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PLAY590 VERSION 1.0 RELEASE DOCUMENTATION Written November 13th 1990 by Mark Everingham INTRODUCTION The quality of sound obtainable from the Amiga using a sound-sampler is truly amazing, often being completely indistinguishable from the real thing. However, the main problem with sound sampling is that it does require huge amounts of memory. At a reasonable sample speed, say 16Khz, the maximum length sample on an unexpanded A500, is about half a minute, and even with 3Mb of ram, two minutes is about the limit. I recently (and so it would seem from letters in Format did many readers) bought an A590 hard-disk, and imagined just what could be done with all that disk-space. Imagine, with a 20Mb hard-disk, you could have a continuous sample over twenty minutes long, and with a 40Mb drive you could digitize a whole album in one go! With these thoughts in mind, I wrote Play590, which allows you to play mono or stereo samples at speeds up to 32KHz from any AmigaDOS file. Although the program works best with a hard-disk, as reflected by the name, Play590 will also work with floppy-disks at speeds up to about 12KHz, and can be used to play samples from fast ram by using any standard ram-disk driver, for example RAM, RAD or VD0. There are no limits imposed on the length of the samples to be played other than the capacity of the storage device they are kept on. By sampling chunks of sound using a standard sampler package, then saving to disk and linking together using the AmigaDOS JOIN command, samples of theoretically infinite length can be created. I currently have two 6Mb samples on my hard-drive! Amazingly, Play590 is also very friendly from a multi-tasking point of view. Playing from an A590 hard-disk at 16Khz the program only uses about 2% processor time although floppy-disk access requires considerably more processor time. If you boost Play590's priority to above zero, you can fiddle with workbench, generate a few mandelbrots and even load programs off the same hard-disk Play590 is using while enjoying continuous uninterrupted music. Doing a bit of DTP with PageSetter II while Handel's water-music plays away in the background, or drawing a mandelbrot set to the tune of J.M Jarre's "Oxygene" is a a pretty wild experience (even if I do say so myself)... GENERAL INFORMATION (i) Sample File Formats Play590 will work correctly with samples created using any sound-sampler package saved in the RAW (non IFF) format. If your sampler cannot generate RAW files, you can still use IFF 8SVX files, as you probably won't be able to hear the IFF header information as it is so short. You can in fact play any file, for example the CLI commands, although the results are not guaranteed to be very musical! (ii) Mono and Stereo Samples Play590 will play samples in either mono or stereo at any speed up to 32767Hz. On a hard-disk it is quite possible to play stereo samples, at full speed, but on floppies, the maximum I've achieved successfully is 12Khz in mono. Use of a good disk-optimiser such as B.A.D may enable higher speeds to be achieved. To play samples in stereo, you must have the left channel stored in one file, for example "Music.L" and the right channel stored in another, for example "Music.R". Both samples in stereo are played at the same speed. If you want to play more than two samples at a time, for example if you have a four-track recorder, then you can just run two copies of Play590, one for each pair of samples. (iii) Playing Samples from Memory Play590 can be used in the same way as a conventional sample-player such as BMP by copying the sample files you want to play into a ram disk. This also allows you to play samples which will not fit in chip ram. (iv) Memory Requirements Because Play590 only stores a small amount of a sample in chip ram at one time, it is quite economical on memory, working fine on an a 512k Amiga. You can specify the size of the chip ram buffer which Play590 uses for its samples, and the total chip ram used can be calculated as follows: Chip ram used = buffersize * 2 * (2 if stereo) In order to keep the sample playing perfectly smooth, Play590 uses double-buffering techniques, so the buffersize must be multiplied by two to find the total memory used. If you are playing stereo samples, the memory needed is doubled. Play590 defaults to a buffersize of 32Kb, thus using 64Kb to play mono samples, or 128Kb for stereo samples. You can specify a buffersize between 0 and 64Kb, but bear in mind that the smaller the buffersize, the more processor time the program uses. I have found through practice that 32Kb is a good compromise between processor and memory usage. (v) Audio Channel Allocation When playing a mono sample, Play590 uses the first audio channel it can find, which may be either left or right. When playing stereo samples, or mono samples in the pseudo-stereo mode, Play590 uses a left & right channel pair. If it cannot allocate the correct channels, an error will be generated. RUNNING PLAY590 Play590 may be run either from the CLI, Workbench, or in a script-file. If you like, Play590 can open a title window so that you can abort the playing of a sample, or you can choose to have no window, making Play590 suitable for use in a demo of your own making. Play590 can also be run as a background task allowing the CLI or Shell window to be closed after running it. CLI AND SCRIPT-FILE USAGE Play590 has a number of special options which can be specified from the CLI or in a script-file using options of the form "-<option>[value]". You can specify most of these options anywhere in your command-line, in any order, before or after the filenames of your samples and options may be in either upper or lower-case. The only restriction imposed is that the file-name of your samples must not begin with a hyphen ("-") character. The recommended format of the command-line is as follows:- Play590 <samplename1> [samplename2] [option 