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// midi for embedded chips,
// Copyright 2010 Alex Norman
//
// This file is part of avr-midi.
//
// avr-midi is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
//(at your option) any later version.
//
// avr-midi 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 General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with avr-midi. If not, see <http://www.gnu.org/licenses/>.
#ifndef SYSEX_TOOLS_H
#define SYSEX_TOOLS_H
#ifdef __cplusplus
extern "C" {
#endif
#include <inttypes.h>
/**
* @file
* @brief Sysex utility functions
*
* These functions are for converting data to and from a "midi-safe" format,
* which can be use to send data with sysex messages. Sysex messages may only
* contain data where the to bit is not set.
*
* An "encoded" midi message is one that contains all of the data from its
* original state, but does not have any of the top bits set.
*
* Every 7 bytes of decoded data is converted into 8 bytes of encoded data and
* visa-versa. If you'd like to operate on small segments, make sure that you
* encode in 7 byte increments and decode in 8 byte increments.
*
*/
/** @defgroup sysex_tools Sysex utility functions
* @{
*/
/**
* @brief Compute the length of a message after it is encoded.
*
* @param decoded_length The length, in bytes, of the message to encode.
*
* @return The length, in bytes, of the message after encodeing.
*/
uint16_t sysex_encoded_length(uint16_t decoded_length);
/**
* @brief Compute the length of a message after it is decoded.
*
* @param encoded_length The length, in bytes, of the encoded message.
*
* @return The length, in bytes, of the message after it is decoded.
*/
uint16_t sysex_decoded_length(uint16_t encoded_length);
/**
* @brief Encode data so that it can be transmitted safely in a sysex message.
*
* @param encoded The output data buffer, must be at least sysex_encoded_length(length) bytes long.
* @param source The input buffer of data to be encoded.
* @param length The number of bytes from the input buffer to encode.
*
* @return number of bytes encoded.
*/
uint16_t sysex_encode(uint8_t *encoded, const uint8_t *source, uint16_t length);
/**
* @brief Decode encoded data.
*
* @param decoded The output data buffer, must be at least sysex_decoded_length(length) bytes long.
* @param source The input buffer of data to be decoded.
* @param length The number of bytes from the input buffer to decode.
*
* @return number of bytes decoded.
*/
uint16_t sysex_decode(uint8_t *decoded, const uint8_t *source, uint16_t length);
/**@}*/
#ifdef __cplusplus
}
#endif
#endif
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