Reference encoder MSB/LSB bit order shifting changeable via MSB_FIRST

szabolor · Aug 28, 2015 · 2876aeb · 2876aeb
1 parent c9ae4ae
commit 2876aeb
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Showing 2 changed files with 8 additions and 1 deletion.
diff --git a/smog_ref/v0.2/encode/enc_ref.c b/smog_ref/v0.2/encode/enc_ref.c
@@ -270,7 +270,13 @@ void encode_data_bit(uint8_t (*data)[256], uint8_t (*bit_encoded)[5200]) {
 
   // convert to bit format: simply put 0 and 1 to the corresponding byte
   for (i = 0; i < 5200; ++i) {
+#if (MSBFIRST == 1)
+    // MSB first
     (*bit_encoded)[i] = ( (encoded[i >> 3] & (1 << (7 - (i & 7)))) != 0 );
+#else
+    // LSB first
+    (*bit_encoded)[i] = ( (encoded[i >> 3] & (1 << (i & 7))) != 0 );
+#endif
   }
 }
 #endif
diff --git a/smog_ref/v0.2/encode/enc_ref.h b/smog_ref/v0.2/encode/enc_ref.h
@@ -4,7 +4,8 @@
 #include <stdint.h>
 
 #define LOW_MEMORY        1 // low memory workaround to avoid LUT (and preserve 512byte)
-#define ENABLE_BIT_OUTPUT 0 // enable 
+#define ENABLE_BIT_OUTPUT 1 // enable 
+#define MSBFISRT          1 // the first bit of bytes of encode_data_bit is the MSB
 
 void encode_data(uint8_t (*data)[256], uint8_t (*encoded)[650]);