rtpvp8: Add simple payloaders and depayloaders for VP8

Minimal implementation of http://www.webmproject.org/code/specs/rtp/,
version 0.3.2

configure.ac

@@ -334,6 +334,7 @@ AG_GST_CHECK_PLUGIN(qtmux)
 AG_GST_CHECK_PLUGIN(rawparse)
 AG_GST_CHECK_PLUGIN(real)
 AG_GST_CHECK_PLUGIN(rtpmux)
+AG_GST_CHECK_PLUGIN(rtpvp8)
 AG_GST_CHECK_PLUGIN(scaletempo)
 AG_GST_CHECK_PLUGIN(sdp)
 AG_GST_CHECK_PLUGIN(segmentclip)
@@ -1755,6 +1756,7 @@ gst/qtmux/Makefile
 gst/rawparse/Makefile
 gst/real/Makefile
 gst/rtpmux/Makefile
+gst/rtpvp8/Makefile
 gst/scaletempo/Makefile
 gst/sdp/Makefile
 gst/segmentclip/Makefile

gst/rtpvp8/Makefile.am

@@ -0,0 +1,14 @@
+plugin_LTLIBRARIES = libgstrtpvp8.la
+
+libgstrtpvp8_la_SOURCES = gstrtpvp8.c \
+  gstrtpvp8depay.c \
+  gstrtpvp8pay.c
+
+noinst_HEADERS = gstrtpvp8depay.h \
+  gstrtpvp8pay.h
+
+libgstrtpvp8_la_CFLAGS = $(GST_CFLAGS) $(GST_PLUGINS_BASE_CFLAGS)
+libgstrtpvp8_la_LIBADD = $(GST_PLUGINS_BASE_LIBS) $(GST_LIBS) \
+    -lgstrtp-@GST_MAJORMINOR@ 
+libgstrtpvp8_la_LDFLAGS = $(GST_PLUGIN_LDFLAGS)
+libgstrtpvp8_la_LIBTOOLFLAGS = --tag=disable-static

gst/rtpvp8/gstrtpvp8.c

@@ -0,0 +1,21 @@
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include "gstrtpvp8pay.h"
+#include "gstrtpvp8depay.h"
+
+static gboolean
+plugin_init (GstPlugin *plugin)
+{
+  gst_rtp_vp8_depay_plugin_init (plugin);
+  gst_rtp_vp8_pay_plugin_init (plugin);
+
+  return TRUE;
+}
+
+GST_PLUGIN_DEFINE (GST_VERSION_MAJOR,
+    GST_VERSION_MINOR,
+    "rtpvp8",
+    "rtpvp8",
+    plugin_init, VERSION, GST_LICENSE, GST_PACKAGE_NAME, GST_PACKAGE_ORIGIN)