1] .. [option n] or Play590 [option 1] .. [option n] <samplename1> [samplename2] If the file-names of your samples include spaces, you can enclose the names in quotes ('"'). As I have mentioned, Play590 can also be run in the background so that you can close down your CLI/Shell or terminate your script-file. You can either use the Workbench 1.3 (not 1.2) RUN command or the RUNBACK command to run Play590 in the background. This is shown below. Standard RUN command: RUN >NIL: Play590 <samplename1> etc.. or: RUNBACK command: RUNBACK Play590 <samplename1> etc.. I would personally recommend using the RUN >NIL: command, since it is a standard AmigaDOS command, which nobody ever seems to use! (i) CLI Command Line Options -S<speed> (1-32767) The -S (SPEED) option is the most important of the options, being used to specify the speed at which your samples will be played back. The speed is specified in Hertz - If your sample was recorder at say 20KHz, use 20000, or if at 1.23Khz, use 12300. If you do not specify a speed option in your command-line, the default speed of 16Khz will be used. -W The -W (WINDOW) option is used to specify that you DO want Play590 to open a title window. This window just shows that Play590 is running, and can be used to stop a sample playing by clicking on the close gadget. By default, Play590 does not open a window when run from the CLI since this is more suitable be script-file usage. Be warned though that if you don't open a window, there is no way of aborting a sample. -R<repeats> (0-32767) The -R (REPEATS) option is used to specify how many times Play590 will play your samples. If you specify a value between 1 and 32767, Play590 will play the samples that number of times and then stop. If you specify a value of zero, Play590 will repeat the samples forever, or until the close gadget on its window is activated. By default, Play590 plays the samples once then stops. -V<volume> <0-64> The -V (VOLUME) option is used to specify how loud Play590 plays your samples. Zero (0) is inaudible, and 64 is maximum loudness. The default volume is 64. -F The -F (FILTER) option enables you to switch the low-pass filter (power light) off on a post A1000 Amiga, improving the sound quality on certain types of sounds. If you do not specify this option, the filter will be left on. -B<buffer> <1-65535> The -B (BUFFER) option specifies how much chip ram Play590 will use for each of its sample buffers, as discussed earlier. You specify the value in bytes, with 1 being 1 byte (not recommended!) and 65535 being 64Kb. The default value is 32Kb (32768 bytes). -P<priority> (-128..127) The -P (PRIORITY) option specifies the priority at which the Play590 program runs, between -128 and +127. This option is equivalent to running Play590 and then using the CHANGETASKPRI command. The default priority is that of the current CLI, which is usually zero. If you want to make sure that Play590 is never interrupted, you can set the priority above zero (10 is a good value). It is unadvisable to use values above +10 or below -10, as this is seriously unfriendly to the operating system. -2 The -2 (STEREO) option lets you play a single sample as if it were a stereo sample, like playing a mono cassette on a stereo cassette- player. This option makes Play590 use two audio channels - a left and right pair, and play the same sample on both channels. It does however use more processor time than playing in true mono. <samplename1/2> The only other command-line arguments are the names of the sample files themselves. Usual AmigaDOS file-name restrictions apply. (ii) Example Command Lines Play590 "DF0:MySample" -S28000 - Play the mono sample "DF0:MySample" once at 28KHz. RUN Play590 "DH1:Sample.L" "DH1:Sample.R" -s18000 -r0 -w -p10 - Open the Play590 window and play the two samples specified as a stereo pair at the speed of 18KHz. Keep repeating the samples until the user closes the Play590 window (or the world ends...). Boost Play590's priority to +10 to make sure the samples are never interrupted. RUN Play590 "RAM:MonoSample" -S12000 -2 -F -V32 - Play the mono sample as if it were a stereo sample, on a pair of left and right channels. Turn the low pass filter off to improve the sound quality, and play the sample at half volume. Play590 "Sample" - Play the (imaginatively titled) sample "Sample" using all the default settings. WORKBENCH USAGE For those who go weak at the thought of entering the untold horrors of a CLI or Shell window, Play590 can also be run from the Workbench. You can use of the CLI command-line options by using the Workbench INFO tool, and can choose the samples you want to play either by specifying their names using the INFO tool again, or by shift-clicking with the Play590 icon. (i) Specifying Sample File-Names In order for Play590 to run, you must specify one or two samples for it to play. There are three ways of doing this. (a) Using the Workbench INFO tool Using the Workbench INFO tool, add a tooltype entry (select the ADD tool) as shown below:- SAMPLE1=<samplename1> or: SAMPLE2=<samplename2> You replace <samplename> with the filename of a sample. Note that you cannot use quote characters to enclose the name, but can use spaces in the name without them. As with all other tooltype options, you must use UPPER CASE, so "SAMPLE1" will work, but "sample1" will not. If you are playing only a mono sample, you can use either SAMPLE1 or SAMPLE2, it does not make any difference which. When playing two samples in stereo, SAMPLE1 is the left sample and SAMPLE2 the right sample. (b) Shift-Clicking with Sample Icons The second way to specify samples to be played by Play590 is to shift-click on an icon representing a sample. This method only works if (a) your samples have an icon, and (b) the icon is of the type PROJECT. To play a mono sample, just click on the sample icon, then double- click on the Play590 icon while holding down the <SHIFT> key. To play two stereo