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Amiga computer related discussion => Amiga Hardware Issues and discussion => Topic started by: gizz72 on December 15, 2011, 12:57:20 PM

Title: SID loves Paula
Post by: gizz72 on December 15, 2011, 12:57:20 PM
Greetings,

I used to connect my C64c, back in the late 90's, on a HIFI system while playing Turrican. I was awsome! Then connecting an Amiga500+, playing the same game was awesomer! Then came MP3, it began to sound like really bad! Specially those with 128mhz frequency. Old Paula did not stand a chance! I had to convert these MP3 to Amiga Audio IFFs to be able to achive a better sound quality, but in MONO. Emulating SID with Paula did sound good as well! With these classic machines, I find SID plays better along if Paula makes the beats and rythms, I bet it would sound alot better than an MP3 and plugged on a hifi!

Regards,

GiZz72
Title: Re: SID loves Paula
Post by: Tension on December 15, 2011, 07:08:19 PM
You're comparing analogue and digital.
Title: Re: SID loves Paula
Post by: Zac67 on December 15, 2011, 08:03:57 PM
Quote
... those with 128mhz frequency.


I suppose you mean 128 kb/s? For decent MP3 quality you need at least 192 kb/s, I mostly use 256 kb/s.
Title: Re: SID loves Paula
Post by: tone007 on December 15, 2011, 08:22:55 PM
(http://blog.prosperyourmind.com/wp-content/uploads/2010/10/tumblr_l4fnymv1Sn1qb3a60o1_400.jpg)

...oh, wait.
Title: Re: SID loves Paula
Post by: Crumb on December 15, 2011, 08:45:31 PM
Quote from: Zac67;671507
I suppose you mean 128 kb/s? For decent MP3 quality you need at least 192 kb/s, I mostly use 256 kb/s.


Encoder used also helps. Fraunhofer one achieved better results than LAME in the tests I did in the past. Avoiding quick-modes also helps as these quick compression modes degrade quality quite a lot.
Title: Re: SID loves Paula
Post by: freqmax on December 16, 2011, 12:42:06 AM
I compressed some "Jean-Michel Jarre" to mp3 using Fraunhofer. And I had to use 256 kbit/s "slow"-mode for some of them. They just wouldn't sound right otherwise. The other clue is that that kind of music consist of many quite pure sinewaves. It wouldn't be a far stretch to imagine that SID and Paula have similar characteristics and thus compress badly. Especially when the algorithm tries to skip sinewaves it think won't be missed. And the same waves makes up the music.
The software implementation of the algorithm also tend to cut frequencies above 16 kHz.

I would recommend the lossless compression algorithm FLAC (https://en.wikipedia.org/wiki/FLAC).
Title: Re: SID loves Paula
Post by: commodorejohn on December 16, 2011, 12:45:20 AM
I've never noticed much lossage with Mr. Jarre (even at 160kbps.) But I will tell you what, you take something with isolated cymbal sounds ("Lark's Tongues in Aspic, Part One" or "The Sailor's Tale" by King Crimson, for example) and 128kpbs MP3 will absolutely murder them.
Title: Re: SID loves Paula
Post by: Zac67 on December 16, 2011, 07:33:51 AM
Quote
The other clue is that that kind of music consist of many quite pure sinewaves.


Actually, sines can be reproduced very accurately in MP3 since it works by splitting a sample into its frequency portions (via FFT).
Title: Re: SID loves Paula
Post by: hooligan on December 16, 2011, 08:46:03 AM
Sometimes it doesn't help even if you use 320kb/s.. a song of mine has fuxxored low frequencys on any bitrate, while OGG performs a lot better.

remember the times when 128kbs mp3 was marketed as "cd-quality" :)
Title: Re: SID loves Paula
Post by: hooligan on December 16, 2011, 08:49:12 AM
Quote from: gizz72;671477
I had to convert these MP3 to Amiga Audio IFFs to be able to achive a better sound quality, but in MONO.


So you converted already screwed stereo sound into another format in mono and it sounded BETTER? :confused:
Title: Re: SID loves Paula
Post by: gizz72 on December 16, 2011, 09:18:07 AM
Quote from: hooligan;671562
So you converted already screwed stereo sound into another format in mono and it sounded BETTER? :confused:


Yes, once converted to iff audio, it sounded better than being played directely as MP3 which sounds more like the tone of a bell. I use a converter program called mp3 to iff from aminet.