gst/rtpvp8/gstrtpvp8depay.c

@@ -0,0 +1,193 @@
+/*
+ * gst-rtp-vp8-depay.c - Source for GstRtpVP8Depay
+ * Copyright (C) 2011 Sjoerd Simons <sjoerd@luon.net>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ */
+
+
+#ifdef HAVE_CONFIG_H
+# include "config.h"
+#endif
+
+#include "gstrtpvp8depay.h"
+
+GST_DEBUG_CATEGORY_STATIC (gst_rtp_vp8_depay_debug);
+#define GST_CAT_DEFAULT gst_rtp_vp8_depay_debug
+
+GST_BOILERPLATE (GstRtpVP8Depay, gst_rtp_vp8_depay, GstBaseRTPDepayload,
+    GST_TYPE_BASE_RTP_DEPAYLOAD);
+
+static GstStaticPadTemplate gst_rtp_vp8_depay_src_template =
+GST_STATIC_PAD_TEMPLATE ("src",
+    GST_PAD_SRC,
+    GST_PAD_ALWAYS,
+    GST_STATIC_CAPS ("video/x-vp8"));
+
+static GstStaticPadTemplate gst_rtp_vp8_depay_sink_template =
+GST_STATIC_PAD_TEMPLATE ("sink",
+    GST_PAD_SINK,
+    GST_PAD_ALWAYS,
+    GST_STATIC_CAPS ("application/x-rtp, "
+        "payload = (int) " GST_RTP_PAYLOAD_DYNAMIC_STRING ","
+        "clock-rate = (int) 90000,"
+        "media = (string) \"video\","
+        "encoding-name = (string) \"VP8-DRAFT-0-3-2\""));
+
+static void
+gst_rtp_vp8_depay_init (GstRtpVP8Depay * self, GstRtpVP8DepayClass * klass)
+{
+  self->adapter = gst_adapter_new ();
+  self->started = FALSE;
+}
+
+static void gst_rtp_vp8_depay_dispose (GObject * object);
+static GstBuffer *gst_rtp_vp8_depay_process (GstBaseRTPDepayload * depayload,
+    GstBuffer * buf);
+static gboolean gst_rtp_vp8_depay_set_caps (GstBaseRTPDepayload * depayload,
+    GstCaps * caps);
+
+static void
+gst_rtp_vp8_depay_base_init (gpointer klass)
+{
+  GstElementClass *element_class = GST_ELEMENT_CLASS (klass);
+
+  gst_element_class_add_pad_template (element_class,
+      gst_static_pad_template_get (&gst_rtp_vp8_depay_sink_template));
+  gst_element_class_add_pad_template (element_class,
+      gst_static_pad_template_get (&gst_rtp_vp8_depay_src_template));
+
+  gst_element_class_set_details_simple (element_class, "RTP VP8 depayloader",
+      "Codec/Depayloader/Network/RTP",
+      "Extracts VP8 video from RTP packets)",
+      "Sjoerd Simons <sjoerd@luon.net>");
+}
+
+static void
+gst_rtp_vp8_depay_class_init (GstRtpVP8DepayClass * gst_rtp_vp8_depay_class)
+{
+  GObjectClass *object_class = G_OBJECT_CLASS (gst_rtp_vp8_depay_class);
+  GstBaseRTPDepayloadClass *depay_class =
+      (GstBaseRTPDepayloadClass *) (gst_rtp_vp8_depay_class);
+
+  object_class->dispose = gst_rtp_vp8_depay_dispose;
+
+  depay_class->process = gst_rtp_vp8_depay_process;
+  depay_class->set_caps = gst_rtp_vp8_depay_set_caps;
+
+  GST_DEBUG_CATEGORY_INIT (gst_rtp_vp8_depay_debug, "rtpvp8depay", 0,
+      "VP8 Video RTP Depayloader");
+}
+
+static void
+gst_rtp_vp8_depay_dispose (GObject * object)
+{
+  GstRtpVP8Depay *self = GST_RTP_VP8_DEPAY (object);
+
+  if (self->adapter != NULL)
+    g_object_unref (self->adapter);
+  self->adapter = NULL;
+
+  /* release any references held by the object here */
+
+  if (G_OBJECT_CLASS (parent_class)->dispose)
+    G_OBJECT_CLASS (parent_class)->dispose (object);
+}
+
+static GstBuffer *
+gst_rtp_vp8_depay_process (GstBaseRTPDepayload * depay, GstBuffer * buf)
+{
+  GstRtpVP8Depay *self = GST_RTP_VP8_DEPAY (depay);
+  GstBuffer *payload;
+  guint8 *data;
+  guint offset;
+  guint size = gst_rtp_buffer_get_payload_len (buf);
+
+  if (G_UNLIKELY (GST_BUFFER_IS_DISCONT (buf))) {
+    GST_LOG_OBJECT (self, "Discontinuity, flushing adapter");
+    gst_adapter_clear (self->adapter);
+    self->started = FALSE;
+  }
+
+  if (G_UNLIKELY (size < 2))
+    goto too_small;
+
+  data = gst_rtp_buffer_get_payload (buf);
+
+  if (G_UNLIKELY (!self->started)) {
+    /* Check if this is the start of a VP8 frame, otherwise bail */
+    if ((data[0] & 0x1) == 0)
+      return NULL;
+
+    self->started = TRUE;
+  }
+
+  offset = 1;
+  if ((data[0] & 0x10) != 0) {
+    /* Skip Picture identifier bytes */
+    for (; (data[offset] & 0x80) != 0; offset++) {
+      /* should be at least one more pictureID byte and at least one byte in
+       * the vp8 payload */
+      if (offset + 2 >= size)
+        goto too_small;
+    }
+    offset++;
+  }
+
+  if (offset + 1 >= size)
+    goto too_small;
+
+  payload = gst_rtp_buffer_get_payload_subbuffer (buf, offset, -1);
+  gst_adapter_push (self->adapter, payload);
+
+  /* Marker indicates that it was the last rtp packet for this frame */
+  if (gst_rtp_buffer_get_marker (buf)) {
+    GstBuffer *out;
+
+    out = gst_adapter_take_buffer (self->adapter,
+        gst_adapter_available (self->adapter));
+
+    self->started = FALSE;
+    return out;
+  }
+
+  return NULL;
+
+too_small:
+  GST_LOG_OBJECT (self, "Invalid rtp packet (too small), ignoring");
+  gst_adapter_clear (self->adapter);
+  self->started = FALSE;
+  return NULL;
+}
+
+static gboolean
+gst_rtp_vp8_depay_set_caps (GstBaseRTPDepayload * depayload, GstCaps * caps)
+{
+  GstCaps *srccaps = gst_caps_new_simple ("video/x-vp8",
+      "framerate", GST_TYPE_FRACTION, 0, 1,
+      NULL);
+
+  gst_pad_set_caps (GST_BASE_RTP_DEPAYLOAD_SRCPAD (depayload), srccaps);
+  gst_caps_unref (srccaps);
+
+  return TRUE;
+}
+
+gboolean
+gst_rtp_vp8_depay_plugin_init (GstPlugin * plugin)
+{
+  return gst_element_register (plugin, "rtpvp8depay",
+      GST_RANK_MARGINAL, GST_TYPE_RTP_VP8_DEPAY);
+}