samples, click on the left sample icon, then click on the right sample icon while holding down <SHIFT>, then double- click on the Play590 icon while still holding down <SHIFT>. Note that for the samples to play on the correct channels, you must click on the left sample first. (c) Setting a Sample Icon's Default Tool The third way to play a sample with Play590 is to set the default tool of a sample, although this method may only be used for playing mono samples. Again, you must have an icon for a sample, and the icon must be of type PROJECT. Using the Workbench INFO tool, change the "Default Tool" setting of the sample icon to "DF0:Play590/Play590" or whatever name you have given to the Play590 program on your floppy or hard-disk. Select SAVE, then to play your sample, just double-click on the sample's icon. (ii) Workbench Tool-Type Options When running Play590 from the Workbench you can use all the options which are available from the CLI command-line. This is done using the Workbench INFO tool. To specify an option, you just ADD a tooltype entry to an icon. You can specify these tooltype options either in the Play590 icon itself, or in the icon of a sample to be played. Tooltypes entered in the Play590 icon may be regarded as default selections, and will be overridden by tooltypes specified in a sample icon. Here is an example, of setting the default speed of the Play590 tool, and the specific speed of an individual sample. Click on the Play590 icon, and select the INFO option from the Workbench menu. Click on the ADD gadget, and type in "SPEED=20000". Select the SAVE gadget to finalize your choice. This specifies that when Play590 is run from its icon, by default it will use a speed of 20000Hz or 20KHz. Now click on a sample icon, and repeat the process, adding a tooltype entry "SPEED=25000". SAVE this, and try playing this sample. You will notice that the sample plays back at 25KHz not 20KHz, since the tooltype in the sample overrides the tooltype in the Play590 icon. If you now delete the tooltype from the sample icon, it will then play at 20KHz again. Note that if you don't specify any tooltypes, the global Play590 default values are used, and these values are included below. Remember that you must use UPPERCASE for each option. SPEED=<speed> (1-32767) Set the sample playback speed: See "-S" option. Default value: 16000. WINDOW=<ON|OFF> Switch the Play590 window on or off: See "-W" option. Default value: ON. REPEATS=<repeats> (0-32767) Set the number of repeats: See "-R" option. Default value: 1. VOLUME=<volume> (0-64) Set the playback volume: See "-V" option. Default value: 64. FILTER=<ON|OFF> Switch the low-pass filter on or odd. Default value: ON. BUFFER=<buffer> (1-65535) Sets the sample buffer size. See "-B" option. Default value: 32768. PRIORITY=<-128..+127> Sets priority at which Play590 runs. See "-P" option. Default value: 0. MODE=<STEREO|MONO> Chooses either (pseudo-)stereo or mono playback for single samples. See "-2" option. Default value: MONO. SAMPLE<1|2>=<samplename> These options specify the files to be played by Play590 when the tool is double- clicked by itself. You must delete these entries if you want to play other samples by shift-clicking. There are no default settings. PLAY590 ERROR MESSAGES When something goes wrong while Play590 is trying to run (as it inevitably will at some point), the program will generate an error message. If you run the program from the CLI, the error message will be printed and the program will terminate. When run from Workbench, Play590 will display the error message in the title-bar of the Workbench screen. If you have run Play590 in the background, which means that no print-out is possible, the program will just terminate with a returncode of 20 indicating an error serious enough to stop a script-file executing. These error messages and their meanings are listed here. "Bad arguments" When run from a CLI, you have specified an illegal number of arguments, or an option which Play590 does not recognize. When run from the Workbench, this error indicates an error in a tooltype entry. "Illegal argument value" You have specified a value for an option in your command-line or tooltypes which is outside the valid range. "No sample files specified" You did not specify any sample files to be played. For example, 'Play590', or running from Workbench with no icons selected. "Unable to open intuition library" Play590 could not open the ROM intuition library. This either indicates a lack of memory, or serious problems with your Amiga! "Unable to open window" Play590 could not open its title window. This usually indicates a lack of free chip memory. "Unable to open sample file" A sample file which you specified in your command-line or tooltypes could not be opened. This is probably a typing error or incorrect pathname. "Unable to open audio device" Play590 could not open the audio device or allocate enough audio channels to play your samples. Either another program is already using too many of the Amiga's four audio channels, or a crashed program has not released its channels for re-use. "Unable to open icon library" This error should only occur when Play590 is run from the Workbench. It indicates that the disk-based icon library could not be opened. For Play590 to work from Workbench, the file "icon.library" must be in the current "LIBS:" directory. However, since Workbench itself needs the icon library in order to run Play590, I would be surprised if you ever come across this error! "Out of memory" Anyone care to hazard a guess at what this one means? If you don't see this error once in a while, I'll eat your hat. And that's it! I hope you find Play590 fun, or useful, or whatever. If you find any bugs, can suggest any improvements, or are just feeling generally well-disposed (note, not to people Douglas), write to me, and a PD disk will guarantee 0% a reply. Mark Everingham 17 Collingwood Road Redland Bristol BS6 6PD