lib functions for simple buffer encoding/decoding

diff --git a/src/decode.c b/src/decode.c
index 179cf7f..36a88c7 100644 (file)
--- a/src/decode.c
+++ b/src/decode.c
@@ -607,3 +607,16 @@ int aec_decode(struct aec_stream *strm, int flush)
 req_buffer:
     return AEC_OK;
 }
+
+int aec_buf_decode(struct aec_stream *strm)
+{
+    int status;
+
+    status = aec_decode_init(strm);
+    if (status != AEC_OK)
+        return status;
+
+    status = aec_decode(strm, AEC_FLUSH);
+    aec_decode_end(strm);
+    return status;
+}

diff --git a/src/encode.c b/src/encode.c
index 7747f8f..82fa56b 100644 (file)
--- a/src/encode.c
+++ b/src/encode.c
@@ -737,3 +737,18 @@ int aec_encode_end(struct aec_stream *strm)
     free(state);
     return AEC_OK;
 }
+
+int aec_buf_encode(struct aec_stream *strm)
+{
+    int status;
+
+    status = aec_encode_init(strm);
+    if (status != AEC_OK)
+        return status;
+    status = aec_encode(strm, AEC_FLUSH);
+    if (strm->avail_in > 0 || strm->avail_out == 0)
+        status = AEC_DATA_ERROR;
+
+    aec_encode_end(strm);
+    return status;
+}

diff --git a/src/libaec.h b/src/libaec.h
index 4d1f0f6..1587857 100644 (file)
--- a/src/libaec.h
+++ b/src/libaec.h
@@ -7,30 +7,41 @@ struct internal_state;
 
 struct aec_stream {
     const unsigned char *next_in;
-    size_t avail_in;         /* number of bytes available at
-                              * next_in */
-    size_t total_in;         /* total number of input bytes read so
-                              * far */
+    size_t avail_in;            /* number of bytes available at
+                                 * next_in
+                                 */
+    size_t total_in;            /* total number of input bytes read so
+                                 * far
+                                 */
     unsigned char *next_out;
-    size_t avail_out;        /* remaining free space at next_out */
-    size_t total_out;        /* total number of bytes output so far */
-    int bit_per_sample;      /* resolution in bits per sample (n =
-                              * 1,..., 32) */
-    int block_size;          /* block size in samples */
-    int rsi;                 /* Reference sample interval, the number of
-                                blocks between consecutive reference
-                                samples. */
+    size_t avail_out;           /* remaining free space at next_out */
+    size_t total_out;           /* total number of bytes output so far */
+    int bit_per_sample;         /* resolution in bits per sample (n =
+                                 * 1, ..., 32)
+                                 */
+    int block_size;             /* block size in samples */
+    int rsi;                    /* Reference sample interval, the number
+                                 * of _blocks_ between consecutive
+                                 * reference samples (up to 4096).
+                                 */
     int flags;
 
     struct internal_state *state;
 };
 
-/* Coder flags */
-#define AEC_DATA_UNSIGNED     0
-#define AEC_DATA_SIGNED       1
-#define AEC_DATA_3BYTE        2  /* 24 bit samples coded in 3 bytes */
-#define AEC_DATA_LSB          0
-#define AEC_DATA_MSB         16
+/* Sample data description flags */
+#define AEC_DATA_UNSIGNED     0  /* Samples are unsigned integers (default) */
+#define AEC_DATA_SIGNED       1  /* Samples are signed. Telling libaec
+                                  * this results in a slightly better
+                                  * compression ratio.
+                                  */
+#define AEC_DATA_3BYTE        2  /* 24 bit samples are coded in 3 bytes */
+#define AEC_DATA_MSB         16  /* Samples are stored with their most
+                                  * significant bit first. This has
+                                  * nothing to do with the endianness
+                                  * of the host.
+                                  */
+#define AEC_DATA_LSB          0  /* Samples are stored LSB first (default) */
 #define AEC_DATA_PREPROCESS  32  /* Set if preprocessor should be used */
 
 /* Return codes of library functions */
@@ -41,27 +52,32 @@ struct aec_stream {
 #define AEC_MEM_ERROR    (-4)
 
