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authorMarcelo Galvăo Póvoa <marspeoplester@gmail.com>2010-09-10 19:51:08 +0000
committerVitor Sessak <vitor1001@gmail.com>2010-09-10 19:51:08 +0000
commitc7bb7eff818cb91d6f49da2fe810127ae7184758 (patch)
tree72f604ae99a669edf63b04bd1754a0cd753b5bc6
parent6f9932476dac9fde855ea84aa07bf424c5836967 (diff)
Move AMR-NB frame unpacking code to a common file so it can be reused in
the AMR-WB decoder. Patch by Marcelo Galvăo Póvoa. Originally committed as revision 25100 to svn://svn.ffmpeg.org/ffmpeg/trunk
-rw-r--r--libavcodec/amr.h66
-rw-r--r--libavcodec/amrnbdec.c22
2 files changed, 70 insertions, 18 deletions
diff --git a/libavcodec/amr.h b/libavcodec/amr.h
new file mode 100644
index 0000000000..58a0dde14a
--- /dev/null
+++ b/libavcodec/amr.h
@@ -0,0 +1,66 @@
+/*
+ * Shared functions between AMR codecs
+ *
+ * Copyright (c) 2010 Marcelo Galvao Povoa
+ *
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * FFmpeg 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#ifndef AVCODEC_AMR_H
+#define AVCODEC_AMR_H
+
+#ifdef AMR_USE_16BIT_TABLES
+#define R_TABLE_TYPE uint16_t
+#else
+#define R_TABLE_TYPE uint8_t
+#endif
+
+/**
+ * Fill the frame structure variables from bitstream by parsing the
+ * given reordering table that uses the following format:
+ *
+ * Each field (16 bits) in the AMR Frame is stored as:
+ * - one byte for the number of bits in the field
+ * - one byte for the field index
+ * - then, one byte for each bit of the field (from most-significant to least)
+ * of the position of that bit in the AMR frame.
+ *
+ * @param out pointer to the frame struct
+ * @param size the size in bytes of the frame struct
+ * @param data input bitstream after the frame header
+ * @param ord_table the reordering table as above
+ */
+static inline void ff_amr_bit_reorder(uint16_t *out, int size,
+ const uint8_t *data,
+ const R_TABLE_TYPE *ord_table)
+{
+ int field_size;
+
+ memset(out, 0, size);
+ while ((field_size = *ord_table++)) {
+ int field = 0;
+ int field_offset = *ord_table++;
+ while (field_size--) {
+ int bit = *ord_table++;
+ field <<= 1;
+ field |= data[bit >> 3] >> (bit & 7) & 1;
+ }
+ out[field_offset] = field;
+ }
+}
+
+#endif /* AVCODEC_AMR_H */
diff --git a/libavcodec/amrnbdec.c b/libavcodec/amrnbdec.c
index 616be9710e..e878019bd2 100644
--- a/libavcodec/amrnbdec.c
+++ b/libavcodec/amrnbdec.c
@@ -52,6 +52,7 @@
#include "acelp_vectors.h"
#include "acelp_pitch_delay.h"
#include "lsp.h"
+#include "amr.h"
#include "amrnbdata.h"
@@ -195,24 +196,9 @@ static enum Mode unpack_bitstream(AMRContext *p, const uint8_t *buf,
p->bad_frame_indicator = !get_bits1(&gb); // quality bit
skip_bits(&gb, 2); // two padding bits
- if (mode < MODE_DTX) {
- uint16_t *data = (uint16_t *)&p->frame;
- const uint8_t *order = amr_unpacking_bitmaps_per_mode[mode];
- int field_size;
-
- memset(&p->frame, 0, sizeof(AMRNBFrame));
- buf++;
- while ((field_size = *order++)) {
- int field = 0;
- int field_offset = *order++;
- while (field_size--) {
- int bit = *order++;
- field <<= 1;
- field |= buf[bit >> 3] >> (bit & 7) & 1;
- }
- data[field_offset] = field;
- }
- }
+ if (mode < MODE_DTX)
+ ff_amr_bit_reorder((uint16_t *) &p->frame, sizeof(AMRNBFrame), buf + 1,
+ amr_unpacking_bitmaps_per_mode[mode]);
return mode;
}