ref: 707b36935a3758e531ffeb03beee06da24aedb2b
dir: /src/ima_rw.h/
/* libSoX ima_rw.h -- codex utilities for WAV_FORMAT_IMA_ADPCM * Copyright (C) 1999 Stanley J. Brooks <stabro@megsinet.net> * * This library 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. * * This library 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 this library; if not, write to the Free Software Foundation, * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ #include "sox.h" #ifndef SAMPL #define SAMPL short #endif /* * call lsx_ima_init_table() before any other Ima* functions, * to create the fast lookup tables */ extern void lsx_ima_init_table(void); /* lsx_ima_block_expand_i() outputs interleaved samples into one output buffer */ extern void lsx_ima_block_expand_i( unsigned chans, /* total channels */ const unsigned char *ibuff,/* input buffer[blockAlign] */ SAMPL *obuff, /* output samples, n*chans */ int n /* samples to decode PER channel, REQUIRE n % 8 == 1 */ ); /* lsx_ima_block_expand_m() outputs non-interleaved samples into chan separate output buffers */ extern void lsx_ima_block_expand_m( unsigned chans, /* total channels */ const unsigned char *ibuff,/* input buffer[blockAlign] */ SAMPL **obuffs, /* chan output sample buffers, each takes n samples */ int n /* samples to decode PER channel, REQUIRE n % 8 == 1 */ ); /* mash one block. if you want to use opt>0, 9 is a reasonable value */ extern void lsx_ima_block_mash_i( unsigned chans, /* total channels */ const SAMPL *ip, /* ip[] is interleaved input samples */ int n, /* samples to encode PER channel, REQUIRE n % 8 == 1 */ int *st, /* input/output state[chans], REQUIRE 0 <= st[ch] <= ISSTMAX */ unsigned char *obuff, /* output buffer[blockAlign] */ int opt /* non-zero allows some cpu-intensive code to improve output */ ); /* Some helper functions for computing samples/block and blockalign */ /* * lsx_ima_samples_in(dataLen, chans, blockAlign, samplesPerBlock) * returns the number of samples/channel which would go * in the dataLen, given the other parameters ... * if input samplesPerBlock is 0, then returns the max * samplesPerBlock which would go into a block of size blockAlign * Yes, it is confusing usage. */ extern size_t lsx_ima_samples_in( size_t dataLen, size_t chans, size_t blockAlign, size_t samplesPerBlock ); /* * size_t lsx_ima_bytes_per_block(chans, samplesPerBlock) * return minimum blocksize which would be required * to encode number of chans with given samplesPerBlock */ extern size_t lsx_ima_bytes_per_block( size_t chans, size_t samplesPerBlock );