gst_plugins_base/ext/theora/theoraenc.c
branchRCL_3
changeset 30 7e817e7e631c
parent 0 0e761a78d257
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gst_plugins_base/ext/theora/theoraenc.c	Wed Sep 01 12:16:41 2010 +0100
@@ -0,0 +1,1104 @@
+/* GStreamer
+ * Copyright (C) 2004 Wim Taymans <wim@fluendo.com>
+ *
+ * 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.
+ */
+
+/**
+ * SECTION:element-theoraenc
+ * @see_also: theoradec, oggmux
+ *
+ * <refsect2>
+ * <para>
+ * This element encodes raw video into a Theora stream.
+ * <ulink url="http://www.theora.org/">Theora</ulink> is a royalty-free
+ * video codec maintained by the <ulink url="http://www.xiph.org/">Xiph.org
+ * Foundation</ulink>, based on the VP3 codec.
+ * </para>
+ * <para>
+ * The theora codec internally only supports encoding of images that are a
+ * multiple of 16 pixels in both X and Y direction. It is however perfectly
+ * possible to encode images with other dimensions because an arbitrary
+ * rectangular cropping region can be set up. This element will automatically
+ * set up a correct cropping region if the dimensions are not multiples of 16
+ * pixels. The "border" and "center" properties control how this cropping
+ * region will be set up.
+ * </para>
+ * <para>
+ * To control the quality of the encoding, the "bitrate" and "quality"
+ * properties can be used. These two properties are mutualy exclusive. Setting
+ * the bitrate property will produce a constant bitrate (CBR) stream while
+ * setting the quality property will produce a variable bitrate (VBR) stream.
+ * </para>
+ * <title>Example pipeline</title>
+ * <programlisting>
+ * gst-launch -v videotestsrc num-buffers=1000 ! theoraenc ! oggmux ! filesink location=videotestsrc.ogg
+ * </programlisting>
+ * This example pipeline will encode a test video source to theora muxed in an
+ * ogg container. Refer to the theoradec documentation to decode the create
+ * stream.
+ * </refsect2>
+ *
+ * Last reviewed on 2006-03-01 (0.10.4)
+ */
+
+#ifdef HAVE_CONFIG_H
+#  include "config.h"
+#endif
+
+#include "gsttheoraenc.h"
+
+#include <string.h>
+#include <stdlib.h>             /* free */
+
+#include <gst/tag/tag.h>
+
+#define GST_CAT_DEFAULT theoraenc_debug
+GST_DEBUG_CATEGORY_STATIC (GST_CAT_DEFAULT);
+
+/* With libtheora-1.0beta1 the granulepos scheme was changed:
+ * where earlier the granulepos refered to the index/beginning
+ * of a frame, it now refers to the end, which matches the use
+ * in vorbis/speex. There don't seem to be defines for the
+ * theora version we're compiling against, so we'll just use
+ * a run-time check for now. See theora_enc_get_ogg_packet_end_time().
+ */
+static gboolean use_old_granulepos;
+
+#define GST_TYPE_BORDER_MODE (gst_border_mode_get_type())
+static GType
+gst_border_mode_get_type (void)
+{
+  static GType border_mode_type = 0;
+  static const GEnumValue border_mode[] = {
+    {BORDER_NONE, "No Border", "none"},
+    {BORDER_BLACK, "Black Border", "black"},
+    {BORDER_MIRROR, "Mirror image in borders", "mirror"},
+    {0, NULL, NULL},
+  };
+
+  if (!border_mode_type) {
+    border_mode_type =
+        g_enum_register_static ("GstTheoraEncBorderMode", border_mode);
+  }
+  return border_mode_type;
+}
+
+/* taken from theora/lib/toplevel.c */
+static int
+_ilog (unsigned int v)
+{
+  int ret = 0;
+
+  while (v) {
+    ret++;
+    v >>= 1;
+  }
+  return (ret);
+}
+
+#define THEORA_DEF_CENTER               TRUE
+#define THEORA_DEF_BORDER               BORDER_BLACK
+#define THEORA_DEF_BITRATE              0
+#define THEORA_DEF_QUALITY              16
+#define THEORA_DEF_QUICK                TRUE
+#define THEORA_DEF_KEYFRAME_AUTO        TRUE
+#define THEORA_DEF_KEYFRAME_FREQ        64
+#define THEORA_DEF_KEYFRAME_FREQ_FORCE  64
+#define THEORA_DEF_KEYFRAME_THRESHOLD   80
+#define THEORA_DEF_KEYFRAME_MINDISTANCE 8
+#define THEORA_DEF_NOISE_SENSITIVITY    1
+#define THEORA_DEF_SHARPNESS            0
+enum
+{
+  ARG_0,
+  ARG_CENTER,
+  ARG_BORDER,
+  ARG_BITRATE,
+  ARG_QUALITY,
+  ARG_QUICK,
+  ARG_KEYFRAME_AUTO,
+  ARG_KEYFRAME_FREQ,
+  ARG_KEYFRAME_FREQ_FORCE,
+  ARG_KEYFRAME_THRESHOLD,
+  ARG_KEYFRAME_MINDISTANCE,
+  ARG_NOISE_SENSITIVITY,
+  ARG_SHARPNESS,
+  /* FILL ME */
+};
+
+/* this function does a straight granulepos -> timestamp conversion */
+static GstClockTime
+granulepos_to_timestamp (GstTheoraEnc * theoraenc, ogg_int64_t granulepos)
+{
+  guint64 iframe, pframe;
+  int shift = theoraenc->granule_shift;
+
