Initial revision

Original commit message from CVS:
Initial revision

5 files changed, 874 insertions, 0 deletions

diff --git a/gst/mpeg2sub/.gitignore b/gst/mpeg2sub/.gitignore
new file mode 100644
index 00000000..08f5ed37
--- /dev/null
+++ b/gst/mpeg2sub/.gitignore
@@ -0,0 +1,7 @@
+Makefile
+Makefile.in
+*.o
+*.lo
+*.la
+.deps
+.libs
diff --git a/gst/mpeg2sub/Makefile.am b/gst/mpeg2sub/Makefile.am
new file mode 100644
index 00000000..d8bfe888
--- /dev/null
+++ b/gst/mpeg2sub/Makefile.am
@@ -0,0 +1,18 @@
+filterdir = $(libdir)/gst
+
+filter_LTLIBRARIES = libgstmpeg2subt.la
+
+libgstmpeg2subt_la_SOURCES = gstmpeg2subt.c  
+
+if HAVE_CPU_I386
+ARCHCFLAGS = -m486
+else
+ARCHCFLAGS = 
+endif
+
+libgstmpeg2subt_la_CFLAGS = -O3 $(ARCHCFLAGS) -fschedule-insns2 $(FOMIT_FRAME_POINTER) -finline-functions -ffast-math $(GST_CFLAGS)
+
+noinst_HEADERS = gstmpeg2subt.h 
+
+EXTRA_DIST = Notes.txt
+
diff --git a/gst/mpeg2sub/Notes.txt b/gst/mpeg2sub/Notes.txt
new file mode 100644
index 00000000..a0e56e3c
--- /dev/null
+++ b/gst/mpeg2sub/Notes.txt
@@ -0,0 +1,324 @@
+

+          DVD subtitles

+         ---------------

+

+

+  0. Introduction

+  1. Basics

+  2. The data structure

+  3. Reading the control header

+  4. Decoding the graphics

+  5. What I do not know yet / What I need

+  6. Thanks

+  7. Changes

+

+

+

+

+

+The latest version of this document can be found here:

+http://www.via.ecp.fr/~sam/doc/dvd/

+

+

+

+

+

+0. Introduction

+

+  One of the last things we missed in DVD decoding under my system was the

+decoding of subtitles. I found no information on the web or Usenet about them,

+apart from a few words on them being run-length encoded in the DVD FAQ.

+

+  So we decided to reverse-engineer their format (it's completely legal in

+France, since we did it on interoperability purposes), and managed to get

+almost all of it.

+

+

+

+

+

+1. Basics

+

+  DVD subtitles are hidden in private PS packets (0x000001ba), just like AC3

+streams are.

+

+  Within the PS packet, there are PES packets, and like AC3, the header for the

+ones containing subtitles have a 0x000001bd header.

+  As for AC3, where there's an ID like (0x80 + x), there's a subtitle ID equal

+to (0x20 + x), where x is the subtitle ID. Thus there seems to be only

+16 possible different subtitles on a DVD (my Taxi Driver copy has 16).

+

+  I'll suppose you know how to extract AC3 from a DVD, and jump to the

+interesting part of this documentation. Anyway you're unlikely to have

+understood what I said without already being familiar with MPEG2.

+

+

+

+

+

+2. The data structure

+

+A subtitle packet, after its parts have been collected and appended, looks

+like this :

+

+   +----------------------------------------------------------+    

+   |                                                          |

+   |   0    2                                         size    |

+   |   +----+------------------------+-----------------+      |

+   |   |size|       data packet      |     control     |      |

+   |   +----+------------------------+-----------------+      |

+   |                                                          |

+   |                     a subtitle packet                    |

+   |                                                          |

+   +----------------------------------------------------------+    

+

+size is a 2 bytes word, and data packet and control may have any size.

+

+

+Here is the structure of the data packet :

+

+   +----------------------------------------------------------+    

+   |                                                          |

+   |   2    4                                        S0+2     |

+   |   +----+------------------------------------------+      |

+   |   | S0 |                  data                    |      |

+   |   +----+------------------------------------------+      |

+   |                                                          |

+   |                      the data packet                     |

+   |                                                          |

+   +----------------------------------------------------------+    

+

+S0, the data packet size, is a 2 bytes word.

