diff --git a/libavcodec/mpegvideo.c b/libavcodec/mpegvideo.c
index 2ab32946fe..a52d04af83 100644
--- a/libavcodec/mpegvideo.c
+++ b/libavcodec/mpegvideo.c
@@ -59,10 +59,6 @@ static void dct_unquantize_h263_intra_c(MpegEncContext *s,
 static void dct_unquantize_h263_inter_c(MpegEncContext *s,
                                   int16_t *block, int n, int qscale);
 
-
-/* enable all paranoid tests for rounding, overflows, etc... */
-//#define PARANOID
-
 //#define DEBUG
 
 
diff --git a/libavcodec/mpegvideo_enc.c b/libavcodec/mpegvideo_enc.c
index b2078e9488..24b775e5b6 100644
--- a/libavcodec/mpegvideo_enc.c
+++ b/libavcodec/mpegvideo_enc.c
@@ -60,9 +60,6 @@ static int sse_mb(MpegEncContext *s);
 static void denoise_dct_c(MpegEncContext *s, int16_t *block);
 static int dct_quantize_trellis_c(MpegEncContext *s, int16_t *block, int n, int qscale, int *overflow);
 
-/* enable all paranoid tests for rounding, overflows, etc... */
-//#define PARANOID
-
 //#define DEBUG
 
 static uint8_t default_mv_penalty[MAX_FCODE + 1][MAX_MV * 2 + 1];
diff --git a/libavcodec/x86/mpegvideo.c b/libavcodec/x86/mpegvideo.c
index 55cff74e3f..68f3b62fdd 100644
--- a/libavcodec/x86/mpegvideo.c
+++ b/libavcodec/x86/mpegvideo.c
@@ -164,36 +164,6 @@ __asm__ volatile(
         );
 }
 
-
-/*
-  NK:
-  Note: looking at PARANOID:
-  "enable all paranoid tests for rounding, overflows, etc..."
-
-#ifdef PARANOID
-                if (level < -2048 || level > 2047)
-                    fprintf(stderr, "unquant error %d %d\n", i, level);
-#endif
-  We can suppose that result of two multiplications can't be greater than 0xFFFF
-  i.e. is 16-bit, so we use here only PMULLW instruction and can avoid
-  a complex multiplication.
-=====================================================
- Full formula for multiplication of 2 integer numbers
- which are represent as high:low words:
- input: value1 = high1:low1
-        value2 = high2:low2
- output: value3 = value1*value2
- value3=high3:low3 (on overflow: modulus 2^32 wrap-around)
- this mean that for 0x123456 * 0x123456 correct result is 0x766cb0ce4
- but this algorithm will compute only 0x66cb0ce4
- this limited by 16-bit size of operands
- ---------------------------------
- tlow1 = high1*low2
- tlow2 = high2*low1
- tlow1 = tlow1 + tlow2
- high3:low3 = low1*low2
- high3 += tlow1
-*/
 static void dct_unquantize_mpeg1_intra_mmx(MpegEncContext *s,
                                      int16_t *block, int n, int qscale)
 {