+  if (granulepos < 0)
+    return GST_CLOCK_TIME_NONE;
+
+  iframe = granulepos >> shift;
+  pframe = granulepos - (iframe << shift);
+
+  /* num and den are 32 bit, so we can safely multiply with GST_SECOND */
+  return gst_util_uint64_scale ((guint64) (iframe + pframe),
+      GST_SECOND * theoraenc->info.fps_denominator,
+      theoraenc->info.fps_numerator);
+}
+
+static const GstElementDetails theora_enc_details =
+GST_ELEMENT_DETAILS ("Theora video encoder",
+    "Codec/Encoder/Video",
+    "encode raw YUV video to a theora stream",
+    "Wim Taymans <wim@fluendo.com>");
+
+static GstStaticPadTemplate theora_enc_sink_factory =
+GST_STATIC_PAD_TEMPLATE ("sink",
+    GST_PAD_SINK,
+    GST_PAD_ALWAYS,
+    GST_STATIC_CAPS ("video/x-raw-yuv, "
+        "format = (fourcc) I420, "
+        "framerate = (fraction) [0/1, MAX], "
+        "width = (int) [ 1, MAX ], " "height = (int) [ 1, MAX ]")
+    );
+
+static GstStaticPadTemplate theora_enc_src_factory =
+GST_STATIC_PAD_TEMPLATE ("src",
+    GST_PAD_SRC,
+    GST_PAD_ALWAYS,
+    GST_STATIC_CAPS ("video/x-theora")
+    );
+
+GST_BOILERPLATE (GstTheoraEnc, gst_theora_enc, GstElement, GST_TYPE_ELEMENT);
+
+static gboolean theora_enc_sink_event (GstPad * pad, GstEvent * event);
+static GstFlowReturn theora_enc_chain (GstPad * pad, GstBuffer * buffer);
+static GstStateChangeReturn theora_enc_change_state (GstElement * element,
+    GstStateChange transition);
+static gboolean theora_enc_sink_setcaps (GstPad * pad, GstCaps * caps);
+static void theora_enc_get_property (GObject * object, guint prop_id,
+    GValue * value, GParamSpec * pspec);
+static void theora_enc_set_property (GObject * object, guint prop_id,
+    const GValue * value, GParamSpec * pspec);
+static void theora_enc_finalize (GObject * object);
+
+static void
+gst_theora_enc_base_init (gpointer g_class)
+{
+  GstElementClass *element_class = GST_ELEMENT_CLASS (g_class);
+
+  gst_element_class_add_pad_template (element_class,
+      gst_static_pad_template_get (&theora_enc_src_factory));
+  gst_element_class_add_pad_template (element_class,
+      gst_static_pad_template_get (&theora_enc_sink_factory));
+  gst_element_class_set_details (element_class, &theora_enc_details);
+}
+
+static void
+gst_theora_enc_class_init (GstTheoraEncClass * klass)
+{
+  GObjectClass *gobject_class = (GObjectClass *) klass;
+  GstElementClass *gstelement_class = GST_ELEMENT_CLASS (klass);
+
+  gobject_class->set_property = theora_enc_set_property;
+  gobject_class->get_property = theora_enc_get_property;
+  gobject_class->finalize = theora_enc_finalize;
+
+  g_object_class_install_property (gobject_class, ARG_CENTER,
+      g_param_spec_boolean ("center", "Center",
+          "Center image when sizes not multiple of 16", THEORA_DEF_CENTER,
+          (GParamFlags) G_PARAM_READWRITE));
+  g_object_class_install_property (gobject_class, ARG_BORDER,
+      g_param_spec_enum ("border", "Border",
+          "Border color to add when sizes not multiple of 16",
+          GST_TYPE_BORDER_MODE, THEORA_DEF_BORDER,
+          (GParamFlags) G_PARAM_READWRITE));
+  /* general encoding stream options */
+  g_object_class_install_property (gobject_class, ARG_BITRATE,
+      g_param_spec_int ("bitrate", "Bitrate", "Compressed video bitrate (kbps)",
+          0, 2000, THEORA_DEF_BITRATE, (GParamFlags) G_PARAM_READWRITE));
+  g_object_class_install_property (gobject_class, ARG_QUALITY,
+      g_param_spec_int ("quality", "Quality", "Video quality",
+          0, 63, THEORA_DEF_QUALITY, (GParamFlags) G_PARAM_READWRITE));
+  g_object_class_install_property (gobject_class, ARG_QUICK,
+      g_param_spec_boolean ("quick", "Quick", "Quick encoding",
+          THEORA_DEF_QUICK, (GParamFlags) G_PARAM_READWRITE));
+  g_object_class_install_property (gobject_class, ARG_KEYFRAME_AUTO,
+      g_param_spec_boolean ("keyframe-auto", "Keyframe Auto",
+          "Automatic keyframe detection", THEORA_DEF_KEYFRAME_AUTO,
+          (GParamFlags) G_PARAM_READWRITE));
+  g_object_class_install_property (gobject_class, ARG_KEYFRAME_FREQ,
+      g_param_spec_int ("keyframe-freq", "Keyframe frequency",
+          "Keyframe frequency", 1, 32768, THEORA_DEF_KEYFRAME_FREQ,
+          (GParamFlags) G_PARAM_READWRITE));
+  g_object_class_install_property (gobject_class, ARG_KEYFRAME_FREQ_FORCE,
+      g_param_spec_int ("keyframe-force", "Keyframe force",
+          "Force keyframe every N frames", 1, 32768,
