diff --git a/CHANGELOG.md b/CHANGELOG.md
index eb119d14..cbfc4517 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,4 +1,5 @@
 
+ * Increase thread safety of `FFmpegFrameFilter`, `FFmpegFrameGrabber`, and `FFmpegFrameRecorder` with `volatile boolean started` flag ([pull #1325](https://github.com/bytedeco/javacv/pull/1325))
  * Let `FFmpegFrameFilter.push(null)` indicate EOF to audio filters as well ([issue #1315](https://github.com/bytedeco/javacv/issues/1315))
  * Add `RealSense2FrameGrabber` to capture images with librealsense2 ([pull #1316](https://github.com/bytedeco/javacv/pull/1316))
  * Disable seek function in `FFmpegFrameGrabber` when `maximumSize <= 0` ([issue #1304](https://github.com/bytedeco/javacv/issues/1304))
diff --git a/src/main/java/org/bytedeco/javacv/FFmpegFrameFilter.java b/src/main/java/org/bytedeco/javacv/FFmpegFrameFilter.java
index 2d7b1508..ed4da749 100644
--- a/src/main/java/org/bytedeco/javacv/FFmpegFrameFilter.java
+++ b/src/main/java/org/bytedeco/javacv/FFmpegFrameFilter.java
@@ -145,6 +145,8 @@ public FFmpegFrameFilter(String afilters, int audioChannels) {
         }
     }
     public void releaseUnsafe() throws Exception {
+        started = false;
+
         if (filter_graph != null) {
             avfilter_graph_free(filter_graph);
             buffersink_ctx = null;
@@ -202,6 +204,8 @@ public void releaseUnsafe() throws Exception {
     Buffer[] samples_buf;
     Frame frame, inframe;
 
+    private volatile boolean started = false;
+
     @Override public int getImageWidth() {
         return buffersink_ctx != null ? av_buffersink_get_w(buffersink_ctx) : super.getImageWidth();
     }
@@ -277,6 +281,8 @@ public void startUnsafe() throws Exception {
         if (afilters != null && audioChannels > 0 && audioInputs > 0) {
             startAudioUnsafe();
         }
+
+        started = true;
     }
 
     void startVideoUnsafe() throws Exception {
@@ -493,6 +499,10 @@ public void push(int n, Frame frame) throws Exception {
         push(n, frame, frame != null && frame.opaque instanceof AVFrame ? ((AVFrame)frame.opaque).format() : AV_PIX_FMT_NONE);
     }
     public void push(int n, Frame frame, int pixelFormat) throws Exception {
+        if (!started) {
+            throw new Exception("start() was not called successfully!");
+        }
+
         inframe = frame;
         if (frame != null && frame.image != null && buffersrc_ctx != null) {
             image_frame.pts(frame.timestamp * time_base.den() / (1000000L * time_base.num()));
@@ -515,6 +525,10 @@ public void push(int n, Frame frame, int pixelFormat) throws Exception {
     }
 
     public void pushImage(int n, int width, int height, int depth, int channels, int stride, int pixelFormat, Buffer ... image) throws Exception {
+        if (!started) {
+            throw new Exception("start() was not called successfully!");
+        }
+
         int ret;
         int step = stride * Math.abs(depth) / 8;
         BytePointer data = image[0] instanceof ByteBuffer
@@ -555,6 +569,10 @@ public void pushImage(int n, int width, int height, int depth, int channels, int
     }
 
     public void pushSamples(int n, int audioChannels, int sampleRate, int sampleFormat, Buffer ... samples) throws Exception {
+        if (!started) {
+            throw new Exception("start() was not called successfully!");
+        }
+
         int ret;
         Pointer[] data = new Pointer[samples.length];
         int sampleSize = samples != null ? ((samples[0].limit() - samples[0].position()) / (samples.length > 1 ? 1 : audioChannels)) : 0;
@@ -606,6 +624,10 @@ public void pushSamples(int n, int audioChannels, int sampleRate, int sampleForm
     }
 
     @Override public Frame pull() throws Exception {
+        if (!started) {
+            throw new Exception("start() was not called successfully!");
+        }
+
         frame.keyFrame = false;
         frame.imageWidth = 0;
         frame.imageHeight = 0;
@@ -633,6 +655,10 @@ public void pushSamples(int n, int audioChannels, int sampleRate, int sampleForm
     }
 
     public Frame pullImage() throws Exception {
+        if (!started) {
+            throw new Exception("start() was not called successfully!");
+        }
+
         av_frame_unref(filt_frame);
 
         /* pull a filtered frame from the filtergraph */
@@ -678,6 +704,10 @@ public Frame pullImage() throws Exception {
     }
 
     public Frame pullSamples() throws Exception {
+        if (!started) {
+            throw new Exception("start() was not called successfully!");
+        }
+
         av_frame_unref(filt_frame);
 
         /* pull a filtered frame from the filtergraph */
diff --git a/src/main/java/org/bytedeco/javacv/FFmpegFrameGrabber.java b/src/main/java/org/bytedeco/javacv/FFmpegFrameGrabber.java
index 7a9342d0..bd0142e1 100644
--- a/src/main/java/org/bytedeco/javacv/FFmpegFrameGrabber.java
+++ b/src/main/java/org/bytedeco/javacv/FFmpegFrameGrabber.java
@@ -157,6 +157,7 @@ public void release() throws Exception {
         }
     }
     public void releaseUnsafe() throws Exception {
+        started = false;
         if (pkt != null && pkt2 != null) {
             if (pkt2.size() > 0) {
                 av_packet_unref(pkt);
@@ -364,6 +365,8 @@ static class SeekCallback extends Seek_Pointer_long_int {
     private boolean         frameGrabbed;
     private Frame           frame;
 
