@@ -652,10 +652,11 @@ static int poll_filter(OutputStream *ost)

         return ret;

     if (filtered_frame->pts != AV_NOPTS_VALUE) {

+        int64_t start_time = (of->start_time == AV_NOPTS_VALUE) ? 0 : of->start_time;

         filtered_frame->pts = av_rescale_q(filtered_frame->pts,

                                            ost->filter->filter->inputs[0]->time_base,

                                            ost->st->codec->time_base) -

-                              av_rescale_q(of->start_time,

+                              av_rescale_q(start_time,

                                            AV_TIME_BASE_Q,

                                            ost->st->codec->time_base);

     }

@@ -948,7 +949,7 @@ static int check_output_constraints(InputStream *ist, OutputStream *ost)

     if (ost->source_index != ist_index)

         return 0;

-    if (of->start_time && ist->last_dts < of->start_time)

+    if (of->start_time != AV_NOPTS_VALUE && ist->last_dts < of->start_time)

         return 0;

     return 1;

@@ -957,7 +958,8 @@ static int check_output_constraints(InputStream *ist, OutputStream *ost)

 static void do_streamcopy(InputStream *ist, OutputStream *ost, const AVPacket *pkt)

 {

     OutputFile *of = output_files[ost->file_index];

-    int64_t ost_tb_start_time = av_rescale_q(of->start_time, AV_TIME_BASE_Q, ost->st->time_base);

+    int64_t start_time = (of->start_time == AV_NOPTS_VALUE) ? 0 : of->start_time;

+    int64_t ost_tb_start_time = av_rescale_q(start_time, AV_TIME_BASE_Q, ost->st->time_base);

     AVPacket opkt;

     av_init_packet(&opkt);

@@ -967,7 +969,7 @@ static void do_streamcopy(InputStream *ist, OutputStream *ost, const AVPacket *p

         return;

     if (of->recording_time != INT64_MAX &&

-        ist->last_dts >= of->recording_time + of->start_time) {

+        ist->last_dts >= of->recording_time + start_time) {

         ost->finished = 1;

         return;

     }

@@ -183,7 +183,7 @@ static int insert_trim(OutputStream *ost, AVFilterContext **last_filter, int *pa

     char filter_name[128];

     int ret = 0;

-    if (of->recording_time == INT64_MAX && !of->start_time)

+    if (of->recording_time == INT64_MAX && of->start_time == AV_NOPTS_VALUE)

         return 0;

     trim = avfilter_get_by_name(name);

@@ -203,7 +203,7 @@ static int insert_trim(OutputStream *ost, AVFilterContext **last_filter, int *pa

         ret = av_opt_set_double(ctx, "duration", (double)of->recording_time / 1e6,

                                 AV_OPT_SEARCH_CHILDREN);

     }

-    if (ret >= 0 && of->start_time) {

+    if (ret >= 0 && of->start_time != AV_NOPTS_VALUE) {

         ret = av_opt_set_double(ctx, "start", (double)of->start_time / 1e6,

                                 AV_OPT_SEARCH_CHILDREN);

     }

@@ -113,6 +113,7 @@ static void init_options(OptionsContext *o)

     memset(o, 0, sizeof(*o));

     o->mux_max_delay  = 0.7;

+    o->start_time     = AV_NOPTS_VALUE;

     o->recording_time = INT64_MAX;

     o->limit_filesize = UINT64_MAX;

     o->chapters_input_file = INT_MAX;

@@ -658,13 +659,13 @@ static int open_input_file(OptionsContext *o, const char *filename)

         exit_program(1);

     }

-    timestamp = o->start_time;

+    timestamp = (o->start_time == AV_NOPTS_VALUE) ? 0 : o->start_time;

     /* add the stream start time */

     if (ic->start_time != AV_NOPTS_VALUE)

         timestamp += ic->start_time;

     /* if seeking requested, we execute it */

-    if (o->start_time != 0) {

+    if (o->start_time != AV_NOPTS_VALUE) {

         ret = av_seek_frame(ic, -1, timestamp, AVSEEK_FLAG_BACKWARD);

         if (ret < 0) {

             av_log(NULL, AV_LOG_WARNING, "%s: could not seek to position %0.3f\n",

@@ -1212,7 +1213,8 @@ static int copy_chapters(InputFile *ifile, OutputFile *ofile, int copy_metadata)

     for (i = 0; i < is->nb_chapters; i++) {

         AVChapter *in_ch = is->chapters[i], *out_ch;

-        int64_t ts_off   = av_rescale_q(ofile->start_time - ifile->ts_offset,

+        int64_t start_time = (ofile->start_time == AV_NOPTS_VALUE) ? 0 : ofile->start_time;

+        int64_t ts_off   = av_rescale_q(start_time - ifile->ts_offset,

                                        AV_TIME_BASE_Q, in_ch->time_base);

         int64_t rt       = (ofile->recording_time == INT64_MAX) ? INT64_MAX :

                            av_rescale_q(ofile->recording_time, AV_TIME_BASE_Q, in_ch->time_base);