diff --git a/src/DummyReader.cpp b/src/DummyReader.cpp
index e6c5fce1..d8d7d694 100644
--- a/src/DummyReader.cpp
+++ b/src/DummyReader.cpp
@@ -38,7 +38,7 @@ void DummyReader::init(Fraction fps, int width, int height, int sample_rate, int
 	// Set key info settings
 	info.has_audio = false;
 	info.has_video = true;
-	info.file_size = width * height * sizeof(int);
+	info.file_size = static_cast<size_t>(width * height * sizeof(int));
 	info.vcodec = "raw";
 	info.fps = fps;
 	info.width = width;
diff --git a/src/FFmpegReader.cpp b/src/FFmpegReader.cpp
index c1eaa748..c5c72a63 100644
--- a/src/FFmpegReader.cpp
+++ b/src/FFmpegReader.cpp
@@ -1535,7 +1535,13 @@ void FFmpegReader::ProcessAudioPacket(int64_t requested_frame, int64_t target_fr
 							 audio_frame->nb_samples);       // number of input samples to convert
 
 	// Copy audio samples over original samples
-	memcpy(audio_buf, audio_converted->data[0], audio_converted->nb_samples * av_get_bytes_per_sample(AV_SAMPLE_FMT_S16) * info.channels);
+	memcpy(audio_buf,
+	       audio_converted->data[0],
+	       static_cast<size_t>(
+	           audio_converted->nb_samples
+	           * av_get_bytes_per_sample(AV_SAMPLE_FMT_S16)
+	           * info.channels)
+	      );
 
 	// Deallocate resample buffer
 	SWR_CLOSE(avr);
diff --git a/src/FFmpegWriter.cpp b/src/FFmpegWriter.cpp
index 8707756c..33c6da82 100644
--- a/src/FFmpegWriter.cpp
+++ b/src/FFmpegWriter.cpp
@@ -1672,7 +1672,10 @@ void FFmpegWriter::write_audio_packets(bool is_final) {
         );
 
         // Copy audio samples over original samples
-        memcpy(all_resampled_samples, audio_converted->data[0], nb_samples * info.channels * av_get_bytes_per_sample(output_sample_fmt));
+        memcpy(all_resampled_samples, audio_converted->data[0],
+               static_cast<size_t>(
+                   nb_samples * info.channels
+                   * av_get_bytes_per_sample(output_sample_fmt)));
 
         // Remove converted audio
         av_freep(&(audio_frame->data[0]));
@@ -1706,7 +1709,8 @@ void FFmpegWriter::write_audio_packets(bool is_final) {
                        av_get_bytes_per_sample(AV_SAMPLE_FMT_S16) )
                 ),
                 all_resampled_samples + samples_position,
-                diff * av_get_bytes_per_sample(output_sample_fmt)
+                static_cast<size_t>(
+                    diff * av_get_bytes_per_sample(output_sample_fmt))
             );
 
         // Increment counters
@@ -1760,7 +1764,10 @@ void FFmpegWriter::write_audio_packets(bool is_final) {
             );
 
             // Copy audio into buffer for frame
-            memcpy(final_samples_planar, samples, audio_frame->nb_samples * info.channels * av_get_bytes_per_sample(output_sample_fmt));
+            memcpy(final_samples_planar, samples,
+                   static_cast<size_t>(
+                       audio_frame->nb_samples * info.channels
+                       * av_get_bytes_per_sample(output_sample_fmt)));
 
             // Fill input frame with sample data
             avcodec_fill_audio_frame(audio_frame, info.channels, output_sample_fmt,
@@ -1786,10 +1793,13 @@ void FFmpegWriter::write_audio_packets(bool is_final) {
             );
 
             // Copy audio samples over original samples
-            if (nb_samples > 0) {
-                memcpy(samples, frame_final->data[0],
-                    nb_samples * av_get_bytes_per_sample(audio_codec_ctx->sample_fmt) * info.channels);
-            }
+            const auto copy_length = static_cast<size_t>(
+                nb_samples
+                * av_get_bytes_per_sample(audio_codec_ctx->sample_fmt)
+                * info.channels);
+
+            if (nb_samples > 0)
+                memcpy(samples, frame_final->data[0], copy_length);
 
             // deallocate AVFrame
             av_freep(&(audio_frame->data[0]));
@@ -1800,11 +1810,13 @@ void FFmpegWriter::write_audio_packets(bool is_final) {
 
         } else {
             // Create a new array
-            final_samples = (int16_t *) av_malloc(
-                sizeof(int16_t) * audio_input_position
+            const auto buf_size = static_cast<size_t>(
+                audio_input_position
                 * (av_get_bytes_per_sample(audio_codec_ctx->sample_fmt) /
-                   av_get_bytes_per_sample(AV_SAMPLE_FMT_S16) )
-            );
+                   av_get_bytes_per_sample(AV_SAMPLE_FMT_S16))
+                );
+            final_samples = reinterpret_cast<int16_t*>(
+                    av_malloc(sizeof(int16_t) * buf_size));
 
             // Copy audio into buffer for frame
             memcpy(final_samples, samples,
diff --git a/src/Frame.cpp b/src/Frame.cpp
index aed38777..28c04eef 100644
--- a/src/Frame.cpp
+++ b/src/Frame.cpp
@@ -438,8 +438,10 @@ juce::AudioSampleBuffer *Frame::GetAudioSampleBuffer()
 int64_t Frame::GetBytes()
 {
 	int64_t total_bytes = 0;
-	if (image)
-		total_bytes += (width * height * sizeof(char) * 4);
+	if (image) {
+		total_bytes += static_cast<int64_t>(
+		    width * height * sizeof(char) * 4);
+	}
 	if (audio) {
 		// approximate audio size (sample rate / 24 fps)
 		total_bytes += (sample_rate / 24.0) * sizeof(float);