diff --git a/libavcodec/Makefile b/libavcodec/Makefile
index 43a6add..edadb0f 100644
--- a/libavcodec/Makefile
+++ b/libavcodec/Makefile
@@ -539,6 +539,7 @@ OBJS-$(CONFIG_SVQ1_ENCODER)            += svq1enc.o svq1.o  h263data.o  \
 OBJS-$(CONFIG_SVQ3_DECODER)            += svq3.o svq13.o mpegutils.o h264data.o
 OBJS-$(CONFIG_TEXT_DECODER)            += textdec.o ass.o
 OBJS-$(CONFIG_TEXT_ENCODER)            += srtenc.o ass_split.o
+OBJS-$(CONFIG_TEXTST_DECODER)          += textstdec.o ass.o
 OBJS-$(CONFIG_TAK_DECODER)             += takdec.o tak.o takdsp.o
 OBJS-$(CONFIG_TARGA_DECODER)           += targa.o
 OBJS-$(CONFIG_TARGA_ENCODER)           += targaenc.o rle.o
@@ -945,6 +946,7 @@ OBJS-$(CONFIG_RV30_PARSER)             += rv34_parser.o
 OBJS-$(CONFIG_RV40_PARSER)             += rv34_parser.o
 OBJS-$(CONFIG_SIPR_PARSER)             += sipr_parser.o
 OBJS-$(CONFIG_TAK_PARSER)              += tak_parser.o tak.o
+OBJS-$(CONFIG_TEXTST_PARSER)           += textst_parser.o
 OBJS-$(CONFIG_VC1_PARSER)              += vc1_parser.o vc1.o vc1data.o  \
                                           simple_idct.o wmv2data.o
 OBJS-$(CONFIG_VP3_PARSER)              += vp3_parser.o
diff --git a/libavcodec/allcodecs.c b/libavcodec/allcodecs.c
index f92b2b7..9a90533 100644
--- a/libavcodec/allcodecs.c
+++ b/libavcodec/allcodecs.c
@@ -581,6 +581,7 @@ void avcodec_register_all(void)
     REGISTER_DECODER(SUBVIEWER,         subviewer);
     REGISTER_DECODER(SUBVIEWER1,        subviewer1);
     REGISTER_ENCDEC (TEXT,              text);
+    REGISTER_DECODER(TEXTST,            textst);
     REGISTER_DECODER(VPLAYER,           vplayer);
     REGISTER_ENCDEC (WEBVTT,            webvtt);
     REGISTER_ENCDEC (XSUB,              xsub);
@@ -704,6 +705,7 @@ void avcodec_register_all(void)
     REGISTER_PARSER(RV40,               rv40);
     REGISTER_PARSER(SIPR,               sipr);
     REGISTER_PARSER(TAK,                tak);
+    REGISTER_PARSER(TEXTST,             textst);
     REGISTER_PARSER(VC1,                vc1);
     REGISTER_PARSER(VORBIS,             vorbis);
     REGISTER_PARSER(VP3,                vp3);
diff --git a/libavcodec/textst_parser.c b/libavcodec/textst_parser.c
new file mode 100644
index 0000000..5079a96
--- /dev/null
+++ b/libavcodec/textst_parser.c
@@ -0,0 +1,49 @@
+/*
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * FFmpeg is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+/**
+ * @file
+ * HDMV TextST subtitle parser
+ */
+
+#include "libavutil/intreadwrite.h"
+#include "parser.h"
+
+static int textst_parse(AVCodecParserContext *s1, AVCodecContext *avctx,
+                        const uint8_t **poutbuf, int *poutbuf_size,
+                        const uint8_t *buf, int buf_size)
+{
+    if (buf_size > 13) {
+        int64_t end;
+
+        s1->pts = ((int64_t)(buf[3] & 1) << 32) | AV_RB32(&buf[4]);
+        end = ((int64_t)(buf[8] & 1) << 32) | AV_RB32(&buf[9]);
+        s1->duration = (end - s1->pts);
+    }
+
+    /* always return the full packet. this parser isn't doing any splitting or
+       combining, only packet analysis */
+    *poutbuf      = buf;
+    *poutbuf_size = buf_size;
+    return buf_size;
+}
+
+AVCodecParser ff_textst_parser = {
+    .codec_ids      = { AV_CODEC_ID_HDMV_TEXT_SUBTITLE },
+    .parser_parse   = textst_parse,
+};
diff --git a/libavcodec/textstdec.c b/libavcodec/textstdec.c
new file mode 100644
