diff --git a/libavformat/matroskaenc.c b/libavformat/matroskaenc.c
index 3fa4babbdb..e6230f95c7 100644
--- a/libavformat/matroskaenc.c
+++ b/libavformat/matroskaenc.c
@@ -696,13 +696,15 @@ static int mkv_write_codecprivate(AVFormatContext *s, AVIOContext *pb,
 
 
 static int mkv_write_stereo_mode(AVFormatContext *s, AVIOContext *pb,
-                                 AVStream *st, int mode)
+                                 AVStream *st, int mode, int *h_width, int *h_height)
 {
     int i;
     int ret = 0;
     AVDictionaryEntry *tag;
     MatroskaVideoStereoModeType format = MATROSKA_VIDEO_STEREOMODE_TYPE_NB;
 
+    *h_width = 1;
+    *h_height = 1;
     // convert metadata into proper side data and add it to the stream
     if ((tag = av_dict_get(st->metadata, "stereo_mode", NULL, 0)) ||
         (tag = av_dict_get( s->metadata, "stereo_mode", NULL, 0))) {
@@ -722,6 +724,7 @@ static int mkv_write_stereo_mode(AVFormatContext *s, AVIOContext *pb,
         }
     }
 
+    // iterate to find the stereo3d side data
     for (i = 0; i < st->nb_side_data; i++) {
         AVPacketSideData sd = st->side_data[i];
         if (sd.type == AV_PKT_DATA_STEREO3D) {
@@ -735,11 +738,13 @@ static int mkv_write_stereo_mode(AVFormatContext *s, AVIOContext *pb,
                 format = (stereo->flags & AV_STEREO3D_FLAG_INVERT)
                     ? MATROSKA_VIDEO_STEREOMODE_TYPE_RIGHT_LEFT
                     : MATROSKA_VIDEO_STEREOMODE_TYPE_LEFT_RIGHT;
+                *h_width = 2;
                 break;
             case AV_STEREO3D_TOPBOTTOM:
                 format = MATROSKA_VIDEO_STEREOMODE_TYPE_TOP_BOTTOM;
                 if (stereo->flags & AV_STEREO3D_FLAG_INVERT)
                     format--;
+                *h_height = 2;
                 break;
             case AV_STEREO3D_CHECKERBOARD:
                 format = MATROSKA_VIDEO_STEREOMODE_TYPE_CHECKERBOARD_LR;
@@ -750,11 +755,13 @@ static int mkv_write_stereo_mode(AVFormatContext *s, AVIOContext *pb,
                 format = MATROSKA_VIDEO_STEREOMODE_TYPE_ROW_INTERLEAVED_LR;
                 if (stereo->flags & AV_STEREO3D_FLAG_INVERT)
                     format--;
+                *h_height = 2;
                 break;
             case AV_STEREO3D_COLUMNS:
                 format = MATROSKA_VIDEO_STEREOMODE_TYPE_COL_INTERLEAVED_LR;
                 if (stereo->flags & AV_STEREO3D_FLAG_INVERT)
                     format--;
+                *h_width = 2;
                 break;
             case AV_STEREO3D_FRAMESEQUENCE:
                 format = MATROSKA_VIDEO_STEREOMODE_TYPE_BOTH_EYES_BLOCK_LR;
@@ -762,8 +769,6 @@ static int mkv_write_stereo_mode(AVFormatContext *s, AVIOContext *pb,
                     format++;
                 break;
             }
-            ret = stereo->type;
-
             break;
         }
     }
@@ -771,6 +776,7 @@ static int mkv_write_stereo_mode(AVFormatContext *s, AVIOContext *pb,
     if (format == MATROSKA_VIDEO_STEREOMODE_TYPE_NB)
         return ret;
 
+    // if webm, do not write unsupported modes
     if ((mode == MODE_WEBM &&
         format > MATROSKA_VIDEO_STEREOMODE_TYPE_TOP_BOTTOM &&
         format != MATROSKA_VIDEO_STEREOMODE_TYPE_RIGHT_LEFT)
@@ -781,6 +787,7 @@ static int mkv_write_stereo_mode(AVFormatContext *s, AVIOContext *pb,
         return AVERROR(EINVAL);
     }
 
+    // write StereoMode if format is valid
     put_ebml_uint(pb, MATROSKA_ID_VIDEOSTEREOMODE, format);
 
     return ret;
@@ -926,27 +933,20 @@ static int mkv_write_track(AVFormatContext *s, MatroskaMuxContext *mkv,
 
         // check both side data and metadata for stereo information,
         // write the result to the bitstream if any is found
-        ret = mkv_write_stereo_mode(s, pb, st, mkv->mode);
+        ret = mkv_write_stereo_mode(s, pb, st, mkv->mode,
+                                    &display_width_div,
+                                    &display_height_div);
         if (ret < 0)
             return ret;
 
-        switch (ret) {
-        case AV_STEREO3D_SIDEBYSIDE:
-        case AV_STEREO3D_COLUMNS:
-            display_width_div = 2;
-            break;
-        case AV_STEREO3D_TOPBOTTOM:
-        case AV_STEREO3D_LINES:
-            display_height_div = 2;
-            break;
-        }
-
         if (((tag = av_dict_get(st->metadata, "alpha_mode", NULL, 0)) && atoi(tag->value)) ||
             ((tag = av_dict_get( s->metadata, "alpha_mode", NULL, 0)) && atoi(tag->value)) ||
             (codec->pix_fmt == AV_PIX_FMT_YUVA420P)) {
             put_ebml_uint(pb, MATROSKA_ID_VIDEOALPHAMODE, 1);
         }
 
+        // write DisplayWidth and DisplayHeight, they contain the size of
+        // a single source view and/or the display aspect ratio
         if (st->sample_aspect_ratio.num) {
             int64_t d_width = av_rescale(codec->width, st->sample_aspect_ratio.num, st->sample_aspect_ratio.den);
             if (d_width > INT_MAX) {
@@ -964,6 +964,7 @@ static int mkv_write_track(AVFormatContext *s, MatroskaMuxContext *mkv,
             uint32_t color_space = av_le2ne32(codec->codec_tag);
             put_ebml_binary(pb, MATROSKA_ID_VIDEOCOLORSPACE, &color_space, sizeof(color_space));
         }
+
         end_ebml_master(pb, subinfo);
         break;