which gives the URLs for a number of streams so
that people can use the software of their choice. Why oh why
can't the BBC do the same? They hide the iPlayer streams behind
Flash (which I refuse to have on the grounds of too many
security problems) and now they are hiding the surround sound
stream behind only one browser which works on a non-Microsoft
operating system. From my point of view Chrome is not an option
because it includes Flash.

http://www.radiojackie.com/listennowpage.asp

Thats simply because its run by knowledgeable people who care about what
there're doing ..

... Its that simple;!....



See if you can persuade someone at the BBC that there are people
who have a clue, who want to use their own choice of software,
and therefore only need the stream's URL. On one of the web
pages, of course, not in a private email.

--
Tony Sayer

On Sun, 20 Jul 2014 13:39:25 +0100, Jim Lesurf wrote:

Agreed. Yes I recall it. The new 22+ channel hyper vector systems seem
to be rather over-re-inventing it!

I thought you might.

That raises the question of iplayer on the RPi. Will Chrome run on the
RPi distros? It would be hard for the BBC to ignore RPi given how many
are in use now.

Yes. All we really need from the BBC is a portable library (OSS or not,
but its easier to debug if it is) that can be built into whatever app
best suits the target system. This probably means that the NRDC library
should be written in C. If its binary, that would be a pain, but at least
it would keep the BBC PHBs, of which there are too many, more or less
happy. Provided, of course, that its APIs are properly documented!


--
martin@ | Martin Gregorie
gregorie. | Essex, UK
org |

In article , Martin Gregorie
wrote:
On Sun, 20 Jul 2014 13:39:25 +0100, Jim Lesurf wrote:

Agreed. Yes I recall it. The new 22+ channel hyper vector systems seem
to be rather over-re-inventing it!

I thought you might.

That raises the question of iplayer on the RPi. Will Chrome run on the
RPi distros? It would be hard for the BBC to ignore RPi given how many
are in use now.

Yes. All we really need from the BBC is a portable library (OSS or not,
but its easier to debug if it is) that can be built into whatever app
best suits the target system. This probably means that the NRDC library
should be written in C. If its binary, that would be a pain, but at
least it would keep the BBC PHBs, of which there are too many, more or
less happy. Provided, of course, that its APIs are properly documented!

Moving sldeways back to the 4.0 stream. I'm told that the BBC are trying to
ensure that the stream conforms with the open HTML5 standards. So their
view is that *any* browser developers can support and handle the streams if
they wish. They *don't* want this to be limited to Chrome or any other one
or two browsers, or OSs. But are approaching this by way of the standards.

That makes sense to me. By default its what I'd want them to do. However I
have a recollection that the FF people said they weren't going to support
some part of this (DASH?). If so, the ball may be in the court of FF
developers, and those of other browsers.

I've asked the BBC what codec they are using given the comment that a
Chrome codec is closed.

BTW Again this morning I found the iplayer wasn't co-operating for
normal 'listen again' radio. Almost everything during recent days
was 'not available'.

Jim

--
Please use the address on the audiomisc page if you wish to email me.
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html
Audio Misc http://www.audiomisc.co.uk/index.html

On 21 Jul, wrote:

I've asked the BBC what codec they are using given the comment that a
Chrome codec is closed.

The codec for the 4.0 tests is the standard aac-lc nailed to 320kbps. AIUI
the challenge for FF, etc, is to deal with the Media Source Extension and
Audio API involved. Apparently ME11 also works. They want it work with as
many browsers, etc, as possible so nothing is 'special' or targetted at
Chrome or ME.

Has anyone with a surround system tried FF? Or is it known not to work
because it doesn't support the above?

Jim

--
Please use the address on the audiomisc page if you wish to email me.
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html
Audio Misc http://www.audiomisc.co.uk/index.html