@@ -741,6 +741,10 @@ Reset timestamps at the begin of each segment, so that each segment

 will start with near-zero timestamps. It is meant to ease the playback

 of the generated segments. May not work with some combinations of

 muxers/codecs. It is set to @code{0} by default.

+

+@item initial_offset @var{offset}

+Specify timestamp offset to apply to the output packet timestamps. The

+argument must be a time duration specification, and defaults to 0.

 @end table

 @subsection Examples

@@ -43,6 +43,7 @@ typedef struct SegmentListEntry {

     int index;

     double start_time, end_time;

     int64_t start_pts;

+    int64_t offset_pts;

     char filename[1024];

     struct SegmentListEntry *next;

 } SegmentListEntry;

@@ -91,6 +92,7 @@ typedef struct {

     int  write_header_trailer; /**< Set by a private option. */

     int reset_timestamps;  ///< reset timestamps at the begin of each segment

+    int64_t initial_offset;    ///< initial timestamps offset, expressed in microseconds

     char *reference_stream_specifier; ///< reference stream specifier

     int   reference_stream_index;

@@ -644,7 +646,7 @@ static int seg_write_packet(AVFormatContext *s, AVPacket *pkt)

     SegmentContext *seg = s->priv_data;

     AVFormatContext *oc = seg->avf;

     AVStream *st = s->streams[pkt->stream_index];

-    int64_t end_pts = INT64_MAX;

+    int64_t end_pts = INT64_MAX, offset;

     int start_frame = INT_MAX;

     int ret;

@@ -694,7 +696,7 @@ static int seg_write_packet(AVFormatContext *s, AVPacket *pkt)

         seg->is_first_pkt = 0;

     }

-    if (seg->reset_timestamps) {

+    /* todo: reindent */

         av_log(s, AV_LOG_DEBUG, "stream:%d start_pts_time:%s pts:%s pts_time:%s dts:%s dts_time:%s",

                pkt->stream_index,

                av_ts2timestr(seg->cur_entry.start_pts, &AV_TIME_BASE_Q),

@@ -702,15 +704,16 @@ static int seg_write_packet(AVFormatContext *s, AVPacket *pkt)

                av_ts2str(pkt->dts), av_ts2timestr(pkt->dts, &st->time_base));

         /* compute new timestamps */

+        offset = av_rescale_q(seg->initial_offset - (seg->reset_timestamps ? seg->cur_entry.start_pts : 0),

+                              AV_TIME_BASE_Q, st->time_base);

         if (pkt->pts != AV_NOPTS_VALUE)

-            pkt->pts -= av_rescale_q(seg->cur_entry.start_pts, AV_TIME_BASE_Q, st->time_base);

+            pkt->pts += offset;

         if (pkt->dts != AV_NOPTS_VALUE)

-            pkt->dts -= av_rescale_q(seg->cur_entry.start_pts, AV_TIME_BASE_Q, st->time_base);

+            pkt->dts += offset;

         av_log(s, AV_LOG_DEBUG, " -> pts:%s pts_time:%s dts:%s dts_time:%s\n",

                av_ts2str(pkt->pts), av_ts2timestr(pkt->pts, &st->time_base),

                av_ts2str(pkt->dts), av_ts2timestr(pkt->dts, &st->time_base));

-    }

     ret = ff_write_chained(oc, pkt->stream_index, pkt, s);

@@ -793,6 +796,7 @@ static const AVOption options[] = {

     { "individual_header_trailer", "write header/trailer to each segment", OFFSET(individual_header_trailer), AV_OPT_TYPE_INT, {.i64 = 1}, 0, 1, E },

     { "write_header_trailer", "write a header to the first segment and a trailer to the last one", OFFSET(write_header_trailer), AV_OPT_TYPE_INT, {.i64 = 1}, 0, 1, E },

     { "reset_timestamps", "reset timestamps at the begin of each segment", OFFSET(reset_timestamps), AV_OPT_TYPE_INT, {.i64 = 0}, 0, 1, E },

+    { "initial_offset", "set initial timestamp offset", OFFSET(initial_offset), AV_OPT_TYPE_DURATION, {.i64 = 0}, -INT64_MAX, INT64_MAX, E },

     { NULL },

 };

@@ -31,7 +31,7 @@

 #define LIBAVFORMAT_VERSION_MAJOR 55

 #define LIBAVFORMAT_VERSION_MINOR 12

-#define LIBAVFORMAT_VERSION_MICRO 100

+#define LIBAVFORMAT_VERSION_MICRO 101

 #define LIBAVFORMAT_VERSION_INT AV_VERSION_INT(LIBAVFORMAT_VERSION_MAJOR, \

                                                LIBAVFORMAT_VERSION_MINOR, \