home *** CD-ROM | disk | FTP | other *** search
- AP Tracker Version 2
- ====================
-
- This help text details the new features present in version 2 of "AP
- Tracker". For instructions on how to use the program from scratch, you
- are advised to first read the text file "Version1", which, though
- referring to Version 1 of the software, is also applicable to this later
- release due to the upward compatibility. Those already familiar with the
- software should refer only to this text in order to avoid having to read
- about features with which they are already familiar.
-
- Module Additions
-
- As with version 1, AP Tracker version 2 uses a public domain music
- playing module for most of the sound generating bits such as playing
- tunes/patterns. However, the module used by AP Tracker version 2 has
- itself been updated, and the extra features have thus been carried
- through to "AP Tracker". Significantly, "E" (set stereo) commands with
- out of range parameters no longer force the computer to crash, which
- will certainly prove to be a relief to anyone who has had it happen to
- them. Also, command "S" (set speed) has had its parameter range
- extended, and now can take variables in the range 0-&1F (31), allowing
- slower playing of tunes and greater compatibility with music converted
- from the Amiga which uses this facility. Note that, although the module
- has been improved in the time between the release of version 1 and
- version 2 of AP Tracker, it still retains the same version number (4.09
- [development]). You may therefore encounter problems if you have the
- older version 4.09 of the module installed (as the computer will not
- recognise the newer version as such). To solve this, clear the module
- area before loading version 2, load the new version explicitly by double
- clicking on the "PlayMod" file within the application directory, or
- simply replace all of your old copies of version 4.09 with the newer
- module (though you will still have to clear the old version from memory
- in this last case).
-
- Program Additions
-
- One of the first things you may notice if you have used Version 1 of the
- program is that the full help text is no longer built in to the program
- and must be read from outside of it. While an on-line help was
- undoubtedly a very nice feature, it was also rather a burden on memory,
- as it all had to be in the computer's memory all the time the program
- was being used - even if a user was experienced enough never to need to
- refer to it. As a measure of just how much memory this took up, by
- removing this feature in version 2 (and compressing the !RunImage file
- slightly), I have been able to add all of the new features detailed
- below while keeping the Wimp slot the same (224 kilobytes). The full
- help has therefore now been replaced by just one screen of text
- detailing the principal keyboard controls.
-
- Virtually every area of the program has been updated in some way, and
- the additions to each part are listed below. As well as this, one
- completely new section, the Sample Editor, has been introduced, and the
- explanation for this follows those for the new features of the other
- sections.
-
- Desktop Operations
- ==================
-
- This is the part of the program which has changed least, as I have
- really just honed some existing routines rather than introduce any new
- ones. You may notice that there is now an extra option on the "Save"
- submenu. This is for saving details of the synthetic sound currently
- being edited (see later). While on the subject of filing, I have also
- removed the "Convert from Sound Tracker?" and "Convert from Octalyzer?"
- messages, and if you had grown as irritated of them as I had, you will
- probably appreciate this. To check on the initial format of a tune, you
- should now check the tune author field (or watch for the appearance of
- the hourglass when loading which signifies that some form of conversion
- is taking place).
-
- Coconizer conversion has also been enhanced in several ways. Firstly, if
- you load a song (just pattern data, not samples) as opposed to a track
- file, the sample names are copied into the slots, which should aid later
- reconstruction. Secondly, some provision is made for the 8 octave range
- of Coconizer compared to the 3 octave range for Tracker. AP Tracker 2
- does this by allocating vacant sample slots to higher or lower versions
- of existing instruments. For example, all notes played above octave 2
- (Coconizer) on instrument 5 may be translated to notes played on octaves
- 1 and 2 (Tracker) on instrument B, and the sample name for B will be
- changed to reflect this. It is left to the user to create the higher or
- lower versions of the instruments, but this can be accomplished with
- ease using the Resample feature of the sample editor. The parameters for
- the resample are also placed in the sample name, and so this should be
- relatively easy to do. The resample function is a fairly complicated
- feature, so if you do get stuck trying to convert a tune, I can convert
- it for you if you send me a copy (my address is at the end of this
- text).
-
- Another very slight alteration which has taken place is that when you
- create a tune using the "Create" option from the main menu, the stored
- pattern length (on the "Settings" window) is taken into account when
- creating the pattern (and, as before, for each subsequent pattern
- created). I have also (hopefully) cured the problem in Version 1 where
- if you altered the tune or author name for a piece of music, they did
- not always register properly. A small problem whereby dragging save
- boxes did not work properly in screen modes such as 16 or 24 has also
- now been fixed.
