diff --git a/Changelog b/Changelog
index b65d4ba955..ad3e211ac1 100644
--- a/Changelog
+++ b/Changelog
@@ -47,6 +47,7 @@ version <next>:
 - Ut Video encoder
 - Microsoft Screen 2 decoder
 - RTP depacketization of JPEG
+- Smooth Streaming live segmenter muxer
 
 
 version 0.8:
diff --git a/libavformat/Makefile b/libavformat/Makefile
index 1cc7ebe5b3..ae168b6ff4 100644
--- a/libavformat/Makefile
+++ b/libavformat/Makefile
@@ -292,6 +292,7 @@ OBJS-$(CONFIG_SIFF_DEMUXER)              += siff.o
 OBJS-$(CONFIG_SMACKER_DEMUXER)           += smacker.o
 OBJS-$(CONFIG_SMJPEG_DEMUXER)            += smjpegdec.o smjpeg.o
 OBJS-$(CONFIG_SMJPEG_MUXER)              += smjpegenc.o smjpeg.o
+OBJS-$(CONFIG_SMOOTHSTREAMING_MUXER)     += smoothstreamingenc.o
 OBJS-$(CONFIG_SOL_DEMUXER)               += sol.o pcm.o
 OBJS-$(CONFIG_SOX_DEMUXER)               += soxdec.o pcm.o
 OBJS-$(CONFIG_SOX_MUXER)                 += soxenc.o
diff --git a/libavformat/allformats.c b/libavformat/allformats.c
index 40770e5253..39daec70c7 100644
--- a/libavformat/allformats.c
+++ b/libavformat/allformats.c
@@ -207,6 +207,7 @@ void av_register_all(void)
     REGISTER_DEMUXER  (SIFF, siff);
     REGISTER_DEMUXER  (SMACKER, smacker);
     REGISTER_MUXDEMUX (SMJPEG, smjpeg);
+    REGISTER_MUXER    (SMOOTHSTREAMING, smoothstreaming);
     REGISTER_DEMUXER  (SOL, sol);
     REGISTER_MUXDEMUX (SOX, sox);
     REGISTER_MUXDEMUX (SPDIF, spdif);
diff --git a/libavformat/os_support.h b/libavformat/os_support.h
index 8e2eb83ccd..533b06beee 100644
--- a/libavformat/os_support.h
+++ b/libavformat/os_support.h
@@ -38,6 +38,13 @@
 #  define fstat(f,s) _fstati64((f), (s))
 #endif /* defined(__MINGW32__) && !defined(__MINGW32CE__) */
 
+#ifdef _WIN32
+#include <direct.h>
+#define mkdir(a, b) _mkdir(a)
+#else
+#include <sys/stat.h>
+#endif
+
 static inline int is_dos_path(const char *path)
 {
 #if HAVE_DOS_PATHS
diff --git a/libavformat/smoothstreamingenc.c b/libavformat/smoothstreamingenc.c
new file mode 100644
index 0000000000..5ddba7eb06
--- /dev/null
+++ b/libavformat/smoothstreamingenc.c
@@ -0,0 +1,621 @@
+/*
+ * Live smooth streaming fragmenter
+ * Copyright (c) 2012 Martin Storsjo
+ *
+ * This file is part of Libav.
+ *
+ * Libav 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.
