--- a/libavformat/mpegtsenc.c	2016-09-30 19:12:42.000000000 -0600
+++ b/libavformat/mpegtsenc.c	2017-01-25 17:25:58.720017593 -0700
@@ -55,7 +55,7 @@
     int sid;           /* service ID */
     char *name;
     char *provider_name;
-    int pcr_pid;
+    int pcr_sid, pcr_pid;
     int pcr_packet_count;
     int pcr_packet_period;
     AVProgram *program;
@@ -94,8 +94,10 @@
     int service_type;
 
     int pmt_start_pid;
+    int pcr_start_pid;
     int start_pid;
     int m2ts_mode;
+    int64_t pcr_offset;
 
     int reemit_pat_pmt; // backward compatibility
 
@@ -704,6 +706,7 @@
     service->pmt.pid       = ts->pmt_start_pid + ts->nb_services;
     service->sid           = sid;
     service->pcr_pid       = 0x1fff;
+    service->pcr_sid       = 0x1fff;
     service->provider_name = av_strdup(provider_name);
     service->name          = av_strdup(name);
     if (!service->provider_name || !service->name)
@@ -722,7 +725,7 @@
 static int64_t get_pcr(const MpegTSWrite *ts, AVIOContext *pb)
 {
     return av_rescale(avio_tell(pb) + 11, 8 * PCR_TIME_BASE, ts->mux_rate) +
-           ts->first_pcr;
+           ts->first_pcr + ts->pcr_offset;
 }
 
 static void mpegts_prefix_m2ts_header(AVFormatContext *s)
@@ -760,6 +763,14 @@
     if (s->max_delay < 0) /* Not set by the caller */
         s->max_delay = 0;
 
+    if (ts->m2ts_mode == -1) {
+        if (av_match_ext(s->filename, "m2ts")) {
+            ts->m2ts_mode = 1;
+        } else {
+            ts->m2ts_mode = 0;
+        }
+    }
+
     // round up to a whole number of TS packets
     ts->pes_payload_size = (ts->pes_payload_size + 14 + 183) / 184 * 184 - 14;
 
@@ -803,6 +814,8 @@
             service->program          = program;
         }
     }
+    if (ts->m2ts_mode > 1)
+        service->pmt.pid = 0x00ff + ts->service_id;
 
     ts->pat.pid          = PAT_PID;
     /* Initialize at 15 so that it wraps and is equal to 0 for the
@@ -885,10 +898,9 @@
         ts_st->cc              = 15;
         /* update PCR pid by using the first video stream */
         if (st->codecpar->codec_type == AVMEDIA_TYPE_VIDEO &&
-            service->pcr_pid == 0x1fff) {
-            service->pcr_pid = ts_st->pid;
+            service->pcr_sid == 0x1fff)
             pcr_st           = st;
-        }
+
         if (st->codecpar->codec_id == AV_CODEC_ID_AAC &&
             st->codecpar->extradata_size > 0) {
             AVStream *ast;
@@ -924,12 +936,24 @@
     av_freep(&pids);
 
     /* if no video stream, use the first stream as PCR */
-    if (service->pcr_pid == 0x1fff && s->nb_streams > 0) {
-        pcr_st           = s->streams[0];
-        ts_st            = pcr_st->priv_data;
-        service->pcr_pid = ts_st->pid;
-    } else
-        ts_st = pcr_st->priv_data;
+    if (!pcr_st && s->nb_streams > 0)
+        pcr_st = s->streams[0];
+    if (!pcr_st) {
+        av_log(s, AV_LOG_ERROR, "no streams\n");
+        ret = AVERROR(EINVAL);
+        goto fail;
+    }
+    ts_st  = pcr_st->priv_data;
+    if (service->pcr_sid == 0x1fff)
+        service->pcr_sid   = ts_st->pid;
+    if (service->pcr_pid == 0x1fff)
+        service->pcr_pid   = ts->m2ts_mode > 1 ?
+            0x1000 + ts->service_id : service->pcr_sid ;
+    if (service->pmt.pid == service->pcr_pid) {
+        av_log(s, AV_LOG_ERROR, "Duplicate stream id %d\n", service->pcr_pid);
+        ret = AVERROR(EINVAL);
+        goto fail;
+    }
 
     if (ts->mux_rate > 1) {
         service->pcr_packet_period = (int64_t)ts->mux_rate * ts->pcr_period /
@@ -989,14 +1013,6 @@
            service->pcr_packet_period,
            ts->sdt_packet_period, ts->pat_packet_period);
 