-
- The only other real additions are to be found on the "Amend Track"
- window. Whereas before there was a single "Insert Voice" option, there
- are now two, "Insert After" and "Insert Before", allowing more control
- of (and less confusion over) exactly where a newly created voice will be
- inserted. There is also a "Tidy Sample List" option. This has the effect
- of shuffling all of the samples upwards, eliminating any gaps which
- might appear in the samples list. The "Preserve name order" setting
- will, if set, keep all of the sample names the same. This is most useful
- when the "sample names" are not actually sample names at all, but
- contain some form of text message. Without this option set, the sample
- slots which do not contain instruments but do contain text may be moved
- around. Conversely, if you wish to use this feature on a tune you have
- written which has some form of text message, make sure that the text you
- want to keep "belongs" to a valid sample (even if you have to load one
- in temporarily while tidying the list).
-
- I have also introduced a link between playing tunes in the desktop and
- playing them while in "Play Tune" mode in the main editing section. With
- this, if you are playing a tune in the desktop and then enter the main
- editing section (Adjust on the icon bar icon), you are automatically
- taken into "Play Tune" mode, with the tune at the same position as you
- were at outside the desktop. Note that this does not work when a tune
- has just been loaded, and you go to the main editing screen for the
- first time, as in this case the program needs to sort out internal
- pointers and data tables.
-
- The Main Editing Screen
- =======================
-
- It is in this section that most of the additions to the program will
- become apparent. There are some new features which are mode-specific,
- and a few which are global, ie. can occur whatever mode ("Test Samples",
- "Play Pattern" etc.) the program is in. These latter will be dealt with
- first in the text below. Some of the new features (and many of the old
- ones) are accessed using the red function keys, and you are advised to
- print out a copy of the enclosed Draw file keystrip for reference.
-
- I have added an extra state for the voices. Previously, clicking with
- the mouse over a "Voice X" box would toggle it between "On" and "Mute".
- Now, this feature is accomplished by clicking with Select over the
- relevant box. Clicking with Adjust will toggle a voice between "On" and
- "Quiet". While at first sight (or hearing) this latter state may seem to
- be identical to "Mute", there are in fact several differences. Whereas
- "Mute" effectively disables a voice so that any notes currently being
- played on it are stopped, and no further notes are played on it, "Quiet"
- keeps playing the notes, but at volume 0 (silent). The benefit of
- "Quiet" is that when you change the voice back to "On", the volume is
- returned to 255 (normal). This means that existing notes (particularly
- those played on repeating instruments) will resume playing. This is in
- contrast to "Mute", where repeating notes were cancelled, and after
- setting the voice back to "On" you would have to wait until another note
- was played on that channel to get any sound out of it. However, I
- appreciate that this can be useful in some circumstances; hence I have
- implemented both methods. One advantage of using "Mute" is that, having
- less tune data to worry about, the operation of the machine will speed
- up, particularly noticeable on Arm 2 machines (like mine!).
-
- Above the instruments window you should see four digits (initially
- showing "00:00"). This is a timer feature, and is controlled by using
- the function keys F5-F8 in conjunction with the Shift key. At its
- simplest, you can start the timer with Shift-F5, and stop it again with
- Shift-F6 to time between two events. It can also be reset with Shift-F7.
- However, by default the timer uses another mode of operation. In this
- mode the timer will start automatically when you next click on "Play
- Tune", and stop automatically when you leave this mode. It will also
- stop when you pause the tune (middle mouse button over the position
- counter window), and start again when the music resumes. This provides
- more accurate timing while still making the timer very versatile. If you
- press Shift-F8, the timer digits should change to a darker shade of
- green. Press Shift-F8 again to go back to the previous mode of
- operation. Most of the timer functions can also be performed using the
- mouse. Clicking with Select over the timer will start or stop the clock
- (depending on its current status), and Adjust will reset it. One further
- feature here is that by clicking with the Menu button over the digits,
- the display will be toggled between minutes:seconds and
- seconds:hundredths. The latter is useful when writing programs which
- need precise synchronization with music, though the former will be
- adequate for most uses.
-
- There is also a small addition to the "Stored Command" feature. The
- Stored Command is shown to the right of "Voice 8", and holds a command
- (0-Z) and a variable (&00-&FF). This is used when searching for commands
- but the command to be searched for needs to be stored first, and so may
- need to be typed in, stored, and the deleted again. However, by clicking
- on the stored command with the menu and adjust buttons, the stored
- command can be altered directly without needing to be typed in, which I
- have found to be quite useful. The normal operation of this feature
- (involving Tab, Enter, and clicking with Select, while in Edit Pattern
- mode) is unaffected by this addition.
-
- Another global feature here relates to the position numbers displayed to
- the left and right of the pattern being displayed (or underneath if the
- stave is being used). By clicking in either box, the base in which the
- numbers are displayed will be toggled between decimal and hexadecimal.
- The two sides are totally independent, and so they can both be decimal
- (the default), one decimal and one hexadecimal, or both hexadecimal,
- depending on the preferences of the user. One advantage of hexadecimal
- is that as patterns are by default of length 64, the alignment of drum
- beats and the like can (in some cases) be more accurately gauged.
-
- Test Samples Mode
-
- While in "Test Samples" mode, you can now scroll up and down the current
- pattern, using the cursor keys, Shift, and Page Up/Down, as when in
- "Edit Pattern" mode. Also while testing samples, "Alt" will stop a
- repeating (or, indeed, non-repeating) sample playing.
