Remove casting of uint8_t buffer to uint16_t to avoid alignment problems. Performance...

diff --git a/README b/README
index b610feb..5980c67 100644 (file)
--- a/README
+++ b/README
@@ -2,7 +2,7 @@
  libaec - Adaptive Entropy Coding library
 **********************************************************************
 
-libaec provides fast lossless compression of 1 up to 32 bit wide
+Libaec provides fast lossless compression of 1 up to 32 bit wide
 signed or unsigned integers (samples). The library achieves best
 results for low entropy data as often encountered in space imaging
 instrument data or numerical model output from weather or climate
@@ -10,7 +10,7 @@ simulations. While floating point representations are not directly
 supported, they can also be efficiently coded by grouping exponents
 and mantissa.
 
-libaec implements Golomb Rice coding as defined in the Space Data
+Libaec implements Golomb Rice coding as defined in the Space Data
 System Standard document 121.0-B-2 [1], [2].
 
 
@@ -125,10 +125,13 @@ sample size   storage size
 17 - 32 bit   4 bytes (also for 24bit if AEC_DATA_3BYTE is not set)
 
 If you use less bits than the storage size provides, then you have to
-make sure that unused bits are not set. libaec does not check this for
+make sure that unused bits are not set. Libaec does not check this for
 performance reasons and will produce undefined output if unused bits
 are set.
 
+Libaec accesses next_in and next_out buffers only bytewise. There are
+no alignment requirements for these buffers.
+
 Flushing:
 
 aec_encode can be used in a streaming fashion by chunking input and
@@ -181,7 +184,7 @@ and output is reversed.
 
 It is essential for decoding that parameters like bits_per_sample,
 block_size, rsi, and flags are exactly the same as they were for
-encoding. libaec does not store these parameters in the coded stream
+encoding. Libaec does not store these parameters in the coded stream
 so it is up to the calling program to keep the correct parameters
 between encoding and decoding.
 

diff --git a/src/encode_accessors.c b/src/encode_accessors.c
index ea5b69c..1fd55da 100644 (file)
--- a/src/encode_accessors.c
+++ b/src/encode_accessors.c
@@ -68,6 +68,32 @@ uint32_t get_8(struct aec_stream *strm)
     return *strm->next_in++;
 }
 
+uint32_t get_lsb_16(struct aec_stream *strm)
+{
+    uint32_t data;
+
+    data = ((uint32_t)strm->next_in[1] << 8)
+        | (uint32_t)strm->next_in[0];
+
+    strm->next_in += 2;
+    strm->total_in += 2;
+    strm->avail_in -= 2;
+    return data;
+}
+
+uint32_t get_msb_16(struct aec_stream *strm)
+{
+    uint32_t data;
+
+    data = ((uint32_t)strm->next_in[0] << 8)
+        | (uint32_t)strm->next_in[1];
+
+    strm->next_in += 2;
+    strm->total_in += 2;
+    strm->avail_in -= 2;
+    return data;
+}
+
 uint32_t get_lsb_24(struct aec_stream *strm)
 {
     uint32_t data;
@@ -96,44 +122,6 @@ uint32_t get_msb_24(struct aec_stream *strm)
     return data;
 }
 
-#define GET_NATIVE_16(BO)                       \
-uint32_t get_##BO##_16(struct aec_stream *strm) \
-{                                               \
-    uint32_t data;                              \
-                                                \
-    data = *(uint16_t *)strm->next_in;          \
-    strm->next_in += 2;                         \
-    strm->total_in += 2;                        \
-    strm->avail_in -= 2;                        \
-    return data;                                \
-}
-
-#define GET_NATIVE_32(BO)                       \
-uint32_t get_##BO##_32(struct aec_stream *strm) \
-{                                               \
-    uint32_t data;                              \
-                                                \
-    data = *(uint32_t *)strm->next_in;          \
-    strm->next_in += 4;                         \
-    strm->total_in += 4;                        \
-    strm->avail_in -= 4;                        \
-    return data;                                \
-}
-
-#ifdef WORDS_BIGENDIAN
-uint32_t get_lsb_16(struct aec_stream *strm)
-{
-    uint32_t data;
-
-    data = ((uint32_t)strm->next_in[1] << 8)
-        | (uint32_t)strm->next_in[0];
-
-    strm->next_in += 2;
-    strm->total_in += 2;
-    strm->avail_in -= 2;
-    return data;
-}
-
 uint32_t get_lsb_32(struct aec_stream *strm)
 {
     uint32_t data;
@@ -149,23 +137,6 @@ uint32_t get_lsb_32(struct aec_stream *strm)
     return data;
 }
 
