From c7bb7eff818cb91d6f49da2fe810127ae7184758 Mon Sep 17 00:00:00 2001 From: Marcelo Galvăo Póvoa Date: Fri, 10 Sep 2010 19:51:08 +0000 Subject: Move AMR-NB frame unpacking code to a common file so it can be reused in the AMR-WB decoder. MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Patch by Marcelo Galvăo Póvoa. Originally committed as revision 25100 to svn://svn.ffmpeg.org/ffmpeg/trunk --- libavcodec/amr.h | 66 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 66 insertions(+) create mode 100644 libavcodec/amr.h (limited to 'libavcodec/amr.h') 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 */ -- cgit v1.2.3