-
- Play Pattern Mode
-
- While this mode is largely unaltered (after all, it can do little else
- except play patterns!), a small (but very useful) facility has been
- added, whereby you can alter the pattern being played without having to
- keep changing to "Edit Pattern" mode. This is achieved by simply
- clicking on the two arrows to the right of the pattern number, in the
- same way as when changing the pattern in "Edit Pattern" mode. You will
- also notice a "Speed:xx" label appearing in the box directly beneath
- "Edit Sequence". This is to allow patterns to be easily played at speeds
- other than the default (6). By clicking in this box with Select or
- Adjust when a pattern is playing, the speed at which playback occurs can
- be altered. Furthermore, this value is stored, and so if you have a tune
- which needs to be played at Speed 4, altering the Play Pattern speed
- when playing the first pattern means that subsequent patterns will be
- played at Speed 4 by default. Also, every time a "Set Speed" command is
- encountered when playing the pattern, its variable part (the new speed
- value) will be recorded in order to keep the Play Pattern speed up to
- date.
-
- Edit Pattern Mode
-
- I have fixed a minor bug in "Edit Pattern" concerning the "Record Mode"
- and "J" (position jump) commands, and also put in a way to stop
- repeating instruments repeating for ever when using the "Debug" mode.
- This is accomplished by pressing "Caps Lock", and simply clears any
- sound playing at the time. The "Repeat" option for the Debug mode has
- also been updated, and is now more accurate. On my Arm 2, RISC OS 2,
- A3000, a Repeat value of 6 corresponds directly to a playing speed of 6.
- On other machines this may vary (it may need to be one more or one
- less), but at least it is now consistent. Another function is one to
- complement "Ctrl-F" (find next occurrence of stored command), and is
- performed by pressing "Ctrl-M". This does the same as "Ctrl-F", but
- matches both the stored command and variable, rather than just the
- command part. A nicer way of entering both these parts has also been
- provided on the "Used Screen" (see later).
-
- The Monitor Screen
-
- I have altered this screen slightly from Version 1, and the bars
- displayed are now of a height which more accurately represents the
- volume of the note being played (previously whenever a new note was
- played they were just set to the maximum height). Also, faint
- graduations have been added behind the bars.
-
- The "Used" Screen
-
- At first sight, this may seem to be identical to that in the first
- version. However, if you now click on an individual item in either of
- the three lists, further information is given. If you click on a note
- (eg. "D-2"), you are told which instruments this note is played on (and
- how many times). For an instrument, the reverse is shown - which notes
- are played on it. If you click on a command such as "V" (set volume),
- you are told how many times each variable (&00-&FF) is used in
- conjunction with it. The screen for this does look pretty awful I know,
- but I really wanted to get all of the information on a single screen for
- sheer convenience. This "Detailed Command Usage" screen also has another
- function. By clicking on an individual entry on screen with the Adjust
- mouse button, both the command (shown in the top left) and the variable
- (which you will have just clicked on) will be copied into the "Stored
- Command" slot, which can be a great time saver.
-
- The Sequence Editor
-
- There are several additions to the sequence editor. Most important is
- the time value shown. By clicking on "Calculate", the length of time the
- currently loaded tune would take to play will be calculated, and this
- value added to the value in the box. It therefore follows that to work
- out the length of a tune, the value should be initially zero, and the
- "Reset" box carries out this function. The benefit of having this as a
- two-stage process is that it is easy to add up the lengths of more than
- one tune without resorting to pen and paper additions. The timing should
- in theory be precise, but in practice can prove in some cases to be up
- to a few seconds out when compared to the time the tune actually takes
- to play. If this happens it is probably due to anomalous behaviour on
- the part of the playing module or processor.
-
- It is perhaps worth saying a bit about the way in which the calculation
- of the length of a tune works. It takes its cue from the current
- sequence cursor position, and basically works through the tune starting
- from this position until it reaches a position already visited. This
- means that "J" commands do not cause the algorithm to get stuck in
- infinite loops, and consequently means that if you have a music file
- which contains several pieces of music (such as that used in
- "Lemmings"), you can time each piece separately if you know the correct
- starting positions.
-
- The second major new feature in the sequence editor is that you may
- select an area of a sequence and perform a (limited) range of operations
- on it. To mark an area of the sequence, you must move (using the mouse
- or arrow keys) to one end of the area, and hold down F1. You may then
- set the other end of the block using the left and right arrow keys (with
- Shift for faster movement), while still holding down F1. When the block
- is as desired, release F1 and the block will be marked. The current
- block is shown by the squares having a green border. Once an area has
- been marked in this way, there are four boxes at the base of the screen
- which take account of it. The first, "Clear" is the simplest - it simply
- "unmarks" the area again when it is finished with, either to make the
- screen look neater, or to stop you accidentally clicking on "Delete" or
- something. The next two options, "Copy" and "Move", will relocate the
- marked area to the current cursor position. The difference is that
- "Move" will delete the original marked block, whereas "Copy" will leave
- it unaltered. In both cases, the new copy of the block will be marked
- when the operation has been completed. The fourth and final option is
- "Delete", and will fairly obviously just remove the marked area from the
- sequence. Note that you will be unable to do this if the whole sequence
- is marked, and that you will unable to perform the Copy operation
- detailed above if the resulting sequence would be more than 128 patterns
- in length (the maximum imposed by the Tracker file format).