+ *
+ * Libav 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 Libav; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include "config.h"
+#include <float.h>
+#if HAVE_UNISTD_H
+#include <unistd.h>
+#endif
+
+#include "avformat.h"
+#include "internal.h"
+#include "os_support.h"
+#include "avc.h"
+#include "url.h"
+
+#include "libavutil/opt.h"
+#include "libavutil/avstring.h"
+#include "libavutil/mathematics.h"
+#include "libavutil/intreadwrite.h"
+
+typedef struct {
+    char file[1024];
+    char infofile[1024];
+    int64_t start_time, duration;
+    int n;
+    int64_t start_pos, size;
+} Fragment;
+
+typedef struct {
+    AVFormatContext *ctx;
+    int ctx_inited;
+    char dirname[1024];
+    uint8_t iobuf[32768];
+    URLContext *out;  // Current output stream where all output is written
+    URLContext *out2; // Auxillary output stream where all output also is written
+    URLContext *tail_out; // The actual main output stream, if we're currently seeked back to write elsewhere
+    int64_t tail_pos, cur_pos, cur_start_pos;
+    int packets_written;
+    const char *stream_type_tag;
+    int nb_fragments, fragments_size, fragment_index;
+    Fragment **fragments;
+
+    const char *fourcc;
+    char *private_str;
+    int packet_size;
+    int audio_tag;
+} OutputStream;
+
+typedef struct {
+    const AVClass *class;  /* Class for private options. */
+    int window_size;
+    int extra_window_size;
+    int lookahead_count;
+    int min_frag_duration;
+    int remove_at_exit;
+    OutputStream *streams;
+    int has_video, has_audio;
+    int nb_fragments;
+} SmoothStreamingContext;
+
+static int ism_write(void *opaque, uint8_t *buf, int buf_size)
+{
+    OutputStream *os = opaque;
+    if (os->out)
+        ffurl_write(os->out, buf, buf_size);
+    if (os->out2)
+        ffurl_write(os->out2, buf, buf_size);
+    os->cur_pos += buf_size;
+    if (os->cur_pos >= os->tail_pos)
+        os->tail_pos = os->cur_pos;
+    return buf_size;
+}
+
+static int64_t ism_seek(void *opaque, int64_t offset, int whence)
+{
+    OutputStream *os = opaque;
+    int i;
+    if (whence != SEEK_SET)
+        return AVERROR(ENOSYS);
+    if (os->tail_out) {
+        if (os->out) {
+            ffurl_close(os->out);
+        }
+        if (os->out2) {
+            ffurl_close(os->out2);
+        }
+        os->out = os->tail_out;
+        os->out2 = NULL;
+        os->tail_out = NULL;
+    }
+    if (offset >= os->cur_start_pos) {
+        ffurl_seek(os->out, offset - os->cur_start_pos, SEEK_SET);
+        os->cur_pos = offset;
+        return offset;
+    }
+    for (i = os->nb_fragments - 1; i >= 0; i--) {
+        Fragment *frag = os->fragments[i];
+        if (offset >= frag->start_pos && offset < frag->start_pos + frag->size) {
+            int ret;
+            AVDictionary *opts = NULL;
+            os->tail_out = os->out;
+            av_dict_set(&opts, "truncate", "0", 0);
+            ret = ffurl_open(&os->out, frag->file, AVIO_FLAG_READ_WRITE, &os->ctx->interrupt_callback, &opts);
+            av_dict_free(&opts);
+            if (ret < 0) {
+                os->out = os->tail_out;
+                os->tail_out = NULL;
+                return ret;
+            }
+            av_dict_set(&opts, "truncate", "0", 0);
+            ffurl_open(&os->out2, frag->infofile, AVIO_FLAG_READ_WRITE, &os->ctx->interrupt_callback, &opts);
+            av_dict_free(&opts);
+            ffurl_seek(os->out, offset - frag->start_pos, SEEK_SET);
+            if (os->out2)
+                ffurl_seek(os->out2, offset - frag->start_pos, SEEK_SET);
+            os->cur_pos = offset;
+            return offset;
+        }
+    }
+    return AVERROR(EIO);
+}
+
