diff --git a/doc/protocols.texi b/doc/protocols.texi
index 0d40e5eeb9..c777d83dce 100644
--- a/doc/protocols.texi
+++ b/doc/protocols.texi
@@ -564,7 +564,7 @@ The required syntax for a UDP url is:
 udp://@var{hostname}:@var{port}[?@var{options}]
 @end example
 
-@var{options} contains a list of &-seperated options of the form @var{key}=@var{val}.
+@var{options} contains a list of &-separated options of the form @var{key}=@var{val}.
 Follow the list of supported options.
 
 @table @option
diff --git a/libavcodec/aacpsy.c b/libavcodec/aacpsy.c
index e4b4405144..ec889d7e3d 100644
--- a/libavcodec/aacpsy.c
+++ b/libavcodec/aacpsy.c
@@ -804,7 +804,8 @@ static FFPsyWindowInfo psy_lame_window(FFPsyContext *ctx, const float *audio,
                 sum1 += psy_fir_coeffs[j] * (firbuf[i + j] + firbuf[i + PSY_LAME_FIR_LEN - j]);
                 sum2 += psy_fir_coeffs[j + 1] * (firbuf[i + j + 1] + firbuf[i + PSY_LAME_FIR_LEN - j - 1]);
             }
-            /* NOTE: The LAME psymodel expects it's input in the range -32768 to 32768. Tuning this for normalized floats would be difficult. */
+            /* NOTE: The LAME psymodel expects its input in the range -32768 to
+             * 32768. Tuning this for normalized floats would be difficult. */
             hpfsmpl[i] = (sum1 + sum2) * 32768.0f;
         }
 
diff --git a/libavcodec/flac_parser.c b/libavcodec/flac_parser.c
index ee92ee3b0d..155162ad80 100644
--- a/libavcodec/flac_parser.c
+++ b/libavcodec/flac_parser.c
@@ -27,7 +27,7 @@
  * Each time it finds and verifies a CRC-8 header it sees which of the
  * FLAC_MAX_SEQUENTIAL_HEADERS that came before it have a valid CRC-16 footer
  * that ends at the newly found header.
- * Headers are scored by FLAC_HEADER_BASE_SCORE plus the max of it's crc-verified
+ * Headers are scored by FLAC_HEADER_BASE_SCORE plus the max of its crc-verified
  * children, penalized by changes in sample rate, frame number, etc.
  * The parser returns the frame with the highest score.
  **/
diff --git a/libavcodec/flacenc.c b/libavcodec/flacenc.c
index 1699312c8c..15b0e5530d 100644
--- a/libavcodec/flacenc.c
+++ b/libavcodec/flacenc.c
@@ -1232,7 +1232,7 @@ static int flac_encode_frame(AVCodecContext *avctx, AVPacket *avpkt,
 
     frame_bytes = encode_frame(s);
 
-    /* fallback to verbatim mode if the compressed frame is larger than it
+    /* Fall back on verbatim mode if the compressed frame is larger than it
        would be if encoded uncompressed. */
     if (frame_bytes < 0 || frame_bytes > s->max_framesize) {
         s->frame.verbatim_only = 1;
diff --git a/libavcodec/flicvideo.c b/libavcodec/flicvideo.c
index 3d43e5e827..9795ff960e 100644
--- a/libavcodec/flicvideo.c
+++ b/libavcodec/flicvideo.c
@@ -539,7 +539,7 @@ static int flic_decode_frame_15_16BPP(AVCodecContext *avctx,
             break;
 
         case FLI_LC:
-            av_log(avctx, AV_LOG_ERROR, "Unexpected FLI_LC chunk in non-paletised FLC\n");
+            av_log(avctx, AV_LOG_ERROR, "Unexpected FLI_LC chunk in non-palettized FLC\n");
             bytestream2_skip(&g2, chunk_size - 6);
             break;
 
diff --git a/libavcodec/wmavoice.c b/libavcodec/wmavoice.c
index d03c701639..b9a4ad9f4a 100644
--- a/libavcodec/wmavoice.c
+++ b/libavcodec/wmavoice.c
@@ -607,7 +607,7 @@ static void calc_input_response(WMAVoiceContext *s, float *lpcs,
 
