diff --git a/libavformat/hlsenc.c b/libavformat/hlsenc.c
index 30ccf73..5c4f459 100644
--- a/libavformat/hlsenc.c
+++ b/libavformat/hlsenc.c
@@ -45,6 +45,7 @@
 
 #include "avformat.h"
 #include "avio_internal.h"
+#include "hlsenc.h"
 #include "internal.h"
 #include "os_support.h"
 
@@ -73,36 +74,11 @@ typedef struct HLSSegment {
     struct HLSSegment *next;
 } HLSSegment;
 
-typedef enum HLSFlags {
-    // Generate a single media file and use byte ranges in the playlist.
-    HLS_SINGLE_FILE = (1 << 0),
-    HLS_DELETE_SEGMENTS = (1 << 1),
-    HLS_ROUND_DURATIONS = (1 << 2),
-    HLS_DISCONT_START = (1 << 3),
-    HLS_OMIT_ENDLIST = (1 << 4),
-    HLS_SPLIT_BY_TIME = (1 << 5),
-    HLS_APPEND_LIST = (1 << 6),
-    HLS_PROGRAM_DATE_TIME = (1 << 7),
-    HLS_SECOND_LEVEL_SEGMENT_INDEX = (1 << 8), // include segment index in segment filenames when use_localtime  e.g.: %%03d
-    HLS_SECOND_LEVEL_SEGMENT_DURATION = (1 << 9), // include segment duration (microsec) in segment filenames when use_localtime  e.g.: %%09t
-    HLS_SECOND_LEVEL_SEGMENT_SIZE = (1 << 10), // include segment size (bytes) in segment filenames when use_localtime  e.g.: %%014s
-    HLS_TEMP_FILE = (1 << 11),
-    HLS_PERIODIC_REKEY = (1 << 12),
-    HLS_INDEPENDENT_SEGMENTS = (1 << 13),
-} HLSFlags;
-
 typedef enum {
     SEGMENT_TYPE_MPEGTS,
     SEGMENT_TYPE_FMP4,
 } SegmentType;
 
-typedef enum {
-    PLAYLIST_TYPE_NONE,
-    PLAYLIST_TYPE_EVENT,
-    PLAYLIST_TYPE_VOD,
-    PLAYLIST_TYPE_NB,
-} PlaylistType;
-
 typedef struct VariantStream {
     unsigned number;
     int64_t sequence;
@@ -207,6 +183,113 @@ typedef struct HLSContext {
     unsigned int master_publish_rate;
 } HLSContext;
 
