diff --git a/libavformat/matroskaenc.c b/libavformat/matroskaenc.c
index 274f62dd78..104a119acf 100644
--- a/libavformat/matroskaenc.c
+++ b/libavformat/matroskaenc.c
@@ -56,6 +56,10 @@
 #include "libavcodec/mpeg4audio.h"
 #include "libavcodec/internal.h"
 
+/* Level 1 elements we create a SeekHead entry for:
+ * Info, Tracks, Chapters, Attachments, Tags and Cues */
+#define MAX_SEEKHEAD_ENTRIES 6
+
 typedef struct ebml_master {
     int64_t         pos;                ///< absolute offset in the containing AVIOContext where the master's elements start
     int             sizebytes;          ///< how many bytes were reserved for the size
@@ -68,11 +72,9 @@ typedef struct mkv_seekhead_entry {
 
 typedef struct mkv_seekhead {
     int64_t                 filepos;
-    int64_t                 segment_offset;     ///< the file offset to the beginning of the segment
-    int                     reserved_size;      ///< -1 if appending to file
-    int                     max_entries;
-    mkv_seekhead_entry      *entries;
+    mkv_seekhead_entry      entries[MAX_SEEKHEAD_ENTRIES];
     int                     num_entries;
+    int                     reserved_size;
 } mkv_seekhead;
 
 typedef struct mkv_cuepoint {
@@ -126,7 +128,7 @@ typedef struct MatroskaMuxContext {
     int64_t         cluster_pts;
     int64_t         duration_offset;
     int64_t         duration;
-    mkv_seekhead    *seekhead;
+    mkv_seekhead    seekhead;
     mkv_cues        *cues;
     mkv_track       *tracks;
 
@@ -386,10 +388,6 @@ static void mkv_deinit(AVFormatContext *s)
     ffio_free_dyn_buf(&mkv->tracks_bc);
     ffio_free_dyn_buf(&mkv->tags_bc);
 
-    if (mkv->seekhead) {
-        av_freep(&mkv->seekhead->entries);
-        av_freep(&mkv->seekhead);
-    }
     if (mkv->cues) {
         av_freep(&mkv->cues->entries);
         av_freep(&mkv->cues);
@@ -398,61 +396,32 @@ static void mkv_deinit(AVFormatContext *s)
 }
 
 /**
- * Initialize a mkv_seekhead element to be ready to index level 1 Matroska
- * elements. If a maximum number of elements is specified, enough space
- * will be reserved at the current file location to write a seek head of
- * that size.
- *
- * @param segment_offset The absolute offset to the position in the file
- *                       where the segment begins.
- * @param numelements The maximum number of elements that will be indexed
- *                    by this seek head, 0 if unlimited.
+ * Initialize the seekhead element to be ready to index level 1 Matroska
+ * elements. Enough space to write MAX_SEEKHEAD_ENTRIES seekhead entries
+ * will be reserved at the current file location.
  */
-static mkv_seekhead *mkv_start_seekhead(AVIOContext *pb, int64_t segment_offset,
-                                        int numelements)
+static void mkv_start_seekhead(MatroskaMuxContext *mkv, AVIOContext *pb)
 {
-    mkv_seekhead *new_seekhead = av_mallocz(sizeof(mkv_seekhead));
-    if (!new_seekhead)
-        return NULL;
-
-    new_seekhead->segment_offset = segment_offset;
-
-    if (numelements > 0) {
-        new_seekhead->filepos = avio_tell(pb);
+    mkv->seekhead.filepos = avio_tell(pb);
         // 21 bytes max for a seek entry, 10 bytes max for the SeekHead ID
         // and size, 6 bytes for a CRC32 element, and 3 bytes to guarantee
         // that an EBML void element will fit afterwards
-        new_seekhead->reserved_size = numelements * MAX_SEEKENTRY_SIZE + 19;
-        new_seekhead->max_entries   = numelements;
-        put_ebml_void(pb, new_seekhead->reserved_size);
-    }
-    return new_seekhead;
+    mkv->seekhead.reserved_size = MAX_SEEKHEAD_ENTRIES * MAX_SEEKENTRY_SIZE + 19;
+    put_ebml_void(pb, mkv->seekhead.reserved_size);
 }
 