-    if (ts->m2ts_mode == -1) {
-        if (av_match_ext(s->filename, "m2ts")) {
-            ts->m2ts_mode = 1;
-        } else {
-            ts->m2ts_mode = 0;
-        }
-    }
-
     return 0;
 
 fail:
@@ -1010,9 +1026,9 @@
     MpegTSWrite *ts = s->priv_data;
     int i;
 
-    if (++ts->sdt_packet_count == ts->sdt_packet_period ||
+    if ( ts->sdt_period >= 0 && (++ts->sdt_packet_count == ts->sdt_packet_period ||
         (dts != AV_NOPTS_VALUE && ts->last_sdt_ts == AV_NOPTS_VALUE) ||
-        (dts != AV_NOPTS_VALUE && dts - ts->last_sdt_ts >= ts->sdt_period*90000.0)
+        (dts != AV_NOPTS_VALUE && dts - ts->last_sdt_ts >= ts->sdt_period*90000.0))
     ) {
         ts->sdt_packet_count = 0;
         if (dts != AV_NOPTS_VALUE)
@@ -1067,13 +1083,14 @@
 {
     MpegTSWrite *ts = s->priv_data;
     MpegTSWriteStream *ts_st = st->priv_data;
+    uint32_t pcr_pid = ts_st->service->pcr_pid;
     uint8_t *q;
     uint8_t buf[TS_PACKET_SIZE];
 
     q    = buf;
     *q++ = 0x47;
-    *q++ = ts_st->pid >> 8;
-    *q++ = ts_st->pid;
+    *q++ = pcr_pid >> 8;
+    *q++ = pcr_pid;
     *q++ = 0x20 | ts_st->cc;   /* Adaptation only */
     /* Continuity Count field does not increment (see 13818-1 section 2.4.3.3) */
     *q++ = TS_PACKET_SIZE - 5; /* Adaptation Field Length */
@@ -1148,7 +1165,7 @@
     uint8_t buf[TS_PACKET_SIZE];
     uint8_t *q;
     int val, is_start, len, header_len, write_pcr, is_dvb_subtitle, is_dvb_teletext, flags;
-    int afc_len, stuffing_len;
+    int afc_len, stuffing_len, write_null;
     int64_t pcr = -1; /* avoid warning */
     int64_t delay = av_rescale(s->max_delay, 90000, AV_TIME_BASE);
     int force_pat = st->codecpar->codec_type == AVMEDIA_TYPE_VIDEO && key && !ts_st->prev_payload_key;
@@ -1163,8 +1180,8 @@
         retransmit_si_info(s, force_pat, dts);
         force_pat = 0;
 
-        write_pcr = 0;
-        if (ts_st->pid == ts_st->service->pcr_pid) {
+        write_pcr = write_null = 0;
+        if (ts_st->pid == ts_st->service->pcr_sid) {
             if (ts->mux_rate > 1 || is_start) // VBR pcr period is based on frames
                 ts_st->service->pcr_packet_count++;
             if (ts_st->service->pcr_packet_count >=
@@ -1173,15 +1190,17 @@
                 write_pcr = 1;
             }
         }
-
         if (ts->mux_rate > 1 && dts != AV_NOPTS_VALUE &&
-            (dts - get_pcr(ts, s->pb) / 300) > delay) {
-            /* pcr insert gets priority over null packet insert */
-            if (write_pcr)
-                mpegts_insert_pcr_only(s, st);
-            else
-                mpegts_insert_null_packet(s);
-            /* recalculate write_pcr and possibly retransmit si_info */
+               (dts - get_pcr(ts, s->pb) / 300) > delay) {
+            write_null = 1;
+        }
+        /* pcr insert gets priority over null packet insert */
+        if (write_pcr && ts_st->service->pcr_sid != ts_st->service->pcr_pid) {
+            mpegts_insert_pcr_only(s, st);
+            continue;
+        }
+        if (write_null) {
+            mpegts_insert_null_packet(s);
             continue;
         }
 