+static void get_private_data(OutputStream *os)
+{
+    AVCodecContext *codec = os->ctx->streams[0]->codec;
+    uint8_t *ptr = codec->extradata;
+    int size = codec->extradata_size;
+    int i;
+    if (codec->codec_id == AV_CODEC_ID_H264) {
+        ff_avc_write_annexb_extradata(ptr, &ptr, &size);
+        if (!ptr)
+            ptr = codec->extradata;
+    }
+    if (!ptr)
+        return;
+    os->private_str = av_mallocz(2*size + 1);
+    for (i = 0; i < size; i++)
+        snprintf(&os->private_str[2*i], 3, "%02x", ptr[i]);
+    if (ptr != codec->extradata)
+        av_free(ptr);
+}
+
+static void ism_free(AVFormatContext *s)
+{
+    SmoothStreamingContext *c = s->priv_data;
+    int i, j;
+    if (!c->streams)
+        return;
+    for (i = 0; i < s->nb_streams; i++) {
+        OutputStream *os = &c->streams[i];
+        ffurl_close(os->out);
+        ffurl_close(os->out2);
+        ffurl_close(os->tail_out);
+        os->out = os->out2 = os->tail_out = NULL;
+        if (os->ctx && os->ctx_inited)
+            av_write_trailer(os->ctx);
+        if (os->ctx && os->ctx->pb)
+            av_free(os->ctx->pb);
+        if (os->ctx)
+            avformat_free_context(os->ctx);
+        av_free(os->private_str);
+        for (j = 0; j < os->nb_fragments; j++)
+            av_free(os->fragments[j]);
+        av_free(os->fragments);
+    }
+    av_freep(&c->streams);
+}
+
+static int ism_write_header(AVFormatContext *s)
+{
+    SmoothStreamingContext *c = s->priv_data;
+    int ret = 0, i;
+    AVOutputFormat *oformat;
+
+    ret = mkdir(s->filename, 0777);
+    if (ret) {
+        av_log(s, AV_LOG_ERROR, "mkdir(%s): %s\n", s->filename, strerror(errno));
+        return AVERROR(errno);
+    }
+    ret = 0;
+
+    oformat = av_guess_format("ismv", NULL, NULL);
+    if (!oformat) {
+        ret = AVERROR_MUXER_NOT_FOUND;
+        goto fail;
+    }
+
+    c->streams = av_mallocz(sizeof(*c->streams) * s->nb_streams);
+    if (!c->streams) {
+        ret = AVERROR(ENOMEM);
+        goto fail;
+    }
+
+    for (i = 0; i < s->nb_streams; i++) {
+        OutputStream *os = &c->streams[i];
+        AVFormatContext *ctx;
+        AVStream *st;
+        AVDictionary *opts = NULL;
+        char buf[10];
+
+        if (!s->streams[i]->codec->bit_rate) {
+            av_log(s, AV_LOG_ERROR, "No bit rate set for stream %d\n", i);
+            ret = AVERROR(EINVAL);
+            goto fail;
+        }
+        snprintf(os->dirname, sizeof(os->dirname), "%s/QualityLevels(%d)", s->filename, s->streams[i]->codec->bit_rate);
+        mkdir(os->dirname, 0777);
+
+        ctx = avformat_alloc_context();
+        if (!ctx) {
+            ret = AVERROR(ENOMEM);
+            goto fail;
+        }
+        os->ctx = ctx;
+        ctx->oformat = oformat;
+        ctx->interrupt_callback = s->interrupt_callback;
+
+        if (!(st = avformat_new_stream(ctx, NULL))) {
+            ret = AVERROR(ENOMEM);
+            goto fail;
+        }
+        avcodec_copy_context(st->codec, s->streams[i]->codec);
+
+        ctx->pb = avio_alloc_context(os->iobuf, sizeof(os->iobuf), AVIO_FLAG_WRITE, os, NULL, ism_write, ism_seek);
+        if (!ctx->pb) {
+            ret = AVERROR(ENOMEM);
+            goto fail;
+        }
+
+        snprintf(buf, sizeof(buf), "%d", c->lookahead_count);
+        av_dict_set(&opts, "ism_lookahead", buf, 0);
+        av_dict_set(&opts, "movflags", "frag_custom", 0);
+        if ((ret = avformat_write_header(ctx, &opts)) < 0) {
+             goto fail;
+        }
+        os->ctx_inited = 1;
+        avio_flush(ctx->pb);
+        av_dict_free(&opts);
+        s->streams[i]->time_base = st->time_base;
+        if (st->codec->codec_type == AVMEDIA_TYPE_VIDEO) {
