English Amiga Board


Go Back   English Amiga Board > Coders > Coders. General

 
 
Thread Tools
Old 04 September 2003, 21:45   #1
ant512
Registered User
 
Join Date: Dec 2002
Location: California
Posts: 965
Cybiko 8SVX player in C

This is driving me insane. I'm trying to write an IFF-8SVX sample player for the Cybiko (budget PDA) in C, but cannot get the samples to play back properly.

So far, the Cybiko loads the file, but it plays back noise. The problem is (I think) that I don't actually know what the data in the sample represents.

I've found descriptions of the IFF file format, and the body of the file (the sample data itself) apparently consists of signed bytes - values between -128 and 127.

What do these signed bytes represent? At the moment, I'm treating each byte as a frequency, and playing a sound at that frequency (the actual playback frequency is arbitrary, but relative to all other sounds played back, so in theory I should get something that sounds at least vaguely like the original sample). This appears to be completely wrong.

I've looked around on Google, the Aminet, and everywhere else I can think of looking, but have come up with very little. Does this have anything to do with PCM? Do I need to decode the PCM stream, or something? Or is it something to do with cycles? I remember from my OctaMED and Blitz Basic days that the Amiga tends to use "cycles", such as "428" for middle-C, instead of Hz. Is the same true of IFF samples?

The samples I'm working with aren't compressed, so I don't think that's an issue.
ant512 is offline  
Old 05 September 2003, 02:36   #2
FromWithin
Music lord
 
FromWithin's Avatar
 
Join Date: Jun 2003
Location: Liverpool, UK
Age: 50
Posts: 630
Each byte represents a sample of the waveform in time. This should be played out as a stream of data in the Cybiko's output format.

I'd strongly suggest that you read up on digital samples before proceeding any further as you've completely got the wrong end of the stick about how it works.

Don't search for IFF or anything like, just serach for digital audio.
FromWithin is offline  
Old 05 September 2003, 09:30   #3
ant512
Registered User
 
Join Date: Dec 2002
Location: California
Posts: 965
Digital audio, eh? I'll have a look around for that. Thanks for the info!
ant512 is offline  
 


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

Similar Threads
Thread Thread Starter Forum Replies Last Post
I need An IFF/8SVX and an IFF/ANIM Player for PC searcher request.Apps 24 02 July 2020 12:09
WOW! iff 8SVX audio fatboy Amiga scene 9 16 June 2013 19:28
Stupid IFF 8SVX sample problem... Amiga1992 support.Apps 16 01 August 2010 08:45
Looking for good 8svx sounds for game SabreGolly Coders. General 6 04 January 2004 00:44
CD32 Music, IFF 8SVX And Whdload Antiriad Games images which need to be WHDified 15 18 December 2003 10:33

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT +2. The time now is 23:29.

Top

Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Page generated in 0.06420 seconds with 15 queries