Information in this page updated: 23 Sep 95
Short: Play and save digital audio Author: mlelstv@specklec.mpifr-bonn.mpg.de Uploader: mlelstv@specklec.mpifr-bonn.mpg.de Type: disk/cdrom Read audio data from a CD-DA disk (normal audio CDs) and play back via audio.device (22kHz) and store to outputfile either in 16bit, stereo, 44.1kHz AIFF or in 8bit, mono or stereo, 22.05kHz 8SVX. >> This is a small bug fix to version 1.11 which missed to set the SCSIF_WRITE flag when selecting the CDDA transfer mode of Toshiba drives. >> usage: cdda START,LENGTH,TRACK,VOL/N,FILE,8SVX,16BIT/S,MONO/S,MUTE,LIST/S,DEBUG/S,BUFS/N,PLAN START = startblock LENGTH = number of blocks TRACK = start relativ to track number VOL = volume in percent (0..800) FILE = file to save to 8SVX = use 8SVX format instead of AIFF 16BIT = experimental high resolution mode for audio output MONO = map stereo to single channel MUTE = disable audio output completely LIST = show table of contents DEBUG = print lots of debugging info through debug.lib (use sushi!) BUFS = number of CD blocks to do in a single read.. default is 16 PLAN = method to access the CD-ROM, current plans are 'a' and 'b' 'a' is for Sony CDU 8003 and compatible 'b' is for Toshiba XM3401TA and compatible the program detects some drives itself but you can force it to use a specific plan with that option You can use the environment variables CDDA_DEVICE and CDDA_UNIT to choose something else than the default ("scsi.device" and 2). To accomodate for older device drivers you can ask for a specific memory type used for all SCSI-direct buffers. This is done with the environment variable CDDA_BUFMEMTYPE. A value of 2 asks for chip memory, a value of 512 asks for memory reachable by Zorro-2 DMA controllers. Even for controllers that do not need a specific memory type it might show better performance. There's a tiny program called 'led' in the archive which toggles the audio lowpass filter on newer machines. Disabling the lowpass filter will usually get better audio quality but may cause aliasing distortion depending on the bandwidth of your speakers. Version 1.11 and newer of this program no longer saves data in RAW format. Instead it writes an AIFF header so that other programs can easily identify the data. If you select the 8SVX switch then cdda will write in IFF 8SVX format instead. 8SVX output is affected by the VOL and MONO setting so that you can scale the output for maximum dynamic range within the 8 bits of 8SVX, you can also select either mono or stereo output. 8SVX samples are reduced to a sample rate of 22050Hz for easy play back with any Amiga 8SVX player. Actually you get exactly what you hear from cdda. Saving in 8SVX stereo has a slight problem since 8SVX saves each channel in a contigous part of the file. cdda will alternate between both channels which causes lots of head movement and is therefore much slower.. usually too slow for a smooth audio output. I suggest to MUTE audio when saving 8SVX stereo files. Michael van Elst