1 files changed, 99 insertions, 0 deletions
diff --git a/protocol/lufa/midi/sysex_tools.c b/protocol/lufa/midi/sysex_tools.c
new file mode 100755
index 0000000000..7563a3e2aa
--- /dev/null
+++ b/protocol/lufa/midi/sysex_tools.c
@@ -0,0 +1,99 @@
+//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/>.
+
+#include "sysex_tools.h"
+
+uint16_t sysex_encoded_length(uint16_t decoded_length){
+   uint8_t remainder = decoded_length % 7;
+   if (remainder)
+      return (decoded_length / 7) * 8 + remainder + 1;
+   else
+      return (decoded_length / 7) * 8;
+}
+
+uint16_t sysex_decoded_length(uint16_t encoded_length){
+   uint8_t remainder = encoded_length % 8;
+   if (remainder)
+      return (encoded_length / 8) * 7 + remainder - 1;
+   else
+      return (encoded_length / 8) * 7;
+}
+
+uint16_t sysex_encode(uint8_t *encoded, const uint8_t *source, const uint16_t length){
+   uint16_t encoded_full = length / 7; //number of full 8 byte sections from 7 bytes of input
+   uint16_t i,j;
+
+   //fill out the fully encoded sections
+   for(i = 0; i < encoded_full; i++) {
+      uint16_t encoded_msb_idx = i * 8;
+      uint16_t input_start_idx = i * 7;
+      encoded[encoded_msb_idx] = 0;
+      for(j = 0; j < 7; j++){
+         uint8_t current = source[input_start_idx + j];
+         encoded[encoded_msb_idx] |= (0x80 & current) >> (1 + j);
+         encoded[encoded_msb_idx + 1 + j] = 0x7F & current;
+      }
+   }
+
+   //fill out the rest if there is any more
+   uint8_t remainder = length % 7;
+   if (remainder) {
+      uint16_t encoded_msb_idx = encoded_full * 8;
+      uint16_t input_start_idx = encoded_full * 7;
+      encoded[encoded_msb_idx] = 0;
+      for(j = 0; j < remainder; j++){
+         uint8_t current = source[input_start_idx + j];
+         encoded[encoded_msb_idx] |= (0x80 & current) >> (1 + j);
+         encoded[encoded_msb_idx + 1 + j] = 0x7F & current;
+      }
+      return encoded_msb_idx + remainder + 1;
+   } else {
+      return encoded_full * 8;
+   }
+}
+
+uint16_t sysex_decode(uint8_t *decoded, const uint8_t *source, const uint16_t length){
+   uint16_t decoded_full = length / 8;
+   uint16_t i,j;
+
+   if (length < 2)
+      return 0;
+
+   //fill out the fully encoded sections
+   for(i = 0; i < decoded_full; i++) {
+      uint16_t encoded_msb_idx = i * 8;
+      uint16_t output_start_index = i * 7;
+      for(j = 0; j < 7; j++){
+         decoded[output_start_index + j] = 0x7F & source[encoded_msb_idx + j + 1];
+         decoded[output_start_index + j] |= (0x80 & (source[encoded_msb_idx] << (1 + j)));
+      }
+   }
+   uint8_t remainder = length % 8;
+   if (remainder) {
+      uint16_t encoded_msb_idx = decoded_full * 8;
+      uint16_t output_start_index = decoded_full * 7;
+      for(j = 0; j < (remainder - 1); j++) {
+         decoded[output_start_index + j] = 0x7F & source[encoded_msb_idx + j + 1];
+         decoded[output_start_index + j] |= (0x80 & (source[encoded_msb_idx] << (1 + j)));
+      }
+      return decoded_full * 7 + remainder - 1;
+   } else {
+      return decoded_full * 7;
+   }
+}
+