diff --git a/encoder/mjpeg_encoder.cpp b/encoder/mjpeg_encoder.cpp
index edf5db87..eba51ce3 100644
--- a/encoder/mjpeg_encoder.cpp
+++ b/encoder/mjpeg_encoder.cpp
@@ -70,40 +70,20 @@ void MjpegEncoder::encodeJPEG(struct jpeg_compress_struct &cinfo, EncodeItem &it
 	uint8_t *Y = (uint8_t *)item.mem;
 	uint8_t *U = (uint8_t *)Y + item.stride * item.height;
 	uint8_t *V = (uint8_t *)U + stride2 * (item.height / 2);
+	uint8_t *Y_max = U - item.stride;
+	uint8_t *U_max = V - stride2;
+	uint8_t *V_max = U_max + stride2 * (item.height / 2);
 
 	JSAMPROW y_rows[16];
 	JSAMPROW u_rows[8];
 	JSAMPROW v_rows[8];
 
-	unsigned int height_align = item.height & ~15;
-	while (cinfo.next_scanline < height_align)
+	for (uint8_t *Y_row = Y, *U_row = U, *V_row = V; cinfo.next_scanline < item.height;)
 	{
-		uint8_t *Y_row = Y + cinfo.next_scanline * item.stride;
 		for (int i = 0; i < 16; i++, Y_row += item.stride)
-			y_rows[i] = Y_row;
-		uint8_t *U_row = U + (cinfo.next_scanline / 2) * stride2;
-		uint8_t *V_row = V + (cinfo.next_scanline / 2) * stride2;
+			y_rows[i] = std::min(Y_row, Y_max);
 		for (int i = 0; i < 8; i++, U_row += stride2, V_row += stride2)
-			u_rows[i] = U_row, v_rows[i] = V_row;
-
-		JSAMPARRAY rows[] = { y_rows, u_rows, v_rows };
-		jpeg_write_raw_data(&cinfo, rows, 16);
-	}
-	if (cinfo.next_scanline < item.height)
-	{
-		// Raw data has to be written in blocks of 16 rows, so rows beyond the highest
-		// multiple of 16 have to be copied to a 16-row sized buffer and then added.
-		std::vector<uint8_t> y_pixels(16 * item.stride);
-		std::vector<uint8_t> u_pixels(8 * stride2);
-		std::vector<uint8_t> v_pixels(8 * stride2);
-		memcpy(&y_pixels[0], Y + height_align * item.stride, (item.height & 15) * item.stride);
-		memcpy(&u_pixels[1], U + height_align / 2 * stride2, (item.height & 15) / 2 * stride2);
-		memcpy(&v_pixels[1], V + height_align / 2 * stride2, (item.height & 15) / 2 * stride2);
-
-		for (int i = 0; i < 16; i++)
-			y_rows[i] = &y_pixels[i * item.stride];
-		for (int i = 0; i < 8; i++)
-			u_rows[i] = &u_pixels[i * stride2], v_rows[i] = &v_pixels[i * stride2];
+			u_rows[i] = std::min(U_row, U_max), v_rows[i] = std::min(V_row, V_max);
 
 		JSAMPARRAY rows[] = { y_rows, u_rows, v_rows };
 		jpeg_write_raw_data(&cinfo, rows, 16);
diff --git a/image/jpeg.cpp b/image/jpeg.cpp
index 9f1e3a6f..d3a28699 100644
--- a/image/jpeg.cpp
+++ b/image/jpeg.cpp
@@ -332,40 +332,20 @@ static void YUV420_to_JPEG_fast(const uint8_t *input, const unsigned int width,
 	uint8_t *Y = (uint8_t *)input;
 	uint8_t *U = (uint8_t *)Y + stride * height;
 	uint8_t *V = (uint8_t *)U + stride2 * (height / 2);
+	uint8_t *Y_max = U - stride;
+	uint8_t *U_max = V - stride2;
+	uint8_t *V_max = U_max + stride2 * (height / 2);
 
 	JSAMPROW y_rows[16];
 	JSAMPROW u_rows[8];
 	JSAMPROW v_rows[8];
 
-	unsigned int height_align = height & ~15;
-	while (cinfo.next_scanline < height_align)
+	for (uint8_t *Y_row = Y, *U_row = U, *V_row = V; cinfo.next_scanline < height;)
 	{
-		uint8_t *Y_row = Y + cinfo.next_scanline * stride;
 		for (int i = 0; i < 16; i++, Y_row += stride)
-			y_rows[i] = Y_row;
-		uint8_t *U_row = U + (cinfo.next_scanline / 2) * stride2;
-		uint8_t *V_row = V + (cinfo.next_scanline / 2) * stride2;
+			y_rows[i] = std::min(Y_row, Y_max);
 		for (int i = 0; i < 8; i++, U_row += stride2, V_row += stride2)
-			u_rows[i] = U_row, v_rows[i] = V_row;
-
-		JSAMPARRAY rows[] = { y_rows, u_rows, v_rows };
-		jpeg_write_raw_data(&cinfo, rows, 16);
-	}
-	if (cinfo.next_scanline < height)
-	{
-		// Raw data has to be written in blocks of 16 rows, so rows beyond the highest
-		// multiple of 16 have to be copied to a 16-row sized buffer and then added.
-		std::vector<uint8_t> y_pixels(16 * stride);
-		std::vector<uint8_t> u_pixels(8 * stride2);
-		std::vector<uint8_t> v_pixels(8 * stride2);
-		memcpy(&y_pixels[0], Y + height_align * stride, (height & 15) * stride);
-		memcpy(&u_pixels[1], U + height_align / 2 * stride2, (height & 15) / 2 * stride2);
-		memcpy(&v_pixels[1], V + height_align / 2 * stride2, (height & 15) / 2 * stride2);
-
-		for (int i = 0; i < 16; i++)
-			y_rows[i] = &y_pixels[i * stride];
-		for (int i = 0; i < 8; i++)
-			u_rows[i] = &u_pixels[i * stride2], v_rows[i] = &v_pixels[i * stride2];
+			u_rows[i] = std::min(U_row, U_max), v_rows[i] = std::min(V_row, V_max);
 
 		JSAMPARRAY rows[] = { y_rows, u_rows, v_rows };
 		jpeg_write_raw_data(&cinfo, rows, 16);