X-Git-Url: http://git.tuebingen.mpg.de/?p=paraslash.git;a=blobdiff_plain;f=time.c;h=0cb9babe2ae8de65be0fdfdc4e65ee6a626688e8;hp=b77138295c2ded13d8890cf3e626a7a8a0df3494;hb=749779fab22f802e41472a31db5a84b9b6314996;hpb=755bbd9fa36e16f266467bed60b158e5737bd838

diff --git a/time.c b/time.c
index b7713829..0cb9babe 100644
--- a/time.c
+++ b/time.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2005-2007 Andre Noll <maan@systemlinux.org>
+ * Copyright (C) 2005-2009 Andre Noll <maan@systemlinux.org>
  *
  * Licensed under the GPL v2. For licencing details see COPYING.
  */
@@ -106,9 +106,10 @@ void tv_add(const struct timeval *a, const struct timeval *b,
 void tv_scale(const unsigned long mult, const struct timeval *tv,
 	struct timeval *result)
 {
-	result->tv_sec = mult * tv->tv_sec;
-	result->tv_sec += tv->tv_usec * mult / 1000 / 1000;
-	result->tv_usec = tv->tv_usec * mult % (1000 * 1000);
+	uint64_t x = ((uint64_t)tv->tv_sec * 1000 * 1000 + tv->tv_usec) * mult;
+
+	result->tv_sec = x / 1000 / 1000;
+	result->tv_usec = x % (1000 * 1000);
 }
 
 /**
@@ -121,17 +122,10 @@ void tv_scale(const unsigned long mult, const struct timeval *tv,
 void tv_divide(const unsigned long divisor, const struct timeval *tv,
 	struct timeval *result)
 {
-	long unsigned q;
+	uint64_t x = ((uint64_t)tv->tv_sec * 1000 * 1000 + tv->tv_usec) / divisor;
 
-	q = tv->tv_usec / divisor;
-	result->tv_sec = tv->tv_sec / divisor;
-	result->tv_usec = (tv->tv_sec - result->tv_sec * divisor)
-		* 1000 * 1000 / divisor;
-	if (result->tv_usec + q >= 1000 * 1000) {
-		result->tv_sec++;
-		result->tv_usec = 1000 * 1000 - result->tv_usec - q;
-	} else
-		result->tv_usec += q;
+	result->tv_sec = x / 1000 / 1000;
+	result->tv_usec = x % (1000 * 1000);
 }
 
 /**
@@ -176,3 +170,23 @@ int tv_convex_combination(const long a, const struct timeval *tv1,
 			ret = -ret;
 	return ret;
 }
+
+/**
+ * Compute when to send a chunk of an audio file.
+ *
+ * \param chunk_num The number of the chunk.
+ * \param chunk_tv The duration of one chunk.
+ * \param stream_start When the first chunk was sent.
+ * \param result The time when to send chunk number \a chunk_num.
+ *
+ * This function computes stream_start + chunk_num * chunk_time.
+ */
+void compute_chunk_time(long unsigned chunk_num,
+		struct timeval *chunk_tv, struct timeval *stream_start,
+		struct timeval *result)
+{
+	struct timeval tmp;
+
+	tv_scale(chunk_num, chunk_tv, &tmp);
+	tv_add(&tmp, stream_start, result);
+}