opus_celt: Fix arithmetic overflow (per RFC8251)

[ffmpeg] / libavcodec / opus_celt.c

diff --git a/libavcodec/opus_celt.c b/libavcodec/opus_celt.c
index 84d484753b361fe9292d3941a2510a0f771ace51..ff56041ea69ce90af7777c3b2c702cbbd9c70470 100644 (file)
--- a/libavcodec/opus_celt.c
+++ b/libavcodec/opus_celt.c
@@ -481,7 +481,8 @@ static void celt_denormalize(CeltFrame *f, CeltBlock *block, float *data)
 
     for (i = f->start_band; i < f->end_band; i++) {
         float *dst = data + (ff_celt_freq_bands[i] << f->size);
-        float norm = exp2f(block->energy[i] + ff_celt_mean_energy[i]);
+        float log_norm = block->energy[i] + ff_celt_mean_energy[i];
+        float norm = exp2f(FFMIN(log_norm, 32.0f));
 
         for (j = 0; j < ff_celt_freq_range[i] << f->size; j++)
             dst[j] *= norm;