From 766a36afc7208388bb0b44b2235329d3e9ab837d Mon Sep 17 00:00:00 2001
From: sfan5 <sfan5@live.de>
Date: Sat, 1 Jul 2017 15:13:49 +0200
Subject: [PATCH] Avoid AVX-related crashes in FFmpeg by aligning buffer

---
 src/spek-fft.h | 22 ++++++++++++++++++----
 1 file changed, 18 insertions(+), 4 deletions(-)

diff --git a/src/spek-fft.h b/src/spek-fft.h
index 76595fa..990e482 100644
--- a/src/spek-fft.h
+++ b/src/spek-fft.h
@@ -3,6 +3,11 @@
 #include <memory>
 #include <vector>
 
+extern "C" {
+#include <libavutil/mem.h>
+}
+
+
 class FFTPlan;
 
 class FFT
@@ -17,8 +22,17 @@ class FFTPlan
 public:
     FFTPlan(int nbits) :
         input_size(1 << nbits), output_size((1 << (nbits - 1)) + 1),
-        input(input_size), output(output_size) {}
-    virtual ~FFTPlan() {}
+        output(output_size)
+    {
+        // FFmpeg uses various assembly optimizations which expect
+        // input data to be aligned by up to 32 bytes (e.g. AVX)
+        this->input = (float*) av_malloc(sizeof(float) * input_size);
+    }
+
+    virtual ~FFTPlan()
+    {
+        av_freep(this->input);
+    }
 
     int get_input_size() const { return this->input_size; }
     int get_output_size() const { return this->output_size; }
@@ -30,11 +44,11 @@ public:
     virtual void execute() = 0;
 
 protected:
-    float *get_input() { return this->input.data(); }
+    float *get_input() { return this->input; }
 
 private:
     int input_size;
     int output_size;
-    std::vector<float> input;
+    float *input;
     std::vector<float> output;
 };