gst/rtpvp8/gstrtpvp8depay.h

@@ -0,0 +1,63 @@
+/*
+ * gst-rtp-vp8-depay.h - Header for GstRtpVP8Depay
+ * Copyright (C) 2011 Sjoerd Simons <sjoerd@luon.net>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ */
+
+#ifndef __GST_RTP_VP8_DEPAY_H__
+#define __GST_RTP_VP8_DEPAY_H__
+
+#include <glib-object.h>
+#include <gst/base/gstadapter.h>
+#include <gst/rtp/gstbasertpdepayload.h>
+
+G_BEGIN_DECLS typedef struct _GstRtpVP8Depay GstRtpVP8Depay;
+typedef struct _GstRtpVP8DepayClass GstRtpVP8DepayClass;
+
+struct _GstRtpVP8DepayClass
+{
+  GstBaseRTPDepayloadClass parent_class;
+};
+
+struct _GstRtpVP8Depay
+{
+  GstBaseRTPDepayload parent;
+  GstAdapter *adapter;
+  gboolean started;
+};
+
+GType gst_rtp_vp8_depay_get_type (void);
+
+/* TYPE MACROS */
+#define GST_TYPE_RTP_VP8_DEPAY \
+  (gst_rtp_vp8_depay_get_type())
+#define GST_RTP_VP8_DEPAY(obj) \
+  (G_TYPE_CHECK_INSTANCE_CAST((obj), GST_TYPE_RTP_VP8_DEPAY, GstRtpVP8Depay))
+#define GST_RTP_VP8_DEPAY_CLASS(klass) \
+  (G_TYPE_CHECK_CLASS_CAST((klass), GST_TYPE_RTP_VP8_DEPAY, \
+    GstRtpVP8DepayClass))
+#define GST_IS_RTP_VP8_DEPAY(obj) \
+  (G_TYPE_CHECK_INSTANCE_TYPE((obj), GST_TYPE_RTP_VP8_DEPAY))
+#define GST_IS_RTP_VP8_DEPAY_CLASS(klass) \
+  (G_TYPE_CHECK_CLASS_TYPE((klass), GST_TYPE_RTP_VP8_DEPAY))
+#define GST_RTP_VP8_DEPAY_GET_CLASS(obj) \
+  (G_TYPE_INSTANCE_GET_CLASS ((obj), GST_TYPE_RTP_VP8_DEPAY, \
+    GstRtpVP8DepayClass))
+
+gboolean gst_rtp_vp8_depay_plugin_init (GstPlugin * plugin);
+
+G_END_DECLS
+#endif /* #ifndef __GST_RTP_VP8_DEPAY_H__ */

