Merge commit '84c4714f397c9c50eb9d49008cc1c08385f68f31'

[ffmpeg] / libavcodec / on2avc.c

diff --git a/libavcodec/on2avc.c b/libavcodec/on2avc.c
index 04c8e410a8b5495d32b6d4659c8eca63547b9a77..62c71ccea53515c14c646cab29d1ff577b6791b0 100644 (file)
--- a/libavcodec/on2avc.c
+++ b/libavcodec/on2avc.c
@@ -22,6 +22,7 @@
 
 #include "libavutil/channel_layout.h"
 #include "libavutil/float_dsp.h"
+#include "libavutil/internal.h"
 #include "avcodec.h"
 #include "bytestream.h"
 #include "fft.h"
@@ -933,10 +934,13 @@ static av_cold int on2avc_decode_init(AVCodecContext *avctx)
         av_log(avctx, AV_LOG_WARNING,
                "Stereo mode support is not good, patch is welcome\n");
 
+    // We add -0.01 before ceil() to avoid any values to fall at exactly the
+    // midpoint between different ceil values. The results are identical to
+    // using pow(10, i / 10.0) without such bias
     for (i = 0; i < 20; i++)
-        c->scale_tab[i] = ceil(pow(10.0, i * 0.1) * 16) / 32;
+        c->scale_tab[i] = ceil(ff_exp10(i * 0.1) * 16 - 0.01) / 32;
     for (; i < 128; i++)
-        c->scale_tab[i] = ceil(pow(10.0, i * 0.1) * 0.5);
+        c->scale_tab[i] = ceil(ff_exp10(i * 0.1) * 0.5 - 0.01);
 
     if (avctx->sample_rate < 32000 || avctx->channels == 1)
         memcpy(c->long_win, ff_on2avc_window_long_24000,