In article , David Looser
wrote:
"tony sayer" wrote in message
...

You went involved in the MP2 codec tests for the development of DAB?..


No, voice codecs only, but the principle is the same. More to the point
I know just how hard it is, and the lengths we had to go to, to
eliminate bias from listening tests.

FWIW I've now had a chance to record some mp3 streams 'broadcast' by some
of the net stations. This meant I could write the results onto a CDRW and
listen to them on some players. Have examples at 128/192/256kbps. What I've
found interesting is that the results *didn't* show that the 'higher the
bitrate the better the sound'. This was a totally uncontrolled test, so is
suspect, but it does strengthen my bias towards feeling that the way the
specific encoder is used (and the details of the sound patterns to be
encoded) can matter more that the output bitrate chosen.

Slainte,

Jim

--
Change 'noise' to 'jcgl' 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

Jim Lesurf wrote:
In article , David Looser
wrote:
"tony sayer" wrote in message
...
You went involved in the MP2 codec tests for the development of DAB?..

No, voice codecs only, but the principle is the same. More to the point
I know just how hard it is, and the lengths we had to go to, to
eliminate bias from listening tests.

FWIW I've now had a chance to record some mp3 streams 'broadcast' by some
of the net stations. This meant I could write the results onto a CDRW and
listen to them on some players. Have examples at 128/192/256kbps. What I've
found interesting is that the results *didn't* show that the 'higher the
bitrate the better the sound'. This was a totally uncontrolled test, so is
suspect, but it does strengthen my bias towards feeling that the way the
specific encoder is used (and the details of the sound patterns to be
encoded) can matter more that the output bitrate chosen.

Slainte,

Jim


I don't suppose it makes a great deal of difference if you record using
a lossless format, but isn't it more logical to just capture the
streamed audio?

Rob

In article , Rob
wrote:
Jim Lesurf wrote:

FWIW I've now had a chance to record some mp3 streams 'broadcast' by
some of the net stations. This meant I could write the results onto a
CDRW and listen to them on some players. Have examples at
128/192/256kbps. What I've found interesting is that the results
*didn't* show that the 'higher the bitrate the better the sound'. This
was a totally uncontrolled test, so is suspect, but it does strengthen
my bias towards feeling that the way the specific encoder is used (and
the details of the sound patterns to be encoded) can matter more that
the output bitrate chosen.


I don't suppose it makes a great deal of difference if you record using
a lossless format, but isn't it more logical to just capture the
streamed audio?

Erm... that is what I have been doing. Recording the mp3 stream as an mp3
file on my computer. Then writing these files into a CDRW for playing on
various 'audio'/'video' disc players.

Slainte,

Jim

--
Change 'noise' to 'jcgl' 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

Jim Lesurf wrote:
In article , Rob
wrote:
Jim Lesurf wrote:

FWIW I've now had a chance to record some mp3 streams 'broadcast' by
some of the net stations. This meant I could write the results onto a
CDRW and listen to them on some players. Have examples at
128/192/256kbps. What I've found interesting is that the results
*didn't* show that the 'higher the bitrate the better the sound'. This
was a totally uncontrolled test, so is suspect, but it does strengthen
my bias towards feeling that the way the specific encoder is used (and
the details of the sound patterns to be encoded) can matter more that
the output bitrate chosen.


I don't suppose it makes a great deal of difference if you record using
a lossless format, but isn't it more logical to just capture the
streamed audio?

Erm... that is what I have been doing. Recording the mp3 stream as an mp3
file on my computer. Then writing these files into a CDRW for playing on
various 'audio'/'video' disc players.


No, you're not capturing the *stream* AIUI, you're capturing the audio
once it's been through your sound card, and you've then converted it
again to mp3.

To use a video analogy, you're allowing video to stream through your
media player, assuming your clockwork computer has such a thing, and
capturing the video using screen capture software. Better to capture the
stream before it hits software.

If you are going to do it your way (recalcitrance on software noted!)
you're better as a point of accuracy to use lossless capture, and then
do whatever you need in terms of compression. You're still taking a
(tiny) hit through the D-A-D conversion though. I think you might also
have a problem if different compression codecs are used at source (radio
station) and destination (your end).

Stream capture captures the data before it hits the sound card - I use
Xstreamripper. Quality isn't that much of an issue for me - but what
capturing the stream does is record the song data which also contains
things like artist, album and song, so you can save it as a nice
labelled file. I happen to listen to non-English stations so this works
well for me. This also happens to be the 'purest' and quickest method of
capturing the audio.

As ever, happy to stand corrected ;-)

Rob

In article , Rob
wrote:
Jim Lesurf wrote:


Erm... that is what I have been doing. Recording the mp3 stream as an
mp3 file on my computer. Then writing these files into a CDRW for
playing on various 'audio'/'video' disc players.


No, you're not capturing the *stream* AIUI, you're capturing the audio
once it's been through your sound card, and you've then converted it
again to mp3.

Erm, again. My computer doesn't have a 'sound card'. I use an application
(software) that can fetch the steam and this can then either save it to a
file and/or covert it for playing.