         /* 70.57 =~ 1/log10(1.0331663) */
         idx = (pwr * gain_mul - 0.0295) * 70.570526123;
-        if (idx > 127) { // fallback if index falls outside table range
+        if (idx > 127) { // fall back if index falls outside table range
             coeffs[n] = wmavoice_energy_table[127] *
                         powf(1.0331663, idx - 127);
         } else
diff --git a/libavcodec/x86/fpel_mmx.c b/libavcodec/x86/fpel_mmx.c
index be64098e0b..1df5a94133 100644
--- a/libavcodec/x86/fpel_mmx.c
+++ b/libavcodec/x86/fpel_mmx.c
@@ -29,7 +29,7 @@
 
 #if HAVE_MMX_INLINE
 
-// in case more speed is needed - unroling would certainly help
+// in case more speed is needed - unrolling would certainly help
 void ff_avg_pixels8_mmx(uint8_t *block, const uint8_t *pixels,
                         ptrdiff_t line_size, int h)
 {
diff --git a/libavdevice/v4l2.c b/libavdevice/v4l2.c
index 9e5aa5e660..d163cbe81c 100644
--- a/libavdevice/v4l2.c
+++ b/libavdevice/v4l2.c
@@ -485,7 +485,7 @@ static int mmap_read_frame(AVFormatContext *ctx, AVPacket *pkt)
 
     /* Image is at s->buff_start[buf.index] */
     if (avpriv_atomic_int_get(&s->buffers_queued) == FFMAX(s->buffers / 8, 1)) {
-        /* when we start getting low on queued buffers, fallback to copying data */
+        /* when we start getting low on queued buffers, fall back on copying data */
         res = av_new_packet(pkt, buf.bytesused);
         if (res < 0) {
             av_log(ctx, AV_LOG_ERROR, "Error allocating a packet.\n");
diff --git a/libavformat/avformat.h b/libavformat/avformat.h
index 2512e36020..43afa9f526 100644
--- a/libavformat/avformat.h
+++ b/libavformat/avformat.h
@@ -353,8 +353,8 @@ typedef struct AVProbeData {
 #define AVFMT_VARIABLE_FPS  0x0400 /**< Format allows variable fps. */
 #define AVFMT_NODIMENSIONS  0x0800 /**< Format does not need width/height */
 #define AVFMT_NOSTREAMS     0x1000 /**< Format does not require any streams */
-#define AVFMT_NOBINSEARCH   0x2000 /**< Format does not allow to fallback to binary search via read_timestamp */
-#define AVFMT_NOGENSEARCH   0x4000 /**< Format does not allow to fallback to generic search */
+#define AVFMT_NOBINSEARCH   0x2000 /**< Format does not allow to fall back on binary search via read_timestamp */
+#define AVFMT_NOGENSEARCH   0x4000 /**< Format does not allow to fall back on generic search */
 #define AVFMT_NO_BYTE_SEEK  0x8000 /**< Format does not allow seeking by bytes */
 #define AVFMT_ALLOW_FLUSH  0x10000 /**< Format allows flushing. If not set, the muxer will not receive a NULL packet in the write_packet function. */
 #define AVFMT_TS_NONSTRICT 0x20000 /**< Format does not require strictly
@@ -1388,7 +1388,7 @@ void avformat_close_input(AVFormatContext **s);
  *
  * @param s Media file handle, must be allocated with avformat_alloc_context().
  *          Its oformat field must be set to the desired output format;
- *          Its pb field must be set to an already openened AVIOContext.
+ *          Its pb field must be set to an already opened AVIOContext.
  * @param options  An AVDictionary filled with AVFormatContext and muxer-private options.
  *                 On return this parameter will be destroyed and replaced with a dict containing
  *                 options that were not found. May be NULL.
diff --git a/libavformat/idcin.c b/libavformat/idcin.c
index 536e6ee6ff..fa9976bae6 100644
--- a/libavformat/idcin.c
+++ b/libavformat/idcin.c
@@ -136,7 +136,7 @@ static int idcin_probe(AVProbeData *p)
     if (number > 2)
         return 0;
 
