merge upstream 713427c

1 files changed, 92 insertions, 0 deletions

diff --git a/quantum/midi/sysex_tools.h b/quantum/midi/sysex_tools.h
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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/>.
+
+#pragma once
+
+#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