+            c->has_video = 1;
+            os->stream_type_tag = "video";
+            if (st->codec->codec_id == AV_CODEC_ID_H264) {
+                os->fourcc = "H264";
+            } else if (st->codec->codec_id == AV_CODEC_ID_VC1) {
+                os->fourcc = "WVC1";
+            } else {
+                av_log(s, AV_LOG_ERROR, "Unsupported video codec\n");
+                ret = AVERROR(EINVAL);
+                goto fail;
+            }
+        } else {
+            c->has_audio = 1;
+            os->stream_type_tag = "audio";
+            if (st->codec->codec_id == AV_CODEC_ID_AAC) {
+                os->fourcc = "AACL";
+                os->audio_tag = 0xff;
+            } else if (st->codec->codec_id == AV_CODEC_ID_WMAPRO) {
+                os->fourcc = "WMAP";
+                os->audio_tag = 0x0162;
+            } else {
+                av_log(s, AV_LOG_ERROR, "Unsupported audio codec\n");
+                ret = AVERROR(EINVAL);
+                goto fail;
+            }
+            os->packet_size = st->codec->block_align ? st->codec->block_align : 4;
+        }
+        get_private_data(os);
+    }
+
+    if (!c->has_video && c->min_frag_duration <= 0) {
+        av_log(s, AV_LOG_WARNING, "no video stream and no min frag duration set\n");
+        ret = AVERROR(EINVAL);
+    }
+
+fail:
+    if (ret)
+        ism_free(s);
+    return ret;
+}
+
+static int parse_fragment(AVFormatContext *s, const char *filename, int64_t *start_ts, int64_t *duration, int64_t *moof_size, int64_t size)
+{
+    AVIOContext *in;
+    int ret;
+    uint32_t len;
+    if ((ret = avio_open2(&in, filename, AVIO_FLAG_READ, &s->interrupt_callback, NULL)) < 0)
+        return ret;
+    ret = AVERROR(EIO);
+    *moof_size = avio_rb32(in);
+    if (*moof_size < 8 || *moof_size > size)
+        goto fail;
+    if (avio_rl32(in) != MKTAG('m','o','o','f'))
+        goto fail;
+    len = avio_rb32(in);
+    if (len > *moof_size)
+        goto fail;
+    if (avio_rl32(in) != MKTAG('m','f','h','d'))
+        goto fail;
+    avio_seek(in, len - 8, SEEK_CUR);
+    avio_rb32(in); /* traf size */
+    if (avio_rl32(in) != MKTAG('t','r','a','f'))
+        goto fail;
+    while (avio_tell(in) < *moof_size) {
+        uint32_t len = avio_rb32(in);
+        uint32_t tag = avio_rl32(in);
+        int64_t end = avio_tell(in) + len - 8;
+        if (len < 8 || len >= *moof_size)
+            goto fail;
+        if (tag == MKTAG('u','u','i','d')) {
+            const uint8_t tfxd[] = {
+                0x6d, 0x1d, 0x9b, 0x05, 0x42, 0xd5, 0x44, 0xe6,
+                0x80, 0xe2, 0x14, 0x1d, 0xaf, 0xf7, 0x57, 0xb2
+            };
+            uint8_t uuid[16];
+            avio_read(in, uuid, 16);
+            if (!memcmp(uuid, tfxd, 16) && len >= 8 + 16 + 4 + 16) {
+                avio_seek(in, 4, SEEK_CUR);
+                *start_ts = avio_rb64(in);
+                *duration = avio_rb64(in);
+                ret = 0;
+                break;
+            }
+        }
+        avio_seek(in, end, SEEK_SET);
+    }
+fail:
+    avio_close(in);
+    return ret;
+}
+
+static int add_fragment(OutputStream *os, const char *file, const char *infofile, int64_t start_time, int64_t duration, int64_t start_pos, int64_t size)
+{
+    Fragment *frag;
+    if (os->nb_fragments >= os->fragments_size) {
+        os->fragments_size = (os->fragments_size + 1) * 2;
+        os->fragments = av_realloc(os->fragments, sizeof(*os->fragments)*os->fragments_size);
+        if (!os->fragments)
+            return AVERROR(ENOMEM);
+    }
+    frag = av_mallocz(sizeof(*frag));
+    if (!frag)
+        return AVERROR(ENOMEM);
+    av_strlcpy(frag->file, file, sizeof(frag->file));