@@ -1191,13 +1210,17 @@
         val  = ts_st->pid >> 8;
         if (is_start)
             val |= 0x40;
+        if (st->codecpar->codec_type == AVMEDIA_TYPE_AUDIO &&
+          st->codecpar->codec_id == AV_CODEC_ID_AC3 &&
+          ts->m2ts_mode > 1)
+            val |= 0x20;
         *q++      = val;
         *q++      = ts_st->pid;
         ts_st->cc = ts_st->cc + 1 & 0xf;
         *q++      = 0x10 | ts_st->cc; // payload indicator + CC
         if (key && is_start && pts != AV_NOPTS_VALUE) {
             // set Random Access for key frames
-            if (ts_st->pid == ts_st->service->pcr_pid)
+            if (ts_st->pid == ts_st->service->pcr_sid)
                 write_pcr = 1;
             set_af_flag(buf, 0x40);
             q = get_ts_payload_start(buf);
@@ -1310,11 +1333,13 @@
             *q++ = flags;
             *q++ = header_len;
             if (pts != AV_NOPTS_VALUE) {
-                write_pts(q, flags >> 6, pts);
+                int64_t ts_pts = pts + ts->pcr_offset;
+                write_pts(q, flags >> 6, ts_pts);
                 q += 5;
             }
             if (dts != AV_NOPTS_VALUE && pts != AV_NOPTS_VALUE && dts != pts) {
-                write_pts(q, 1, dts);
+                int64_t ts_dts = dts + ts->pcr_offset;
+                write_pts(q, 1, ts_dts);
                 q += 5;
             }
             if (pes_extension && st->codecpar->codec_id == AV_CODEC_ID_DIRAC) {
@@ -1838,12 +1863,18 @@
     { "mpegts_pmt_start_pid", "Set the first pid of the PMT.",
       offsetof(MpegTSWrite, pmt_start_pid), AV_OPT_TYPE_INT,
       { .i64 = 0x1000 }, 0x0010, 0x1f00, AV_OPT_FLAG_ENCODING_PARAM },
+    { "mpegts_pcr_start_pid", "Set the first pid of the PCR.",
+      offsetof(MpegTSWrite, pcr_start_pid), AV_OPT_TYPE_INT,
+      { .i64 = 0x1000 }, 0x0010, 0x1f00, AV_OPT_FLAG_ENCODING_PARAM },
     { "mpegts_start_pid", "Set the first pid.",
       offsetof(MpegTSWrite, start_pid), AV_OPT_TYPE_INT,
       { .i64 = 0x0100 }, 0x0020, 0x0f00, AV_OPT_FLAG_ENCODING_PARAM },
     { "mpegts_m2ts_mode", "Enable m2ts mode.",
       offsetof(MpegTSWrite, m2ts_mode), AV_OPT_TYPE_BOOL,
-      { .i64 = -1 }, -1, 1, AV_OPT_FLAG_ENCODING_PARAM },
+      { .i64 = -1 }, -1, 2, AV_OPT_FLAG_ENCODING_PARAM },
+    { "mpegts_pcr_offset", "clock offset.",
+      offsetof(MpegTSWrite, pcr_offset), AV_OPT_TYPE_BOOL,
+      { .i64 = 0 }, INT_MIN, INT_MAX, AV_OPT_FLAG_ENCODING_PARAM },
     { "muxrate", NULL,
       offsetof(MpegTSWrite, mux_rate), AV_OPT_TYPE_INT,
       { .i64 = 1 }, 0, INT_MAX, AV_OPT_FLAG_ENCODING_PARAM },
@@ -1886,7 +1917,7 @@
       { .dbl = INT_MAX }, 0, INT_MAX, AV_OPT_FLAG_ENCODING_PARAM },
     { "sdt_period", "SDT retransmission time limit in seconds",
       offsetof(MpegTSWrite, sdt_period), AV_OPT_TYPE_DOUBLE,
-      { .dbl = INT_MAX }, 0, INT_MAX, AV_OPT_FLAG_ENCODING_PARAM },
+      { .dbl = INT_MAX }, -1, INT_MAX, AV_OPT_FLAG_ENCODING_PARAM },
     { NULL },
 };