To use a video analogy, you're allowing video to stream through your
media player, assuming your clockwork computer has such a thing, and
capturing the video using screen capture software. Better to capture the
stream before it hits software.

You may be right. However I wonder if you know much about how my computer
system works. It is easy to presume that what happens with the OS/hardware
you are accustomed to is 'universal'.

Slainte,

Jim

--
Change 'noise' to 'jcgl' 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

Jim Lesurf wrote:
In article , Rob
wrote:
Jim Lesurf wrote:

Erm... that is what I have been doing. Recording the mp3 stream as an
mp3 file on my computer. Then writing these files into a CDRW for
playing on various 'audio'/'video' disc players.


No, you're not capturing the *stream* AIUI, you're capturing the audio
once it's been through your sound card, and you've then converted it
again to mp3.

Erm, again. My computer doesn't have a 'sound card'. I use an application
(software) that can fetch the steam and this can then either save it to a
file and/or covert it for playing.

To use a video analogy, you're allowing video to stream through your
media player, assuming your clockwork computer has such a thing, and
capturing the video using screen capture software. Better to capture the
stream before it hits software.

You may be right. However I wonder if you know much about how my computer
system works. It is easy to presume that what happens with the OS/hardware
you are accustomed to is 'universal'.


I may be wrong - which is it to be? Could you tell me a little about the
'capture' software you use, such as the name?

Cheers, Rob

In article , Rob
wrote:
Jim Lesurf wrote:


I may be wrong - which is it to be? Could you tell me a little about the
'capture' software you use, such as the name?

It is based on a RO application called !DigitalCD. With this you can get a
set of modules that decode/play various formats, etc. There is also a
utility to record what is being presented for playing and I've been
experimenting with that. The utility will also fetch the stream if given a
URL so works even with the player not playing. So I can record with or
without listening as I wish. (The snag being knowing when to start/stop
recording if I canna hear what is happening!)

Note that you need a RO machine for the system to work. (It may work with
an emulator, but I can't say.) However the code for what I'm using is based
on source code provided as an example. This is in 'C' so if you can follow
'C' you can read it.

http://users.skynet.be/Andre.Timmerm...r/download.htm

The above is the URL for the main page about this.

if you download the zips, note that the example program for recording is
buried in one of the documents folders (directories). IIRC To find this,
look in the 'docs.zip' file's Docs.Disksample.Example directory for the
DiskPlay command line tool. I've been basing my recordings on this code. It
allows you to choose either the input stream or the results decoded to
LPCM.

Note again that the compiled versions *don't* run under windows or macs or
linux. They require ARM type CPUs and the RO hardware and architecture. But
the 'C' should be clear to programmers. But I'm afraid I can't comment on
how you'd do this on other systems as it involves things like interrupt
controlled buffers, etc. I've modified what is given, but can't say I fully
understand it! Happy enough with what I can do with my "clockwork
computer"... :-)

Good luck. :-)

Jim

--
Change 'noise' to 'jcgl' 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 , Jim Lesurf
scribeth thus
In article , David Looser
wrote:
"tony sayer" wrote in message
...

You went involved in the MP2 codec tests for the development of DAB?..


No, voice codecs only, but the principle is the same. More to the point
I know just how hard it is, and the lengths we had to go to, to
eliminate bias from listening tests.

FWIW I've now had a chance to record some mp3 streams 'broadcast' by some
of the net stations. This meant I could write the results onto a CDRW and
listen to them on some players. Have examples at 128/192/256kbps. What I've
found interesting is that the results *didn't* show that the 'higher the
bitrate the better the sound'. This was a totally uncontrolled test, so is
suspect, but it does strengthen my bias towards feeling that the way the
specific encoder is used (and the details of the sound patterns to be
encoded) can matter more that the output bitrate chosen.


And where it came from in the first place...
Slainte,

Jim


--
Tony Sayer

"Jim Lesurf" wrote in message

In article , David Looser
wrote:
"tony sayer" wrote in message
...

You went involved in the MP2 codec tests for the development of
DAB?..


No, voice codecs only, but the principle is the same. More to the
point
I know just how hard it is, and the lengths we had to go to, to
eliminate bias from listening tests.

FWIW I've now had a chance to record some mp3 streams 'broadcast' by
some
of the net stations. This meant I could write the results onto a
CDRW and
listen to them on some players. Have examples at 128/192/256kbps.
What
I've found interesting is that the results *didn't* show that the
'higher
the bitrate the better the sound'. This was a totally uncontrolled
test,
so is suspect, but it does strengthen my bias towards feeling that
the
way the specific encoder is used (and the details of the sound
patterns
to be encoded) can matter more that the output bitrate chosen.


It is ridiculous to suggest that using a higher bit rate lowers the
audio quality, right?

The reality is that you're just using the garbage-in garbage-out
principle to stick up for the use of low bit rates.

And this is supposed to be a NG on audio. Strewth.



--
Steve - www.digitalradiotech.co.uk - Digital Radio News & Info

The adoption of DAB was the most incompetent technical
decision ever made in the history of UK broadcasting:
http://www.digitalradiotech.co.uk/da...ion_of_dab.htm