+void ff_hls_write_playlist_version(AVIOContext *out, int version) {
+    if (!out)
+        return;
+    avio_printf(out, "#EXTM3U\n");
+    avio_printf(out, "#EXT-X-VERSION:%d\n", version);
+}
+
+void ff_hls_write_stream_info(AVStream *st, AVIOContext *out,
+                              int bandwidth, char *filename) {
+    if (!out || !filename)
+        return;
+
+    if (!bandwidth) {
+        av_log(NULL, AV_LOG_WARNING,
+                "Bandwidth info not available, set audio and video bitrates\n");
+        return;
+    }
+
+    avio_printf(out, "#EXT-X-STREAM-INF:BANDWIDTH=%d", bandwidth);
+    if (st && st->codecpar->width > 0 && st->codecpar->height > 0)
+        avio_printf(out, ",RESOLUTION=%dx%d", st->codecpar->width,
+                st->codecpar->height);
+    avio_printf(out, "\n%s\n\n", filename);
+}
+
+void ff_hls_write_playlist_header(AVIOContext *out, int version, int allowcache,
+                                  int target_duration, int64_t sequence,
+                                  uint32_t playlist_type) {
+    if (!out)
+        return;
+    ff_hls_write_playlist_version(out, version);
+    if (allowcache == 0 || allowcache == 1) {
+        avio_printf(out, "#EXT-X-ALLOW-CACHE:%s\n", allowcache == 0 ? "NO" : "YES");
+    }
+    avio_printf(out, "#EXT-X-TARGETDURATION:%d\n", target_duration);
+    avio_printf(out, "#EXT-X-MEDIA-SEQUENCE:%"PRId64"\n", sequence);
+    av_log(NULL, AV_LOG_VERBOSE, "EXT-X-MEDIA-SEQUENCE:%"PRId64"\n", sequence);
+
+    if (playlist_type == PLAYLIST_TYPE_EVENT) {
+        avio_printf(out, "#EXT-X-PLAYLIST-TYPE:EVENT\n");
+    } else if (playlist_type == PLAYLIST_TYPE_VOD) {
+        avio_printf(out, "#EXT-X-PLAYLIST-TYPE:VOD\n");
+    }
+}
+
+void ff_hls_write_init_file(AVIOContext *out, char *filename,
+                            int byterange_mode, int64_t size, int64_t pos) {
+    avio_printf(out, "#EXT-X-MAP:URI=\"%s\"", filename);
+    if (byterange_mode) {
+        avio_printf(out, ",BYTERANGE=\"%"PRId64"@%"PRId64"\"", size, pos);
+    }
+    avio_printf(out, "\n");
+}
+
+void ff_hls_write_file_entry(AVIOContext *out, int insert_discont,
+                            int byterange_mode, uint32_t flags, double duration,
+                            int64_t size, int64_t pos, //Used only if HLS_SINGLE_FILE flag is set
+                            char *baseurl, //Ignored if NULL
+                            char *filename, double *prog_date_time) {
+    if (!out || !filename)
+        return;
+
+    if (insert_discont) {
+        avio_printf(out, "#EXT-X-DISCONTINUITY\n");
+    }
+    if (flags & HLS_ROUND_DURATIONS)
+        avio_printf(out, "#EXTINF:%ld,\n",  lrint(duration));
+    else
+        avio_printf(out, "#EXTINF:%f,\n", duration);
+    if (byterange_mode)
+        avio_printf(out, "#EXT-X-BYTERANGE:%"PRId64"@%"PRId64"\n", size, pos);
+
+    if ((flags & HLS_PROGRAM_DATE_TIME) && prog_date_time) {
+        time_t tt, wrongsecs;
+        int milli;
+        struct tm *tm, tmpbuf;
+        char buf0[128], buf1[128];
+        tt = (int64_t)prog_date_time;
+        milli = av_clip(lrint(1000*(*prog_date_time - tt)), 0, 999);
+        tm = localtime_r(&tt, &tmpbuf);
+        strftime(buf0, sizeof(buf0), "%Y-%m-%dT%H:%M:%S", tm);
+        if (!strftime(buf1, sizeof(buf1), "%z", tm) || buf1[1]<'0' ||buf1[1]>'2') {
+            int tz_min, dst = tm->tm_isdst;
+            tm = gmtime_r(&tt, &tmpbuf);
+            tm->tm_isdst = dst;
+            wrongsecs = mktime(tm);
+            tz_min = (FFABS(wrongsecs - tt) + 30) / 60;
+            snprintf(buf1, sizeof(buf1),
+                     "%c%02d%02d",
+                     wrongsecs <= tt ? '+' : '-',
+                     tz_min / 60,
+                     tz_min % 60);
+        }
+        avio_printf(out, "#EXT-X-PROGRAM-DATE-TIME:%s.%03d%s\n", buf0, milli, buf1);
+        *prog_date_time += duration;
+    }
+    if (baseurl)
+        avio_printf(out, "%s", baseurl);
+    avio_printf(out, "%s\n", filename);
+}
+
+void ff_hls_write_end_list (AVIOContext *out) {
+    if (!out)
+        return;
+    avio_printf(out, "#EXT-X-ENDLIST\n");
+}
+
 static int get_int_from_double(double val)
 {
     return (int)((val - (int)val) >= 0.001) ? (int)(val + 1) : (int)val;
@@ -1023,19 +1106,6 @@ static void hls_free_segments(HLSSegment *p)
     }
 }
 