+          THEORA_DEF_KEYFRAME_FREQ_FORCE, (GParamFlags) G_PARAM_READWRITE));
+  g_object_class_install_property (gobject_class, ARG_KEYFRAME_THRESHOLD,
+      g_param_spec_int ("keyframe-threshold", "Keyframe threshold",
+          "Keyframe threshold", 0, 32768, THEORA_DEF_KEYFRAME_THRESHOLD,
+          (GParamFlags) G_PARAM_READWRITE));
+  g_object_class_install_property (gobject_class, ARG_KEYFRAME_MINDISTANCE,
+      g_param_spec_int ("keyframe-mindistance", "Keyframe mindistance",
+          "Keyframe mindistance", 1, 32768, THEORA_DEF_KEYFRAME_MINDISTANCE,
+          (GParamFlags) G_PARAM_READWRITE));
+  g_object_class_install_property (gobject_class, ARG_NOISE_SENSITIVITY,
+      g_param_spec_int ("noise-sensitivity", "Noise sensitivity",
+          "Noise sensitivity", 0, 32768, THEORA_DEF_NOISE_SENSITIVITY,
+          (GParamFlags) G_PARAM_READWRITE));
+  g_object_class_install_property (gobject_class, ARG_SHARPNESS,
+      g_param_spec_int ("sharpness", "Sharpness",
+          "Sharpness", 0, 2, THEORA_DEF_SHARPNESS,
+          (GParamFlags) G_PARAM_READWRITE));
+
+  gstelement_class->change_state = theora_enc_change_state;
+  GST_DEBUG_CATEGORY_INIT (theoraenc_debug, "theoraenc", 0, "Theora encoder");
+
+  use_old_granulepos = (theora_version_number () <= 0x00030200);
+}
+
+static void
+gst_theora_enc_init (GstTheoraEnc * enc, GstTheoraEncClass * g_class)
+{
+  enc->sinkpad =
+      gst_pad_new_from_static_template (&theora_enc_sink_factory, "sink");
+  gst_pad_set_chain_function (enc->sinkpad, theora_enc_chain);
+  gst_pad_set_event_function (enc->sinkpad, theora_enc_sink_event);
+  gst_pad_set_setcaps_function (enc->sinkpad, theora_enc_sink_setcaps);
+  gst_element_add_pad (GST_ELEMENT (enc), enc->sinkpad);
+
+  enc->srcpad =
+      gst_pad_new_from_static_template (&theora_enc_src_factory, "src");
+  gst_element_add_pad (GST_ELEMENT (enc), enc->srcpad);
+
+  enc->center = THEORA_DEF_CENTER;
+  enc->border = THEORA_DEF_BORDER;
+
+  enc->video_bitrate = THEORA_DEF_BITRATE;
+  enc->video_quality = THEORA_DEF_QUALITY;
+  enc->quick = THEORA_DEF_QUICK;
+  enc->keyframe_auto = THEORA_DEF_KEYFRAME_AUTO;
+  enc->keyframe_freq = THEORA_DEF_KEYFRAME_FREQ;
+  enc->keyframe_force = THEORA_DEF_KEYFRAME_FREQ_FORCE;
+  enc->keyframe_threshold = THEORA_DEF_KEYFRAME_THRESHOLD;
+  enc->keyframe_mindistance = THEORA_DEF_KEYFRAME_MINDISTANCE;
+  enc->noise_sensitivity = THEORA_DEF_NOISE_SENSITIVITY;
+  enc->sharpness = THEORA_DEF_SHARPNESS;
+
+  enc->granule_shift = _ilog (enc->info.keyframe_frequency_force - 1);
+  GST_DEBUG_OBJECT (enc,
+      "keyframe_frequency_force is %d, granule shift is %d",
+      enc->info.keyframe_frequency_force, enc->granule_shift);
+  enc->expected_ts = GST_CLOCK_TIME_NONE;
+}
+
+static void
+theora_enc_finalize (GObject * object)
+{
+  GstTheoraEnc *enc = GST_THEORA_ENC (object);
+
+  GST_DEBUG_OBJECT (enc, "Finalizing");
+  theora_clear (&enc->state);
+  theora_comment_clear (&enc->comment);
+  theora_info_clear (&enc->info);
+
+  G_OBJECT_CLASS (parent_class)->finalize (object);
+}
+
+static void
+theora_enc_reset (GstTheoraEnc * enc)
+{
+  theora_clear (&enc->state);
+  theora_encode_init (&enc->state, &enc->info);
+}
+
+static void
+theora_enc_clear (GstTheoraEnc * enc)
+{
+  enc->packetno = 0;
+  enc->bytes_out = 0;
+  enc->granulepos_offset = 0;
+  enc->timestamp_offset = 0;
+
+  enc->next_ts = GST_CLOCK_TIME_NONE;
+  enc->next_discont = FALSE;
+  enc->expected_ts = GST_CLOCK_TIME_NONE;
+}
+
+static gboolean
+theora_enc_sink_setcaps (GstPad * pad, GstCaps * caps)
+{
+  GstStructure *structure = gst_caps_get_structure (caps, 0);
+  GstTheoraEnc *enc = GST_THEORA_ENC (gst_pad_get_parent (pad));
+  const GValue *par;
+  gint fps_n, fps_d;
+
+  gst_structure_get_int (structure, "width", &enc->width);
+  gst_structure_get_int (structure, "height", &enc->height);
+  gst_structure_get_fraction (structure, "framerate", &fps_n, &fps_d);
+  par = gst_structure_get_value (structure, "pixel-aspect-ratio");
+
+  theora_info_clear (&enc->info);
+  theora_info_init (&enc->info);
+  /* Theora has a divisible-by-sixteen restriction for the encoded video size but
+   * we can define a visible area using the frame_width/frame_height */
+  enc->info_width = enc->info.width = (enc->width + 15) & ~15;
+  enc->info_height = enc->info.height = (enc->height + 15) & ~15;
+  enc->info.frame_width = enc->width;
+  enc->info.frame_height = enc->height;
+
+  /* center image if needed */
+  if (enc->center) {