+

+

+Finally, here's the structure of the control packet :

+

+   +----------------------------------------------------------+    

+   |                                                          |

+   | S0+2  S0+4                                 S1       size |

+   |   +----+---------+---------+--+---------+--+---------+   |

+   |   | S1 |ctrl seq |ctrl seq |..|ctrl seq |ff| end seq |   |

+   |   +----+---------+---------+--+---------+--+---------+   |

+   |                                                          |

+   |                     the control packet                   |

+   |                                                          |

+   +----------------------------------------------------------+    

+

+To summarize :

+

+ - S1, at offset S0+2, the position of the end sequence

+ - several control sequences

+ - the 'ff' byte

+ - the end sequence

+

+

+

+

+

+3. Reading the control header

+

+The first thing to read is the control sequences. There are several

+types of them, and each type is determined by its first byte. As far

+as I know, each type has a fixed length.

+

+ * type 0x01 : '01' - 1 byte

+  it seems to be an empty control sequence.

+

+ * type 0x03 : '03wxyz' - 3 bytes

+  this one has the palette information ; it basically says 'encoded color 0

+ is the wth color of the palette, encoded color 1 is the xth color, aso.

+

+ * type 0x04 : '04wxyz' - 3 bytes

+  I *think* this is the alpha channel information ; I only saw values of 0 or f

+ for those nibbles, so I can't really be sure, but it seems plausable.

+

+ * type 0x05 : '05xxxXXXyyyYYY' - 7 bytes

+  the coordinates of the subtitle on the screen :

+   xxx is the first column of the subtitle

+   XXX is the last column of the subtitle

+   yyy is the first line of the subtitle

+   YYY is the last line of the subtitle

+  thus the subtitle's size is (XXX-xxx+1) x (YYY-yyy+1)

+

+ * type 0x06 : '06xxxxyyyy' - 5 bytes

+  xxxx is the position of the first graphic line, and yyyy is the position of

+ the second one (the graphics are interlaced, so it helps a lot :p)

+

+The end sequence has this structure:

+

+ xxxx yyyy 02 ff (ff)

+

+ it ends with 'ff' or 'ffff', to make the whole packet have an even length.

+

+FIXME: I absolutely don't know what xxxx is. I suppose it may be some date

+information since I found it nowhere else, but I can't be sure.

+

+ yyyy is equal to S1 (see picture).

+

+

+Example of a control header :

+----

+0A 0C 01 03 02 31 04 0F F0 05 00 02 CF 00 22 3E 06 00 06 04 E9 FF 00 93 0A 0C 02 FF

+----

+Let's decode it. First of all, S1 = 0x0a0c.

+

+The control sequences are :

+ 01

+   Nothing to say about this one

+ 03 02 31

+   Color 0 is 0, color 1 is 2, color 2 is 3, and color 3 is 1.

+ 04 0F F0

+   Colors 0 and 3 are transparent, and colors 2 and 3 are opaque (not sure of this one)

+ 05 00 02 CF 00 22 3E

+   The first column is 0x000, the last one is 0x2cf, the first line is 0x002, and

+   the last line is 0x23e. Thus the subtitle's size is 0x2d0 x 0x23d.

+ 06 00 06 04 E9

+   The first encoded image starts at offset 0x006, and the second one starts at 0x04e9.

+

+And the end sequence is :

+  00 93 0A 0C 02 FF

+   Which means... well, not many things now. We can at least verify that S1 (0x0a0c) is

+   there.

+

+

+

+

+

+4. Decoding the graphics

+

+   The graphics are rather easy to decode (at least, when you know how to do it - it

+  took us one whole week to figure out what the encoding was :p).

+

+   The picture is interlaced, for instance for a 40 lines picture :

+

+  line 0  ---------------#----------

+  line 2  ------#-------------------

+   ...

+  line 38 ------------#-------------

+  line 1  ------------------#-------

+  line 3  --------#-----------------

+   ...

+  line 39 -------------#------------

+

+   When decoding you should get:

+

+  line 0  ---------------#----------

+  line 1  ------------------#-------

+  line 2  ------#-------------------

+  line 3  --------#-----------------

+   ...

+  line 38 ------------#-------------

+  line 39 -------------#------------

+

+   Computers with weak processors could choose only to decode even lines

+  in order to gain some time, for instance.