+    private volatile boolean started = false;
+
     public boolean isCloseInputStream() {
         return closeInputStream;
     }
@@ -976,6 +979,7 @@ public void startUnsafe() throws Exception {
             samples_ptr = new BytePointer[] { null };
             samples_buf = new Buffer[] { null };
         }
+        started = true;
     }
 
     private void initPictureRGB() {
@@ -1216,6 +1220,10 @@ public Frame grabFrame(boolean doAudio, boolean doVideo, boolean doProcessing, b
         } else if ((!doVideo || video_st == null) && (!doAudio || audio_st == null)) {
             return null;
         }
+        if (!started) {
+            throw new Exception("start() was not called successfully!");
+        }
+
         boolean videoFrameGrabbed = frameGrabbed && frame.image != null;
         boolean audioFrameGrabbed = frameGrabbed && frame.samples != null;
         frameGrabbed = false;
@@ -1324,7 +1332,10 @@ public Frame grabFrame(boolean doAudio, boolean doVideo, boolean doProcessing, b
 
     public AVPacket grabPacket() throws Exception {
         if (oc == null || oc.isNull()) {
-            throw new Exception("Could not trigger: No AVFormatContext. (Has start() been called?)");
+            throw new Exception("Could not grab: No AVFormatContext. (Has start() been called?)");
+        }
+        if (!started) {
+            throw new Exception("start() was not called successfully!");
         }
 
         // Return the next frame of a stream.
diff --git a/src/main/java/org/bytedeco/javacv/FFmpegFrameRecorder.java b/src/main/java/org/bytedeco/javacv/FFmpegFrameRecorder.java
index 62591f0f..9bffe9f9 100644
--- a/src/main/java/org/bytedeco/javacv/FFmpegFrameRecorder.java
+++ b/src/main/java/org/bytedeco/javacv/FFmpegFrameRecorder.java
@@ -188,6 +188,8 @@ public void release() throws Exception {
         }
     }
     public void releaseUnsafe() throws Exception {
+        started = false;
+
         /* close each codec */
         if (video_c != null) {
             avcodec_free_context(video_c);
@@ -348,6 +350,8 @@ static class WriteCallback extends Write_packet_Pointer_BytePointer_int {
     private int[] got_video_packet, got_audio_packet;
     private AVFormatContext ifmt_ctx;
 
+    private volatile boolean started = false;
+
     public boolean isCloseOutputStream() {
         return closeOutputStream;
     }
@@ -370,8 +374,8 @@ public void setCloseOutputStream(boolean closeOutputStream) {
         setFrameNumber((int)Math.round(timestamp * getFrameRate() / 1000000L));
     }
 
-    public void start(AVFormatContext ifmt_ctx) throws Exception {
-        this.ifmt_ctx = ifmt_ctx;
+    public void start(AVFormatContext inputFormatContext) throws Exception {
+        this.ifmt_ctx = inputFormatContext;
         start();
     }
 
@@ -862,12 +866,18 @@ public void startUnsafe() throws Exception {
             av_dict_set(metadata, e.getKey(), e.getValue(), 0);
         }
         /* write the stream header, if any */
-        avformat_write_header(oc.metadata(metadata), options);
+        if ((ret = avformat_write_header(oc.metadata(metadata), options)) < 0) {
+            releaseUnsafe();
+            av_dict_free(options);
+            throw new Exception("avformat_write_header error() error " + ret + ": Could not write header to '" + filename + "'");
+        }
         av_dict_free(options);
 
         if (av_log_get_level() >= AV_LOG_INFO) {
             av_dump_format(oc, 0, filename, 1);
         }
+
+        started = true;
     }
 
     public void flush() throws Exception {
@@ -918,6 +928,9 @@ public boolean recordImage(int width, int height, int depth, int channels, int s
         if (video_st == null) {
             throw new Exception("No video output stream (Is imageWidth > 0 && imageHeight > 0 and has start() been called?)");
         }
+        if (!started) {
+            throw new Exception("start() was not called successfully!");
+        }
         int ret;
 
         if (image == null || image.length == 0) {
@@ -1026,6 +1039,9 @@ public boolean recordSamples(int sampleRate, int audioChannels, Buffer ... sampl
         if (audio_st == null) {
             throw new Exception("No audio output stream (Is audioChannels > 0 and has start() been called?)");
         }
+        if (!started) {
+            throw new Exception("start() was not called successfully!");
+        }
 
         if (samples == null && samples_out[0].position() > 0) {
             // Typically samples_out[0].limit() is double the audio_input_frame_size --> sampleDivisor = 2
@@ -1230,6 +1246,12 @@ private void writePacket(int mediaType, AVPacket avPacket) throws Exception {
     }
 
     public boolean recordPacket(AVPacket pkt) throws Exception {
+        if (ifmt_ctx == null) {
+            throw new Exception("No input format context (Has start(AVFormatContext) been called?)");
+        }
+        if (!started) {
+            throw new Exception("start() was not called successfully!");
+        }
 
         if (pkt == null) {
             return false;