gst/rtpvp8/gstrtpvp8pay.c

@@ -0,0 +1,473 @@
+/*
+ * gst-rtp-vp8-pay.c - Source for GstRtpVP8Pay
+ * Copyright (C) 2011 Sjoerd Simons <sjoerd@luon.net>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ */
+
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include <gst/base/gstbitreader.h>
+#include <gst/rtp/gstrtppayloads.h>
+#include <gst/rtp/gstrtpbuffer.h>
+#include "gstrtpvp8pay.h"
+
+#define FI_FRAG_UNFRAGMENTED 0x0
+#define FI_FRAG_START 0x1
+#define FI_FRAG_MIDDLE 0x2
+#define FI_FRAG_END 0x3
+
+GST_DEBUG_CATEGORY_STATIC (gst_rtp_vp8_pay_debug);
+#define GST_CAT_DEFAULT gst_rtp_vp8_pay_debug
+
+GST_BOILERPLATE (GstRtpVP8Pay, gst_rtp_vp8_pay, GstBaseRTPPayload,
+    GST_TYPE_BASE_RTP_PAYLOAD);
+
+static GstStaticPadTemplate gst_rtp_vp8_pay_src_template =
+GST_STATIC_PAD_TEMPLATE ("src",
+    GST_PAD_SRC,
+    GST_PAD_ALWAYS,
+    GST_STATIC_CAPS ("application/x-rtp, "
+        "payload = (int) " GST_RTP_PAYLOAD_DYNAMIC_STRING ","
+        "clock-rate = (int) 90000, encoding-name = (string) \"VP8-DRAFT-0-3-2\""));
+
+static GstStaticPadTemplate gst_rtp_vp8_pay_sink_template =
+GST_STATIC_PAD_TEMPLATE ("sink",
+    GST_PAD_SINK,
+    GST_PAD_ALWAYS,
+    GST_STATIC_CAPS ("video/x-vp8"));
+
+static void
+gst_rtp_vp8_pay_init (GstRtpVP8Pay * obj, GstRtpVP8PayClass * klass)
+{
+}
+
+static GstFlowReturn gst_rtp_vp8_pay_handle_buffer (GstBaseRTPPayload * payload,
+    GstBuffer * buffer);
+static gboolean gst_rtp_vp8_pay_set_caps (GstBaseRTPPayload * payload,
+    GstCaps * caps);
+
+static void
+gst_rtp_vp8_pay_base_init (gpointer klass)
+{
+  GstElementClass *element_class = GST_ELEMENT_CLASS (klass);
+
+  gst_element_class_add_pad_template (element_class,
+      gst_static_pad_template_get (&gst_rtp_vp8_pay_sink_template));
+  gst_element_class_add_pad_template (element_class,
+      gst_static_pad_template_get (&gst_rtp_vp8_pay_src_template));
+
+  gst_element_class_set_details_simple (element_class, "RTP VP8 payloader",
+      "Codec/Payloader/Network/RTP",
+      "Puts VP8 video in RTP packets)", "Sjoerd Simons <sjoerd@luon.net>");
+}
+
+static void
+gst_rtp_vp8_pay_class_init (GstRtpVP8PayClass * gst_rtp_vp8_pay_class)
+{
+  GstBaseRTPPayloadClass *pay_class =
+      GST_BASE_RTP_PAYLOAD_CLASS (gst_rtp_vp8_pay_class);
+
+  pay_class->handle_buffer = gst_rtp_vp8_pay_handle_buffer;
+  pay_class->set_caps = gst_rtp_vp8_pay_set_caps;
+
+  GST_DEBUG_CATEGORY_INIT (gst_rtp_vp8_pay_debug, "rtpvp8pay", 0,
+      "VP8 Video RTP Payloader");
+}
+
+static gsize