-    /* return half certainly since this check is a bit sketchy */
+    /* return half certainty since this check is a bit sketchy */
     return AVPROBE_SCORE_MAX / 2;
 }
 
diff --git a/libavformat/pmpdec.c b/libavformat/pmpdec.c
index 6cdce107c4..484be43ce9 100644
--- a/libavformat/pmpdec.c
+++ b/libavformat/pmpdec.c
@@ -157,7 +157,7 @@ static int pmp_seek(AVFormatContext *s, int stream_idx, int64_t ts, int flags)
 {
     PMPContext *pmp = s->priv_data;
     pmp->cur_stream = 0;
-    // fallback to default seek now
+    // fall back on default seek now
     return -1;
 }
 
diff --git a/libavformat/utils.c b/libavformat/utils.c
index 89eb759bc9..e1acb254b6 100644
--- a/libavformat/utils.c
+++ b/libavformat/utils.c
@@ -722,7 +722,7 @@ int ff_get_audio_frame_size(AVCodecContext *enc, int size, int mux)
     if ((frame_size = av_get_audio_frame_duration(enc, size)) > 0)
         return frame_size;
 
-    /* fallback to using frame_size if muxing */
+    /* Fall back on using frame_size if muxing. */
     if (enc->frame_size > 1)
         return enc->frame_size;
 
@@ -1790,8 +1790,8 @@ int avformat_seek_file(AVFormatContext *s, int stream_index, int64_t min_ts, int
         //try to seek via read_timestamp()
     }
 
-    //Fallback to old API if new is not implemented but old is
-    //Note the old has somewat different sematics
+    // Fall back on old API if new is not implemented but old is.
+    // Note the old API has somewhat different semantics.
     if(s->iformat->read_seek || 1)
         return av_seek_frame(s, stream_index, ts, flags | ((uint64_t)ts - min_ts > (uint64_t)max_ts - ts ? AVSEEK_FLAG_BACKWARD : 0));
 
diff --git a/libavformat/wavdec.c b/libavformat/wavdec.c
index 1b427117ba..07df9232d7 100644
--- a/libavformat/wavdec.c
+++ b/libavformat/wavdec.c
@@ -73,9 +73,9 @@ static int wav_probe(AVProbeData *p)
         return 0;
     if (!memcmp(p->buf + 8, "WAVE", 4)) {
         if (!memcmp(p->buf, "RIFF", 4))
-            /* Since ACT demuxer has standard WAV header at top of it's
-             * own, returning score is decreased to avoid probe conflict
-             * between ACT and WAV. */
+            /* Since the ACT demuxer has a standard WAV header at the top of
+             * its own, the returned score is decreased to avoid a probe
+             * conflict between ACT and WAV. */
             return AVPROBE_SCORE_MAX - 1;
         else if (!memcmp(p->buf,      "RF64", 4) &&
                  !memcmp(p->buf + 12, "ds64", 4))
diff --git a/tools/patcheck b/tools/patcheck
index 514da9fe9b..e681d6d29e 100755
--- a/tools/patcheck
+++ b/tools/patcheck
@@ -67,7 +67,7 @@ $EGREP $OPT '^\+ *(const *|)static' $*| $EGREP --color=always '[^=]= *(0|NULL)[^
 cat $TMP
 hiegrep '# *ifdef * (HAVE|CONFIG)_' 'ifdefs that should be #if' $*
 
-hiegrep '\b(awnser|cant|dont|wont|usefull|successfull|occured|teh|alot|wether|skiped|heigth|informations|colums|loosy|loosing|seperate|preceed|upto|paket|posible|unkown|inpossible|dimention|acheive)\b' 'common typos' $*
+hiegrep '\b(awnser|cant|dont|wont|doesnt|usefull|successfull|occured|teh|alot|wether|skiped|heigth|informations|colums|loosy|loosing|seperate|preceed|upto|paket|posible|unkown|inpossible|dimention|acheive)\b' 'common typos' $*
 
 hiegrep 'av_log\( *NULL' 'Missing context in av_log' $*
 hiegrep '[^sn]printf' 'Please use av_log' $*