-static int mkv_add_seekhead_entry(mkv_seekhead *seekhead, uint32_t elementid, uint64_t filepos)
+static void mkv_add_seekhead_entry(MatroskaMuxContext *mkv, uint32_t elementid, uint64_t filepos)
 {
-    mkv_seekhead_entry *entries = seekhead->entries;
+    mkv_seekhead *seekhead = &mkv->seekhead;
 
-    // don't store more elements than we reserved space for
-    if (seekhead->max_entries > 0 && seekhead->max_entries <= seekhead->num_entries)
-        return -1;
-
-    entries = av_realloc_array(entries, seekhead->num_entries + 1, sizeof(mkv_seekhead_entry));
-    if (!entries)
-        return AVERROR(ENOMEM);
-    seekhead->entries = entries;
+    av_assert1(seekhead->num_entries < MAX_SEEKHEAD_ENTRIES);
 
     seekhead->entries[seekhead->num_entries].elementid    = elementid;
-    seekhead->entries[seekhead->num_entries++].segmentpos = filepos - seekhead->segment_offset;
-
-    return 0;
+    seekhead->entries[seekhead->num_entries++].segmentpos = filepos - mkv->segment_offset;
 }
 
 /**
- * Write the seek head to the file and free it. If a maximum number of
- * elements was specified to mkv_start_seekhead(), the seek head will
- * be written at the location reserved for it. Otherwise, it is written
- * at the current location in the file.
+ * Write the seek head to the file at the location reserved for it.
  *
  * @return The file offset where the seekhead was written,
  * -1 if an error occurred.
@@ -460,19 +429,17 @@ static int mkv_add_seekhead_entry(mkv_seekhead *seekhead, uint32_t elementid, ui
 static int64_t mkv_write_seekhead(AVIOContext *pb, MatroskaMuxContext *mkv)
 {
     AVIOContext *dyn_cp;
-    mkv_seekhead *seekhead = mkv->seekhead;
+    mkv_seekhead *seekhead = &mkv->seekhead;
     ebml_master seekentry;
-    int64_t currentpos;
+    int64_t currentpos, remaining;
     int i;
 
     currentpos = avio_tell(pb);
 
-    if (seekhead->reserved_size > 0) {
         if (avio_seek(pb, seekhead->filepos, SEEK_SET) < 0) {
             currentpos = -1;
             goto fail;
         }
-    }
 
     if (start_ebml_master_crc32(pb, &dyn_cp, mkv, MATROSKA_ID_SEEKHEAD) < 0) {
         currentpos = -1;
@@ -493,17 +460,13 @@ static int64_t mkv_write_seekhead(AVIOContext *pb, MatroskaMuxContext *mkv)
     }
     end_ebml_master_crc32(pb, &dyn_cp, mkv);
 
-    if (seekhead->reserved_size > 0) {
-        uint64_t remaining = seekhead->filepos + seekhead->reserved_size - avio_tell(pb);
+    remaining = seekhead->filepos + seekhead->reserved_size - avio_tell(pb);
         put_ebml_void(pb, remaining);
         avio_seek(pb, currentpos, SEEK_SET);
 
         currentpos = seekhead->filepos;
-    }
-fail:
-    av_freep(&mkv->seekhead->entries);
-    av_freep(&mkv->seekhead);
 
+fail:
     return currentpos;
 }
 
@@ -1422,9 +1385,7 @@ static int mkv_write_tracks(AVFormatContext *s)
     AVIOContext *pb = s->pb;
     int i, ret, default_stream_exists = 0;
 
-    ret = mkv_add_seekhead_entry(mkv->seekhead, MATROSKA_ID_TRACKS, avio_tell(pb));
-    if (ret < 0)
-        return ret;
+    mkv_add_seekhead_entry(mkv, MATROSKA_ID_TRACKS, avio_tell(pb));
 
     ret = start_ebml_master_crc32(pb, &mkv->tracks_bc, mkv, MATROSKA_ID_TRACKS);
     if (ret < 0)
@@ -1459,8 +1420,7 @@ static int mkv_write_chapters(AVFormatContext *s)
     if (!s->nb_chapters || mkv->wrote_chapters)
         return 0;
 
