summaryrefslogtreecommitdiffstats
path: root/libtoolame-dab/availbits.c
diff options
context:
space:
mode:
Diffstat (limited to 'libtoolame-dab/availbits.c')
-rw-r--r--libtoolame-dab/availbits.c67
1 files changed, 67 insertions, 0 deletions
diff --git a/libtoolame-dab/availbits.c b/libtoolame-dab/availbits.c
new file mode 100644
index 0000000..809c28e
--- /dev/null
+++ b/libtoolame-dab/availbits.c
@@ -0,0 +1,67 @@
+/*
+ * toolame - an optimized mpeg 1/2 layer 2 audio encoder
+ * Copyright (C) 2001 Michael Cheng
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+#include <stdio.h>
+#include "common.h"
+#include "encoder.h"
+#include "musicin.h"
+#include "options.h"
+#include "availbits.h"
+
+
+struct slotinfo {
+ double average;
+ double frac;
+ int whole;
+ double lag;
+ int extra;
+} slots;
+
+/* function returns the number of available bits */
+int available_bits (frame_header *header, options * glopts)
+{
+ int adb;
+
+ slots.extra = 0; /* be default, no extra slots */
+
+ slots.average =
+ (1152.0 / s_freq[header->version][header->sampling_frequency]) *
+ ((double) bitrate[header->version][header->bitrate_index] / 8.0);
+
+ slots.whole = (int) slots.average;
+ slots.frac = slots.average - (double) slots.whole;
+
+ /* never allow padding for a VBR frame.
+ Don't ask me why, I've forgotten why I set this */
+ if (slots.frac != 0 && glopts->usepadbit && glopts->vbr == FALSE) {
+ if (slots.lag > (slots.frac - 1.0)) { /* no padding for this frame */
+ slots.lag -= slots.frac;
+ slots.extra = 0;
+ header->padding = 0;
+ } else { /* padding */
+
+ slots.extra = 1;
+ header->padding = 1;
+ slots.lag += (1 - slots.frac);
+ }
+ }
+
+ adb = (slots.whole + slots.extra) * 8;
+
+ return adb;
+}