+    av_strlcpy(frag->infofile, infofile, sizeof(frag->infofile));
+    frag->start_time = start_time;
+    frag->duration = duration;
+    frag->start_pos = start_pos;
+    frag->size = size;
+    frag->n = os->fragment_index;
+    os->fragments[os->nb_fragments++] = frag;
+    os->fragment_index++;
+    return 0;
+}
+
+static int copy_moof(AVFormatContext *s, const char* infile, const char *outfile, int64_t size)
+{
+    AVIOContext *in, *out;
+    int ret = 0;
+    if ((ret = avio_open2(&in, infile, AVIO_FLAG_READ, &s->interrupt_callback, NULL)) < 0)
+        return ret;
+    if ((ret = avio_open2(&out, outfile, AVIO_FLAG_WRITE, &s->interrupt_callback, NULL)) < 0) {
+        avio_close(in);
+        return ret;
+    }
+    while (size > 0) {
+        uint8_t buf[8192];
+        int n = FFMIN(size, sizeof(buf));
+        n = avio_read(in, buf, n);
+        if (n <= 0) {
+            ret = AVERROR(EIO);
+            break;
+        }
+        avio_write(out, buf, n);
+        size -= n;
+    }
+    avio_flush(out);
+    avio_close(out);
+    avio_close(in);
+    return ret;
+}
+
+static void output_chunk_list(OutputStream *os, AVIOContext *out, int final, int skip, int window_size)
+{
+    int removed = 0, i, start = 0;
+    if (os->nb_fragments <= 0)
+        return;
+    if (os->fragments[0]->n > 0)
+        removed = 1;
+    if (final)
+        skip = 0;
+    if (window_size)
+        start = FFMAX(os->nb_fragments - skip - window_size, 0);
+    for (i = start; i < os->nb_fragments - skip; i++) {
+        Fragment *frag = os->fragments[i];
+        if (!final || removed)
+            avio_printf(out, "<c t=\"%"PRIu64"\" d=\"%"PRIu64"\" />\n", frag->start_time, frag->duration);
+        else
+            avio_printf(out, "<c n=\"%d\" d=\"%"PRIu64"\" />\n", frag->n, frag->duration);
+    }
+}
+
+static int write_manifest(AVFormatContext *s, int final)
+{
+    SmoothStreamingContext *c = s->priv_data;
+    AVIOContext *out;
+    char filename[1024];
+    int ret, i, video_chunks = 0, audio_chunks = 0, video_streams = 0, audio_streams = 0;
+    int64_t duration = 0;
+
+    snprintf(filename, sizeof(filename), "%s/Manifest", s->filename);
+    ret = avio_open2(&out, filename, AVIO_FLAG_WRITE, &s->interrupt_callback, NULL);
+    if (ret < 0)
+        return ret;
+    avio_printf(out, "<?xml version=\"1.0\" encoding=\"utf-8\"?>\n");
+    for (i = 0; i < s->nb_streams; i++) {
+        OutputStream *os = &c->streams[i];
+        if (os->nb_fragments > 0) {
+            Fragment *last = os->fragments[os->nb_fragments - 1];
+            duration = last->start_time + last->duration;
+        }
+        if (s->streams[i]->codec->codec_type == AVMEDIA_TYPE_VIDEO) {
+            video_chunks = os->nb_fragments;
+            video_streams++;
+        } else {
+            audio_chunks = os->nb_fragments;
+            audio_streams++;
+        }
+    }
+    if (!final) {
+        duration = 0;
+        video_chunks = audio_chunks = 0;
+    }
+    if (c->window_size) {
+        video_chunks = FFMIN(video_chunks, c->window_size);
+        audio_chunks = FFMIN(audio_chunks, c->window_size);
+    }
+    avio_printf(out, "<SmoothStreamingMedia MajorVersion=\"2\" MinorVersion=\"0\" Duration=\"%"PRIu64"\"", duration);
+    if (!final)
+        avio_printf(out, " IsLive=\"true\" LookAheadFragmentCount=\"%d\" DVRWindowLength=\"0\"", c->lookahead_count);
+    avio_printf(out, ">\n");
+    if (c->has_video) {
+        int last = -1, index = 0;
+        avio_printf(out, "<StreamIndex Type=\"video\" QualityLevels=\"%d\" Chunks=\"%d\" Url=\"QualityLevels({bitrate})/Fragments(video={start time})\">\n", video_streams, video_chunks);
+        for (i = 0; i < s->nb_streams; i++) {
