Introduce subdivide_tukey apodization

Subdivide_tukey is intended to replace partial_tukey and
punchout_tukey. It works in rougly the same way, but uses a more
efficient algorithm, recyling more data.

subdivide_tukey has 2 arguments, of which 1 is optional. The
first states the maximum number of parts the signal has to be
split up in, the second is the tukey parameter, divided by the
max num of parts.

subdivide_tukey(3) analyses audio with an unsplit block, with the
block split in 2 and split in 3. Here the default p of 0.5 applies
to the smallest parts, so the unsplit block effectively has a p of
0.5/3. subdivide_tukey(3/2e-1) does the same but with p of 0.2.

1 files changed, 6 insertions, 6 deletions

diff --git a/src/flac/main.c b/src/flac/main.c
index c87bc00d..2b9d8ca5 100644
--- a/src/flac/main.c
+++ b/src/flac/main.c
@@ -1622,12 +1622,12 @@ void show_explain(void)
 	printf("                                     connes, flattop, gauss(STDDEV), hamming,\n");
 	printf("                                     hann, kaiser_bessel, nuttall, rectangle,\n");
 	printf("                                     triangle, tukey(P), welch, partial_tukey(n)\n");
-	printf("                                     punchout_tukey(n). More than one may be\n");
-	printf("                                     specified but encoding time is a multiple\n");
-	printf("                                     of the number of functions since they are\n");
-	printf("                                     each tried in turn.  The encoder chooses\n");
-	printf("                                     suitable defaults in the absence of any -A\n");
-	printf("                                     options.\n");
+	printf("                                     punchout_tukey(n) and subdivide_tukey(n).\n");
+	printf("                                     More than one may be specified but encoding\n");
+	printf("                                     time is a multiple of the number of\n");
+	printf("                                     functions since they are each tried in \n");
+	printf("                                     turn.  The encoder chooses suitable\n");
+	printf("                                     defaults in the absence of any -A options.\n");
 	printf("  -l, --max-lpc-order=#              Max LPC order; 0 => only fixed predictors.\n");
 	printf("                                     Must be <= 12 for Subset streams if sample\n");
 	printf("                                     rate is <=48kHz.\n");