-
- One very small change which has also been made to this screen is that
- you can now delete the last pattern in a sequence, by clicking on
- "Delete" with the cursor at the end of the sequence. This was not
- possible with version 1 of the software.
-
-
- The Sample Editor
- =================
-
- This is by far the most major addition to the program, and therefore
- that worthy of most explanation. The purpose of this section is to allow
- manipulation of the actual instruments used in a tune themselves rather
- than just manipulation of the music patterns which use those
- instruments. It is also very useful for setting Repeat markers, and in
- trimming samples (and consequently the music files of which they are a
- part) down by removing extraneous data.
-
- I would also like to say something about sample lengths at this point.
- The Tracker music format restricts samples to a length of 64K (65536
- bytes). However, you may load samples longer than this (memory
- permitting) into AP Tracker by dragging them to the samples window in
- the desktop. They will not play correctly in the "Test Samples" mode or
- the Sample Editor, but they may still be manipulated in the latter.
- However, you can use the "Play Marked Area" feature in the Sample Editor
- to play a part of the sample beyond the 64K marker, and this will play
- properly as long as the area marked does not exceed 64K in length.
- Another problem is that the sample length will not be displayed
- correctly (as 99999 in the main editor, and slightly differently in the
- desktop). Fades, echos, boost operations, and such like will all work
- correctly on the sample (or a marked block of it), though as mentioned
- above you will not be able to play it properly. However, you can mark a
- block and use "Delete Marked/Unmarked" which may leave you with a sample
- of a valid length. You can also use the "Resample" function (see below)
- to reduce the sample to a more manageable length (though with a
- corresponding loss in quality). With many of the sample editing
- functions described below, if an operation would cause a sample to be
- over 64K in length, an error will be displayed and you will be unable to
- carry out that operation.
-
- To access the sample editor, click on the "Instruments/Edit" box on the
- main editing screen while in "Test Samples", "Edit Pattern" or "Play
- Tune" mode. This should then invoke the sample editor screen, of which a
- large window the width of the screen should take up about half. This
- large window will show (as a waveform) the currently selected sample. If
- the currently selected sample slot is empty, this window will be blank.
- You should have no problems getting to grips with the sample editor if
- you have used the rest of "AP Tracker", as the user interface is
- virtually identical (do you think I'm going to bother designing another
- one?). To select another sample slot (for instance if the current one is
- empty), use the left and right arrows next to the "Sample:" box.
- Clicking on these arrows with Select will move through the samples one
- at a time. Clicking with Adjust however, will move to the next sample
- slot which contains an instrument (ie. skipping the blank ones). Also,
- clicking on the sample name will allow you to alter it, like in "Test
- Samples" mode.
-
- You can zoom in on the centre of the sample by altering the zoom value
- just beneath the sample window. The purple bar directly beneath the
- waveform is a scroll bar, and can be used to move through the sample
- when a zoom of greater than 1 is used. To play a sample either click on
- the on-screen keyboard or use the computer's keyboard (same keys as for
- tune editing). When the sample is playing, a blue vertical bar moves
- through the sample showing the part currently playing. There are also
- four other vertical markers, a red, a green, and two goldish ones. These
- represent the start and end of the marked block, and the repeat markers
- respectively. There is also a toggle box which will say either "Marked"
- or "All". This affects certain operations, and determines whether an
- operation is performed on the whole sample or just on the area between
- the start and end marker. To move a marker, either click near it and
- drag it about, or use the arrows near its printed value to alter it more
- precisely. One thing about these visual markers - they are not plotted
- with absolute accuracy, and this is particularly noticeable on short
- samples. If in doubt, trust to the numerical values displayed, as these
- are precise. When dragging, Select just drags the nearest marker (of
- whatever type), Menu drags the nearest repeat marker, and Adjust will
- drag either the start or the end of the marked block -whichever is
- nearer. To focus on any of these four markers, simply click on the box
- containing its name. The scroll offset will then be adjusted so that the
- marker is displayed at the centre of the screen (depending on the zoom
- factor). Similarly, clicking on the "Zoom:" window with Select will
- alter the zoom factor and scroll offset to focus on the marked block.
- Clicking on it with Adjust will automatically return the zoom factor
- back to 1.
