diff --git a/src/main/java/org/bytedeco/javacv/FFmpegFrameGrabber.java b/src/main/java/org/bytedeco/javacv/FFmpegFrameGrabber.java
index 034f247a..540b3b37 100644
--- a/src/main/java/org/bytedeco/javacv/FFmpegFrameGrabber.java
+++ b/src/main/java/org/bytedeco/javacv/FFmpegFrameGrabber.java
@@ -68,6 +68,9 @@
 import org.bytedeco.javacpp.Loader;
 import org.bytedeco.javacpp.Pointer;
 import org.bytedeco.javacpp.PointerScope;
+import org.bytedeco.javacv.FFmpegFrameGrabber.ReadCallback;
+import org.bytedeco.javacv.FrameGrabber.ImageMode;
+import org.bytedeco.javacv.FrameGrabber.SampleMode;
 import org.bytedeco.javacpp.PointerPointer;
 
 import org.bytedeco.ffmpeg.avcodec.*;
@@ -989,6 +992,7 @@ public synchronized void startUnsafe(boolean findStreamInfo) throws Exception {
                 throw new Exception("avformat_open_input() error " + ret + ": Could not open input \"" + filename + "\". (Has setFormat() been called?)");
             }
         }
+        logRejectedOptions(options, "avformat_open_input");
         av_dict_free(options);
 
         oc.max_delay(maxDelay);
@@ -1072,6 +1076,7 @@ public synchronized void startUnsafe(boolean findStreamInfo) throws Exception {
             if ((ret = avcodec_open2(video_c, codec, options)) < 0) {
                 throw new Exception("avcodec_open2() error " + ret + ": Could not open video codec.");
             }
+            logRejectedOptions(options, "avcodec_open2");
             av_dict_free(options);
 
             // Hack to correct wrong frame rates that seem to be generated by some codecs
@@ -1123,6 +1128,7 @@ public synchronized void startUnsafe(boolean findStreamInfo) throws Exception {
             if ((ret = avcodec_open2(audio_c, codec, options)) < 0) {
                 throw new Exception("avcodec_open2() error " + ret + ": Could not open audio codec.");
             }
+            logRejectedOptions(options, "avcodec_open2");
             av_dict_free(options);
 
             // Allocate audio samples frame
@@ -1138,6 +1144,16 @@ public synchronized void startUnsafe(boolean findStreamInfo) throws Exception {
         }
     }
 
+    private void logRejectedOptions(final AVDictionary options, final String command) {
+        if (av_log_get_level() >= AV_LOG_INFO && av_dict_count(options) > 0) {
+            AVDictionaryEntry e = null;
+            System.out.println(command + " rejected some options:");
+            while ((e = av_dict_iterate(options, e)) != null) {
+                System.out.println("\tOption: " + e.key().getString() + ", value: " + e.value().getString());
+            }
+        }
+    }
+
     private void initPictureRGB() {
         int width  = imageWidth  > 0 ? imageWidth  : video_c.width();
         int height = imageHeight > 0 ? imageHeight : video_c.height();
diff --git a/src/main/java/org/bytedeco/javacv/FFmpegFrameRecorder.java b/src/main/java/org/bytedeco/javacv/FFmpegFrameRecorder.java
index f6567fbe..220676f1 100644
--- a/src/main/java/org/bytedeco/javacv/FFmpegFrameRecorder.java
+++ b/src/main/java/org/bytedeco/javacv/FFmpegFrameRecorder.java
@@ -75,7 +75,7 @@
 import org.bytedeco.javacpp.PointerScope;
 import org.bytedeco.javacpp.PointerPointer;
 import org.bytedeco.javacpp.ShortPointer;
-
+import org.bytedeco.javacv.FFmpegFrameRecorder.WriteCallback;
 import org.bytedeco.ffmpeg.avcodec.*;
 import org.bytedeco.ffmpeg.avdevice.*;
 import org.bytedeco.ffmpeg.avformat.*;
@@ -798,6 +798,7 @@ public synchronized void startUnsafe() throws Exception {
                 av_dict_free(options);
                 throw new Exception("avcodec_open2() error " + ret + ": Could not open video codec.");
             }
+            logRejectedOptions(options, "avcodec_open2");
             av_dict_free(options);
 
             video_outbuf = null;
@@ -879,6 +880,7 @@ public synchronized void startUnsafe() throws Exception {
                 av_dict_free(options);
                 throw new Exception("avcodec_open2() error " + ret + ": Could not open audio codec.");
             }
+            logRejectedOptions(options, "avcodec_open2");
             av_dict_free(options);
 
             audio_outbuf_size = 256 * 1024;
@@ -962,6 +964,7 @@ public synchronized void startUnsafe() throws Exception {
                 av_dict_free(options);
                 throw new Exception(errorMsg);
             }
+            logRejectedOptions(options, "avio_open2");
             oc.pb(pb);
         }
 
@@ -976,6 +979,7 @@ public synchronized void startUnsafe() throws Exception {
             av_dict_free(options);
             throw new Exception(errorMsg);
         }
+        logRejectedOptions(options, "avformat_write_header");
         av_dict_free(options);
 
         if (av_log_get_level() >= AV_LOG_INFO) {
@@ -1311,6 +1315,16 @@ public synchronized boolean recordSamples(int sampleRate, int audioChannels, Buf
         }
     }
 
+    private void logRejectedOptions(final AVDictionary options, final String command) {
+        if (av_log_get_level() >= AV_LOG_INFO && av_dict_count(options) > 0) {
+            AVDictionaryEntry e = null;
+            System.out.println(command + " rejected some options:");
+            while ((e = av_dict_iterate(options, e)) != null) {
+                System.out.println("\tOption: " + e.key().getString() + ", value: " + e.value().getString());
+            }
+        }
+    }
+
     private void writeSamples(int nb_samples) throws Exception {
         if (samples_out == null || samples_out.length == 0) {
             return;