+

+

+   The encoding is run-length encoded, with the following alphabet:

+

+   0xf

+   0xe

+   0xd

+   0xc

+   0xb

+   0xa

+   0x9

+   0x8

+   0x7

+   0x6

+   0x5

+   0x4

+   0x3-

+   0x2-

+   0x1-

+   0x0f-

+   0x0e-

+   0x0d-

+   0x0c-

+   0x0b-

+   0x0a-

+   0x09-

+   0x08-

+   0x07-

+   0x06-

+   0x05-

+   0x04-

+   0x03--

+   0x02--

+   0x01--

+   0x0000

+

+   '-' stands for any other nibble. Once a sequence X of this alphabet has

+  been read, the pixels can be displayed : (X >> 2) is the number of pixels

+  to display, and (X & 0x3) is the color of the pixel.

+

+   For instance, 0x23 means "8 pixels of color 3".

+

+   "0000" has a special meaning : it's a carriage return. The decoder should

+  do a carriage return when reaching the end of the line, or when encountering

+  this "0000" sequence. When doing a carriage return, the parser should be

+  reset to the next even position (it cannot be nibble-aligned at the start

+  of a line).

+

+   After a carriage return, the parser should read a line on the other

+  interlaced picture, and swap like this after each carriage return.

+

+   Perhaps I don't explain this very well, so you'd better have a look at

+  the enclosed source.

+

+

+

+

+

+5. What I do not know yet / What I need

+

+I don't know what's in the end sequence yet.

+

+Also, I don't know exactly when to display subtitles, and when to remove them.

+

+I don't know if there are other types of control sequences (in my programs I consider

+0xff as a control sequence type, as well as 0x02. I don't know if it's correct or not,

+so please comment on this).

+

+I don't know what the "official" color palette is.

+

+I don't know how to handle transparency information.

+

+I don't know if this document is generic enough.

+

+So what I need is you :

+

+ - if you can, patch this document or my programs to fix strange behaviour with your subtitles.

+

+ - send me your subtitles (there's a program to extract them enclosed) ; the first 10 KB

+  of subtitles in a VOB should be enough, but it would be cool if you sent me one subtitle

+  file per language.

+

+

+

+

+

+6. Thanks

+

+ Thanks to Michel Lespinasse <walken@via.ecp.fr> for his great help on understanding

+the RLE stuff, and for all the ideas he had.

+

+ Thanks to mass (David Waite) and taaz (David I. Lehn) from irc at

+openprojects.net for sending me their subtitles.

+

+

+

+

+

+7. Changes

+

+ 20000116: added the 'changes' section.

+ 20000116: added David Waite's and David I. Lehn's name.

+ 20000116: changed "x0" and "x1" to "S0" and "S1" to make it less confusing.