@zak67 Thanks for the correction. Not much an expert on this things, but I know a good sound when I hear it. ;)
Title: Re: SID loves Paula
Post by: hooligan on December 16, 2011, 10:06:17 AM
Quote from: gizz72;671569
Yes, once converted to iff audio, it sounded better than being played directely as MP3 which sounds more like the tone of a bell. I use a converter program called mp3 to iff from aminet.


This conversion alone can not make it sound "better" ... due to stereo -> mono it can sound DIFFERENT as the soundfield has changed, but no way it can sound better at least when it comes to soundquality. Granted, it can sound better in yours ears depending on audio source (mods have 2+2 channels for example, mixing them as mono might sound more pleasing to ear)

If I paint my car from black to white, it doesn't make it better.. yes, more pleasing to an eye, but not better ;-)
Title: Re: SID loves Paula
Post by: Britelite on December 16, 2011, 10:37:16 AM
Quote from: hooligan;671572
This conversion alone can not make it sound "better" ... due to stereo -> mono it can sound DIFFERENT as the soundfield has changed, but no way it can sound better at least when it comes to soundquality. Granted, it can sound better in yours ears depending on audio source (mods have 2+2 channels for example, mixing them as mono might sound more pleasing to ear)


Actually, if he replayed the mp3's on the Amiga with some crap AHI-settings and/or bad mp3-decoder, then the IFF-file might actually sound better on the Amiga :)
Title: Re: SID loves Paula
Post by: bloodline on December 16, 2011, 10:43:54 AM
Quote from: Britelite;671575
Actually, if he replayed the mp3's on the Amiga with some crap AHI-settings and/or bad mp3-decoder, then the IFF-file might actually sound better on the Amiga :)
Actually that is true... I had an integer decoder that played mp3's in "real time" that sounded horrible compared to the "offline" floating point decoder that converted the mp3 to a wav file (if my memory serves).
Title: Re: SID loves Paula
Post by: psxphill on December 16, 2011, 10:44:34 AM
Quote from: Britelite;671575
Actually, if he replayed the mp3's on the Amiga with some crap AHI-settings and/or bad mp3-decoder, then the IFF-file might actually sound better on the Amiga :)

Also real time playback of mp3 on the Amiga was pretty CPU intensive, you could help it by dropping the quality. If that is what he is comparing then it may be true. Although the mono/stereo thing sounds like something in his Amiga may have been broken, once in IFF then stereo should be fine.
 
Having the AHI sample rate set low could explain his problem. Or if he was outputting 14bit audio and it was't calibrated properly.
 
I'm intrigued what setup he had, an 030@50mhz (which is what I had) was still too slow for full quality mp3 playback.
 
I quite like the crunchy sound of low sample rate audio after hearing digital samples on the c64 for so long, so it didn't bother me that much.
Title: Re: SID loves Paula
Post by: hooligan on December 16, 2011, 11:33:55 AM
Quote from: Britelite;671575
Actually, if he replayed the mp3's on the Amiga with some crap AHI-settings and/or bad mp3-decoder, then the IFF-file might actually sound better on the Amiga :)


True :)
Title: Re: SID loves Paula
Post by: itix on December 16, 2011, 11:55:37 AM
Quote from: gizz72;671477
Emulating SID with Paula did sound good as well! With these classic machines, I find SID plays better along if Paula makes the beats and rythms, I bet it would sound alot better than an MP3 and plugged on a hifi!


It sounds better because PlaySID emulation is far from accurate. Especially digitized samples sound better on Paula because technique to replay sample data is completely different than in the original SID chip.
Title: Re: SID loves Paula
Post by: commodorejohn on December 16, 2011, 03:38:07 PM
Quote from: psxphill;671577
I quite like the crunchy sound of low sample rate audio after hearing digital samples on the c64 for so long, so it didn't bother me that much.
It depends on the kind of music, but yeah, when it's something actually written with that in mind, it has an enjoyably raw feel to it.
Title: Re: SID loves Paula
Post by: freqmax on December 16, 2011, 03:54:25 PM
Quote from: Zac67;671559
Actually, sines can be reproduced very accurately in MP3 since it works by splitting a sample into its frequency portions (via FFT).


More precisely many C64 sounds are square, triangle, sine, noise modified in frequency and amplitude vs time. And likely to contain many high frequencies to make it sound right. Exactly the frequencies that lossy compression will remove.

Also intentionally used misaligned sample frequencies on Amiga can suffer in the compression process.
Title: Re: SID loves Paula
Post by: commodorejohn on December 16, 2011, 04:10:55 PM
SID doesn't generate sine waves - that third one is saw.