@@ -416,9 +416,34 @@ This option is useful to avoid to fill the disk with many segment

 files, and limits the maximum number of segment files written to disk

 to @var{wrap}.

+

+@item hls_start_number_source

+Start the playlist sequence number (@code{#EXT-X-MEDIA-SEQUENCE}) according to the specified source.

+Unless @code{hls_flags single_file} is set, it also specifies source of starting sequence numbers of

+segment and subtitle filenames. In any case, if @code{hls_flags append_list}

+is set and read playlist sequence number is greater than the specified start sequence number,

+then that value will be used as start value.

+

+It accepts the following values:

+

+@table @option

+

+@item generic (default)

+Set the starting sequence numbers according to @var{start_number} option value.

+

+@item epoch

+The start number will be the seconds since epoch (1970-01-01 00:00:00)

+

+@item datetime

+The start number will be based on the current date/time as YYYYmmddHHMMSS. e.g. 20161231235759.

+

+@end table

+

 @item start_number @var{number}

-Start the playlist sequence number from @var{number}. Default value is

-0.

+Start the playlist sequence number (@code{#EXT-X-MEDIA-SEQUENCE}) from the specified @var{number}

+when @var{hls_start_number_source} value is @var{generic}. (This is the default case.)

+Unless @code{hls_flags single_file} is set, it also specifies starting sequence numbers of segment and subtitle filenames.

+Default value is 0.

 @item hls_allow_cache @var{allowcache}

 Explicitly set whether the client MAY (1) or MUST NOT (0) cache media segments.

@@ -39,6 +39,12 @@

 #include "internal.h"

 #include "os_support.h"

+typedef enum {

+  HLS_START_SEQUENCE_AS_START_NUMBER = 0,

+  HLS_START_SEQUENCE_AS_SECONDS_SINCE_EPOCH = 1,

+  HLS_START_SEQUENCE_AS_FORMATTED_DATETIME = 2,  // YYYYMMDDhhmmss

+} StartSequenceSourceType;

+

 #define KEYSIZE 16

 #define LINE_BUFFER_SIZE 1024

@@ -83,6 +89,7 @@ typedef struct HLSContext {

     unsigned number;

     int64_t sequence;

     int64_t start_sequence;

+    uint32_t start_sequence_source_type;  // enum StartSequenceSourceType

     AVOutputFormat *oformat;

     AVOutputFormat *vtt_oformat;

@@ -594,7 +601,16 @@ static int parse_playlist(AVFormatContext *s, const char *url)

     while (!avio_feof(in)) {

         read_chomp_line(in, line, sizeof(line));

         if (av_strstart(line, "#EXT-X-MEDIA-SEQUENCE:", &ptr)) {

-            hls->sequence = atoi(ptr);

+            int64_t tmp_sequence = strtoll(ptr, NULL, 10);

+            if (tmp_sequence < hls->sequence)

+              av_log(hls, AV_LOG_VERBOSE,

+                     "Found playlist sequence number was smaller """

+                     "than specified start sequence number: %"PRId64" < %"PRId64", "

+                     "omitting\n", tmp_sequence, hls->start_sequence);

+            else {

+              av_log(hls, AV_LOG_DEBUG, "Found playlist sequence number: %"PRId64"\n", tmp_sequence);

+              hls->sequence = tmp_sequence;

+            }

         } else if (av_strstart(line, "#EXT-X-DISCONTINUITY", &ptr)) {

             is_segment = 1;

             hls->discontinuity = 1;

@@ -805,9 +821,8 @@ static int hls_start(AVFormatContext *s)

             av_strlcpy(vtt_oc->filename, c->vtt_basename,

                   sizeof(vtt_oc->filename));

     } else if (c->max_seg_size > 0) {

-        if (av_get_frame_filename2(oc->filename, sizeof(oc->filename),

-            c->basename, c->wrap ? c->sequence % c->wrap : c->sequence,

-            AV_FRAME_FILENAME_FLAGS_MULTIPLE) < 0) {

+        if (replace_int_data_in_filename(oc->filename, sizeof(oc->filename),

+            c->basename, 'd', c->wrap ? c->sequence % c->wrap : c->sequence) < 1) {

                 av_log(oc, AV_LOG_ERROR, "Invalid segment filename template '%s', you can try to use -use_localtime 1 with it\n", c->basename);

                 return AVERROR(EINVAL);

         }

@@ -882,16 +897,14 @@ static int hls_start(AVFormatContext *s)

                 }

                 av_free(fn_copy);