 /* Options for flushing */
-#define AEC_NO_FLUSH      0 /* Do not enforce output flushing. More
-                             * input may be provided with later
-                             * calls. So far only relevant for
-                             * encoding.
-                             */
-#define AEC_FLUSH         1 /* Flush output and end encoding. The last
-                             * call to aec_encode() must set AEC_FLUSH to
-                             * drain all output.
-                             *
-                             * It is not possible to continue encoding
-                             * of the same stream after it has been
-                             * flushed because the last byte may be
-                             * padded with fill bits.
-                             */
+#define AEC_NO_FLUSH      0      /* Do not enforce output
+                                  * flushing. More input may be
+                                  * provided with later calls. So far
+                                  * only relevant for encoding.
+                                  */
+#define AEC_FLUSH         1      /* Flush output and end encoding. The
+                                  * last call to aec_encode() must set
+                                  * AEC_FLUSH to drain all output.
+                                  *
+                                  * It is not possible to continue
+                                  * encoding of the same stream after it
+                                  * has been flushed because the last byte
+                                  * may be padded with fill bits.
+                                  */
+
+/* Streaming encoding and decoding functions */
+int aec_encode_init(struct aec_stream *strm);
+int aec_encode(struct aec_stream *strm, int flush);
+int aec_encode_end(struct aec_stream *strm);
 
 int aec_decode_init(struct aec_stream *strm);
 int aec_decode(struct aec_stream *strm, int flush);
 int aec_decode_end(struct aec_stream *strm);
 
-int aec_encode_init(struct aec_stream *strm);
-int aec_encode(struct aec_stream *strm, int flush);
-int aec_encode_end(struct aec_stream *strm);
+/* Utility functions for encoding or decoding a memory buffer. */
+int aec_buffer_encode(struct aec_stream *strm);
+int aec_buffer_decode(struct aec_stream *strm);
 
 #endif /* LIBAEC_H */

diff --git a/src/sz_compat.c b/src/sz_compat.c
index 288cce3..b4798c9 100644 (file)
--- a/src/sz_compat.c
+++ b/src/sz_compat.c
@@ -1,8 +1,11 @@
 #include <stdio.h>
 #include <stddef.h>
 #include "szlib.h"
+#include "libaec.h"
 
-int SZ_BufftoBuffCompress(void *dest, size_t *destLen, const void *source, size_t sourceLen, SZ_com_t *param)
+int SZ_BufftoBuffCompress(void *dest, size_t *destLen,
+                          const void *source, size_t sourceLen,
+                          SZ_com_t *param)
 {
     int status;
     struct aec_stream strm;
@@ -16,21 +19,17 @@ int SZ_BufftoBuffCompress(void *dest, size_t *destLen, const void *source, size_
     strm.next_out = dest;
     strm.next_in = source;
 
-    if ((status = aec_encode_init(&strm)) != AEC_OK)
-        return status;
-
-    if ((status = aec_encode(&strm, AEC_FLUSH)) != AEC_OK)
+    status = aec_buf_encode(&strm);
+    if (status != AEC_OK)
         return status;
 
     *destLen = strm.total_out;
-
-    if ((status = aec_encode_end(&strm)) != AEC_OK)
-        return status;
-
     return SZ_OK;
 }
 
-int SZ_BufftoBuffDecompress(void *dest, size_t *destLen, const void *source, size_t sourceLen, SZ_com_t *param)
+int SZ_BufftoBuffDecompress(void *dest, size_t *destLen,
+                            const void *source, size_t sourceLen,
+                            SZ_com_t *param)
 {
     int status;
     struct aec_stream strm;
@@ -44,16 +43,10 @@ int SZ_BufftoBuffDecompress(void *dest, size_t *destLen, const void *source, siz
     strm.next_out = dest;
     strm.next_in = source;
 
-    if ((status = aec_decode_init(&strm)) != AEC_OK)
-        return status;
-
-    if ((status = aec_decode(&strm, AEC_FLUSH)) != AEC_OK)
+    status = aec_buf_decode(&strm);
+    if (status != AEC_OK)
         return status;
 
     *destLen = strm.total_out;
-
-    if ((status = aec_decode_end(&strm)) != AEC_OK)
-        return status;
-
     return SZ_OK;
 }

diff --git a/src/szlib.h b/src/szlib.h
index 5d303df..5ce9e65 100644 (file)
--- a/src/szlib.h
+++ b/src/szlib.h
@@ -22,7 +22,11 @@ typedef struct SZ_com_t_s
     int pixels_per_scanline;
 } SZ_com_t;
 
-int SZ_BufftoBuffCompress(void *dest, size_t *destLen, const void *source, size_t sourceLen, SZ_com_t *param);
-int SZ_BufftoBuffDecompress(void *dest, size_t *destLen, const void *source, size_t sourceLen, SZ_com_t *param);
+int SZ_BufftoBuffCompress(void *dest, size_t *destLen,
+                          const void *source, size_t sourceLen,
+                          SZ_com_t *param);
+int SZ_BufftoBuffDecompress(void *dest, size_t *destLen,
+                            const void *source, size_t sourceLen,
+                            SZ_com_t *param);
 
 #endif /* SZLIB_H */