-    ret = mkv_add_seekhead_entry(mkv->seekhead, MATROSKA_ID_CHAPTERS, avio_tell(pb));
-    if (ret < 0) return ret;
+    mkv_add_seekhead_entry(mkv, MATROSKA_ID_CHAPTERS, avio_tell(pb));
 
     ret = start_ebml_master_crc32(pb, &dyn_cp, mkv, MATROSKA_ID_CHAPTERS);
     if (ret < 0) return ret;
@@ -1549,8 +1509,7 @@ static int mkv_write_tag_targets(AVFormatContext *s, uint32_t elementid,
     int ret;
 
     if (!mkv->tags_bc) {
-        ret = mkv_add_seekhead_entry(mkv->seekhead, MATROSKA_ID_TAGS, avio_tell(s->pb));
-        if (ret < 0) return ret;
+        mkv_add_seekhead_entry(mkv, MATROSKA_ID_TAGS, avio_tell(s->pb));
 
         ret = start_ebml_master_crc32(s->pb, &mkv->tags_bc, mkv, MATROSKA_ID_TAGS);
         if (ret < 0)
@@ -1718,8 +1677,7 @@ static int mkv_write_attachments(AVFormatContext *s)
     if (!mkv->have_attachments)
         return 0;
 
-    ret = mkv_add_seekhead_entry(mkv->seekhead, MATROSKA_ID_ATTACHMENTS, avio_tell(pb));
-    if (ret < 0) return ret;
+    mkv_add_seekhead_entry(mkv, MATROSKA_ID_ATTACHMENTS, avio_tell(pb));
 
     ret = start_ebml_master_crc32(pb, &dyn_cp, mkv, MATROSKA_ID_ATTACHMENTS);
     if (ret < 0) return ret;
@@ -1839,16 +1797,10 @@ static int mkv_write_header(AVFormatContext *s)
     mkv->segment_offset = avio_tell(pb);
 
     // we write a seek head at the beginning to point to all other level
-    // one elements, which aren't more than 10 elements as we write only one
-    // of every other currently defined level 1 element
-    mkv->seekhead = mkv_start_seekhead(pb, mkv->segment_offset, 10);
-    if (!mkv->seekhead) {
-        return AVERROR(ENOMEM);
-    }
+    // one elements (except clusters).
+    mkv_start_seekhead(mkv, pb);
 
-    ret = mkv_add_seekhead_entry(mkv->seekhead, MATROSKA_ID_INFO, avio_tell(pb));
-    if (ret < 0)
-        return ret;
+    mkv_add_seekhead_entry(mkv, MATROSKA_ID_INFO, avio_tell(pb));
 
     ret = start_ebml_master_crc32(pb, &mkv->info_bc, mkv, MATROSKA_ID_INFO);
     if (ret < 0)
@@ -2537,10 +2489,7 @@ static int mkv_write_trailer(AVFormatContext *s)
                 cuespos = mkv_write_cues(s, mkv->cues, mkv->tracks, s->nb_streams);
             }
 
-            ret = mkv_add_seekhead_entry(mkv->seekhead, MATROSKA_ID_CUES,
-                                         cuespos);
-            if (ret < 0)
-                return ret;
+            mkv_add_seekhead_entry(mkv, MATROSKA_ID_CUES, cuespos);
         }
 
         mkv_write_seekhead(pb, mkv);
diff --git a/tests/fate/matroska.mak b/tests/fate/matroska.mak
index 98a49a4d74..f5b2ea710d 100644
--- a/tests/fate/matroska.mak
+++ b/tests/fate/matroska.mak
@@ -4,7 +4,7 @@
 FATE_MATROSKA-$(call DEMMUX, MATROSKA, MATROSKA) += fate-matroska-remux
 fate-matroska-remux: CMD = md5pipe -i $(TARGET_SAMPLES)/vp9-test-vectors/vp90-2-2pass-akiyo.webm -color_trc 4 -c:v copy -fflags +bitexact -strict -2 -f matroska
 fate-matroska-remux: CMP = oneline
-fate-matroska-remux: REF = e5457e5fa606d564a54914bd12f426c8
+fate-matroska-remux: REF = cae35b5b959e3d9ac878c6dfefc4e508
 