-
- In addition, the following keys may also be used:
- Alt - Mute any sound playing
- Control - Toggle background lines on and off
- Tab - Expand marked area to whole sample
- Space - Repeat last note played
- In addition to Tab, which expands the marked block to the whole sample,
- you may also click with Adjust on either the "Block Start:" or "Length:"
- boxes. This has the effect of moving the relevant marker to its extreme
- position; the start of block marker to the start of the sample, and the
- end of block marker to the end of the sample.
-
- It is probably worth saying a little about the way in which the Repeat
- markers work. By clicking on "No Repeat", the repeat markers for the
- current sample are returned to their default values (0 and 2); in which
- state the sample will not repeat. The repeat markers will also be
- ignored when you are playing a marked block as opposed to the whole
- sample, as when doing this you could conceivably play an area of the
- sample which is outside the bounds of the repeat. There are two values
- which affect the repeat - repeat offset and repeat length. In general
- terms, when the sample position being played exceeds the end of the
- repeat block, it is reset to the beginning, and so on ad infinitum. The
- end of the repeat block is actually the repeat offset plus the repeat
- length, but this is transparent to the user while using the sample
- editor. A repeat length of 2, however, is treated as "repeat to end of
- sample", and the end of the repeat block is effectively the end of the
- sample. This may account for seemingly strange results when dragging
- repeat markers. If this repeat length of 2 is combined with a repeat
- offset of 0, there will be no repeat, and this is the default setting.
- Any other combination of values will cause a repeat to occur. You may
- find some samples whose repeat offset + repeat length actually come to
- greater than the total sample length (presumably due to a bad editing
- program). If this is the case, then you should really try to alter the
- repeat settings so that they lie within the sample, which should avoid
- any potential problems though safeguards are built into AP Tracker.
-
- Sample Menus
- ============
-
- The majority of the actual sample editing functions are to be found on
- menus. The 7 boxes starting with "Vol" refer to the menus available (in
- effect a menu of menus). Clicking on one of these will alter the
- contents of the four boxes below the actual menu headings to the
- relevant menu functions. You must then click on one of these four boxes
- to actually perform the operation. As mentioned above, certain
- operations take the current setting of the "Marked/All" flag into
- account. When the pointer is above one of these functions, the word
- "Marked" or "All" (depending on the current setting) will flash on and
- off. This acts both as a notice to tell you which operations will work
- either on the whole sample or just the marked part, and also as a
- reminder to set the flag. The functions of these various menus are
- explained below.
-
- Vol
-
- This menu is concerned with the volume of the sample. The first thing
- you may notice is that the two options on the left are not actually
- options at all. Instead, these boxes have been combined into an
- oscilloscope-type display. This shows the portion of the sample
- currently being displayed, and the distance of the trace from the centre
- line is a measure of the volume of the sound. Note that this displays
- the contents of the sound buffer itself rather than just the sample
- itself, and so its contents will change as the pitch of note being
- played varies. If nothing else, this may give you an insight into the
- way samples are played, but if not, well, it looks nice! One thing you
- can do with this feature, though, is click on it. This stops all sound
- playing (effectively doing the same thing as pressing "Alt"), and can
- save you resorting to the keyboard when editing with the mouse. The two
- "proper" volume options are "Boost" and "Quiescence". These act either
- on the whole sample or the marked block and will increase or decrease
- its volume respectively. Note that this will have an effect on every
- note played with the sample, as the actual sample data itself is being
- altered, as opposed to just using a "V" command in the tune where the
- existing sample data is played at a different volume.
-
- Fade
-
- The functions on this menu allow you to fade parts of a sample in or
- out. The boxes marked "Fade In" and "Fade Out" perform the actual
- operations, whereas the two below allow you to set the parameters of the
- fade. These two values refer to the two end volumes, and are in the same
- format as the numbers used by the "V" (set volume command) when writing
- music. Therefore, 255 refers to full (standard) volume, and 0 means
- silence. However, due to the logarithmic nature of the volume scale this
- does not always give the best results as the resulting sample tends more
- towards silence than to full volume - hence the ability to specify the
- volumes. Fades between 255 and about 60 or 70 seem to produce the best
- results, but you should experiment with this. It does not matter which
- order the values are in - the order in which they are used is determined
- by whether you click on "Fade In" or "Fade Out", but you should remember
- that they are in the same format as the numbers used by the "V" command,
- and that the higher number is the louder of the two.
-
- Delete
-
- To carry out any of the four deletion functions, you need to hold down
- all three mouse buttons (to prevent triggering them accidentally).
- Delete Marked and Unmarked are self-explanatory, and Delete Unused will
- delete the part of the sample lying beyond the second repeat marker, as
- this is unused when playing anyway. You should, therefore, only use this
- when the sample is in its finished state and is not going to need any
- more alteration. Delete zeros will remove all trailing zeros (silence)
- from the end of the sample, and this should prove to be quite useful.