+    /* make sure offset is even, for easier decoding */
+    enc->offset_x = GST_ROUND_UP_2 ((enc->info_width - enc->width) / 2);
+    enc->offset_y = GST_ROUND_UP_2 ((enc->info_height - enc->height) / 2);
+  } else {
+    enc->offset_x = 0;
+    enc->offset_y = 0;
+  }
+  enc->info.offset_x = enc->offset_x;
+  enc->info.offset_y = enc->offset_y;
+
+  enc->info.fps_numerator = enc->fps_n = fps_n;
+  enc->info.fps_denominator = enc->fps_d = fps_d;
+  if (par) {
+    enc->info.aspect_numerator = gst_value_get_fraction_numerator (par);
+    enc->info.aspect_denominator = gst_value_get_fraction_denominator (par);
+  } else {
+    /* setting them to 0 indicates that the decoder can chose a good aspect
+     * ratio, defaulting to 1/1 */
+    enc->info.aspect_numerator = 0;
+    enc->info.aspect_denominator = 0;
+  }
+
+  enc->info.colorspace = OC_CS_UNSPECIFIED;
+  enc->info.target_bitrate = enc->video_bitrate;
+  enc->info.quality = enc->video_quality;
+
+  enc->info.dropframes_p = 0;
+  enc->info.quick_p = (enc->quick ? 1 : 0);
+  enc->info.keyframe_auto_p = (enc->keyframe_auto ? 1 : 0);
+  enc->info.keyframe_frequency = enc->keyframe_freq;
+  enc->info.keyframe_frequency_force = enc->keyframe_force;
+  enc->info.keyframe_data_target_bitrate = enc->video_bitrate * 1.5;
+  enc->info.keyframe_auto_threshold = enc->keyframe_threshold;
+  enc->info.keyframe_mindistance = enc->keyframe_mindistance;
+  enc->info.noise_sensitivity = enc->noise_sensitivity;
+  enc->info.sharpness = enc->sharpness;
+
+  /* as done in theora */
+  enc->granule_shift = _ilog (enc->info.keyframe_frequency_force - 1);
+  GST_DEBUG_OBJECT (enc,
+      "keyframe_frequency_force is %d, granule shift is %d",
+      enc->info.keyframe_frequency_force, enc->granule_shift);
+
+  theora_enc_reset (enc);
+  enc->initialised = TRUE;
+
+  gst_object_unref (enc);
+
+  return TRUE;
+}
+
+static guint64
+granulepos_add (guint64 granulepos, guint64 addend, gint shift)
+{
+  guint64 iframe, pframe;
+
+  iframe = granulepos >> shift;
+  pframe = granulepos - (iframe << shift);
+  iframe += addend;
+
+  return (iframe << shift) + pframe;
+}
+
+/* prepare a buffer for transmission by passing data through libtheora */
+static GstFlowReturn
+theora_buffer_from_packet (GstTheoraEnc * enc, ogg_packet * packet,
+    GstClockTime timestamp, GstClockTime duration, GstBuffer ** buffer)
+{
+  GstBuffer *buf;
+  GstFlowReturn ret = GST_FLOW_OK;
+
+  buf = gst_buffer_new_and_alloc (packet->bytes);
+  if (!buf) {
+    GST_WARNING_OBJECT (enc, "Could not allocate buffer");
+    ret = GST_FLOW_ERROR;
+    goto done;
+  }
+
+  memcpy (GST_BUFFER_DATA (buf), packet->packet, packet->bytes);
+  gst_buffer_set_caps (buf, GST_PAD_CAPS (enc->srcpad));
+  /* see ext/ogg/README; OFFSET_END takes "our" granulepos, OFFSET its
+   * time representation */
+  GST_BUFFER_OFFSET_END (buf) =
+      granulepos_add (packet->granulepos, enc->granulepos_offset,
+      enc->granule_shift);
+  GST_BUFFER_OFFSET (buf) = granulepos_to_timestamp (enc,
+      GST_BUFFER_OFFSET_END (buf));
+
+  GST_BUFFER_TIMESTAMP (buf) = timestamp + enc->timestamp_offset;
+  GST_BUFFER_DURATION (buf) = duration;
+
+  if (enc->next_discont) {
+    GST_BUFFER_FLAG_SET (buf, GST_BUFFER_FLAG_DISCONT);
+    enc->next_discont = FALSE;
+  }
+
+  /* the second most significant bit of the first data byte is cleared
+   * for keyframes */
+  if ((packet->packet[0] & 0x40) == 0) {
+    GST_BUFFER_FLAG_UNSET (buf, GST_BUFFER_FLAG_DELTA_UNIT);
+  } else {
+    GST_BUFFER_FLAG_SET (buf, GST_BUFFER_FLAG_DELTA_UNIT);
+  }
+  enc->packetno++;
+
+done:
+  *buffer = buf;
+  return ret;
+}
+
+/* push out the buffer and do internal bookkeeping */
+static GstFlowReturn
+theora_push_buffer (GstTheoraEnc * enc, GstBuffer * buffer)
+{
+  GstFlowReturn ret;
+
+  enc->bytes_out += GST_BUFFER_SIZE (buffer);
+
+  ret = gst_pad_push (enc->srcpad, buffer);
+
+  return ret;
+}
+
+static GstFlowReturn
+theora_push_packet (GstTheoraEnc * enc, ogg_packet * packet,
+    GstClockTime timestamp, GstClockTime duration)
+{
+  GstBuffer *buf;
+  GstFlowReturn ret;
+
+  ret = theora_buffer_from_packet (enc, packet, timestamp, duration, &buf);
+  if (ret == GST_FLOW_OK)
+    ret = theora_push_buffer (enc, buf);
+
+  return ret;
+}
+
+static GstCaps *
+theora_set_header_on_caps (GstCaps * caps, GstBuffer * buf1,
+    GstBuffer * buf2, GstBuffer * buf3)
+{
+  GstStructure *structure;
+  GValue array = { 0 };
+  GValue value = { 0 };
+
