[FFmpeg-devel] [PATCH 2/2] avfilter/ebur128: fix relative threshold calculation for multiple contexts

[Marton Balint]

Also disallow NULL contexts.

Fixes Coverity CID 1396273, 1396279.

Signed-off-by: Marton Balint <cus at passwd.hu>
---
 libavfilter/ebur128.c | 40 +++++++++++++++++++---------------------
 1 file changed, 19 insertions(+), 21 deletions(-)

diff --git a/libavfilter/ebur128.c b/libavfilter/ebur128.c
index 012df54..e064c59 100644
--- a/libavfilter/ebur128.c
+++ b/libavfilter/ebur128.c
@@ -519,49 +519,45 @@ FF_EBUR128_ADD_FRAMES(int)
 FF_EBUR128_ADD_FRAMES(float)
 FF_EBUR128_ADD_FRAMES(double)
 
-static int ebur128_calc_relative_threshold(FFEBUR128State * st,
+static void ebur128_sum_relative_threshold(FFEBUR128State * st,
                                            size_t * above_thresh_counter,
                                            double *relative_threshold)
 {
     size_t i;
-    *relative_threshold = 0.0;
-    *above_thresh_counter = 0;
 
     for (i = 0; i < 1000; ++i) {
         *relative_threshold += st->d->block_energy_histogram[i] *
             histogram_energies[i];
         *above_thresh_counter += st->d->block_energy_histogram[i];
     }
+}
 
+static void ebur128_finalize_relative_threshold(size_t *above_thresh_counter,
+                                                double *relative_threshold)
+{
     if (*above_thresh_counter != 0) {
         *relative_threshold /= (double) *above_thresh_counter;
         *relative_threshold *= RELATIVE_GATE_FACTOR;
     }
-
-    return 0;
 }
 
 static int ebur128_gated_loudness(FFEBUR128State ** sts, size_t size,
                                   double *out)
 {
     double gated_loudness = 0.0;
-    double relative_threshold;
-    size_t above_thresh_counter;
+    double relative_threshold = 0.0;
+    size_t above_thresh_counter = 0;
     size_t i, j, start_index;
 
-    for (i = 0; i < size; i++) {
-        if (sts[i]
-            && (sts[i]->mode & FF_EBUR128_MODE_I) != FF_EBUR128_MODE_I) {
+    for (i = 0; i < size; i++)
+        if ((sts[i]->mode & FF_EBUR128_MODE_I) != FF_EBUR128_MODE_I)
             return AVERROR(EINVAL);
-        }
-    }
 
-    for (i = 0; i < size; i++) {
-        if (!sts[i])
-            continue;
-        ebur128_calc_relative_threshold(sts[i], &above_thresh_counter,
+    for (i = 0; i < size; i++)
+        ebur128_sum_relative_threshold(sts[i], &above_thresh_counter,
+                                       &relative_threshold);
+    ebur128_finalize_relative_threshold(&above_thresh_counter,
                                         &relative_threshold);
-    }
     if (!above_thresh_counter) {
         *out = -HUGE_VAL;
         return 0;
@@ -596,14 +592,16 @@ static int ebur128_gated_loudness(FFEBUR128State ** sts, size_t size,
 
 int ff_ebur128_relative_threshold(FFEBUR128State * st, double *out)
 {
-    double relative_threshold;
-    size_t above_thresh_counter;
+    double relative_threshold = 0.0;
+    size_t above_thresh_counter = 0;
 
     if ((st->mode & FF_EBUR128_MODE_I) != FF_EBUR128_MODE_I)
         return AVERROR(EINVAL);
 
-    ebur128_calc_relative_threshold(st, &above_thresh_counter,
-                                    &relative_threshold);
+    ebur128_sum_relative_threshold(st, &above_thresh_counter,
+                                   &relative_threshold);
+    ebur128_finalize_relative_threshold(&above_thresh_counter,
+                                        &relative_threshold);
 
     if (!above_thresh_counter) {
         *out = -70.0;
-- 
2.10.2