-static void write_m3u8_head_block(HLSContext *hls, AVIOContext *out, int version,
-                                  int target_duration, int64_t sequence)
-{
-    avio_printf(out, "#EXTM3U\n");
-    avio_printf(out, "#EXT-X-VERSION:%d\n", version);
-    if (hls->allowcache == 0 || hls->allowcache == 1) {
-        avio_printf(out, "#EXT-X-ALLOW-CACHE:%s\n", hls->allowcache == 0 ? "NO" : "YES");
-    }
-    avio_printf(out, "#EXT-X-TARGETDURATION:%d\n", target_duration);
-    avio_printf(out, "#EXT-X-MEDIA-SEQUENCE:%"PRId64"\n", sequence);
-    av_log(hls, AV_LOG_VERBOSE, "EXT-X-MEDIA-SEQUENCE:%"PRId64"\n", sequence);
-}
-
 static void hls_rename_temp_file(AVFormatContext *s, AVFormatContext *oc)
 {
     size_t len = strlen(oc->filename);
@@ -1101,8 +1171,7 @@ static int create_master_playlist(AVFormatContext *s,
         goto fail;
     }
 
-    avio_printf(master_pb, "#EXTM3U\n");
-    avio_printf(master_pb, "#EXT-X-VERSION:%d\n", hls->version);
+    ff_hls_write_playlist_version(master_pb, hls->version);
 
     /* For variant streams with video add #EXT-X-STREAM-INF tag with attributes*/
     for (i = 0; i < hls->nb_varstreams; i++) {
@@ -1143,18 +1212,7 @@ static int create_master_playlist(AVFormatContext *s,
             bandwidth += aud_st->codecpar->bit_rate;
         bandwidth += bandwidth / 10;
 
-        if (!bandwidth) {
-            av_log(NULL, AV_LOG_WARNING,
-                    "Bandwidth info not available, set audio and video bitrates\n");
-            av_freep(&m3u8_rel_name);
-            continue;
-        }
-
-        avio_printf(master_pb, "#EXT-X-STREAM-INF:BANDWIDTH=%d", bandwidth);
-        if (vid_st && vid_st->codecpar->width > 0 && vid_st->codecpar->height > 0)
-            avio_printf(master_pb, ",RESOLUTION=%dx%d", vid_st->codecpar->width,
-                    vid_st->codecpar->height);
-        avio_printf(master_pb, "\n%s\n\n", m3u8_rel_name);
+        ff_hls_write_stream_info(vid_st, master_pb, bandwidth, m3u8_rel_name);
 
         av_freep(&m3u8_rel_name);
     }
@@ -1213,12 +1271,8 @@ static int hls_window(AVFormatContext *s, int last, VariantStream *vs)
     }
 
     vs->discontinuity_set = 0;
-    write_m3u8_head_block(hls, out, hls->version, target_duration, sequence);
-    if (hls->pl_type == PLAYLIST_TYPE_EVENT) {
-        avio_printf(out, "#EXT-X-PLAYLIST-TYPE:EVENT\n");
-    } else if (hls->pl_type == PLAYLIST_TYPE_VOD) {
-        avio_printf(out, "#EXT-X-PLAYLIST-TYPE:VOD\n");
-    }
+    ff_hls_write_playlist_header(out, hls->version, hls->allowcache,
+                                 target_duration, sequence, hls->pl_type);
 
     if((hls->flags & HLS_DISCONT_START) && sequence==hls->start_sequence && vs->discontinuity_set==0 ){
         avio_printf(out, "#EXT-X-DISCONTINUITY\n");
@@ -1238,74 +1292,34 @@ static int hls_window(AVFormatContext *s, int last, VariantStream *vs)
             iv_string = en->iv_string;
         }
 