+  caps = gst_caps_make_writable (caps);
+  structure = gst_caps_get_structure (caps, 0);
+
+  /* mark buffers */
+  GST_BUFFER_FLAG_SET (buf1, GST_BUFFER_FLAG_IN_CAPS);
+  GST_BUFFER_FLAG_SET (buf2, GST_BUFFER_FLAG_IN_CAPS);
+  GST_BUFFER_FLAG_SET (buf3, GST_BUFFER_FLAG_IN_CAPS);
+
+  /* Copy buffers, because we can't use the originals -
+   * it creates a circular refcount with the caps<->buffers */
+  buf1 = gst_buffer_copy (buf1);
+  buf2 = gst_buffer_copy (buf2);
+  buf3 = gst_buffer_copy (buf3);
+
+  /* put copies of the buffers in a fixed list */
+  g_value_init (&array, GST_TYPE_ARRAY);
+
+  g_value_init (&value, GST_TYPE_BUFFER);
+  gst_value_set_buffer (&value, buf1);
+  gst_value_array_append_value (&array, &value);
+  g_value_unset (&value);
+
+  g_value_init (&value, GST_TYPE_BUFFER);
+  gst_value_set_buffer (&value, buf2);
+  gst_value_array_append_value (&array, &value);
+  g_value_unset (&value);
+
+  g_value_init (&value, GST_TYPE_BUFFER);
+  gst_value_set_buffer (&value, buf3);
+  gst_value_array_append_value (&array, &value);
+  g_value_unset (&value);
+
+  gst_structure_set_value (structure, "streamheader", &array);
+  g_value_unset (&array);
+
+  /* Unref our copies */
+  gst_buffer_unref (buf1);
+  gst_buffer_unref (buf2);
+  gst_buffer_unref (buf3);
+
+  return caps;
+}
+
+static GstClockTime
+theora_enc_get_ogg_packet_end_time (GstTheoraEnc * enc, ogg_packet * op)
+{
+  ogg_int64_t end_granule;
+
+  /* FIXME: remove this hack once we depend on libtheora >= 1.0beta1 */
+  if (G_UNLIKELY (use_old_granulepos)) {
+    /* This is where we hack around theora's broken idea of what granulepos
+     * is -- normally we wouldn't need to add the 1, because granulepos
+     * should be the presentation time of the last sample in the packet, but
+     * theora starts with 0 instead of 1... (update: this only applies to old
+     * bitstream/theora versions, this is fixed with bitstream version 3.2.1) */
+    end_granule = granulepos_add (op->granulepos, 1, enc->granule_shift);
+  } else {
+    end_granule = op->granulepos;
+  }
+  return theora_granule_time (&enc->state, end_granule) * GST_SECOND;
+}
+
+static gboolean
+theora_enc_sink_event (GstPad * pad, GstEvent * event)
+{
+  GstTheoraEnc *enc;
+  ogg_packet op;
+  gboolean res;
+
+  enc = GST_THEORA_ENC (GST_PAD_PARENT (pad));
+
+  switch (GST_EVENT_TYPE (event)) {
+    case GST_EVENT_EOS:
+      if (enc->initialised) {
+        /* push last packet with eos flag */
+        while (theora_encode_packetout (&enc->state, 1, &op)) {
+          GstClockTime next_time =
+              theora_enc_get_ogg_packet_end_time (enc, &op);
+
+          theora_push_packet (enc, &op, enc->next_ts, next_time - enc->next_ts);
+          enc->next_ts = next_time;
+        }
+      }
+      res = gst_pad_push_event (enc->srcpad, event);
+      break;
+    case GST_EVENT_CUSTOM_DOWNSTREAM:
+    {
+      const GstStructure *s;
+
+      s = gst_event_get_structure (event);
+
+      if (gst_structure_has_name (s, "GstForceKeyUnit")) {
+        GstClockTime next_ts;
+
+        /* make sure timestamps increment after resetting the decoder */
+        next_ts = enc->next_ts + enc->timestamp_offset;
+
+        theora_enc_reset (enc);
+        enc->granulepos_offset =
+            gst_util_uint64_scale (next_ts, enc->fps_n,
+            GST_SECOND * enc->fps_d);
+        enc->timestamp_offset = next_ts;
+        enc->next_ts = 0;
+      }
+      res = gst_pad_push_event (enc->srcpad, event);
+      break;
+    }
+    default:
+      res = gst_pad_push_event (enc->srcpad, event);
+      break;
+  }
+  return res;
+}
+
+static gboolean
+theora_enc_is_discontinuous (GstTheoraEnc * enc, GstBuffer * buffer)
+{
+  GstClockTime ts = GST_BUFFER_TIMESTAMP (buffer);
+  GstClockTimeDiff max_diff;
+  gboolean ret = FALSE;
+
+  /* Allow 3/4 a frame off */
+  max_diff = (enc->info.fps_denominator * GST_SECOND * 3) /
+      (enc->info.fps_numerator * 4);
+
+  if (ts != GST_CLOCK_TIME_NONE && enc->expected_ts != GST_CLOCK_TIME_NONE) {
+    if ((GstClockTimeDiff) (ts - enc->expected_ts) > max_diff) {
+      GST_DEBUG_OBJECT (enc, "Incoming TS %" GST_TIME_FORMAT
+          " exceeds expected value %" GST_TIME_FORMAT
+          " by too much, marking discontinuity",
+          GST_TIME_ARGS (ts), GST_TIME_ARGS (enc->expected_ts));
+      ret = TRUE;
+    }
+  }
+
+  if (GST_CLOCK_TIME_IS_VALID (GST_BUFFER_DURATION (buffer)))
+    enc->expected_ts = ts + GST_BUFFER_DURATION (buffer);
