From c874d974baefc35d6300938997131efd1a4da48b Mon Sep 17 00:00:00 2001
From: Cory Fields <theuni-nospam-@xbmc.org>
Date: Fri, 9 Jul 2010 16:43:31 -0400
Subject: [PATCH 08/17] Read PID timestamps as well as PCR timestamps to find
 location in mpegts stream

---
 libavformat/mpegts.c | 48 ++++++++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 46 insertions(+), 2 deletions(-)

diff --git a/libavformat/mpegts.c b/libavformat/mpegts.c
index c946449..772df83 100644
--- a/libavformat/mpegts.c
+++ b/libavformat/mpegts.c
@@ -2388,6 +2388,44 @@ static void seek_back(AVFormatContext *s, AVIOContext *pb, int64_t pos) {
         av_log(s, pb->seekable ? AV_LOG_ERROR : AV_LOG_INFO, "Unable to seek back to the start\n");
 }
 
+static int parse_timestamp(int64_t *ts, const uint8_t *buf)
+{
+    int afc, flags;
+    const uint8_t *p;
+
+    if(!(buf[1] & 0x40)) /* must be a start packet */
+        return -1;
+
+    afc = (buf[3] >> 4) & 3;
+    p = buf + 4;
+    if (afc == 0 || afc == 2) /* invalid or only adaption field */
+        return -1;
+    if (afc == 3)
+        p += p[0] + 1;
+    if (p >= buf + TS_PACKET_SIZE)
+        return -1;
+
+    if (p[0] != 0x00 || p[1] != 0x00 || p[2] != 0x01)  /* packet_start_code_prefix */
+        return -1;
+
+    flags = p[3] | 0x100; /* stream type */
+    if (!((flags >= 0x1c0 && flags <= 0x1df) ||
+          (flags >= 0x1e0 && flags <= 0x1ef) ||
+          (flags == 0x1bd) || (flags == 0x1fd)))
+        return -1;
+
+    flags = p[7];
+    if ((flags & 0xc0) == 0x80) {
+        *ts = ff_parse_pes_pts(p+9);
+        return 0;
+    } else if ((flags & 0xc0) == 0xc0) {
+        *ts = ff_parse_pes_pts(p+9+5);
+        return 0;
+    }
+    return -1;
+}
+
+
 static int mpegts_read_header(AVFormatContext *s)
 {
     MpegTSContext *ts = s->priv_data;
@@ -2587,6 +2625,7 @@ static av_unused int64_t mpegts_get_pcr(AVFormatContext *s, int stream_index,
     uint8_t buf[TS_PACKET_SIZE];
     int pcr_l, pcr_pid =
         ((PESContext *)s->streams[stream_index]->priv_data)->pcr_pid;
+    int pid = ((PESContext*)s->streams[stream_index]->priv_data)->pid;
     int pos47 = ts->pos47_full % ts->raw_packet_size;
     pos =
         ((*ppos + ts->raw_packet_size - 1 - pos47) / ts->raw_packet_size) *
@@ -2608,6 +2647,11 @@ static av_unused int64_t mpegts_get_pcr(AVFormatContext *s, int stream_index,
             *ppos = pos;
             return timestamp;
         }
+        if ((pid < 0 || (AV_RB16(buf + 1) & 0x1fff) == pid) &&
+            parse_timestamp(&timestamp, buf) == 0) {
+            *ppos = pos;
+            return timestamp;
+        }
         pos += ts->raw_packet_size;
     }
 
@@ -2707,7 +2751,7 @@ AVInputFormat ff_mpegts_demuxer = {
     .read_header    = mpegts_read_header,
     .read_packet    = mpegts_read_packet,
     .read_close     = mpegts_read_close,
-    .read_timestamp = mpegts_get_dts,
+    .read_timestamp = mpegts_get_pcr,
     .flags          = AVFMT_SHOW_IDS | AVFMT_TS_DISCONT,
     .priv_class     = &mpegts_class,
 };
@@ -2719,7 +2763,7 @@ AVInputFormat ff_mpegtsraw_demuxer = {
     .read_header    = mpegts_read_header,
     .read_packet    = mpegts_raw_read_packet,
     .read_close     = mpegts_read_close,
-    .read_timestamp = mpegts_get_dts,
+    .read_timestamp = mpegts_get_pcr,
     .flags          = AVFMT_SHOW_IDS | AVFMT_TS_DISCONT,
     .priv_class     = &mpegtsraw_class,
 };
-- 
1.9.3