+

+

+

+

+-- 

+Paris, January 16th 2000

+Samuel Hocevar <sam@via.ecp.fr>

diff --git a/gst/mpeg2sub/gstmpeg2subt.c b/gst/mpeg2sub/gstmpeg2subt.c
new file mode 100644
index 00000000..ee51d067
--- /dev/null
+++ b/gst/mpeg2sub/gstmpeg2subt.c
@@ -0,0 +1,443 @@
+/* Gnome-Streamer
+ * Copyright (C) <1999> Erik Walthinsen <omega@cse.ogi.edu>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ */
+
+
+/*#define DEBUG_ENABLED */
+#include <mpeg2subt.h>
+
+static void	gst_mpeg2subt_class_init	(GstMpeg2SubtClass *klass);
+static void	gst_mpeg2subt_init		(GstMpeg2Subt *mpeg2subt);
+
+static void	gst_mpeg2subt_chain_video	(GstPad *pad,GstBuffer *buf);
+static void	gst_mpeg2subt_chain_subtitle	(GstPad *pad,GstBuffer *buf);
+
+static void	gst_mpeg2subt_merge_title	(GstMpeg2Subt *mpeg2subt, GstBuffer *buf);
+
+static void	gst_mpeg2subt_set_property		(GObject *object, guint prop_id, const GValue *value, GParamSpec *pspec);
+static void	gst_mpeg2subt_get_property		(GObject *object, guint prop_id, GValue *value, GParamSpec *pspec);
+
+/* elementfactory information */
+static GstElementDetails mpeg2subt_details = {
+  "MPEG2 subtitle Decoder",
+  "Filter/Decoder/Video",
+  "Decodes and merges MPEG2 subtitles into a video frame",
+  VERSION,
+  "Samuel Hocevar <sam@via.ecp.fr>\n"
+  "Michel Lespinasse <walken@via.ecp.fr>\n"
+  "Wim Taymans <wim.taymans@chello.be>",
+  "(C) 2000",
+};
+
+static GstTypeDefinition mpeg2subtitledefinition = {
+  "mpeg2subt_video/mpeg2ubtitle",
+  "video/mpeg2subtitle",
+  NULL,
+  NULL,
+};
+
+/* GstMpeg2Subt signals and args */
+enum {
+  /* FILL ME */
+  LAST_SIGNAL
+};
+
+enum {
+  ARG_0,
+  ARG_SKIP,
+  /* FILL ME */
+};
+
+static guchar yuv_color[16] = {
+  0x99,
+  0x00,
+  0xFF,
+  0x00,
+  0x40,
+  0x50,
+  0x60,
+  0x70,
+  0x80,
+  0x90,
+  0xA0,
+  0xB0,
+  0xC0,
+  0xD0,
+  0xE0,
+  0xF0
+};
+
+
+
+
+static GstElementClass *parent_class = NULL;
+/*static guint gst_mpeg2subt_signals[LAST_SIGNAL] = { 0 };*/
+
+GType
+gst_mpeg2subt_get_type (void)
+{
+  static GType mpeg2subt_type = 0;
+
+  if (!mpeg2subt_type) {
+    static const GTypeInfo mpeg2subt_info = {
+      sizeof(GstMpeg2SubtClass),      NULL,
+      NULL,
+      (GClassInitFunc)gst_mpeg2subt_class_init,
+      NULL,
+      NULL,
+      sizeof(GstMpeg2Subt),
+      0,
+      (GInstanceInitFunc)gst_mpeg2subt_init,
+    };
+    mpeg2subt_type = g_type_register_static(GST_TYPE_ELEMENT, "GstMpeg2Subt", &mpeg2subt_info, 0);
+  }
+  return mpeg2subt_type;
+}
+
+static void
+gst_mpeg2subt_class_init (GstMpeg2SubtClass *klass)
+{
+  GObjectClass *gobject_class;
+  GstElementClass *gstelement_class;
+
+  gobject_class = (GObjectClass*)klass;
+  gstelement_class = (GstElementClass*)klass;
+
+  g_object_class_install_property(G_OBJECT_CLASS(klass), ARG_SKIP,
+    g_param_spec_int("skip","skip","skip",
+                     G_MININT,G_MAXINT,0,G_PARAM_READWRITE)); /* CHECKME */
+
+  parent_class = g_type_class_ref(GST_TYPE_ELEMENT);
+
+  gobject_class->set_property = gst_mpeg2subt_set_property;
+  gobject_class->get_property = gst_mpeg2subt_get_property;
+
+}
+
+static void
+gst_mpeg2subt_init (GstMpeg2Subt *mpeg2subt)
+{
+  mpeg2subt->videopad = gst_pad_new("video",GST_PAD_SINK);
+  gst_element_add_pad(GST_ELEMENT(mpeg2subt),mpeg2subt->videopad);
+  gst_pad_set_chain_function(mpeg2subt->videopad,gst_mpeg2subt_chain_video);