-        if (en->discont) {
-            avio_printf(out, "#EXT-X-DISCONTINUITY\n");
-        }
-
         if ((hls->segment_type == SEGMENT_TYPE_FMP4) && (en == vs->segments)) {
-            avio_printf(out, "#EXT-X-MAP:URI=\"%s\"", vs->fmp4_init_filename);
-            if (hls->flags & HLS_SINGLE_FILE) {
-                avio_printf(out, ",BYTERANGE=\"%"PRId64"@%"PRId64"\"", en->size, en->pos);
-            }
-            avio_printf(out, "\n");
+            ff_hls_write_init_file(out, vs->fmp4_init_filename,
+                                   hls->flags & HLS_SINGLE_FILE, en->size, en->pos);
         }
-        if (hls->flags & HLS_ROUND_DURATIONS)
-            avio_printf(out, "#EXTINF:%ld,\n",  lrint(en->duration));
-        else
-            avio_printf(out, "#EXTINF:%f,\n", en->duration);
-        if (byterange_mode)
-            avio_printf(out, "#EXT-X-BYTERANGE:%"PRId64"@%"PRId64"\n",
-                        en->size, en->pos);
-
-        if (hls->flags & HLS_PROGRAM_DATE_TIME) {
-            time_t tt, wrongsecs;
-            int milli;
-            struct tm *tm, tmpbuf;
-            char buf0[128], buf1[128];
-            tt = (int64_t)prog_date_time;
-            milli = av_clip(lrint(1000*(prog_date_time - tt)), 0, 999);
-            tm = localtime_r(&tt, &tmpbuf);
-            strftime(buf0, sizeof(buf0), "%Y-%m-%dT%H:%M:%S", tm);
-            if (!strftime(buf1, sizeof(buf1), "%z", tm) || buf1[1]<'0' ||buf1[1]>'2') {
-                int tz_min, dst = tm->tm_isdst;
-                tm = gmtime_r(&tt, &tmpbuf);
-                tm->tm_isdst = dst;
-                wrongsecs = mktime(tm);
-                tz_min = (FFABS(wrongsecs - tt) + 30) / 60;
-                snprintf(buf1, sizeof(buf1),
-                         "%c%02d%02d",
-                         wrongsecs <= tt ? '+' : '-',
-                         tz_min / 60,
-                         tz_min % 60);
-            }
-            avio_printf(out, "#EXT-X-PROGRAM-DATE-TIME:%s.%03d%s\n", buf0, milli, buf1);
-            prog_date_time += en->duration;
-        }
-        if (vs->baseurl)
-            avio_printf(out, "%s", vs->baseurl);
-        avio_printf(out, "%s\n", en->filename);
+
+        ff_hls_write_file_entry(out, en->discont, byterange_mode, hls->flags,
+                                en->duration, en->size, en->pos, vs->baseurl,
+                                en->filename, &prog_date_time);
+
     }
 
     if (last && (hls->flags & HLS_OMIT_ENDLIST)==0)
-        avio_printf(out, "#EXT-X-ENDLIST\n");
+        ff_hls_write_end_list(out);
 
     if( vs->vtt_m3u8_name ) {
         if ((ret = s->io_open(s, &sub_out, vs->vtt_m3u8_name, AVIO_FLAG_WRITE, &options)) < 0)
             goto fail;
-        write_m3u8_head_block(hls, sub_out, hls->version, target_duration, sequence);
+        ff_hls_write_playlist_header(sub_out, hls->version, hls->allowcache,
+                                     target_duration, sequence, PLAYLIST_TYPE_NONE);
 
