From fa493f9874b9ecf0ea1e93170041902d82a0c3dc Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Andreas=20=C3=96man?= <andreas@lonelycoder.com>
Date: Sun, 31 Oct 2010 13:07:38 +0000
Subject: [PATCH] matroska: Write the 'unknown segment size' as '01 ff ff ff ff
 ff ff ff' instead of just 'ff'. Seems to help some players When recording is
 done, seek back and overwrite with actual segment size.

---
 src/dvr/mkmux.c | 34 ++++++++++++++++++++++++++++++----
 1 file changed, 30 insertions(+), 4 deletions(-)

diff --git a/src/dvr/mkmux.c b/src/dvr/mkmux.c
index c8ad8751..5c967e98 100644
--- a/src/dvr/mkmux.c
+++ b/src/dvr/mkmux.c
@@ -80,6 +80,8 @@ struct mk_mux {
   off_t cluster_pos;
 
 
+  off_t segment_header_pos;
+
   off_t segment_pos;
 
   off_t segmentinfo_pos;
@@ -370,14 +372,27 @@ mk_write_master(mk_mux_t *mkm, uint32_t id, htsbuf_queue_t *p)
  *
  */
 static void
-mk_write_segment(mk_mux_t *mkm)
+mk_write_segment_header(mk_mux_t *mkm, int64_t size)
 {
   htsbuf_queue_t q;
-  char ff = 0xff;
+  uint8_t u8[8];
   htsbuf_queue_init(&q, 0);
 
   ebml_append_id(&q, 0x18538067);
-  htsbuf_append(&q, &ff, 1);
+  
+  u8[0] = 1;
+  if(size == 0) {
+    memset(u8+1, 0xff, 7);
+  } else {
+    u8[1] = size >> 56;
+    u8[2] = size >> 48;
+    u8[3] = size >> 32;
+    u8[4] = size >> 24;
+    u8[5] = size >> 16;
+    u8[6] = size >> 8;
+    u8[7] = size;
+  }
+  htsbuf_append(&q, &u8, 8);
   
   mk_write_queue(mkm, &q);
 }
@@ -590,7 +605,9 @@ mk_mux_create(const char *filename,
   TAILQ_INIT(&mkm->cues);
 
   mk_write_master(mkm, 0x1a45dfa3, mk_build_ebmlheader());
-  mk_write_segment(mkm);
+
+  mkm->segment_header_pos = mkm->fdpos;
+  mk_write_segment_header(mkm, 0);
 
   mkm->segment_pos = mkm->fdpos;
   mk_write_metaseek(mkm, 1); // Must be first in segment
@@ -794,10 +811,12 @@ mk_write_cues(mk_mux_t *mkm)
 void
 mk_mux_close(mk_mux_t *mkm)
 {
+  int64_t totsize;
   mk_close_cluster(mkm);
   mk_write_cues(mkm);
 
   mk_write_metaseek(mkm, 0);
+  totsize = mkm->fdpos;
 
   // Rewrite segment info to update duration
   if(lseek(mkm->fd, mkm->segmentinfo_pos, SEEK_SET) == mkm->segmentinfo_pos)
@@ -806,6 +825,13 @@ mk_mux_close(mk_mux_t *mkm)
     tvhlog(LOG_ERR, "MKV", "%s: Unable to write duration, seek failed -- %s",
 	   mkm->filename, strerror(errno));
 
+  // Rewrite segment header to update total size
+  if(lseek(mkm->fd, mkm->segment_header_pos, SEEK_SET) == mkm->segment_header_pos) {
+    mk_write_segment_header(mkm, totsize - mkm->segment_header_pos - 12);
+  } else
+    tvhlog(LOG_ERR, "MKV", "%s: Unable to write total size, seek failed -- %s",
+	   mkm->filename, strerror(errno));
+
   close(mkm->fd);
   free(mkm->filename);
   free(mkm->tracks);