+  else
+    enc->expected_ts = GST_CLOCK_TIME_NONE;
+
+  return ret;
+}
+
+static GstFlowReturn
+theora_enc_chain (GstPad * pad, GstBuffer * buffer)
+{
+  GstTheoraEnc *enc;
+  ogg_packet op;
+  GstClockTime in_time;
+  GstFlowReturn ret;
+
+  enc = GST_THEORA_ENC (GST_PAD_PARENT (pad));
+
+  in_time = GST_BUFFER_TIMESTAMP (buffer);
+
+  if (enc->packetno == 0) {
+    /* no packets written yet, setup headers */
+    GstCaps *caps;
+    GstBuffer *buf1, *buf2, *buf3;
+
+    enc->granulepos_offset = 0;
+    enc->timestamp_offset = 0;
+
+    GST_DEBUG_OBJECT (enc, "output headers");
+    /* Theora streams begin with three headers; the initial header (with
+       most of the codec setup parameters) which is mandated by the Ogg
+       bitstream spec.  The second header holds any comment fields.  The
+       third header holds the bitstream codebook.  We merely need to
+       make the headers, then pass them to libtheora one at a time;
+       libtheora handles the additional Ogg bitstream constraints */
+
+    /* first packet will get its own page automatically */
+    if (theora_encode_header (&enc->state, &op) != 0)
+      goto encoder_disabled;
+
+    ret = theora_buffer_from_packet (enc, &op, GST_CLOCK_TIME_NONE,
+        GST_CLOCK_TIME_NONE, &buf1);
+    if (ret != GST_FLOW_OK) {
+      goto header_buffer_alloc;
+    }
+
+    /* create the remaining theora headers */
+    theora_comment_clear (&enc->comment);
+    theora_comment_init (&enc->comment);
+
+    if (theora_encode_comment (&enc->comment, &op) != 0)
+      goto encoder_disabled;
+
+    ret = theora_buffer_from_packet (enc, &op, GST_CLOCK_TIME_NONE,
+        GST_CLOCK_TIME_NONE, &buf2);
+    /* Theora expects us to put this packet buffer into an ogg page,
+     * in which case it becomes the ogg library's responsibility to
+     * free it. Since we're copying and outputting a gst_buffer,
+     * we need to free it ourselves. */
+    if (op.packet)
+      free (op.packet);
+
+    if (ret != GST_FLOW_OK) {
+      gst_buffer_unref (buf1);
+      goto header_buffer_alloc;
+    }
+
+    if (theora_encode_tables (&enc->state, &op) != 0)
+      goto encoder_disabled;
+
+    ret = theora_buffer_from_packet (enc, &op, GST_CLOCK_TIME_NONE,
+        GST_CLOCK_TIME_NONE, &buf3);
+    if (ret != GST_FLOW_OK) {
+      gst_buffer_unref (buf1);
+      gst_buffer_unref (buf2);
+      goto header_buffer_alloc;
+    }
+
+    /* mark buffers and put on caps */
+    caps = gst_pad_get_caps (enc->srcpad);
+    caps = theora_set_header_on_caps (caps, buf1, buf2, buf3);
+    GST_DEBUG ("here are the caps: %" GST_PTR_FORMAT, caps);
+    gst_pad_set_caps (enc->srcpad, caps);
+
+    gst_buffer_set_caps (buf1, caps);
+    gst_buffer_set_caps (buf2, caps);
+    gst_buffer_set_caps (buf3, caps);
+
+    gst_caps_unref (caps);
+
+    /* push out the header buffers */
+    if ((ret = theora_push_buffer (enc, buf1)) != GST_FLOW_OK) {
+      gst_buffer_unref (buf2);
+      gst_buffer_unref (buf3);
+      goto header_push;
+    }
+    if ((ret = theora_push_buffer (enc, buf2)) != GST_FLOW_OK) {
+      gst_buffer_unref (buf3);
+      goto header_push;
+    }
+    if ((ret = theora_push_buffer (enc, buf3)) != GST_FLOW_OK) {
+      goto header_push;
+    }
+
+    enc->granulepos_offset =
+        gst_util_uint64_scale (in_time, enc->fps_n, GST_SECOND * enc->fps_d);
+    enc->timestamp_offset = in_time;
+    enc->next_ts = 0;
+  }
+
+  {
+    yuv_buffer yuv;
+    gint res;
+    gint y_size;
+    guint8 *pixels;
+
+    yuv.y_width = enc->info_width;
+    yuv.y_height = enc->info_height;
+    yuv.y_stride = enc->info_width;
+
+    yuv.uv_width = enc->info_width / 2;
+    yuv.uv_height = enc->info_height / 2;
+    yuv.uv_stride = yuv.uv_width;
+
+    y_size = enc->info_width * enc->info_height;
+
+    if (enc->width == enc->info_width && enc->height == enc->info_height) {
+      GST_LOG_OBJECT (enc, "no cropping/conversion needed");
+      /* easy case, no cropping/conversion needed */
+      pixels = GST_BUFFER_DATA (buffer);
+
+      yuv.y = pixels;
+      yuv.u = yuv.y + y_size;
+      yuv.v = yuv.u + y_size / 4;
+    } else {
+      GstBuffer *newbuf;
+      gint i;
+      guchar *dest_y, *src_y;
+      guchar *dest_u, *src_u;
+      guchar *dest_v, *src_v;
+      gint src_y_stride, src_uv_stride;
+      gint dst_y_stride, dst_uv_stride;
+      gint width, height;
+      gint cwidth, cheight;
+      gint offset_x, right_x, right_border;
+