+            OutputStream *os = &c->streams[i];
+            if (s->streams[i]->codec->codec_type != AVMEDIA_TYPE_VIDEO)
+                continue;
+            last = i;
+            avio_printf(out, "<QualityLevel Index=\"%d\" Bitrate=\"%d\" FourCC=\"%s\" MaxWidth=\"%d\" MaxHeight=\"%d\" CodecPrivateData=\"%s\" />\n", index, s->streams[i]->codec->bit_rate, os->fourcc, s->streams[i]->codec->width, s->streams[i]->codec->height, os->private_str);
+            index++;
+        }
+        output_chunk_list(&c->streams[last], out, final, c->lookahead_count, c->window_size);
+        avio_printf(out, "</StreamIndex>\n");
+    }
+    if (c->has_audio) {
+        int last = -1, index = 0;
+        avio_printf(out, "<StreamIndex Type=\"audio\" QualityLevels=\"%d\" Chunks=\"%d\" Url=\"QualityLevels({bitrate})/Fragments(audio={start time})\">\n", audio_streams, audio_chunks);
+        for (i = 0; i < s->nb_streams; i++) {
+            OutputStream *os = &c->streams[i];
+            if (s->streams[i]->codec->codec_type != AVMEDIA_TYPE_AUDIO)
+                continue;
+            last = i;
+            avio_printf(out, "<QualityLevel Index=\"%d\" Bitrate=\"%d\" FourCC=\"%s\" SamplingRate=\"%d\" Channels=\"%d\" BitsPerSample=\"16\" PacketSize=\"%d\" AudioTag=\"%d\" CodecPrivateData=\"%s\" />\n", index, s->streams[i]->codec->bit_rate, os->fourcc, s->streams[i]->codec->sample_rate, s->streams[i]->codec->channels, os->packet_size, os->audio_tag, os->private_str);
+            index++;
+        }
+        output_chunk_list(&c->streams[last], out, final, c->lookahead_count, c->window_size);
+        avio_printf(out, "</StreamIndex>\n");
+    }
+    avio_printf(out, "</SmoothStreamingMedia>\n");
+    avio_flush(out);
+    avio_close(out);
+    return 0;
+}
+
+static int ism_flush(AVFormatContext *s, int final)
+{
+    SmoothStreamingContext *c = s->priv_data;
+    int i, ret = 0;
+
+    for (i = 0; i < s->nb_streams; i++) {
+        OutputStream *os = &c->streams[i];
+        char filename[1024], target_filename[1024], header_filename[1024];
+        int64_t start_pos = os->tail_pos, size;
+        int64_t start_ts, duration, moof_size;
+        if (!os->packets_written)
+            continue;
+
+        snprintf(filename, sizeof(filename), "%s/temp", os->dirname);
+        ret = ffurl_open(&os->out, filename, AVIO_FLAG_WRITE, &s->interrupt_callback, NULL);
+        if (ret < 0)
+            break;
+        os->cur_start_pos = os->tail_pos;
+        av_write_frame(os->ctx, NULL);
+        avio_flush(os->ctx->pb);
+        os->packets_written = 0;
+        if (!os->out || os->tail_out)
+            return AVERROR(EIO);
+
+        ffurl_close(os->out);
+        os->out = NULL;
+        size = os->tail_pos - start_pos;
+        if ((ret = parse_fragment(s, filename, &start_ts, &duration, &moof_size, size)) < 0)
+            break;
+        snprintf(header_filename, sizeof(header_filename), "%s/FragmentInfo(%s=%"PRIu64")", os->dirname, os->stream_type_tag, start_ts);
+        snprintf(target_filename, sizeof(target_filename), "%s/Fragments(%s=%"PRIu64")", os->dirname, os->stream_type_tag, start_ts);
+        copy_moof(s, filename, header_filename, moof_size);
+        rename(filename, target_filename);
+        add_fragment(os, target_filename, header_filename, start_ts, duration, start_pos, size);
+    }
+
+    if (c->window_size || (final && c->remove_at_exit)) {
+        for (i = 0; i < s->nb_streams; i++) {
+            OutputStream *os = &c->streams[i];
+            int j;
+            int remove = os->nb_fragments - c->window_size - c->extra_window_size - c->lookahead_count;
+            if (final && c->remove_at_exit)
+                remove = os->nb_fragments;