-
- Merge
-
- The Merge menu contains functions which operate on two sample blocks -
- the current one and one specified by the user. This latter sample number
- is contained in the box marked "Sample:", and can be altered by clicking
- in this box with Select (decrease) or Adjust (increase). This value can
- either be displayed in a goldish colour the same as the menu text, or in
- a red colour. The significance of this is in the type of sample; red
- means that there is an actual sample present in this slot; gold means
- that there is not. There are three operations which act on the selected
- samples. "Copy to Slot" will make an exact copy of the sample currently
- being edited in the selected slot. This will completely overwrite what
- was previously there, and so should be used with caution. This is useful
- when editing a sample, as it means that (memory permitting) you can
- first copy a sample to a blank slot, work on it there, and copy it back
- again when you are happy with it. Any mistakes made during processing
- will thus not have irreversible effects on the original sample. "Insert
- Sample" will insert the selected sample into the current one (again,
- memory permitting). The position at which the selected sample is
- inserted is determined by the start of block (green) marker. When the
- sample has been inserted, the marked block will be around the new
- section. This is so that if you are not happy with the result you can
- use the "Delete Marked" feature to return the sample to precisely what
- it was originally. The final, "Add Samples", allows you to merge the
- actual sounds of the two samples together. Again, it takes effect at the
- start of block marker, and merges bytes of the selected sample with the
- current one until the end of either is reached.
-
- RS
-
- This actually stands for "Resample", as this is what the majority of the
- functions in this menu are concerned with. The one which isn't is the
- first, "Reverse", which is put here because it really fits in with
- nothing else, there was a blank space here, and with a bit of
- imagination "RS" could almost stand for "Reverse" I suppose ... Anyway,
- forget the logic, it's here anyway. Fairly obviously, it just reverses
- all or part of a sample, which produces some strange (and occasionally
- useful) results (and, more to the point, is nice and simple to program
- unlike "Insert Sample" and certain other functions I could mention).
- Resample is a fairly complex function, though has a number of uses. What
- is does basically is to "rescale" a sample so that it actually looks the
- same (in the sense of the waveform), but in actual fact is a different
- length. This means that its effective pitch when played at a certain
- note (eg. C-3) has actually changed. One use for this is to reduce the
- space taken up by some samples. By sampling the sample down one octave,
- its length is halved. By then playing notes an octave higher than usual,
- the actual sound will be the same, but the file length will be shorter.
- In practice, resampling downwards will always lose some data, but even
- going down by more than an octave can (as long the sample was of a
- sufficiently high quality to start with) produce acceptable results.
- This is especially useful with samples (particularly speech samples)
- which are only ever played at one pitch in the tune. Resampling can also
- be used to extend the three-octave range of the Tracker music format. By
- resampling up or down by one, two, or even three octaves, notes played
- on the new samples will be above or below the normal Tracker range
- (although loss of sound quality can limit the usefulness of this for
- some samples). So much for theory. To actually resample a sample, you
- must tell the program something about the final sample. First of all,
- play the sample using either the computer's or the on-screen keyboard,
- at a certain pitch. The last note played will be displayed in the bottom
- left of the screen, and this is one variable which the Resample function
- uses. The other variable is another note value, the one displayed in the
- bottom left box of the RS menu. This can be altered by clicking on the
- arrows next to it with either Select, Menu, or Adjust. As you change
- either of these notes, the "Bytes:" value will change telling you how
- long the resulting sample will be if you carry out the Resample function
- with the current parameters. What these note values mean is best
- explained by an example. If the note in the bottom left is "F#3" and
- that in the menu box is "C-2", the the resample function will produce a
- sample which when played at "C-2" sounds like the original sample played
- at "F#3". This to me seemed more intuitive and friendly than
- manipulating frequency values directly. As a guide, if the "Bytes:"
- value is less than the original sample length, the new sample will sound
- higher than the original; if it is greater then the sample will sound
- lower. As another guide, if the two notes differ by an octave (eg. D#2
- to D#3), the length will alter by a factor of 2. Two octaves different
- means a factor of 4, and so on. The Coconizer conversion (see above)
- makes use of the fact that this feature exists in order to handle the 8
- octave range of this format. An error will be displayed if a resample
- operation requested would produce a sample of over 64K in length.
- However, this is permitted if the original sample was over 64K to start
- with, as this is a slightly different case.
-
- FR
-
- The options on this menu are concerned either with sound filters or the
- repeat markers, and while these two things are entirely distinct I had
- to put them on the same menu for reasons of space-saving. The top two
- options will carry out either a low or a high pass filtering operation
- on all or part of the sample. In theory, one emphasises the lower
- frequencies of a sample, the other the high ones. This is of particular
- use in removing unwanted background noise from certain samples. In
- practice, however, the algorithms (especially the high-pass one) are a
- bit dodgy, and so it is perhaps better to think of them as just effects
- which can be applied to samples, and you are advised to experiment with
- them to see what they can do. If you have tried to set the repeat
- markers for a sample, you will be aware that this can be very difficult
- and the transition from the end of the repeat back to the beginning
- seldom sounds smooth without a lot of experimenting. The two repeat scan
- functions (one for the repeat offset marker, one for the repeat length)
- offer a partial solution to this. They will scan the sample and try to
- find suitable positions for the repeat markers, based on what the sample
- looks like at the byte level. When scanning for one marker, the other is
- fixed, and what the sample is like at that point is taken as the
- criterion for the search. If a marker does not move when you click on
- scan, no suitable repeat point has been found, and in this case you
- should move the other marker a little and try again, or simply scan from
- the other marker. You can scan backwards and forwards (by clicking on
- the different arrows), and so you can easily return to a previous point
- if no better one is found. The repeat scanning does not always produce
- perfect results (though occasionally it can), and often the values need
- slight manual adjustment, but it should take some of the hard work out
- of finding suitable points.