+      GST_LOG_OBJECT (enc, "cropping/conversion needed for strides");
+      /* source width/height */
+      width = enc->width;
+      height = enc->height;
+      /* soucre chroma width/height */
+      cwidth = width / 2;
+      cheight = height / 2;
+
+      /* source strides as defined in videotestsrc */
+      src_y_stride = GST_ROUND_UP_4 (width);
+      src_uv_stride = GST_ROUND_UP_8 (width) / 2;
+
+      /* destination strides from the real picture width */
+      dst_y_stride = enc->info_width;
+      dst_uv_stride = enc->info_width / 2;
+
+      newbuf = gst_buffer_new_and_alloc (y_size * 3 / 2);
+      if (!newbuf) {
+        ret = GST_FLOW_ERROR;
+        goto no_buffer;
+      }
+      GST_BUFFER_OFFSET (newbuf) = GST_BUFFER_OFFSET_NONE;
+      gst_buffer_set_caps (newbuf, GST_PAD_CAPS (enc->srcpad));
+
+      dest_y = yuv.y = GST_BUFFER_DATA (newbuf);
+      dest_u = yuv.u = yuv.y + y_size;
+      dest_v = yuv.v = yuv.u + y_size / 4;
+
+      src_y = GST_BUFFER_DATA (buffer);
+      src_u = src_y + src_y_stride * GST_ROUND_UP_2 (height);
+      src_v = src_u + src_uv_stride * GST_ROUND_UP_2 (height) / 2;
+
+      if (enc->border != BORDER_NONE) {
+        /* fill top border */
+        for (i = 0; i < enc->offset_y; i++) {
+          memset (dest_y, 0, dst_y_stride);
+          dest_y += dst_y_stride;
+        }
+      } else {
+        dest_y += dst_y_stride * enc->offset_y;
+      }
+
+      offset_x = enc->offset_x;
+      right_x = width + enc->offset_x;
+      right_border = dst_y_stride - right_x;
+
+      /* copy Y plane */
+      for (i = 0; i < height; i++) {
+        memcpy (dest_y + offset_x, src_y, width);
+        if (enc->border != BORDER_NONE) {
+          memset (dest_y, 0, offset_x);
+          memset (dest_y + right_x, 0, right_border);
+        }
+
+        dest_y += dst_y_stride;
+        src_y += src_y_stride;
+      }
+
+      if (enc->border != BORDER_NONE) {
+        /* fill bottom border */
+        for (i = height + enc->offset_y; i < enc->info.height; i++) {
+          memset (dest_y, 0, dst_y_stride);
+          dest_y += dst_y_stride;
+        }
+
+        /* fill top border chroma */
+        for (i = 0; i < enc->offset_y / 2; i++) {
+          memset (dest_u, 128, dst_uv_stride);
+          memset (dest_v, 128, dst_uv_stride);
+          dest_u += dst_uv_stride;
+          dest_v += dst_uv_stride;
+        }
+      } else {
+        dest_u += dst_uv_stride * enc->offset_y / 2;
+        dest_v += dst_uv_stride * enc->offset_y / 2;
+      }
+
+      offset_x = enc->offset_x / 2;
+      right_x = cwidth + offset_x;
+      right_border = dst_uv_stride - right_x;
+
+      /* copy UV planes */
+      for (i = 0; i < cheight; i++) {
+        memcpy (dest_v + offset_x, src_v, cwidth);
+        memcpy (dest_u + offset_x, src_u, cwidth);
+
+        if (enc->border != BORDER_NONE) {
+          memset (dest_u, 128, offset_x);
+          memset (dest_u + right_x, 128, right_border);
+          memset (dest_v, 128, offset_x);
+          memset (dest_v + right_x, 128, right_border);
+        }
+
+        dest_u += dst_uv_stride;
+        dest_v += dst_uv_stride;
+        src_u += src_uv_stride;
+        src_v += src_uv_stride;
+      }
+
+      if (enc->border != BORDER_NONE) {
+        /* fill bottom border */
+        for (i = cheight + enc->offset_y / 2; i < enc->info_height / 2; i++) {
+          memset (dest_u, 128, dst_uv_stride);
+          memset (dest_v, 128, dst_uv_stride);
+          dest_u += dst_uv_stride;
+          dest_v += dst_uv_stride;
+        }
+      }
+
+      gst_buffer_unref (buffer);
+      buffer = newbuf;
+    }
+
+    if (theora_enc_is_discontinuous (enc, buffer)) {
+      theora_enc_reset (enc);
+      enc->granulepos_offset =
+          gst_util_uint64_scale (in_time, enc->fps_n, GST_SECOND * enc->fps_d);
+      enc->timestamp_offset = in_time;
+      enc->next_ts = 0;
+      enc->next_discont = TRUE;
+    }
+
+    res = theora_encode_YUVin (&enc->state, &yuv);
+
+    ret = GST_FLOW_OK;
+    while (theora_encode_packetout (&enc->state, 0, &op)) {
+      GstClockTime next_time = theora_enc_get_ogg_packet_end_time (enc, &op);
+
+      ret =
+          theora_push_packet (enc, &op, enc->next_ts, next_time - enc->next_ts);
+      enc->next_ts = next_time;
+      if (ret != GST_FLOW_OK)
+        goto data_push;
+    }
+    gst_buffer_unref (buffer);
+  }
+
+  return ret;
+
+  /* ERRORS */
+header_buffer_alloc:
+  {
+    gst_buffer_unref (buffer);