 FATE_MATROSKA_FFPROBE-$(call ALLYES, MATROSKA_DEMUXER) += fate-matroska-spherical-mono
 fate-matroska-spherical-mono: CMD = run ffprobe$(PROGSSUF)$(EXESUF) -show_entries stream_side_data_list -select_streams v -v 0 $(TARGET_SAMPLES)/mkv/spherical.mkv
diff --git a/tests/fate/wavpack.mak b/tests/fate/wavpack.mak
index 286e17f2ae..387cfda380 100644
--- a/tests/fate/wavpack.mak
+++ b/tests/fate/wavpack.mak
@@ -91,12 +91,12 @@ fate-wavpack-matroskamode: CMD = md5 -i $(TARGET_SAMPLES)/wavpack/special/matros
 FATE_WAVPACK-$(call DEMMUX, WV, MATROSKA) += fate-wavpack-matroska_mux-mono
 fate-wavpack-matroska_mux-mono: CMD = md5pipe -i $(TARGET_SAMPLES)/wavpack/num_channels/mono_16bit_int.wv -c copy -fflags +bitexact -f matroska
 fate-wavpack-matroska_mux-mono: CMP = oneline
-fate-wavpack-matroska_mux-mono: REF = c5a2b46d8b31c9c2e7bfb436f9d56f02
+fate-wavpack-matroska_mux-mono: REF = 931afa765eec5c49372b9fdae0feaf23
 
 FATE_WAVPACK-$(call DEMMUX, WV, MATROSKA) += fate-wavpack-matroska_mux-61
 fate-wavpack-matroska_mux-61: CMD = md5pipe -i $(TARGET_SAMPLES)/wavpack/num_channels/eva_2.22_6.1_16bit-partial.wv -c copy -fflags +bitexact -f matroska
 fate-wavpack-matroska_mux-61: CMP = oneline
-fate-wavpack-matroska_mux-61: REF = 22fc2a591be22657d19cab89ad6eef55
+fate-wavpack-matroska_mux-61: REF = cc11fe2ff9b1887b8a51330d28adbb8e
 