-
- X
-
- Yes, this menu contains the functions which did not fit anywhere else!!
- In actual fact, there are only two things it does, as the remaining two
- boxes contain parameters for these two functions. "Insert Space" will
- insert, at the start of block position, a certain number of zero bytes
- (silence). This is particularly useful when creating Synthetic sounds
- (see below), but may also have other uses. The number of bytes inserted
- is set by the "Bytes:" value below the "Insert Space" option. This can
- be altered by clicking on the arrows. Different mouse buttons alter the
- value by different amounts, and Shift can be used for larger step sizes.
- If the resulting sample (after inserting the zero bytes) would be over
- 64K in length (the maximum allowed by Tracker) you will be warned of
- this and not permitted to insert the bytes. The "Bytes:" value will, in
- this case, be changed to the maximum you can insert. The other function
- is "Add Echo", and this also uses the stored "Bytes:" value, but this
- time as a measure of how far apart the normal sample bytes and the ones
- merged with it to produce the echo should be. For speech samples, values
- of about 1/7th or 1/8th the length of the sample seem to produce the
- best results - but again, experiment. Another setting for the echoing
- facility is "Volume:". This determines the volume of the echo. This is a
- standard Tracker format volume value, as used by the "V" commands, and
- 255 signifies full volume (same as the original), 0 silence, and the
- rest somewhere in between. Values of about 235 tend to be about right,
- but it depends on the particular sample being edited.
-
- Synthetic Sounds
- ================
-
- This is another major new feature, and allows you to create your own
- sounds (not samples, but they are treated as such by the program) for
- use as instruments (or just effects) in tunes. Because this is concerned
- with samples, the entry point is to be found on the main Sample Editor
- screen. The box in the top right hand corner of the screen leads to the
- synthesized sound section, and needs all three mouse buttons pressed to
- access it. This is because it completely overwrites the current sample
- with the synthetic sound used. To save deleting an existing sample, you
- can use the "Insert Space" menu option to create a blank one first, and
- then use that. The sample must be at least 256 bytes in length, though
- should really be at least a few kilobytes.
-
- This section of the program is based upon the "HarmSynth" program
- written by David Radford and published by BBC Acorn User. The method of
- operation is very similar, and "AP Tracker" can load and save
- "HarmSynth" files (just drag to the icon bar icon to load). The Tracker
- file format does not, of course, actually support synthetic sounds. All
- "AP Tracker" does is to allow you to alter the harmonic and envelope
- data which make up a synthetic sound, and then create a "sample" which
- can be used like any other. The length of the sample has an effect on
- the pitch of the final sound (as it is scaled to fit the sample space
- available; cf. the resample function), and so it may sound quite
- different than the equivalent file loaded into the proper "HarmSynth"
- file. There are also other differences between "HarmSynth" and the
- synthetic sounds part of "AP Tracker". Firstly, there is the treatment
- of Repeat. "HarmSynth" handles this in a way which is not possible with
- Tracker, and so the HarmSynth repeat setting is ignored by AP Tracker.
- You can, of course, apply the Repeat Offset and Repeat Length settings
- to the resulting sample if you wish (in the Sample Editor) in the usual
- way. "HarmSynth" also has Vibrato and Tremolo settings. These too are
- ignored by AP Tracker, largely because they are implemented via effects
- when playing notes (though only Vibrato is currently implemented)
-
- When you enter the Synthetics section, you will see the current sound
- waveform. By default, this is just a simple Sine wave, but if you have
- loaded a Harmsynth file you will see that waveform instead. Below this
- waveform are the current harmonic values (see later), and to the right
- of it are four icons containing "Sine", "Triangle", "SawTooth" and
- "Square". You can toggle each of these on and off by clicking on them.
- When one of these types of waves is enabled (shown in pink), its
- harmonic values will contribute to the final sound. If it is disabled
- (shown in grey) it will not, and so setting them all to off will give a
- blank waveform. You can alter the harmonics of one of the four types of
- waves by clicking on its icon below the main waveform window. The
- currently selected one is shown in red, and its name is also displayed.
