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Glitch-free High-quality Internet Audio Streaming

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Oliver Schmidt

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Mar 20, 2022, 6:24:00 PM3/20/22
to
Hi,

The other day I finalized A2Stream, a program that simultaneously
receives a file from any HTTP server and plays it through the stock
Apple II speaker circuit.

Some personal background: For many years by now, I've developed and
maintained Ethernet software for the Apple II. My focus was always on
practicability, portability and reusablitiy. Often I've invested in
tools, trying to enable others to create something cool. However, for
once I wanted to do the opposite: Showing off with a tech demo that
pushes boundaries.

A2Stream follows the general concept of DAC522, but with an improved
audio quality using pulse-width modulation at 22050Hz sample rate with
~5.17 bit resolution. This sample rate is kept consistent during the
complete playback, so A2Stream is supposed to sound better than
everything else using Apple II speaker circuit so far.

Project site - https://github.com/oliverschmidt/A2Stream
Demo video - https://youtu.be/YcYEnYsI-_M

Have fun,
Oliver

Hugh Hood

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Mar 22, 2022, 10:00:44 PM3/22/22
to
Oliver,

Allow me to add my kudos to those that you've already received in the
comments section of your youtube video that demos A2Stream.

Moreover, I was very impressed by the production quality of the video
you prepared.

Nice work.




Hugh Hood

Oliver Schmidt

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Mar 23, 2022, 5:45:46 AM3/23/22
to
Hi Hugh,

>Allow me to add my kudos to those that you've already received in the
>comments section of your youtube video that demos A2Stream.

I really appreciate your nice feedback!

>Moreover, I was very impressed by the production quality of the video
>you prepared.
>
>Nice work.

Yeah, it's for sure a new dimension compared to my previous videos :-)
That's because one of my daughters produced it for me using Kdenlive.
I was barely providing the raw material...

This is her own channel:
https://www.youtube.com/channel/UC6pwcfc4GHU9PVyGl5UNkLg

Regards,
Oliver

TomCh

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Mar 25, 2022, 4:05:39 PM3/25/22
to
On Sunday, 20 March 2022 at 22:24:00 UTC, Oliver Schmidt wrote:
> Hi,
>
> The other day I finalized A2Stream, a program that simultaneously
> receives a file from any HTTP server and plays it through the stock
> Apple II speaker circuit.
>

AppleWin 1.30.9 just released with Uthernet II card support (credit to Andrea Odetti for this great work).
So this means that Oliver's wonderful A2Stream (and many other Uthernet II dependent projects) can be run under emulation.

https://github.com/AppleWin/AppleWin/releases/tag/v1.30.9.0

Tom

Oliver Schmidt

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Mar 25, 2022, 6:15:40 PM3/25/22
to
>AppleWin 1.30.9 just released with Uthernet II card support (credit to Andrea Odetti for this great work).
>So this means that Oliver's wonderful A2Stream (and many other Uthernet II dependent projects) can be run under emulation.
>
>https://github.com/AppleWin/AppleWin/releases/tag/v1.30.9.0

To celebrate AppleWin's support of the Uthernet II card - and thus
A2Stream - I've added another sample (AC/DC). Find it on
https://github.com/oliverschmidt/A2Stream

Michael J. Mahon

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Mar 25, 2022, 11:40:19 PM3/25/22
to
Oliver, this is amazing!

When I was building DAC522, I felt constrained to using 11kHz samples
because of memory limitations, and even then only a few seconds of sampled
sound would fit. That’s one reason why I wrote the wavetable synthesizers,
since they only required a limited palette of samples.

Streaming sound was unthinkable at the time, so I was blown away by
A2Stream!

Doubling the sample rate of course doubles the bandwidth, but I was really
surprised by the great fidelity and the noise reduction. At first hearing,
I thought I was listening to the source sound, not the playback!

And to do this while managing network sample streaming and an animation is
a remarkable programming feat. You’ve set a new benchmark for 8-bit Apple
II sound!

Congratulations! I hope you’ve inspired others by showing what can be
accomplished with skill and vision.

--
-michael - NadaNet 3.1 and AppleCrate II: http://michaeljmahon.com

Oliver Schmidt

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Mar 26, 2022, 9:33:43 AM3/26/22
to
Hi Michael,


>When I was building DAC522, I felt constrained to using 11kHz samples
>because of memory limitations, and even then only a few seconds of sampled
>sound would fit.

Yeah. Usually everything about the Apple II is about memory
limitations. So coming from programming the Uthernet cards, I was
asking myself: "What can be done with the Apple II if memory isn't
limited, if the CPU is the only limitation."

>And to do this while managing network sample streaming and an animation is
>a remarkable programming feat. You've set a new benchmark for 8-bit Apple
>II sound!
>
>Congratulations! I hope you've inspired others by showing what can be
>accomplished with skill and vision.

I really, really appreciate your kind acknowledgement :-)

Regards,
Oliver

Barana

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Apr 5, 2022, 2:28:47 AM4/5/22
to
ol...@web.de (Oliver Schmidt) Wrote in message:r
> Hi,The other day I finalized A2Stream, a program that simultaneouslyreceives a file from any HTTP server and plays it through the stockApple II speaker circuit.Some personal background: For many years by now, I've developed andmaintained Ethernet software for the Apple II. My focus was always onpracticability, portability and reusablitiy. Often I've invested intools, trying to enable others to create something cool. However, foronce I wanted to do the opposite: Showing off with a tech demo thatpushes boundaries.A2Stream follows the general concept of DAC522, but with an improvedaudio quality using pulse-width modulation at 22050Hz sample rate with~5.17 bit resolution. This sample rate is kept consistent during thecomplete playback, so A2Stream is supposed to sound better thaneverything else using Apple II speaker circuit so far.Project site - https://github.com/oliverschmidt/A2StreamDemo video - https://youtu.be/YcYEnYsI-_MHave fun,Oliver

I think youve just won kansasfest this year mate! The Sydney,
Australia club just got this running on a IIe at its WOZfest, and
im still digging bits of skull out of the plasterboard.
Your innovation deserves some high praise indeed.
Thanks.
--
die thensoar


----Android NewsGroup Reader----
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Oliver Schmidt

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Apr 5, 2022, 2:30:28 PM4/5/22
to
Hi,

>I think youve just won kansasfest this year mate!

I hope to present a session on A2Stream.

> The Sydney,
> Australia club just got this running on a IIe at its WOZfest, and
> im still digging bits of skull out of the plasterboard.

Hm, I'm having a real hard time to guess which song you guys were
listening too ;-))

> Your innovation deserves some high praise indeed.

Thanks for the great feedback :-)

>Thanks.

You're welcome!

Regards,
Oliver
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