| /* |
| ** Copyright (C) 2007-2011 Erik de Castro Lopo <erikd@mega-nerd.com> |
| ** Copyright (c) 2007 <robs@users.sourceforge.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 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, |
| ** Fifth Floor, 51 Franklin Street, Boston, MA 02111-1301, USA. |
| */ |
| |
| /* ADPCM: IMA, OKI <==> 16-bit PCM. */ |
| |
| |
| #define IMA_OKI_ADPCM_CODE_LEN 256 |
| #define IMA_OKI_ADPCM_PCM_LEN (IMA_OKI_ADPCM_CODE_LEN *2) |
| |
| typedef struct |
| { |
| /* private: */ |
| int mask ; |
| int last_output ; |
| int step_index ; |
| int max_step_index ; |
| int const * steps ; |
| |
| /* public: */ |
| int errors ; |
| int code_count, pcm_count ; |
| |
| unsigned char codes [IMA_OKI_ADPCM_CODE_LEN] ; |
| short pcm [IMA_OKI_ADPCM_PCM_LEN] ; |
| } IMA_OKI_ADPCM ; |
| |
| typedef enum |
| { IMA_OKI_ADPCM_TYPE_IMA, |
| IMA_OKI_ADPCM_TYPE_OKI |
| } IMA_OKI_ADPCM_TYPE ; |
| |
| void ima_oki_adpcm_init (IMA_OKI_ADPCM * state, IMA_OKI_ADPCM_TYPE type) ; |
| |
| int adpcm_decode (IMA_OKI_ADPCM * state, int /* 0..15 */ code) ; |
| int adpcm_encode (IMA_OKI_ADPCM * state, int /* -32768..32767 */ sample) ; |
| |
| void ima_oki_adpcm_decode_block (IMA_OKI_ADPCM * state) ; |
| void ima_oki_adpcm_encode_block (IMA_OKI_ADPCM * state) ; |