+
+  mpeg2subt->subtitlepad = gst_pad_new("subtitle",GST_PAD_SINK);
+  gst_element_add_pad(GST_ELEMENT(mpeg2subt),mpeg2subt->subtitlepad);
+  gst_pad_set_chain_function(mpeg2subt->subtitlepad,gst_mpeg2subt_chain_subtitle);
+
+  mpeg2subt->srcpad = gst_pad_new("src",GST_PAD_SRC);
+  gst_element_add_pad(GST_ELEMENT(mpeg2subt),mpeg2subt->srcpad);
+
+  mpeg2subt->partialbuf = NULL;
+  mpeg2subt->have_title = FALSE;
+}
+
+static void
+gst_mpeg2subt_chain_video (GstPad *pad, GstBuffer *buf)
+{
+  GstMpeg2Subt *mpeg2subt;
+  guchar *data;
+  glong size;
+
+  g_return_if_fail(pad != NULL);
+  g_return_if_fail(GST_IS_PAD(pad));
+  g_return_if_fail(buf != NULL);
+
+  mpeg2subt = GST_MPEG2SUBT (GST_OBJECT_PARENT (pad));
+
+  data = GST_BUFFER_DATA(buf);
+  size = GST_BUFFER_SIZE(buf);
+
+  if (mpeg2subt->have_title && mpeg2subt->duration != 0) {
+    gst_mpeg2subt_merge_title(mpeg2subt, buf);
+    mpeg2subt->duration--;
+  }
+
+  gst_pad_push(mpeg2subt->srcpad, buf);
+}
+
+
+static void
+gst_mpeg2subt_parse_header (GstMpeg2Subt *mpeg2subt)
+{
+  guchar *buffer = GST_BUFFER_DATA(mpeg2subt->partialbuf);
+  guchar dummy;
+  guint i;
+
+  i = mpeg2subt->data_size + 4;
+  while (i < mpeg2subt->packet_size)
+  {
+    dummy = buffer [i];
+    switch (dummy)
+    {
+      case 0x01: /* null packet ? */
+        i++;
+        break;
+      case 0x02: /* 02 ff (ff) is the end of the packet */
+        i = mpeg2subt->packet_size;
+        break;
+      case 0x03: /* palette */
+        mpeg2subt->color[0] = yuv_color[buffer [i+1] >> 4];
+        mpeg2subt->color[1] = yuv_color[buffer [i+1] & 0xf];
+        mpeg2subt->color[2] = yuv_color[buffer [i+2] >> 4];
+        mpeg2subt->color[3] = yuv_color[buffer [i+2] & 0xf];
+        mpeg2subt->color[4] = yuv_color[0xf];
+	GST_DEBUG (0,"mpeg2subt: colors %d %d %d %d\n", mpeg2subt->color[0],mpeg2subt->color[1],mpeg2subt->color[2],mpeg2subt->color[3]);
+        i += 3;
+        break;
+      case 0x04: /* transparency palette */
+        mpeg2subt->trans[3] = buffer [i+1] >> 4;
+	mpeg2subt->trans[2] = buffer [i+1] & 0xf;
+	mpeg2subt->trans[1] = buffer [i+2] >> 4;
+	mpeg2subt->trans[0] = buffer [i+2] & 0xf;
+	GST_DEBUG (0,"mpeg2subt: transparency %d %d %d %d\n", mpeg2subt->trans[0],mpeg2subt->trans[1],mpeg2subt->trans[2],mpeg2subt->trans[3]);
+	i += 3;
+	break;
+      case 0x05: /* image coordinates */
+        mpeg2subt->width = 1 + ( ((buffer[i+2] & 0x0f) << 8) + buffer[i+3] )
+                  - ( (((unsigned int)buffer[i+1]) << 4) + (buffer[i+2] >> 4) );
+        mpeg2subt->height = 1 + ( ((buffer[i+5] & 0x0f) << 8) + buffer[i+6] )
+                   - ( (((unsigned int)buffer[i+4]) << 4) + (buffer[i+5] >> 4) );
+        i += 7;
+	break;
+      case 0x06: /* image 1 / image 2 offsets */
+        mpeg2subt->offset[0] = (((unsigned int)buffer[i+1]) << 8) + buffer[i+2];
+        mpeg2subt->offset[1] = (((unsigned int)buffer[i+3]) << 8) + buffer[i+4];
+	i += 5;
+	break;
+      case 0xff: /* "ff xx yy zz uu" with 'zz uu' == start of control packet
+		  *  xx and yy are the end time in 90th/sec
+	          */
+	mpeg2subt->duration = (((buffer[i+1] << 8) + buffer[i+2]) * 25)/90;
+
+	GST_DEBUG (0,"duration %d\n", mpeg2subt->duration);
+
+	if ( (buffer[i+3] != buffer[mpeg2subt->data_size+2])
+	     || (buffer[i+4] != buffer[mpeg2subt->data_size+3]) )
