indeo3data: add missing config.h #include for HAVE_BIGENDIAN

[ffmpeg] / libavutil / adler32.c

diff --git a/libavutil/adler32.c b/libavutil/adler32.c
index ab0b86da74feaf27f5e5c0745359c8ba9cc0d109..9d3d8965063b95f2baf24be134be317dd8a64b9e 100644 (file)
--- a/libavutil/adler32.c
+++ b/libavutil/adler32.c
@@ -1,41 +1,87 @@
-/* adler32.c -- compute the Adler-32 checksum of a data stream
+/*
+ * Compute the Adler-32 checksum of a data stream.
+ * This is a modified version based on adler32.c from the zlib library.
+ *
  * Copyright (C) 1995 Mark Adler
- * For conditions of distribution and use, see copyright notice in zlib.h
+ *
+ * This software is provided 'as-is', without any express or implied
+ * warranty.  In no event will the authors be held liable for any damages
+ * arising from the use of this software.
+ *
+ * Permission is granted to anyone to use this software for any purpose,
+ * including commercial applications, and to alter it and redistribute it
+ * freely, subject to the following restrictions:
+ *
+ * 1. The origin of this software must not be misrepresented; you must not
+ *    claim that you wrote the original software. If you use this software
+ *    in a product, an acknowledgment in the product documentation would be
+ *    appreciated but is not required.
+ * 2. Altered source versions must be plainly marked as such, and must not be
+ *    misrepresented as being the original software.
+ * 3. This notice may not be removed or altered from any source distribution.
  */
 
-#include "common.h"
+#include "config.h"
 #include "adler32.h"
 
 #define BASE 65521L /* largest prime smaller than 65536 */
-#define NMAX 5552
-/* NMAX is the largest n such that 255n(n+1)/2 + (n+1)(BASE-1) <= 2^32-1 */
 
-#define DO1(buf)  {s1 += *buf++; s2 += s1;}
-#define DO2(buf)  DO1(buf); DO1(buf);
-#define DO4(buf)  DO2(buf); DO2(buf);
-#define DO8(buf)  DO4(buf); DO4(buf);
-#define DO16(buf) DO8(buf); DO8(buf);
+#define DO1(buf)  { s1 += *buf++; s2 += s1; }
+#define DO4(buf)  DO1(buf); DO1(buf); DO1(buf); DO1(buf);
+#define DO16(buf) DO4(buf); DO4(buf); DO4(buf); DO4(buf);
 
-unsigned long av_adler32_update(unsigned long adler, const uint8_t *buf, unsigned int len)
+unsigned long av_adler32_update(unsigned long adler, const uint8_t * buf,
+                                unsigned int len)
 {
     unsigned long s1 = adler & 0xffff;
-    unsigned long s2 = (adler >> 16) & 0xffff;
-    int k;
-
-    if (buf == NULL) return 1L;
+    unsigned long s2 = adler >> 16;
 
     while (len > 0) {
-        k = len < NMAX ? len : NMAX;
-        len -= k;
-        while (k >= 16) {
+#if CONFIG_SMALL
+        while (len > 4  && s2 < (1U << 31)) {
+            DO4(buf);
+            len -= 4;
+        }
+#else
+        while (len > 16 && s2 < (1U << 31)) {
             DO16(buf);
-            k -= 16;
+            len -= 16;
         }
-        if (k != 0) do {
-            DO1(buf);
-        } while (--k);
+#endif
+        DO1(buf); len--;
         s1 %= BASE;
         s2 %= BASE;
     }
     return (s2 << 16) | s1;
 }
+
+#ifdef TEST
+#include <string.h>
+#include "log.h"
+#include "timer.h"
+#define LEN 7001
+volatile int checksum;
+int main(int argc, char **argv)
+{
+    int i;
+    char data[LEN];
+
+    av_log_set_level(AV_LOG_DEBUG);
+
+    for (i = 0; i < LEN; i++)
+        data[i] = ((i * i) >> 3) + 123 * i;
+
+    if (argc > 1 && !strcmp(argv[1], "-t")) {
+        for (i = 0; i < 1000; i++) {
+            START_TIMER;
+            checksum = av_adler32_update(1, data, LEN);
+            STOP_TIMER("adler");
+        }
+    } else {
+        checksum = av_adler32_update(1, data, LEN);
+    }
+
+    av_log(NULL, AV_LOG_DEBUG, "%X (expected 50E6E508)\n", checksum);
+    return checksum == 0x50e6e508 ? 0 : 1;
+}
+#endif