fix some a/an typos

Signed-off-by: Lou Logan <lou@lrcd.com>

7 files changed, 8 insertions, 8 deletions

diff --git a/libavformat/asfdec_f.c b/libavformat/asfdec_f.c
index 3ee0fcd473..711341328d 100644
--- a/libavformat/asfdec_f.c
+++ b/libavformat/asfdec_f.c
@@ -828,7 +828,7 @@ static int asf_read_header(AVFormatContext *s)
         } else if (!ff_guidcmp(&g, &ff_asf_ext_stream_header)) {
             asf_read_ext_stream_properties(s, gsize);
 
-            // there could be a optional stream properties object to follow
+            // there could be an optional stream properties object to follow
             // if so the next iteration will pick it up
             continue;
         } else if (!ff_guidcmp(&g, &ff_asf_head1_guid)) {
diff --git a/libavformat/avformat.h b/libavformat/avformat.h
index ccb8033f9a..5e918a04c3 100644
--- a/libavformat/avformat.h
+++ b/libavformat/avformat.h
@@ -2449,7 +2449,7 @@ int av_write_frame(AVFormatContext *s, AVPacket *pkt);
 int av_interleaved_write_frame(AVFormatContext *s, AVPacket *pkt);
 
 /**
- * Write a uncoded frame to an output media file.
+ * Write an uncoded frame to an output media file.
  *
  * The frame must be correctly interleaved according to the container
  * specification; if not, then av_interleaved_write_frame() must be used.
@@ -2460,7 +2460,7 @@ int av_write_uncoded_frame(AVFormatContext *s, int stream_index,
                            AVFrame *frame);
 
 /**
- * Write a uncoded frame to an output media file.
+ * Write an uncoded frame to an output media file.
  *
  * If the muxer supports it, this function makes it possible to write an AVFrame
  * structure directly, without encoding it into a packet.
diff --git a/libavformat/movenc.c b/libavformat/movenc.c
index 9af44e3b71..efaac36ba6 100644
--- a/libavformat/movenc.c
+++ b/libavformat/movenc.c
@@ -2523,7 +2523,7 @@ static int mov_write_edts_tag(AVIOContext *pb, MOVMuxContext *mov,
     } else {
         /* Avoid accidentally ending up with start_ct = -1 which has got a
          * special meaning. Normally start_ct should end up positive or zero
-         * here, but use FFMIN in case dts is a a small positive integer
+         * here, but use FFMIN in case dts is a small positive integer
          * rounded to 0 when represented in MOV_TIMESCALE units. */
         av_assert0(av_rescale_rnd(start_dts, MOV_TIMESCALE, track->timescale, AV_ROUND_DOWN) <= 0);
         start_ct  = -FFMIN(start_dts, 0);
diff --git a/libavformat/mxfdec.c b/libavformat/mxfdec.c
index f1495e6e41..40b4d79996 100644
--- a/libavformat/mxfdec.c
+++ b/libavformat/mxfdec.c
@@ -2608,7 +2608,7 @@ static int mxf_handle_missing_index_segment(MXFContext *mxf)
     if (mxf->op != OPAtom)
         return 0;
 
-    /* TODO: support raw video without a index if they exist */
+    /* TODO: support raw video without an index if they exist */
     if (s->nb_streams != 1 || s->streams[0]->codec->codec_type != AVMEDIA_TYPE_AUDIO || !is_pcm(s->streams[0]->codec->codec_id))
         return 0;
 
diff --git a/libavformat/oggdec.c b/libavformat/oggdec.c
index 2d99b4af25..9f1e0abb31 100644
--- a/libavformat/oggdec.c
+++ b/libavformat/oggdec.c
@@ -864,7 +864,7 @@ static int64_t ogg_read_timestamp(AVFormatContext *s, int stream_index,
            && !ogg_packet(s, &i, &pstart, &psize, pos_arg)) {
         if (i == stream_index) {
             struct ogg_stream *os = ogg->streams + stream_index;
-            // Do not trust the last timestamps of a ogm video
+            // Do not trust the last timestamps of an ogm video
             if (    (os->flags & OGG_FLAG_EOS)
                 && !(os->flags & OGG_FLAG_BOS)
                 && os->codec == &ff_ogm_video_codec)
diff --git a/libavformat/utils.c b/libavformat/utils.c
index 67d4d1b70a..3bd2df3013 100644
--- a/libavformat/utils.c
+++ b/libavformat/utils.c
@@ -3124,7 +3124,7 @@ void ff_rfps_calculate(AVFormatContext *ic)
         if (st->codec->codec_type != AVMEDIA_TYPE_VIDEO)
             continue;
         // the check for tb_unreliable() is not completely correct, since this is not about handling
-        // a unreliable/inexact time base, but a time base that is finer than necessary, as e.g.
+        // an unreliable/inexact time base, but a time base that is finer than necessary, as e.g.
         // ipmovie.c produces.
         if (tb_unreliable(st->codec) && st->info->duration_count > 15 && st->info->duration_gcd > FFMAX(1, st->time_base.den/(500LL*st->time_base.num)) && !st->r_frame_rate.num)
             av_reduce(&st->r_frame_rate.num, &st->r_frame_rate.den, st->time_base.den, st->time_base.num * st->info->duration_gcd, INT_MAX);
diff --git a/libavformat/yuv4mpegenc.c b/libavformat/yuv4mpegenc.c
index 23d2eda45c..033badb0af 100644
--- a/libavformat/yuv4mpegenc.c
+++ b/libavformat/yuv4mpegenc.c
@@ -267,7 +267,7 @@ static int yuv4_write_header(AVFormatContext *s)
     case AV_PIX_FMT_YUV422P16:
     case AV_PIX_FMT_YUV444P16:
         if (s->strict_std_compliance >= FF_COMPLIANCE_NORMAL) {
-            av_log(s, AV_LOG_ERROR, "'%s' is not a official yuv4mpegpipe pixel format. "
+            av_log(s, AV_LOG_ERROR, "'%s' is not an official yuv4mpegpipe pixel format. "
                    "Use '-strict -1' to encode to this pixel format.\n",
                    av_get_pix_fmt_name(s->streams[0]->codec->pix_fmt));
             return AVERROR(EINVAL);