+	{
+	  g_print("mpeg2subt: invalid control header (%.2x%.2x != %.2x%.2x) !\n",
+		buffer[i+3], buffer[i+4], buffer[mpeg2subt->data_size+2], buffer[mpeg2subt->data_size+3] );
+/* FIXME */
+/*          exit(1); */
+	}
+	i += 5;
+	break;
+      default:
+	g_print("mpeg2subt: invalid sequence in control header (%.2x) !\n", dummy);
+	break;
+    }
+  }
+}
+
+static int
+get_nibble (guchar *buffer, gint *offset, gint id, gint *aligned)
+{
+  static int next;
+
+  if (*aligned)
+  {
+    next = buffer[offset[id]];
+    offset[id]++;
+
+    *aligned = 0;
+    return next >> 4;
+  }
+  else
+  {
+    *aligned = 1;
+    return next & 0xf;
+  }
+}
+
+static void
+gst_mpeg2subt_merge_title (GstMpeg2Subt *mpeg2subt, GstBuffer *buf)
+{
+  gint x=0, y=0;
+  gint width = mpeg2subt->width;
+  gint height = mpeg2subt->height;
+  guchar *buffer = GST_BUFFER_DATA(mpeg2subt->partialbuf);
+  guchar *target = GST_BUFFER_DATA(buf);
+  gint id=0, aligned=1;
+  gint offset[2];
+
+  offset[0] = mpeg2subt->offset[0];
+  offset[1] = mpeg2subt->offset[1];
+#define get_nibble() get_nibble (buffer, offset, id, &aligned)
+
+  GST_DEBUG (0,"mpeg2subt: merging subtitle\n");
+
+  while ((offset[1] < mpeg2subt->data_size + 2) && (y < height))
+  {
+    gint code;
+    gint length, colorid;
+
+    code = get_nibble();
+    if (code >= 0x4)	/* 4 .. f */
+    {
+found_code:
+      length = code >> 2;
+      colorid = code & 3;
+      while (length--)
+        if (x++ < width) {
+	  if (mpeg2subt->trans[colorid] != 0x0) {
+            *target++ = mpeg2subt->color[colorid];
+	  }
+          else target++;
+	}
+
+      if (x >= width)
+      {
+        if (!aligned)
+          get_nibble ();
+        goto next_line;
+      }
+      continue;
+    }
+
+    code = (code << 4) + get_nibble();
+    if (code >= 0x10)	/* 1x .. 3x */
+      goto found_code;
+
+    code = (code << 4) + get_nibble();
+    if (code >= 0x40)	/* 04x .. 0fx */
+      goto found_code;
+
+    code = (code << 4) + get_nibble();
+    if (code >= 0x100)	/* 01xx .. 03xx */
+      goto found_code;
+
+    /* 00xx - should only happen for 00 00 */
+    if (!aligned)
+      code = (code << 4) + get_nibble(); /* 0 0x xx */
+
+    if (code)
+    {
+      g_print("mpeg2subt: got unknown code 00%x (offset %x side %x, x=%d, y=%d)\n", code, mpeg2subt->offset[id], id, x, y);
+      goto next_line;
+    }
+next_line:
+    /* aligned 00 00 */
+    if (y < height) {
+      target+=(width-x);
+      x = 0;
+      y++;
+      id = 1 - id;
+    }
+  }
+}
+
+static void
+gst_mpeg2subt_chain_subtitle (GstPad *pad, GstBuffer *buf)
+{
+  GstMpeg2Subt *mpeg2subt;
+  guchar *data;
+  glong size = 0;
+
+  g_return_if_fail(pad != NULL);
+  g_return_if_fail(GST_IS_PAD(pad));
+  g_return_if_fail(buf != NULL);
+/*  g_return_if_fail(GST_IS_BUFFER(buf)); */
+
+  mpeg2subt = GST_MPEG2SUBT (GST_OBJECT_PARENT (pad));
+
+  if (mpeg2subt->have_title) {
+    gst_buffer_unref(mpeg2subt->partialbuf);
+    mpeg2subt->partialbuf = NULL;
+    mpeg2subt->have_title = FALSE;
+  }
+
+  GST_DEBUG (0,"presentation time %llu\n", GST_BUFFER_TIMESTAMP(buf));
+
+  /* deal with partial frame from previous buffer */
+  if (mpeg2subt->partialbuf) {
+
+    mpeg2subt->partialbuf = gst_buffer_append(mpeg2subt->partialbuf, buf);;
+    /* and the one we received.. */
+    gst_buffer_unref(buf);
+  }