+            if (remove > 0) {
+                for (j = 0; j < remove; j++) {
+                    unlink(os->fragments[j]->file);
+                    unlink(os->fragments[j]->infofile);
+                    av_free(os->fragments[j]);
+                }
+                os->nb_fragments -= remove;
+                memmove(os->fragments, os->fragments + remove, os->nb_fragments * sizeof(*os->fragments));
+            }
+            if (final && c->remove_at_exit)
+                rmdir(os->dirname);
+        }
+    }
+
+    write_manifest(s, final);
+    return ret;
+}
+
+static int ism_write_packet(AVFormatContext *s, AVPacket *pkt)
+{
+    SmoothStreamingContext *c = s->priv_data;
+    AVStream *st = s->streams[pkt->stream_index];
+    OutputStream *os = &c->streams[pkt->stream_index];
+    int64_t end_pts = (c->nb_fragments + 1) * c->min_frag_duration;
+
+    if ((!c->has_video || st->codec->codec_type == AVMEDIA_TYPE_VIDEO) &&
+        av_compare_ts(pkt->pts, st->time_base,
+                      end_pts, AV_TIME_BASE_Q) >= 0 &&
+        pkt->flags & AV_PKT_FLAG_KEY && os->packets_written) {
+
+        ism_flush(s, 0);
+        c->nb_fragments++;
+    }
+
+    os->packets_written++;
+    return ff_write_chained(os->ctx, 0, pkt, s);
+}
+
+static int ism_write_trailer(AVFormatContext *s)
+{
+    SmoothStreamingContext *c = s->priv_data;
+    ism_flush(s, 1);
+
+    if (c->remove_at_exit) {
+        char filename[1024];
+        snprintf(filename, sizeof(filename), "%s/Manifest", s->filename);
+        unlink(filename);
+        rmdir(s->filename);
+    }
+
+    ism_free(s);
+    return 0;
+}
+
+#define OFFSET(x) offsetof(SmoothStreamingContext, x)
+#define E AV_OPT_FLAG_ENCODING_PARAM
+static const AVOption options[] = {
+    { "window_size", "number of fragments kept in the manifest", OFFSET(window_size), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, INT_MAX, E },
+    { "extra_window_size", "number of fragments kept outside of the manifest before removing from disk", OFFSET(extra_window_size), AV_OPT_TYPE_INT, { .i64 = 5 }, 0, INT_MAX, E },
+    { "lookahead_count", "number of lookahead fragments", OFFSET(lookahead_count), AV_OPT_TYPE_INT, { .i64 = 2 }, 0, INT_MAX, E },
+    { "min_frag_duration", "minimum fragment duration (in microseconds)", OFFSET(min_frag_duration), AV_OPT_TYPE_INT64, { .i64 = 5000000 }, 0, INT_MAX, E },
+    { "remove_at_exit", "remove all fragments when finished", OFFSET(remove_at_exit), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, 1, E },
+    { NULL },
+};
+
+static const AVClass ism_class = {
+    .class_name = "smooth streaming muxer",
+    .item_name  = av_default_item_name,
+    .option     = options,
+    .version    = LIBAVUTIL_VERSION_INT,
+};
+
+
+AVOutputFormat ff_smoothstreaming_muxer = {
+    .name           = "smoothstreaming",
+    .long_name      = NULL_IF_CONFIG_SMALL("Smooth Streaming Muxer"),
+    .priv_data_size = sizeof(SmoothStreamingContext),
+    .audio_codec    = AV_CODEC_ID_AAC,
+    .video_codec    = AV_CODEC_ID_H264,
+    .flags          = AVFMT_GLOBALHEADER | AVFMT_NOFILE,
+    .write_header   = ism_write_header,
+    .write_packet   = ism_write_packet,
+    .write_trailer  = ism_write_trailer,
+    .priv_class     = &ism_class,
+};
diff --git a/libavformat/version.h b/libavformat/version.h
index a90f01ae02..fa4d49a33a 100644
--- a/libavformat/version.h
+++ b/libavformat/version.h
@@ -30,7 +30,7 @@
 #include "libavutil/avutil.h"
 
 #define LIBAVFORMAT_VERSION_MAJOR 54
-#define LIBAVFORMAT_VERSION_MINOR 15
+#define LIBAVFORMAT_VERSION_MINOR 16
 #define LIBAVFORMAT_VERSION_MICRO  0
 
 #define LIBAVFORMAT_VERSION_INT AV_VERSION_INT(LIBAVFORMAT_VERSION_MAJOR, \