diff --git a/ffmpeg.c b/ffmpeg.c
index 7621e9d9971dc1bf0f3ec89020caebcdeac77bd1..3eb15a64944cb1ad99274d44089faecf221bad6a 100644
--- a/ffmpeg.c
+++ b/ffmpeg.c
@@ -1340,6 +1340,10 @@ static void do_streamcopy(InputStream *ist, OutputStream *ost, const AVPacket *p
         !ost->copy_initial_nonkeyframes)
         return;
 
+    if (!ost->frame_number && ist->pts < of->start_time &&
+        !ost->copy_prior_start)
+        return;
+
     if (of->recording_time != INT64_MAX &&
         ist->pts >= of->recording_time + of->start_time) {
         close_output_stream(ost);
diff --git a/ffmpeg.h b/ffmpeg.h
index 85a11a01d9fa4198c69befb00c96ab76419f1faf..56f8dfc5f18ff534f04e937ba3d3e349d7a46b82 100644
--- a/ffmpeg.h
+++ b/ffmpeg.h
@@ -157,6 +157,8 @@ typedef struct OptionsContext {
     int        nb_presets;
     SpecifierOpt *copy_initial_nonkeyframes;
     int        nb_copy_initial_nonkeyframes;
+    SpecifierOpt *copy_prior_start;
+    int        nb_copy_prior_start;
     SpecifierOpt *filters;
     int        nb_filters;
     SpecifierOpt *fix_sub_duration;
@@ -326,6 +328,7 @@ typedef struct OutputStream {
     int stream_copy;
     const char *attachment_filename;
     int copy_initial_nonkeyframes;
+    int copy_prior_start;
 
     int keep_pix_fmt;
 } OutputStream;
diff --git a/ffmpeg_opt.c b/ffmpeg_opt.c
index 3d73564aa20873fd25854d1ab8a8f9b08dc475f2..2c5fbfb6b2d77045a03b8b9fbb25ad33bc53a670 100644
--- a/ffmpeg_opt.c
+++ b/ffmpeg_opt.c
@@ -960,6 +960,9 @@ static OutputStream *new_output_stream(OptionsContext *o, AVFormatContext *oc, e
     ost->max_frames = INT64_MAX;
     MATCH_PER_STREAM_OPT(max_frames, i64, ost->max_frames, oc, st);
 
+    ost->copy_prior_start = -1;
+    MATCH_PER_STREAM_OPT(copy_prior_start, i, ost->copy_prior_start, oc ,st);
+
     MATCH_PER_STREAM_OPT(bitstream_filters, str, bsf, oc, st);
     while (bsf) {
         if (next = strchr(bsf, ','))
@@ -2316,6 +2319,8 @@ const OptionDef options[] = {
         "exit on error", "error" },
     { "copyinkf",       OPT_BOOL | OPT_EXPERT | OPT_SPEC,            { .off = OFFSET(copy_initial_nonkeyframes) },
         "copy initial non-keyframes" },
+    { "copypriorss",    OPT_INT | HAS_ARG | OPT_EXPERT | OPT_SPEC,   { .off = OFFSET(copy_prior_start) },
+        "copy or discard frames before start time" },
     { "frames",         OPT_INT64 | HAS_ARG | OPT_SPEC,              { .off = OFFSET(max_frames) },
         "set the number of frames to record", "number" },
     { "tag",            OPT_STRING | HAS_ARG | OPT_SPEC | OPT_EXPERT,{ .off = OFFSET(codec_tags) },