 FATE_SAMPLES_AVCONV += $(FATE_WAVPACK-yes)
 fate-wavpack: $(FATE_WAVPACK-yes)
diff --git a/tests/ref/fate/aac-autobsf-adtstoasc b/tests/ref/fate/aac-autobsf-adtstoasc
index 9bf9dfe78f..2f361d678c 100644
--- a/tests/ref/fate/aac-autobsf-adtstoasc
+++ b/tests/ref/fate/aac-autobsf-adtstoasc
@@ -1,5 +1,5 @@
-b09fc2f554712adbf84fe7899eb679d4 *tests/data/fate/aac-autobsf-adtstoasc.matroska
-6695 tests/data/fate/aac-autobsf-adtstoasc.matroska
+3bb278ab6ca22a00c3f14bd00f887332 *tests/data/fate/aac-autobsf-adtstoasc.matroska
+6611 tests/data/fate/aac-autobsf-adtstoasc.matroska
 #extradata 0:        2, 0x0030001c
 #tb 0: 1/1000
 #media_type 0: audio
diff --git a/tests/ref/fate/binsub-mksenc b/tests/ref/fate/binsub-mksenc
index 4b13ef217a..d95b91a6ed 100644
--- a/tests/ref/fate/binsub-mksenc
+++ b/tests/ref/fate/binsub-mksenc
@@ -1 +1 @@
-a5811caa0caba3a3f9a449b91569745c
+f02cb042bd50fa62d485a43ad4726533
diff --git a/tests/ref/fate/rgb24-mkv b/tests/ref/fate/rgb24-mkv
index b9db53f592..37cd21c48a 100644
--- a/tests/ref/fate/rgb24-mkv
+++ b/tests/ref/fate/rgb24-mkv
@@ -1,5 +1,5 @@
-ffe2c21083d56764aaae7945fd146326 *tests/data/fate/rgb24-mkv.matroska
-58305 tests/data/fate/rgb24-mkv.matroska
+0e20df482bba3820a4179ea7273a65a1 *tests/data/fate/rgb24-mkv.matroska
+58221 tests/data/fate/rgb24-mkv.matroska
 #tb 0: 1/10
 #media_type 0: video
 #codec_id 0: rawvideo
diff --git a/tests/ref/lavf/mka b/tests/ref/lavf/mka
index a244893cf2..ede6398ca8 100644
--- a/tests/ref/lavf/mka
+++ b/tests/ref/lavf/mka
@@ -1,3 +1,3 @@
-a91bfdb08ff5a1e62b039748d16b07f7 *tests/data/lavf/lavf.mka
-43652 tests/data/lavf/lavf.mka
+2ad63aec397720fe3e173476bc10c2a1 *tests/data/lavf/lavf.mka
+43568 tests/data/lavf/lavf.mka
 tests/data/lavf/lavf.mka CRC=0x3a1da17e
diff --git a/tests/ref/lavf/mkv b/tests/ref/lavf/mkv
index 05999b79fb..81e4b2076c 100644
--- a/tests/ref/lavf/mkv
+++ b/tests/ref/lavf/mkv
@@ -1,3 +1,3 @@
-3cddd26ed41f34925d3f34acabab174e *tests/data/lavf/lavf.mkv
-320555 tests/data/lavf/lavf.mkv
+c6cb72a490b1882fe9947e9dc3db3b4c *tests/data/lavf/lavf.mkv
+320471 tests/data/lavf/lavf.mkv
 tests/data/lavf/lavf.mkv CRC=0xec6c3c68
diff --git a/tests/ref/lavf/mkv_attachment b/tests/ref/lavf/mkv_attachment
index 790c0f693b..3d677bc0b2 100644
--- a/tests/ref/lavf/mkv_attachment
+++ b/tests/ref/lavf/mkv_attachment
@@ -1,3 +1,3 @@
-f54cf193e1925eff8a44554116a5e149 *tests/data/lavf/lavf.mkv_attachment
-472703 tests/data/lavf/lavf.mkv_attachment
+7ab0a5b64780ce775652a8c2137de8de *tests/data/lavf/lavf.mkv_attachment
+472619 tests/data/lavf/lavf.mkv_attachment
 tests/data/lavf/lavf.mkv_attachment CRC=0xec6c3c68
diff --git a/tests/ref/seek/lavf-mkv b/tests/ref/seek/lavf-mkv
index 6ed1f3a763..c2f75948d2 100644
--- a/tests/ref/seek/lavf-mkv
+++ b/tests/ref/seek/lavf-mkv
@@ -1,48 +1,48 @@
-ret: 0         st: 1 flags:1 dts: 0.000000 pts: 0.000000 pos:    803 size:   208
+ret: 0         st: 1 flags:1 dts: 0.000000 pts: 0.000000 pos:    719 size:   208
 ret: 0         st:-1 flags:0  ts:-1.000000
-ret: 0         st: 0 flags:1 dts: 0.011000 pts: 0.011000 pos:   1019 size: 27837
+ret: 0         st: 0 flags:1 dts: 0.011000 pts: 0.011000 pos:    935 size: 27837
 ret: 0         st:-1 flags:1  ts: 1.894167
-ret: 0         st: 0 flags:1 dts: 0.971000 pts: 0.971000 pos: 292435 size: 27834
+ret: 0         st: 0 flags:1 dts: 0.971000 pts: 0.971000 pos: 292351 size: 27834
 ret: 0         st: 0 flags:0  ts: 0.788000
-ret: 0         st: 0 flags:1 dts: 0.971000 pts: 0.971000 pos: 292435 size: 27834
+ret: 0         st: 0 flags:1 dts: 0.971000 pts: 0.971000 pos: 292351 size: 27834
 ret: 0         st: 0 flags:1  ts:-0.317000
-ret: 0         st: 0 flags:1 dts: 0.011000 pts: 0.011000 pos:   1019 size: 27837
+ret: 0         st: 0 flags:1 dts: 0.011000 pts: 0.011000 pos:    935 size: 27837