- To actually alter a harmonic, drag one of the bars next to "1st", "2nd",
- "3rd" etc. until its value is as desired. As you do this, the percentage
- indicator will change, as will the current waveform (unless the wave
- whose harmonics you are altering is currently disabled). If you drag
- with the Select button (the norm), the pointer will be restricted to the
- harmonic you clicked on, and this restriction will be enforced until you
- release the button (again, the norm). However, you can also drag with
- Adjust. This does not restrict the pointer to one harmonic, and may be
- useful for zeroing more than one harmonic (click just to the left of the
- bar on one with Adjust and then move the mouse up or down). To test out
- a synthetic sound, either use the usual note keys (Z,S,X,D,C etc.), or
- click on the keyboard at the bottom right of the screen. You may also
- alter either the sample name (in the top left), or the Synthetic name
- (top right), the latter being that which will be saved in the
- "HarmSynth" file. You may also, by clicking with Adjust in the Synthetic
- name box, copy this across to the Sample name.
-
- By now, you should be able to create a vast number of certainly weird
- and possibly wonderful sounds. However, you may be wondering what the
- "Amplitude Envelope" and "Pitch Envelope" boxes on the right do. The
- amplitude (volume) envelope allows you to specify how the volume of the
- sound changes throughout the resulting sample. If you return to the
- Sample Editor (the box in the top left), you should see that the shape
- of the sample follows roughly the shape of the amplitude envelope, and
- if you play the sample, you will probably hear it increase and decrease
- in volume. To actually alter the amplitude envelope you must click in
- the envelope box. The envelope is made up of straight lines joining
- control points or nodes. By altering the positions of these nodes, you
- can alter the amplitude envelope and hence the sound of the final
- sample. If you click in the box with Select, a new node will be created
- at the mouse position. Click with Menu to delete a point, and Adjust to
- drag an existing one around (though you will only be able to drag it
- between its two immediate neighbours). The exceptions to these rules are
- the first and last point (those on the extreme right and left). These
- must always be present, and cannot be deleted. They can, though, be
- dragged up and down to set the start and end volume of the sample. As
- you alter these nodes, you should see the values in the upper
- information box change. This tells you the current number of nodes, and
- the co-ordinates of the last one created or dragged. You may have up to
- ten nodes in the amplitude envelope, including the two at the ends. You
- can also reset the envelope to its default setting (three points in a
- triangular arrangement) by clicking on "Reset".
-
- Below the amplitude envelope is the pitch envelope. Like the amplitude
- envelope, this is made up of nodes joined together. These can be
- dragged, created and deleted in exactly the same way as for the
- amplitude envelope, and the "Reset" button has a corresponding effect.
- The obvious difference is that the resulting envelope influences the way
- in which the pitch, not the amplitude, changes throughout the sound. The
- centre (zero) line is the default, and will cause the whole note to be
- at the pitch you play it. Points above this line represent increases in
- pitch while those below it mean that the sound will be lower. This
- feature is great for sound effects, and, as with virtually every other
- aspect of the program, you are advised to experiment with it in order to
- see what effects are possible.
-
- A final word on synthetic sounds. Once you return to the actual sample
- editor screen, the sound can only be edited as a sample, and so if you
- want to alter the harmonic values or the amplitude/ pitch envelopes
- again in another session, you must use the "Save Synthetic" option from
- the desktop. Having said this, there is no denying that synthetic sounds
- sound, well, synthetic, when compared to actual sampled instruments. By
- using the sample editing facilities, such as Boost, Fade, Echo, etc. it
- is possible to improve the "feel" of such sounds and make them seem less
- artificial. Similarly, using them in conjunction with effects like
- Arpeggio and Vibrato when writing music will do the same thing. Bear in
- mind though, that this only has an effect on the finished sample -
- returning to the synthetic sounds section again will nullify any sample
- operations performed.
-
- Credits
-
- Firstly, thanks to Matthew Farrow for updates to the PD player module
- used by AP Tracker 2, and also for comments on, and suggestions for, the
- program. I must also thank Simon Forrest for suggestions for
- improvements, writing loads of tunes (currently 9) with the program, and
- designing a nice icon for it. Thanks also to David Radford for writing
- the "HarmSynth" program (copyright BBC Acorn User), which shows what is
- possible with synthetic sounds and introduces some sort of standard into
- this field. Thanks too to Karl Hardy for all the nice demos and for
- writing in the first place. Credit should also go to I D Griffiths, the
- author of a great little PD utility, "!FileSee". This basically performs
- a "*Dump" in a desktop window, can handle multiple files, and is great
- for figuring out weird file formats.
-
- If you want to write to me for any reason; if you've written a good
- piece of music with AP Tracker 2, if you can't because you don't know
- how to perform an operation(s), or if you've found any bugs, my address
- is as follows:
-
- Andrew Pepperell,
- 20 Orchard Park,
- Grimoldby,
- Louth,
- Lincs.
- LN11 8TN
-
- ( During term time, my address is:
-
- Andrew Pepperell,
- Churchill College,
- Cambridge,
- CB3 0DS.
-
- E-Mail: AP10014@hermes.cam.ac.uk )
-
-