p-to-p: fix seek to start pts source initial PTS != 0

When a file demuxed by libav does not start to time 0, our seek
to the initial start pts tried to seek too far forward.

git-svn-id: svn://svn.handbrake.fr/HandBrake/trunk@7124 b64f7644-9d1e-0410-96f1-a4d463321fa5

2 files changed, 6 insertions, 20 deletions

diff --git a/libhb/reader.c b/libhb/reader.c
index d5b37c38b..3e1c0c48b 100644
--- a/libhb/reader.c
+++ b/libhb/reader.c
@@ -455,19 +455,7 @@ void ReadLoop( void * _w )
     } 
     else if ( r->stream && r->job->pts_to_start )
     {
-        int64_t pts_to_start = r->job->pts_to_start;
-        
-        // Find out what the first timestamp of the stream is
-        // and then seek to the appropriate offset from it
-        if ( ( buf = hb_stream_read( r->stream ) ) )
-        {
-            if (buf->s.start != AV_NOPTS_VALUE)
-            {
-                pts_to_start += buf->s.start;
-            }
-        }
-        
-        if ( hb_stream_seek_ts( r->stream, pts_to_start ) >= 0 )
+        if ( hb_stream_seek_ts( r->stream, r->job->pts_to_start ) >= 0 )
         {
             // Seek takes us to the nearest I-frame before the timestamp
             // that we want.  So we will retrieve the start time of the
@@ -475,12 +463,9 @@ void ReadLoop( void * _w )
             // inspect the reset of the frames in sync.
             r->start_found = 2;
             r->duration -= r->job->pts_to_start;
-            r->job->pts_to_start = pts_to_start;
-            hb_buffer_close(&buf);
         }
         // hb_stream_seek_ts does nothing for TS streams and will return
-        // an error.  In this case, the current buf remains valid and
-        // gets processed below.
+        // an error.
     } 
     else if( r->stream )
     {
diff --git a/libhb/stream.c b/libhb/stream.c
index b1e15cea9..5713f6dee 100644
--- a/libhb/stream.c
+++ b/libhb/stream.c
@@ -5746,10 +5746,11 @@ hb_buffer_t * hb_ffmpeg_read( hb_stream_t *stream )
     // compute a conversion factor to go from the ffmpeg
     // timebase for the stream to HB's 90kHz timebase.
     AVStream *s = stream->ffmpeg_ic->streams[stream->ffmpeg_pkt->stream_index];
-    double tsconv = 90000. * (double)s->time_base.num / (double)s->time_base.den;
+    double tsconv = (double)90000. * s->time_base.num / s->time_base.den;
+    int64_t offset = 90000L * ffmpeg_initial_timestamp(stream) / AV_TIME_BASE;
 
-    buf->s.start = av_to_hb_pts( stream->ffmpeg_pkt->pts, tsconv );
-    buf->s.renderOffset = av_to_hb_pts( stream->ffmpeg_pkt->dts, tsconv );
+    buf->s.start = av_to_hb_pts(stream->ffmpeg_pkt->pts, tsconv) - offset;
+    buf->s.renderOffset = av_to_hb_pts(stream->ffmpeg_pkt->dts, tsconv) - offset;
     if ( buf->s.renderOffset >= 0 && buf->s.start == AV_NOPTS_VALUE )
     {
         buf->s.start = buf->s.renderOffset;