diff --git a/libavcodec/imgconvert.c b/libavcodec/imgconvert.c
index 477a62bf09..db8709f6ee 100644
--- a/libavcodec/imgconvert.c
+++ b/libavcodec/imgconvert.c
@@ -1,5 +1,5 @@
 /*
- * Misc image convertion routines
+ * Misc image conversion routines
  * Copyright (c) 2001, 2002, 2003 Fabrice Bellard.
  *
  * This file is part of FFmpeg.
@@ -21,7 +21,7 @@
 
 /**
  * @file imgconvert.c
- * Misc image convertion routines.
+ * misc image conversion routines
  */
 
 /* TODO:
@@ -1852,7 +1852,7 @@ typedef struct ConvertEntry {
                     const AVPicture *src, int width, int height);
 } ConvertEntry;
 
-/* Add each new convertion function in this table. In order to be able
+/* Add each new conversion function in this table. In order to be able
    to convert from any format to any format, the following constraints
    must be satisfied:
 
diff --git a/libavcodec/imgconvert_template.h b/libavcodec/imgconvert_template.h
index 70c090badd..b5f5cbe77a 100644
--- a/libavcodec/imgconvert_template.h
+++ b/libavcodec/imgconvert_template.h
@@ -1,5 +1,5 @@
 /*
- * Templates for image convertion routines
+ * templates for image conversion routines
  * Copyright (c) 2001, 2002, 2003 Fabrice Bellard.
  *
  * This file is part of FFmpeg.
diff --git a/libavcodec/pngdec.c b/libavcodec/pngdec.c
index 1b7319fe7e..b68ea4db10 100644
--- a/libavcodec/pngdec.c
+++ b/libavcodec/pngdec.c
@@ -72,7 +72,7 @@ static const uint8_t png_pass_dsp_mask[NB_PASSES] = {
 };
 
 /* NOTE: we try to construct a good looking image at each pass. width
-   is the original image width. We also do pixel format convertion at
+   is the original image width. We also do pixel format conversion at
    this stage */
 static void png_put_interlaced_row(uint8_t *dst, int width,
                                    int bits_per_pixel, int pass,
diff --git a/libavcodec/resample.c b/libavcodec/resample.c
index ea5c6d61c8..f4d6a0aae7 100644
--- a/libavcodec/resample.c
+++ b/libavcodec/resample.c
@@ -1,5 +1,5 @@
 /*
- * Sample rate convertion for both audio and video
+ * samplerate conversion for both audio and video
  * Copyright (c) 2000 Fabrice Bellard.
  *
  * This file is part of FFmpeg.
@@ -21,7 +21,7 @@
 
 /**
  * @file resample.c
- * Sample rate convertion for both audio and video.
+ * samplerate conversion for both audio and video
  */
 
 #include "avcodec.h"
diff --git a/libavformat/grab.c b/libavformat/grab.c
index 3db37482fd..5936598e68 100644
--- a/libavformat/grab.c
+++ b/libavformat/grab.c
@@ -212,7 +212,7 @@ static int grab_read_header(AVFormatContext *s1, AVFormatParameters *ap)
             if (aiw_init(s) < 0)
                 goto fail;
             s->aiw_enabled = 1;
-            /* force 420P format because convertion from YUV422 to YUV420P
+            /* force 420P format because conversion from YUV422 to YUV420P
                is done in this driver (ugly) */
             s->frame_format = VIDEO_PALETTE_YUV420P;
         }