+  else {
+    mpeg2subt->partialbuf = buf;
+  }
+
+  data = GST_BUFFER_DATA(mpeg2subt->partialbuf);
+  size = GST_BUFFER_SIZE(mpeg2subt->partialbuf);
+
+  mpeg2subt->packet_size = GUINT16_FROM_BE(*(guint16 *)data);
+
+  if (mpeg2subt->packet_size == size) {
+
+    GST_DEBUG (0,"mpeg2subt: subtitle packet size %d, current size %ld\n", mpeg2subt->packet_size, size);
+
+    mpeg2subt->data_size = GUINT16_FROM_BE(*(guint16 *)(data+2));
+
+    gst_mpeg2subt_parse_header(mpeg2subt);
+    mpeg2subt->have_title = TRUE;
+  }
+}
+
+static void
+gst_mpeg2subt_set_property (GObject *object, guint prop_id, const GValue *value, GParamSpec *pspec)
+{
+  GstMpeg2Subt *src;
+
+  /* it's not null if we got it, but it might not be ours */
+  g_return_if_fail(GST_IS_MPEG2SUBT(object));
+  src = GST_MPEG2SUBT(object);
+
+  switch (prop_id) {
+    default:
+      break;
+  }
+}
+
+static void
+gst_mpeg2subt_get_property (GObject *object, guint prop_id, GValue *value, GParamSpec *pspec)
+{
+  GstMpeg2Subt *src;
+
+  /* it's not null if we got it, but it might not be ours */
+  g_return_if_fail(GST_IS_MPEG2SUBT(object));
+  src = GST_MPEG2SUBT(object);
+
+  switch (prop_id) {
+    default:
+      break;
+  }
+}
+
+static gboolean
+plugin_init (GModule *module, GstPlugin *plugin)
+{
+  GstElementFactory *factory;
+
+  /* create an elementfactory for the mpeg2subt element */
+  factory = gst_elementfactory_new("mpeg2subt",GST_TYPE_MPEG2SUBT,
+                                   &mpeg2subt_details);
+  g_return_val_if_fail(factory != NULL, FALSE);
+
+  gst_plugin_add_feature (plugin, GST_PLUGIN_FEATURE (factory));
+
+  return TRUE;
+}
+
+GstPluginDesc plugin_desc = {
+  GST_VERSION_MAJOR,
+  GST_VERSION_MINOR,
+  "mpeg2subt",
+  plugin_init
+};
diff --git a/gst/mpeg2sub/gstmpeg2subt.h b/gst/mpeg2sub/gstmpeg2subt.h
new file mode 100644
index 00000000..71e88909
--- /dev/null
+++ b/gst/mpeg2sub/gstmpeg2subt.h
@@ -0,0 +1,82 @@
+/* Gnome-Streamer
+ * Copyright (C) <1999> Erik Walthinsen <omega@cse.ogi.edu>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ */
+
+
+#ifndef __GST_MPEG2SUBT_H__
+#define __GST_MPEG2SUBT_H__
+
+
+#include <config.h>
+#include <gst/gst.h>
+
+
+#ifdef __cplusplus
+extern "C" {
+#endif /* __cplusplus */
+
+
+#define GST_TYPE_MPEG2SUBT \
+  (gst_mpeg2subt_get_type())
+#define GST_MPEG2SUBT(obj) \
+  (G_TYPE_CHECK_INSTANCE_CAST((obj),GST_TYPE_MPEG2SUBT,GstMpeg2Subt))
+#define GST_MPEG2SUBT_CLASS(klass) \
+  (G_TYPE_CHECK_CLASS_CAST((klass),GST_TYPE_MPEG2SUBT,GstMpeg2Subt))
+#define GST_IS_MPEG2SUBT(obj) \
+  (G_TYPE_CHECK_INSTANCE_TYPE((obj),GST_TYPE_MPEG2SUBT))
+#define GST_IS_MPEG2SUBT_CLASS(obj) \
+  (G_TYPE_CHECK_CLASS_TYPE((klass),GST_TYPE_MPEG2SUBT))
+
+typedef struct _GstMpeg2Subt GstMpeg2Subt;
+typedef struct _GstMpeg2SubtClass GstMpeg2SubtClass;
+
+struct _GstMpeg2Subt {
+  GstElement element;
+
+  GstPad *videopad,*subtitlepad,*srcpad;
+
+  GstBuffer *partialbuf;	/* previous buffer (if carryover) */
+
+  gboolean have_title;
+
+  guint16 packet_size;
+  guint16 data_size;
+
+  gint offset[2];
+  guchar color[5];
+  guchar trans[4];
+
+  guint duration;
+
+  gint width, height;
+
+};
+
+struct _GstMpeg2SubtClass {
+  GstElementClass parent_class;
+};
+
+GType gst_mpeg2subt_get_type(void);
+
+
+#ifdef __cplusplus
+}
+#endif /* __cplusplus */
+
+
+#endif /* __GST_MPEG2SUBT_H__ */