ref: 364af1c842b21770642afc516b12491381ee79ef
dir: /src/adpcm.h/
/* adpcm.h codex functions for MS_ADPCM data * (hopefully) provides interoperability with * Microsoft's ADPCM format, but, as usual, * see LACK-OF-WARRANTY information below. * * 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 /* default coef sets */ extern const short lsx_ms_adpcm_i_coef[7][2]; /* lsx_ms_adpcm_block_expand_i() outputs interleaved samples into one output buffer */ extern const char *lsx_ms_adpcm_block_expand_i( unsigned chans, /* total channels */ int nCoef, const short *lsx_ms_adpcm_i_coef, const unsigned char *ibuff,/* input buffer[blockAlign] */ SAMPL *obuff, /* output samples, n*chans */ int n /* samples to decode PER channel, REQUIRE n % 8 == 1 */ ); extern void lsx_ms_adpcm_block_mash_i( unsigned chans, /* total channels */ const SAMPL *ip, /* ip[n*chans] is interleaved input samples */ int n, /* samples to encode PER channel, REQUIRE */ int *st, /* input/output steps, 16<=st[i] */ unsigned char *obuff, /* output buffer[blockAlign] */ int blockAlign /* >= 7*chans + n/2 */ ); /* Some helper functions for computing samples/block and blockalign */ /* * lsx_ms_adpcm_samples_in(dataLen, chans, blockAlign, samplesPerBlock) * returns the number of samples/channel which would be * 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 sox_size_t lsx_ms_adpcm_samples_in( sox_size_t dataLen, sox_size_t chans, sox_size_t blockAlign, sox_size_t samplesPerBlock ); /* * sox_size_t lsx_ms_adpcm_bytes_per_block(chans, samplesPerBlock) * return minimum blocksize which would be required * to encode number of chans with given samplesPerBlock */ extern sox_size_t lsx_ms_adpcm_bytes_per_block( sox_size_t chans, sox_size_t samplesPerBlock );