From 48a2bbd6ad982d92bfe797b18dcf99320dc99b21 Mon Sep 17 00:00:00 2001
From: Thiago Sousa Santos <thiagoss@redmoon.(none)>
Date: Tue, 17 Nov 2009 17:25:14 -0300
Subject: [PATCH] asfmux: handle streams with different start times

Prevents losing sync when remuxing streams with different
start times. The smallest start time is selected as
the base time and all timestamps are subtracted
from it to get the actual time to be used when
muxing and building indexes

Fixes #586848
---
 gst/asfmux/gstasfmux.c | 24 +++++++++++++++++++++++-
 gst/asfmux/gstasfmux.h |  3 +++
 2 files changed, 26 insertions(+), 1 deletion(-)

diff --git a/gst/asfmux/gstasfmux.c b/gst/asfmux/gstasfmux.c
index 4d4fa2e5a8..3afc936c9d 100644
--- a/gst/asfmux/gstasfmux.c
+++ b/gst/asfmux/gstasfmux.c
@@ -216,6 +216,7 @@ gst_asf_mux_reset (GstAsfMux * asfmux)
   asfmux->total_data_packets = 0;
   asfmux->file_size = 0;
   asfmux->packet_size = 0;
+  asfmux->first_ts = GST_CLOCK_TIME_NONE;
 
   if (asfmux->payloads) {
     GSList *walk;
@@ -1763,8 +1764,12 @@ gst_asf_mux_process_buffer (GstAsfMux * asfmux, GstAsfPad * pad,
     gst_asf_payload_free (payload);
     return GST_FLOW_ERROR;
   }
+
+  g_assert (GST_CLOCK_TIME_IS_VALID (asfmux->first_ts));
+  g_assert (GST_CLOCK_TIME_IS_VALID (pad->first_ts));
+
   payload->presentation_time = asfmux->preroll +
-      (GST_BUFFER_TIMESTAMP (buf) / GST_MSECOND);
+      ((GST_BUFFER_TIMESTAMP (buf) - asfmux->first_ts) / GST_MSECOND);
 
   /* update counting values */
   pad->media_object_number = (pad->media_object_number + 1) % 256;
@@ -1833,6 +1838,21 @@ gst_asf_mux_collected (GstCollectPads * collect, gpointer data)
       continue;
     }
     time = GST_BUFFER_TIMESTAMP (buf);
+
+    /* check the ts for getting the first time */
+    if (!GST_CLOCK_TIME_IS_VALID (pad->first_ts) &&
+        GST_CLOCK_TIME_IS_VALID (time)) {
+      GST_DEBUG_OBJECT (asfmux, "First ts for stream number %" G_GUINT16_FORMAT
+          ": %" GST_TIME_FORMAT, pad->stream_number, GST_TIME_ARGS (time));
+      pad->first_ts = time;
+      if (!GST_CLOCK_TIME_IS_VALID (asfmux->first_ts) ||
+          time < asfmux->first_ts) {
+        GST_DEBUG_OBJECT (asfmux, "New first ts for file %" GST_TIME_FORMAT,
+            GST_TIME_ARGS (time));
+        asfmux->first_ts = time;
+      }
+    }
+
     gst_buffer_unref (buf);
 
     if (best_pad == NULL || !GST_CLOCK_TIME_IS_VALID (time) ||
@@ -1887,6 +1907,8 @@ gst_asf_mux_pad_reset (GstAsfPad * pad)
     gst_tag_list_free (pad->taglist);
   pad->taglist = NULL;
 
+  pad->first_ts = GST_CLOCK_TIME_NONE;
+
   if (pad->is_audio) {
     GstAsfAudioPad *audiopad = (GstAsfAudioPad *) pad;
     audiopad->audioinfo.rate = 0;
diff --git a/gst/asfmux/gstasfmux.h b/gst/asfmux/gstasfmux.h
index 4e13b36a6d..015c8b9abf 100644
--- a/gst/asfmux/gstasfmux.h
+++ b/gst/asfmux/gstasfmux.h
@@ -65,6 +65,7 @@ struct _GstAsfPad
   guint32 bitrate;
 
   GstClockTime play_duration;
+  GstClockTime first_ts;
 
   GstBuffer *codec_data;
 
@@ -136,6 +137,8 @@ struct _GstAsfMux
   guint64 preroll;              /* milisecs */
   gboolean merge_stream_tags;
 
+  GstClockTime first_ts;
+
   /* pads */
   GstPad *srcpad;