             }

-        } else if (av_get_frame_filename2(oc->filename, sizeof(oc->filename),

-                                  c->basename, c->wrap ? c->sequence % c->wrap : c->sequence,

-                                  AV_FRAME_FILENAME_FLAGS_MULTIPLE) < 0) {

+        } else if (replace_int_data_in_filename(oc->filename, sizeof(oc->filename),

+                   c->basename, 'd', c->wrap ? c->sequence % c->wrap : c->sequence) < 1) {

             av_log(oc, AV_LOG_ERROR, "Invalid segment filename template '%s' you can try to use -use_localtime 1 with it\n", c->basename);

             return AVERROR(EINVAL);

         }

         if( c->vtt_basename) {

-            if (av_get_frame_filename2(vtt_oc->filename, sizeof(vtt_oc->filename),

-                              c->vtt_basename, c->wrap ? c->sequence % c->wrap : c->sequence,

-                              AV_FRAME_FILENAME_FLAGS_MULTIPLE) < 0) {

+            if (replace_int_data_in_filename(vtt_oc->filename, sizeof(vtt_oc->filename),

+                c->vtt_basename, 'd', c->wrap ? c->sequence % c->wrap : c->sequence) < 1) {

                 av_log(vtt_oc, AV_LOG_ERROR, "Invalid segment filename template '%s'\n", c->vtt_basename);

                 return AVERROR(EINVAL);

             }

@@ -979,6 +992,22 @@ static int hls_write_header(AVFormatContext *s)

     int basename_size;

     int vtt_basename_size;

+    if (hls->start_sequence_source_type == HLS_START_SEQUNCE_AS_SECONDS_SINCE_EPOCH || hls->start_sequence_source_type == HLS_START_SEQUNCE_AS_FORMATTED_DATETIME) {

+        time_t t = time(NULL); // we will need it in either case

+        if (hls->start_sequence_source_type == HLS_START_SEQUNCE_AS_SECONDS_SINCE_EPOCH) {

+            hls->start_sequence = (int64_t)t;

+        } else if (hls->start_sequence_source_type == HLS_START_SEQUNCE_AS_FORMATTED_DATETIME) {

+            char b[15];

+            struct tm *p, tmbuf;

+            if (!(p = localtime_r(&t, &tmbuf)))

+                return AVERROR(ENOMEM);

+            if (!strftime(b, sizeof(b), "%Y%m%d%H%M%S", p))

+                return AVERROR(ENOMEM);

+            hls->start_sequence = strtoll(b, NULL, 10);

+        }

+        av_log(hls, AV_LOG_DEBUG, "start_number evaluated to %"PRId64"\n", hls->start_sequence);

+    }

+

     hls->sequence       = hls->start_sequence;

     hls->recording_time = (hls->init_time ? hls->init_time : hls->time) * AV_TIME_BASE;

     hls->start_pts      = AV_NOPTS_VALUE;

@@ -1366,7 +1395,10 @@ static const AVOption options[] = {

     {"event", "EVENT playlist", 0, AV_OPT_TYPE_CONST, {.i64 = PLAYLIST_TYPE_EVENT }, INT_MIN, INT_MAX, E, "pl_type" },

     {"vod", "VOD playlist", 0, AV_OPT_TYPE_CONST, {.i64 = PLAYLIST_TYPE_VOD }, INT_MIN, INT_MAX, E, "pl_type" },

     {"method", "set the HTTP method", OFFSET(method), AV_OPT_TYPE_STRING, {.str = NULL},  0, 0,    E},

-

+    {"hls_start_number_source", "set source of first number in sequence", OFFSET(start_sequence_source_type), AV_OPT_TYPE_INT, {.i64 = HLS_START_SEQUNCE_AS_START_NUMBER }, 0, HLS_START_SEQUNCE_AS_FORMATTED_DATETIME, E, "start_sequence_source_type" },

+    {"generic", "start_number value (default)", 0, AV_OPT_TYPE_CONST, {.i64 = HLS_START_SEQUNCE_AS_START_NUMBER }, INT_MIN, INT_MAX, E, "start_sequence_source_type" },

+    {"epoch", "seconds since epoch", 0, AV_OPT_TYPE_CONST, {.i64 = HLS_START_SEQUNCE_AS_SECONDS_SINCE_EPOCH }, INT_MIN, INT_MAX, E, "start_sequence_source_type" },

+    {"datetime", "current datetime as YYYYMMDDhhmmss", 0, AV_OPT_TYPE_CONST, {.i64 = HLS_START_SEQUNCE_AS_FORMATTED_DATETIME }, INT_MIN, INT_MAX, E, "start_sequence_source_type" },

     { NULL },

 };