Rockbox

This patch adds an A-B Repeat function to Rockbox.

(Current patch is against 20050119 daily source.
Tested on FM Recorder.
Button mappings exist for but are not tested on Player
models.)

A-B Repeat will repeatedly play a segment of a song
between two arbitrary
points (known as marker A and marker B) that are
defined by the listener.
It's especially great for musicians who need to listen
to a musical passage
repeatedly in order to learn it.

ACTIVATION

To turn A-B Repeat mode on, use the normal repeat mode
setting (in the
Settings menu or the Quick menu) and toggle until "ab"
appears. On models
with a bitmapped display, an A-B Repeat icon will show
(the normal repeat
arrow – U on its side – between two vertical lines).
This setting can
also be saved/restored from a config file (repeat: ab).

USAGE

A-B Repeat mode behaves like "repeat one" mode until a
marker(s) has been set.

When the B marker is set and playback reaches the B
marker, playback
automatically jumps back to the A marker position.

- To set the A marker, press ON+PREV during song playback.

- To set the B marker, press ON+NEXT during song
playback. (NOTE: When
the B marker is set, playback immediately jumps to the
A marker position.)

- To clear both markers, press ON+OFF during song
playback. (NOTE: When a song
stops, the markers are cleared automatically.)

It's also possible to use A-B Repeat with only one
marker set:

- To repeat a section at the start of a song, set only
the B marker and playback
will repeat between the start of the song and the B
marker position.

- To repeat a section at the end of a song, set only
the A marker and playback
will repeat between the A marker position and the end
of the song.

You may change the A and B markers at any time by using
FFWD and FREW to
move to the desired new position and pressing the
appropriate key combination
to set the desired marker. You may even FREW to a
position before the A marker
and FFWD to a position after the B marker. Note
however that if you reverse
the order of the markers (i.e. place B before A or A
after B) the other marker
will be unset (e.g. if you set B to a position earlier
in the song than A, the
A marker will be unset).

OTHER NOTES

The NEXT and PREV buttons will stop at the A marker
position if they pass it.
(e.g. If the current playing position is past the A
marker and you press PREV,
playback will jump to the A marker position. Pressing
PREV a second time will
jump to the start of the song.)

On models with a bitmapped display, when either (or
both) of the markers is set
a graphical indication is drawn on the track time
status bar. The A marker is
drawn as a right-pointing arrow and the B marker is
drawn as a left-pointing
arrow. However, if the two markers are positioned too
closely together to fit
the arrow indicators, vertical bars will be drawn instead.

Note that holding down the ON button on some models
will cause the pitch menu
to appear. To avoid this, you should be prepared to
press the ON+PREV and
ON+NEXT button combinations quickly when the desired
position is reached.