diff --git a/libavformat/Makefile b/libavformat/Makefile
index 11514397f0..2d681a707f 100644
--- a/libavformat/Makefile
+++ b/libavformat/Makefile
@@ -173,6 +173,7 @@ OBJS-$(CONFIG_TTA_DEMUXER)               += tta.o
 OBJS-$(CONFIG_TXD_DEMUXER)               += txd.o
 OBJS-$(CONFIG_VC1_DEMUXER)               += raw.o
 OBJS-$(CONFIG_VC1T_DEMUXER)              += vc1test.o
+OBJS-$(CONFIG_VC1T_MUXER)                += vc1testenc.o
 OBJS-$(CONFIG_VMD_DEMUXER)               += sierravmd.o
 OBJS-$(CONFIG_VOC_DEMUXER)               += vocdec.o voc.o
 OBJS-$(CONFIG_VOC_MUXER)                 += vocenc.o voc.o
diff --git a/libavformat/allformats.c b/libavformat/allformats.c
index 81111af660..6441ca996c 100644
--- a/libavformat/allformats.c
+++ b/libavformat/allformats.c
@@ -167,7 +167,7 @@ void av_register_all(void)
     REGISTER_DEMUXER  (TTA, tta);
     REGISTER_DEMUXER  (TXD, txd);
     REGISTER_DEMUXER  (VC1, vc1);
-    REGISTER_DEMUXER  (VC1T, vc1t);
+    REGISTER_MUXDEMUX (VC1T, vc1t);
     REGISTER_DEMUXER  (VMD, vmd);
     REGISTER_MUXDEMUX (VOC, voc);
     REGISTER_MUXDEMUX (WAV, wav);
diff --git a/libavformat/avformat.h b/libavformat/avformat.h
index 23450af1bd..c6586862e9 100644
--- a/libavformat/avformat.h
+++ b/libavformat/avformat.h
@@ -22,7 +22,7 @@
 #define FFMPEG_AVFORMAT_H
 
 #define LIBAVFORMAT_VERSION_MAJOR 52
-#define LIBAVFORMAT_VERSION_MINOR 17
+#define LIBAVFORMAT_VERSION_MINOR 18
 #define LIBAVFORMAT_VERSION_MICRO  0
 
 #define LIBAVFORMAT_VERSION_INT AV_VERSION_INT(LIBAVFORMAT_VERSION_MAJOR, \
diff --git a/libavformat/vc1testenc.c b/libavformat/vc1testenc.c
new file mode 100644
index 0000000000..c1264e5930
--- /dev/null
+++ b/libavformat/vc1testenc.c
@@ -0,0 +1,95 @@
+/*
+ * VC-1 test bitstreams format muxer.
+ * Copyright (c) 2008 Konstantin Shishkov
+ *
+ * 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 "avformat.h"
+
+typedef struct RCVContext {
+    int frames;
+} RCVContext;
+
+static int vc1test_write_header(AVFormatContext *s)
+{
+    RCVContext *ctx = s->priv_data;
+    AVCodecContext *avc = s->streams[0]->codec;
+    ByteIOContext *pb = s->pb;
+
+    if (avc->codec_id != CODEC_ID_WMV3) {
+        av_log(s, AV_LOG_ERROR, "Only WMV3 is accepted!\n");
+        return -1;
+    }
+    put_le24(pb, 0); //frames count will be here
+    put_byte(pb, 0xC5);
+    put_le32(pb, 4);
+    put_buffer(pb, avc->extradata, 4);
+    put_le32(pb, avc->height);
+    put_le32(pb, avc->width);
+    put_le32(pb, 0xC);
+    put_le24(pb, 0); // hrd_buffer
+    put_byte(pb, 0x80); // level|cbr|res1
+    put_le32(pb, 0); // hrd_rate
+    if (s->streams[0]->r_frame_rate.den && s->streams[0]->r_frame_rate.num == 1)
+        put_le32(pb, s->streams[0]->r_frame_rate.den);
+    else
+        put_le32(pb, 0xFFFFFFFF); //variable framerate
+
+    return 0;
+}
+
+static int vc1test_write_packet(AVFormatContext *s, AVPacket *pkt)
+{
+    RCVContext *ctx = s->priv_data;
+    ByteIOContext *pb = s->pb;
+
+    if (!pkt->size)
+        return 0;
+    put_le32(pb, pkt->size | ((pkt->flags & PKT_FLAG_KEY) ? 0x80000000 : 0));
+    put_le32(pb, pkt->pts);
+    put_buffer(pb, pkt->data, pkt->size);
+    put_flush_packet(pb);
+    ctx->frames++;
+
+    return 0;
+}
+
+static int vc1test_write_trailer(AVFormatContext *s)
+{
+    RCVContext *ctx = s->priv_data;
+    ByteIOContext *pb = s->pb;
+
+    if (!url_is_streamed(s->pb)) {
+        url_fseek(pb, 0, SEEK_SET);
+        put_le24(pb, ctx->frames);
+        put_flush_packet(pb);
+    }
+    return 0;
+}
+
+AVOutputFormat vc1t_muxer = {
+    "rcv",
+    NULL_IF_CONFIG_SMALL("VC-1 test bitstream"),
+    "",
+    "rcv",
+    sizeof(RCVContext),
+    CODEC_ID_NONE,
+    CODEC_ID_WMV3,
+    vc1test_write_header,
+    vc1test_write_packet,
+    vc1test_write_trailer,
+};