+    return ret;
+  }
+header_push:
+  {
+    gst_buffer_unref (buffer);
+    return ret;
+  }
+no_buffer:
+  {
+    return ret;
+  }
+data_push:
+  {
+    gst_buffer_unref (buffer);
+    return ret;
+  }
+encoder_disabled:
+  {
+    GST_ELEMENT_ERROR (enc, STREAM, ENCODE, (NULL),
+        ("libtheora has been compiled with the encoder disabled"));
+    gst_buffer_unref (buffer);
+    return GST_FLOW_ERROR;
+  }
+}
+
+static GstStateChangeReturn
+theora_enc_change_state (GstElement * element, GstStateChange transition)
+{
+  GstTheoraEnc *enc;
+  GstStateChangeReturn ret;
+
+  enc = GST_THEORA_ENC (element);
+
+  switch (transition) {
+    case GST_STATE_CHANGE_NULL_TO_READY:
+      break;
+    case GST_STATE_CHANGE_READY_TO_PAUSED:
+      GST_DEBUG_OBJECT (enc, "READY->PAUSED Initing theora state");
+      theora_info_init (&enc->info);
+      theora_comment_init (&enc->comment);
+      enc->packetno = 0;
+      break;
+    case GST_STATE_CHANGE_PAUSED_TO_PLAYING:
+      break;
+    default:
+      break;
+  }
+
+  ret = parent_class->change_state (element, transition);
+
+  switch (transition) {
+    case GST_STATE_CHANGE_PLAYING_TO_PAUSED:
+      break;
+    case GST_STATE_CHANGE_PAUSED_TO_READY:
+      GST_DEBUG_OBJECT (enc, "PAUSED->READY Clearing theora state");
+      theora_clear (&enc->state);
+      theora_comment_clear (&enc->comment);
+      theora_info_clear (&enc->info);
+
+      theora_enc_clear (enc);
+      enc->initialised = FALSE;
+      break;
+    case GST_STATE_CHANGE_READY_TO_NULL:
+      break;
+    default:
+      break;
+  }
+
+  return ret;
+}
+
+static void
+theora_enc_set_property (GObject * object, guint prop_id,
+    const GValue * value, GParamSpec * pspec)
+{
+  GstTheoraEnc *enc = GST_THEORA_ENC (object);
+
+  switch (prop_id) {
+    case ARG_CENTER:
+      enc->center = g_value_get_boolean (value);
+      break;
+    case ARG_BORDER:
+      enc->border = g_value_get_enum (value);
+      break;
+    case ARG_BITRATE:
+      enc->video_bitrate = g_value_get_int (value) * 1000;
+      enc->video_quality = 0;
+      break;
+    case ARG_QUALITY:
+      enc->video_quality = g_value_get_int (value);
+      enc->video_bitrate = 0;
+      break;
+    case ARG_QUICK:
+      enc->quick = g_value_get_boolean (value);
+      break;
+    case ARG_KEYFRAME_AUTO:
+      enc->keyframe_auto = g_value_get_boolean (value);
+      break;
+    case ARG_KEYFRAME_FREQ:
+      enc->keyframe_freq = g_value_get_int (value);
+      break;
+    case ARG_KEYFRAME_FREQ_FORCE:
+      enc->keyframe_force = g_value_get_int (value);
+      break;
+    case ARG_KEYFRAME_THRESHOLD:
+      enc->keyframe_threshold = g_value_get_int (value);
+      break;
+    case ARG_KEYFRAME_MINDISTANCE:
+      enc->keyframe_mindistance = g_value_get_int (value);
+      break;
+    case ARG_NOISE_SENSITIVITY:
+      enc->noise_sensitivity = g_value_get_int (value);
+      break;
+    case ARG_SHARPNESS:
+      enc->sharpness = g_value_get_int (value);
+      break;
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+      break;
+  }
+}
+
+static void
+theora_enc_get_property (GObject * object, guint prop_id,
+    GValue * value, GParamSpec * pspec)
+{
+  GstTheoraEnc *enc = GST_THEORA_ENC (object);
+
+  switch (prop_id) {
+    case ARG_CENTER:
+      g_value_set_boolean (value, enc->center);
+      break;
+    case ARG_BORDER:
+      g_value_set_enum (value, enc->border);
+      break;
+    case ARG_BITRATE:
+      g_value_set_int (value, enc->video_bitrate / 1000);
+      break;
+    case ARG_QUALITY:
+      g_value_set_int (value, enc->video_quality);
+      break;
+    case ARG_QUICK:
+      g_value_set_boolean (value, enc->quick);
+      break;
+    case ARG_KEYFRAME_AUTO:
+      g_value_set_boolean (value, enc->keyframe_auto);
+      break;
+    case ARG_KEYFRAME_FREQ:
+      g_value_set_int (value, enc->keyframe_freq);
+      break;
+    case ARG_KEYFRAME_FREQ_FORCE:
+      g_value_set_int (value, enc->keyframe_force);
+      break;
+    case ARG_KEYFRAME_THRESHOLD:
+      g_value_set_int (value, enc->keyframe_threshold);
+      break;
+    case ARG_KEYFRAME_MINDISTANCE:
+      g_value_set_int (value, enc->keyframe_mindistance);
+      break;
+    case ARG_NOISE_SENSITIVITY:
+      g_value_set_int (value, enc->noise_sensitivity);
+      break;
+    case ARG_SHARPNESS:
+      g_value_set_int (value, enc->sharpness);
+      break;
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+      break;
+  }
+}