-GET_NATIVE_16(msb);
-GET_NATIVE_32(msb);
-
-#else /* !WORDS_BIGENDIAN */
-uint32_t get_msb_16(struct aec_stream *strm)
-{
-    uint32_t data;
-
-    data = ((uint32_t)strm->next_in[0] << 8)
-        | (uint32_t)strm->next_in[1];
-
-    strm->next_in += 2;
-    strm->total_in += 2;
-    strm->avail_in -= 2;
-    return data;
-}
-
 uint32_t get_msb_32(struct aec_stream *strm)
 {
     uint32_t data;
@@ -181,11 +152,6 @@ uint32_t get_msb_32(struct aec_stream *strm)
     return data;
 }
 
-GET_NATIVE_16(lsb);
-GET_NATIVE_32(lsb);
-
-#endif /* !WORDS_BIGENDIAN */
-
 void get_rsi_8(struct aec_stream *strm)
 {
     uint32_t *out = strm->state->data_raw;
@@ -211,10 +177,76 @@ void get_rsi_8(struct aec_stream *strm)
     }
 }
 
+void get_rsi_lsb_16(struct aec_stream *strm)
+{
+    uint32_t *out = strm->state->data_raw;
+    const unsigned char *in = strm->next_in;
+    int rsi = strm->rsi * strm->block_size;
+
+    strm->next_in += 2 * rsi;
+    strm->total_in += 2 * rsi;
+    strm->avail_in -= 2 * rsi;
+
+    while (rsi) {
+        out[0] = (uint32_t)in[0]
+            | ((uint32_t)in[1] << 8);
+        out[1] = (uint32_t)in[2]
+            | ((uint32_t)in[3] << 8);
+        out[2] = (uint32_t)in[4]
+            | ((uint32_t)in[5] << 8);
+        out[3] = (uint32_t)in[6]
+            | ((uint32_t)in[7] << 8);
+        out[4] = (uint32_t)in[8]
+            | ((uint32_t)in[9] << 8);
+        out[5] = (uint32_t)in[10]
+            | ((uint32_t)in[11] << 8);
+        out[6] = (uint32_t)in[12]
+            | ((uint32_t)in[13] << 8);
+        out[7] = (uint32_t)in[14]
+            | ((uint32_t)in[15] << 8);
+        in += 16;
+        out += 8;
+        rsi -= 8;
+    }
+}
+
+void get_rsi_msb_16(struct aec_stream *strm)
+{
+    uint32_t *out = strm->state->data_raw;
+    const unsigned char *in = strm->next_in;
+    int rsi = strm->rsi * strm->block_size;
+
+    strm->next_in += 2 * rsi;
+    strm->total_in += 2 * rsi;
+    strm->avail_in -= 2 * rsi;
+
+    while (rsi) {
+        out[0] = ((uint32_t)in[0] << 8)
+            | (uint32_t)in[1];
+        out[1] = ((uint32_t)in[2] << 8)
+            | (uint32_t)in[3];
+        out[2] = ((uint32_t)in[4] << 8)
+            | (uint32_t)in[5];
+        out[3] = ((uint32_t)in[6] << 8)
+            | (uint32_t)in[7];
+        out[4] = ((uint32_t)in[8] << 8)
+            | (uint32_t)in[9];
+        out[5] = ((uint32_t)in[10] << 8)
+            | (uint32_t)in[11];
+        out[6] = ((uint32_t)in[12] << 8)
+            | (uint32_t)in[13];
+        out[7] = ((uint32_t)in[14] << 8)
+            | (uint32_t)in[15];
+        in += 16;
+        out += 8;
+        rsi -= 8;
+    }
+}
+
 void get_rsi_lsb_24(struct aec_stream *strm)
 {
     uint32_t *out = strm->state->data_raw;
-    unsigned const char *in = strm->next_in;
+    const unsigned char *in = strm->next_in;
     int rsi = strm->rsi * strm->block_size;
 
     strm->next_in += 3 * rsi;
@@ -255,7 +287,7 @@ void get_rsi_lsb_24(struct aec_stream *strm)
 void get_rsi_msb_24(struct aec_stream *strm)
 {
     uint32_t *out = strm->state->data_raw;
-    unsigned const char *in = strm->next_in;
+    const unsigned char *in = strm->next_in;
     int rsi = strm->rsi * strm->block_size;
 
     strm->next_in += 3 * rsi;
@@ -293,32 +325,6 @@ void get_rsi_msb_24(struct aec_stream *strm)
     }
 }
 
