av_rescale: support passing MIN/MAX through

Reviewed-by: Clément Bœsch <ubitux@gmail.com>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

1 files changed, 7 insertions, 0 deletions

diff --git a/libavutil/mathematics.h b/libavutil/mathematics.h
index 0021d523ef..479161e1fd 100644
--- a/libavutil/mathematics.h
+++ b/libavutil/mathematics.h
@@ -70,6 +70,7 @@ enum AVRounding {
     AV_ROUND_DOWN     = 2, ///< Round toward -infinity.
     AV_ROUND_UP       = 3, ///< Round toward +infinity.
     AV_ROUND_NEAR_INF = 5, ///< Round to nearest and halfway cases away from zero.
+    AV_ROUND_PASS_MINMAX = 8192, ///< Flag to pass INT64_MIN/MAX through instead of rescaling, this avoids special cases for AV_NOPTS_VALUE
 };
 
 /**
@@ -88,6 +89,9 @@ int64_t av_rescale(int64_t a, int64_t b, int64_t c) av_const;
 /**
  * Rescale a 64-bit integer with specified rounding.
  * A simple a*b/c isn't possible as it can overflow.
+ *
+ * @return rescaled value a or if AV_ROUND_PASS_MINMAX is set and a is
+ *         INT64_MIN or INT64_MAX than a is passed through unchanged.
  */
 int64_t av_rescale_rnd(int64_t a, int64_t b, int64_t c, enum AVRounding) av_const;
 
@@ -98,6 +102,9 @@ int64_t av_rescale_q(int64_t a, AVRational bq, AVRational cq) av_const;
 
 /**
  * Rescale a 64-bit integer by 2 rational numbers with specified rounding.
+ *
+ * @return rescaled value a or if AV_ROUND_PASS_MINMAX is set and a is
+ *         INT64_MIN or INT64_MAX than a is passed through unchanged.
  */
 int64_t av_rescale_q_rnd(int64_t a, AVRational bq, AVRational cq,
                          enum AVRounding) av_const;