index 0000000..a259d2d
--- /dev/null
+++ b/libavcodec/textstdec.c
@@ -0,0 +1,108 @@
+/*
+ * HDMV TextST decoder
+ * Copyright (c) 2017 Paul B Mahol
+ *
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * FFmpeg is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include <string.h>
+
+#include "libavutil/bprint.h"
+#include "avcodec.h"
+#include "ass.h"
+#include "bytestream.h"
+
+static int textst_event_to_ass(AVBPrint *buf, const char *p, int size)
+{
+    GetByteContext gb;
+    int i, count;
+
+    bytestream2_init(&gb, p, size);
+    count = bytestream2_get_byte(&gb);
+
+    if (count > 127) {
+        int size = bytestream2_get_be16(&gb);
+        bytestream2_skip(&gb, size);
+    }
+    if (bytestream2_get_bytes_left(&gb) > 2) {
+        count = bytestream2_get_byte(&gb);
+
+        for (i = 0; i < count; i++) {
+            int dlength;
+
+            bytestream2_skip(&gb, 2);
+            dlength = bytestream2_get_be16(&gb);
+
+            while (dlength > 3) {
+                int type, length;
+                int code = bytestream2_get_byte(&gb);
+
+                dlength--;
+                if (code != 0x1b)
+                    continue;
+
+                type   = bytestream2_get_byte(&gb);
+                length = bytestream2_get_byte(&gb);
+                dlength -= (2 + length);
+
+                switch (type) {
+                case 1:
+                    av_bprint_append_data(buf, gb.buffer, FFMIN(length, bytestream2_get_bytes_left(&gb)));
+                    bytestream2_skip(&gb, length);
+                    break;
+                case 0x0a:
+                    av_bprintf(buf, "\n");
+                default:
+                    bytestream2_skip(&gb, length);
+                    break;
+                }
+            }
+        }
+    }
+
+    return 0;
+}
+
+static int textst_decode_frame(AVCodecContext *avctx,
+                               void *data, int *got_sub_ptr, AVPacket *avpkt)
+{
+    FFASSDecoderContext *s = avctx->priv_data;
+    const char *ptr = avpkt->data;
+    AVSubtitle *sub = data;
+    AVBPrint buf;
+    int ret = 0;
+
+    av_bprint_init(&buf, 0, AV_BPRINT_SIZE_UNLIMITED);
+    if (ptr && avpkt->size > 13 && !textst_event_to_ass(&buf, ptr + 13, avpkt->size - 13))
+        ret = ff_ass_add_rect(sub, buf.str, s->readorder++, 0, NULL, NULL);
+    av_bprint_finalize(&buf, NULL);
+    if (ret < 0)
+        return ret;
+    *got_sub_ptr = sub->num_rects > 0;
+    return avpkt->size;
+}
+
+AVCodec ff_textst_decoder = {
+    .name           = "textst",
+    .long_name      = NULL_IF_CONFIG_SMALL("HDMV TextST subtitle"),
+    .type           = AVMEDIA_TYPE_SUBTITLE,
+    .id             = AV_CODEC_ID_HDMV_TEXT_SUBTITLE,
+    .decode         = textst_decode_frame,
+    .init           = ff_ass_subtitle_header_default,
+    .flush          = ff_ass_decoder_flush,
+    .priv_data_size = sizeof(FFASSDecoderContext),
+};
diff --git a/libavformat/utils.c b/libavformat/utils.c
index 0711310..74f808f 100644
--- a/libavformat/utils.c
+++ b/libavformat/utils.c
@@ -1445,6 +1445,7 @@ static int parse_packet(AVFormatContext *s, AVPacket *pkt, int stream_index)
 
         out_pkt.stream_index = st->index;
         out_pkt.pts          = st->parser->pts;
+        out_pkt.duration     = st->parser->duration;
         out_pkt.dts          = st->parser->dts;
         out_pkt.pos          = st->parser->pos;
 