-#define GET_RSI_NATIVE_16(BO)                       \
-    void get_rsi_##BO##_16(struct aec_stream *strm) \
-    {                                               \
-        uint32_t *out = strm->state->data_raw;      \
-        uint16_t *in = (uint16_t *)strm->next_in;   \
-        int rsi = strm->rsi * strm->block_size;     \
-                                                    \
-        strm->next_in += 2 * rsi;                   \
-        strm->total_in += 2 * rsi;                  \
-        strm->avail_in -= 2 * rsi;                  \
-                                                    \
-        while (rsi) {                               \
-            out[0] = (uint32_t)in[0];               \
-            out[1] = (uint32_t)in[1];               \
-            out[2] = (uint32_t)in[2];               \
-            out[3] = (uint32_t)in[3];               \
-            out[4] = (uint32_t)in[4];               \
-            out[5] = (uint32_t)in[5];               \
-            out[6] = (uint32_t)in[6];               \
-            out[7] = (uint32_t)in[7];               \
-            in += 8;                                \
-            out += 8;                               \
-            rsi -= 8;                               \
-        }                                           \
-    }
-
 #define GET_RSI_NATIVE_32(BO)                       \
     void get_rsi_##BO##_32(struct aec_stream *strm) \
     {                                               \
@@ -331,43 +337,10 @@ void get_rsi_msb_24(struct aec_stream *strm)
     }
 
 #ifdef WORDS_BIGENDIAN
-void get_rsi_lsb_16(struct aec_stream *strm)
-{
-    uint32_t *out = strm->state->data_raw;
-    unsigned const char *in = strm->next_in;
-    int rsi = strm->rsi * strm->block_size;
-
-    strm->next_in += 2 * rsi;
-    strm->total_in += 2 * rsi;
-    strm->avail_in -= 2 * rsi;
-
-    while (rsi) {
-        out[0] = (uint32_t)in[0]
-            | ((uint32_t)in[1] << 8);
-        out[1] = (uint32_t)in[2]
-            | ((uint32_t)in[3] << 8);
-        out[2] = (uint32_t)in[4]
-            | ((uint32_t)in[5] << 8);
-        out[3] = (uint32_t)in[6]
-            | ((uint32_t)in[7] << 8);
-        out[4] = (uint32_t)in[8]
-            | ((uint32_t)in[9] << 8);
-        out[5] = (uint32_t)in[10]
-            | ((uint32_t)in[11] << 8);
-        out[6] = (uint32_t)in[12]
-            | ((uint32_t)in[13] << 8);
-        out[7] = (uint32_t)in[14]
-            | ((uint32_t)in[15] << 8);
-        in += 16;
-        out += 8;
-        rsi -= 8;
-    }
-}
-
 void get_rsi_lsb_32(struct aec_stream *strm)
 {
     uint32_t *out = strm->state->data_raw;
-    unsigned const char *in = strm->next_in;
+    const unsigned char *in = strm->next_in;
     int rsi = strm->rsi * strm->block_size;
 
     strm->next_in += 4 * rsi;
@@ -413,47 +386,13 @@ void get_rsi_lsb_32(struct aec_stream *strm)
     }
 }
 
-GET_RSI_NATIVE_16(msb);
 GET_RSI_NATIVE_32(msb);
 
 #else /* !WORDS_BIGENDIAN */
-void get_rsi_msb_16(struct aec_stream *strm)
-{
-    uint32_t *out = strm->state->data_raw;
-    unsigned const char *in = strm->next_in;
-    int rsi = strm->rsi * strm->block_size;
-
-    strm->next_in += 2 * rsi;
-    strm->total_in += 2 * rsi;
-    strm->avail_in -= 2 * rsi;
-
-    while (rsi) {
-        out[0] = ((uint32_t)in[0] << 8)
-            | (uint32_t)in[1];
-        out[1] = ((uint32_t)in[2] << 8)
-            | (uint32_t)in[3];
-        out[2] = ((uint32_t)in[4] << 8)
-            | (uint32_t)in[5];
-        out[3] = ((uint32_t)in[6] << 8)
-            | (uint32_t)in[7];
-        out[4] = ((uint32_t)in[8] << 8)
-            | (uint32_t)in[9];
-        out[5] = ((uint32_t)in[10] << 8)
-            | (uint32_t)in[11];
-        out[6] = ((uint32_t)in[12] << 8)
-            | (uint32_t)in[13];
-        out[7] = ((uint32_t)in[14] << 8)
-            | (uint32_t)in[15];
-        in += 16;
-        out += 8;
-        rsi -= 8;
-    }
-}
-
 void get_rsi_msb_32(struct aec_stream *strm)
 {
     uint32_t *out = strm->state->data_raw;
-    unsigned const char *in = strm->next_in;
+    const unsigned char *in = strm->next_in;
     int rsi = strm->rsi * strm->block_size;
 
     strm->next_in += 4 * rsi;
@@ -499,7 +438,6 @@ void get_rsi_msb_32(struct aec_stream *strm)
     }
 }
 
-GET_RSI_NATIVE_16(lsb);
 GET_RSI_NATIVE_32(lsb);
 
 #endif /* !WORDS_BIGENDIAN */