The log is anyway rounded to an integer, so one may use an frexp
based approach. Note that this may be made frexpf; if arguments are less than
2^24 there is no loss. Kept as double precision for simplicity; 2^32 is
exactly representable as a double.
Signed-off-by: Ganesh Ajjanagadde <gajjanaga...@gmail.com>
---
ffmpeg.c | 13 ++++++++++++-
1 file changed, 12 insertions(+), 1 deletion(-)
diff --git a/ffmpeg.c b/ffmpeg.c
index 6d01987..ee72f91 100644
--- a/ffmpeg.c
+++ b/ffmpeg.c
@@ -1486,6 +1486,17 @@ static void print_final_stats(int64_t total_size)
}
}
+static inline int log2i(double d)
+{
+ int exp;
+ double mant;
+
+ mant = frexp(d, &exp);
+ if (mant >= M_SQRT1_2)
+ return exp;
+ return exp-1;
+}
+
static void print_report(int is_last_report, int64_t timer_start, int64_t
cur_time)
{
char buf[1024];
@@ -1559,7 +1570,7 @@ static void print_report(int is_last_report, int64_t
timer_start, int64_t cur_ti
if (qp >= 0 && qp < FF_ARRAY_ELEMS(qp_histogram))
qp_histogram[qp]++;
for (j = 0; j < 32; j++)
- snprintf(buf + strlen(buf), sizeof(buf) - strlen(buf),
"%X", (int)lrintf(log2(qp_histogram[j] + 1)));
+ snprintf(buf + strlen(buf), sizeof(buf) - strlen(buf),
"%X", log2i(qp_histogram[j] + 1));
}
if ((enc->flags & AV_CODEC_FLAG_PSNR) && (ost->pict_type !=
AV_PICTURE_TYPE_NONE || is_last_report)) {
--
2.6.4
_______________________________________________
ffmpeg-devel mailing list
ffmpeg-devel@ffmpeg.org
http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