         for (en = vs->segments; en; en = en->next) {
-            avio_printf(sub_out, "#EXTINF:%f,\n", en->duration);
-            if (byterange_mode)
-                 avio_printf(sub_out, "#EXT-X-BYTERANGE:%"PRIi64"@%"PRIi64"\n",
-                         en->size, en->pos);
-            if (vs->baseurl)
-                avio_printf(sub_out, "%s", vs->baseurl);
-            avio_printf(sub_out, "%s\n", en->sub_filename);
+            ff_hls_write_file_entry(sub_out, 0, byterange_mode,
+                                    hls->flags, en->duration, en->size, en->pos,
+                                    vs->baseurl, en->sub_filename, NULL);
         }
 
         if (last)
-            avio_printf(sub_out, "#EXT-X-ENDLIST\n");
+            ff_hls_write_end_list(sub_out);
 
     }
 
diff --git a/libavformat/hlsenc.h b/libavformat/hlsenc.h
new file mode 100644
index 0000000..03b0cf3
--- /dev/null
+++ b/libavformat/hlsenc.h
@@ -0,0 +1,68 @@
+/*
+ * Apple HTTP Live Streaming segmenter
+ * Copyright (c) 2012, Luca Barbato
+ * Copyright (c) 2017 Akamai Technologies, Inc.
+ *
+ * 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
+ */
+
+#ifndef AVFORMAT_HLSENC_H_
+#define AVFORMAT_HLSENC_H_
+
+#include "libavutil/common.h"
+
+typedef enum HLSFlags {
+    // Generate a single media file and use byte ranges in the playlist.
+    HLS_SINGLE_FILE = (1 << 0),
+    HLS_DELETE_SEGMENTS = (1 << 1),
+    HLS_ROUND_DURATIONS = (1 << 2),
+    HLS_DISCONT_START = (1 << 3),
+    HLS_OMIT_ENDLIST = (1 << 4),
+    HLS_SPLIT_BY_TIME = (1 << 5),
+    HLS_APPEND_LIST = (1 << 6),
+    HLS_PROGRAM_DATE_TIME = (1 << 7),
+    HLS_SECOND_LEVEL_SEGMENT_INDEX = (1 << 8), // include segment index in segment filenames when use_localtime  e.g.: %%03d
+    HLS_SECOND_LEVEL_SEGMENT_DURATION = (1 << 9), // include segment duration (microsec) in segment filenames when use_localtime  e.g.: %%09t
+    HLS_SECOND_LEVEL_SEGMENT_SIZE = (1 << 10), // include segment size (bytes) in segment filenames when use_localtime  e.g.: %%014s
+    HLS_TEMP_FILE = (1 << 11),
+    HLS_PERIODIC_REKEY = (1 << 12),
+    HLS_INDEPENDENT_SEGMENTS = (1 << 13),
+} HLSFlags;
+
+typedef enum {
+    PLAYLIST_TYPE_NONE,
+    PLAYLIST_TYPE_EVENT,
+    PLAYLIST_TYPE_VOD,
+    PLAYLIST_TYPE_NB,
+} PlaylistType;
+
+void ff_hls_write_playlist_version(AVIOContext *out, int version);
+void ff_hls_write_stream_info(AVStream *st, AVIOContext *out,
+                              int bandwidth, char *filename);
+void ff_hls_write_playlist_header(AVIOContext *out, int version, int allowcache,
+                                  int target_duration, int64_t sequence,
+                                  uint32_t playlist_type);
+void ff_hls_write_init_file(AVIOContext *out, char *filename,
+                            int byterange_mode, int64_t size, int64_t pos);
+void ff_hls_write_file_entry(AVIOContext *out, int insert_discont,
+                            int byterange_mode, uint32_t flags, double duration,
+                            int64_t size, int64_t pos, //Used only if HLS_SINGLE_FILE flag is set
+                            char *baseurl, //Ignored if NULL
+                            char *filename, double *prog_date_time);
+void ff_hls_write_end_list (AVIOContext *out);
+
+#endif /* AVFORMAT_HLSENC_H_ */