 ret:-1         st: 1 flags:0  ts: 2.577000
 ret: 0         st: 1 flags:1  ts: 1.471000
-ret: 0         st: 1 flags:1 dts: 0.993000 pts: 0.993000 pos: 320276 size:   209
+ret: 0         st: 1 flags:1 dts: 0.993000 pts: 0.993000 pos: 320192 size:   209
 ret: 0         st:-1 flags:0  ts: 0.365002
-ret: 0         st: 0 flags:1 dts: 0.491000 pts: 0.491000 pos: 146987 size: 27925
+ret: 0         st: 0 flags:1 dts: 0.491000 pts: 0.491000 pos: 146903 size: 27925
 ret: 0         st:-1 flags:1  ts:-0.740831
-ret: 0         st: 0 flags:1 dts: 0.011000 pts: 0.011000 pos:   1019 size: 27837
+ret: 0         st: 0 flags:1 dts: 0.011000 pts: 0.011000 pos:    935 size: 27837
 ret:-1         st: 0 flags:0  ts: 2.153000
 ret: 0         st: 0 flags:1  ts: 1.048000
-ret: 0         st: 0 flags:1 dts: 0.971000 pts: 0.971000 pos: 292435 size: 27834
+ret: 0         st: 0 flags:1 dts: 0.971000 pts: 0.971000 pos: 292351 size: 27834
 ret: 0         st: 1 flags:0  ts:-0.058000
-ret: 0         st: 1 flags:1 dts: 0.000000 pts: 0.000000 pos:    803 size:   208
+ret: 0         st: 1 flags:1 dts: 0.000000 pts: 0.000000 pos:    719 size:   208
 ret: 0         st: 1 flags:1  ts: 2.836000
-ret: 0         st: 1 flags:1 dts: 0.993000 pts: 0.993000 pos: 320276 size:   209
+ret: 0         st: 1 flags:1 dts: 0.993000 pts: 0.993000 pos: 320192 size:   209
 ret:-1         st:-1 flags:0  ts: 1.730004
 ret: 0         st:-1 flags:1  ts: 0.624171
-ret: 0         st: 0 flags:1 dts: 0.491000 pts: 0.491000 pos: 146987 size: 27925
+ret: 0         st: 0 flags:1 dts: 0.491000 pts: 0.491000 pos: 146903 size: 27925
 ret: 0         st: 0 flags:0  ts:-0.482000
-ret: 0         st: 0 flags:1 dts: 0.011000 pts: 0.011000 pos:   1019 size: 27837
+ret: 0         st: 0 flags:1 dts: 0.011000 pts: 0.011000 pos:    935 size: 27837
 ret: 0         st: 0 flags:1  ts: 2.413000
-ret: 0         st: 0 flags:1 dts: 0.971000 pts: 0.971000 pos: 292435 size: 27834
+ret: 0         st: 0 flags:1 dts: 0.971000 pts: 0.971000 pos: 292351 size: 27834
 ret:-1         st: 1 flags:0  ts: 1.307000
 ret: 0         st: 1 flags:1  ts: 0.201000
-ret: 0         st: 1 flags:1 dts: 0.000000 pts: 0.000000 pos:    803 size:   208
+ret: 0         st: 1 flags:1 dts: 0.000000 pts: 0.000000 pos:    719 size:   208
 ret: 0         st:-1 flags:0  ts:-0.904994
-ret: 0         st: 0 flags:1 dts: 0.011000 pts: 0.011000 pos:   1019 size: 27837
+ret: 0         st: 0 flags:1 dts: 0.011000 pts: 0.011000 pos:    935 size: 27837
 ret: 0         st:-1 flags:1  ts: 1.989173
-ret: 0         st: 0 flags:1 dts: 0.971000 pts: 0.971000 pos: 292435 size: 27834
+ret: 0         st: 0 flags:1 dts: 0.971000 pts: 0.971000 pos: 292351 size: 27834
 ret: 0         st: 0 flags:0  ts: 0.883000
-ret: 0         st: 0 flags:1 dts: 0.971000 pts: 0.971000 pos: 292435 size: 27834
+ret: 0         st: 0 flags:1 dts: 0.971000 pts: 0.971000 pos: 292351 size: 27834
 ret: 0         st: 0 flags:1  ts:-0.222000
-ret: 0         st: 0 flags:1 dts: 0.011000 pts: 0.011000 pos:   1019 size: 27837
+ret: 0         st: 0 flags:1 dts: 0.011000 pts: 0.011000 pos:    935 size: 27837
 ret:-1         st: 1 flags:0  ts: 2.672000
 ret: 0         st: 1 flags:1  ts: 1.566000
-ret: 0         st: 1 flags:1 dts: 0.993000 pts: 0.993000 pos: 320276 size:   209
+ret: 0         st: 1 flags:1 dts: 0.993000 pts: 0.993000 pos: 320192 size:   209
 ret: 0         st:-1 flags:0  ts: 0.460008
-ret: 0         st: 0 flags:1 dts: 0.491000 pts: 0.491000 pos: 146987 size: 27925
+ret: 0         st: 0 flags:1 dts: 0.491000 pts: 0.491000 pos: 146903 size: 27925
 ret: 0         st:-1 flags:1  ts:-0.645825
-ret: 0         st: 0 flags:1 dts: 0.011000 pts: 0.011000 pos:   1019 size: 27837
+ret: 0         st: 0 flags:1 dts: 0.011000 pts: 0.011000 pos:    935 size: 27837