+gst_rtp_vp8_calc_payload_len (GstBaseRTPPayload * payload)
+{
+  return gst_rtp_buffer_calc_payload_len (GST_BASE_RTP_PAYLOAD_MTU (payload) -
+      1, 0, 0);
+}
+
+/* When growing the vp8 header keep gst_rtp_vp8_calc_payload_len in sync */
+static GstBuffer *
+gst_rtp_vp8_create_header_buffer (gboolean start, gboolean mark, guint fi,
+    GstBuffer * in)
+{
+  GstBuffer *out;
+  guint8 *p;
+
+  out = gst_rtp_buffer_new_allocate (1, 0, 0);
+  p = gst_rtp_buffer_get_payload (out);
+  /* Hardcode I = 0 and N = 0, only set FI and B */
+  p[0] = (fi & 0x3) << 1 | (start ? 1 : 0);
+
+  gst_rtp_buffer_set_marker (out, mark);
+
+  GST_BUFFER_DURATION (out) = GST_BUFFER_DURATION (in);
+  GST_BUFFER_TIMESTAMP (out) = GST_BUFFER_TIMESTAMP (in);
+
+  return out;
+}
+
+
+static gboolean
+gst_rtp_vp8_pay_parse_frame (GstRtpVP8Pay * self, GstBuffer * buffer)
+{
+  GstBitReader *reader;
+  int i;
+  gboolean keyframe;
+  guint32 header_size;
+  guint8 version;
+  guint8 tmp8;
+  guint8 *data;
+  guint8 partitions;
+
+  reader = gst_bit_reader_new_from_buffer (buffer);
+
+  if (G_UNLIKELY (GST_BUFFER_SIZE (buffer) < 3))
+    goto error;
+
+  data = GST_BUFFER_DATA (buffer);
+
+  self->is_keyframe = keyframe = ((data[0] & 0x1) == 0);
+  version = (data[0] >> 1) & 0x7;
+
+  /* keyframe, version and show_frame use 5 bits */
+  header_size = data[2] << 11 | data[1] << 3 | (data[0] >> 5);
+
+  /* Include the uncompressed data blob in the header */
+  header_size += keyframe ? 10 : 3;
+
+  if (!gst_bit_reader_skip (reader, 24))
+    goto error;
+
+  if (keyframe) {
+    /* check start tag: 0x9d 0x01 0x2a */
+    if (!gst_bit_reader_get_bits_uint8 (reader, &tmp8, 8) || tmp8 != 0x9d)
+      goto error;
+
+    if (!gst_bit_reader_get_bits_uint8 (reader, &tmp8, 8) || tmp8 != 0x01)
+      goto error;
+
+    if (!gst_bit_reader_get_bits_uint8 (reader, &tmp8, 8) || tmp8 != 0x2a)
+      goto error;
+
+    /* Skip horizontal size code (16 bits) vertical size code (16 bits),
+     * color space (1 bit) and clamping type (1 bit) */
+    if (!gst_bit_reader_skip (reader, 34))
+      goto error;
+  }
+
+  /* segmentation_enabled */
+  if (!gst_bit_reader_get_bits_uint8 (reader, &tmp8, 1))
+    goto error;
+
+  if (tmp8 != 0) {
+    gboolean update_mb_segmentation_map;
+    gboolean update_segment_feature_data;
+
+    if (!gst_bit_reader_get_bits_uint8 (reader, &tmp8, 2))
+      goto error;
+
+    update_mb_segmentation_map = (tmp8 & 0x2) != 0;
+    update_segment_feature_data = (tmp8 & 0x1) != 0;
+
+    if (update_segment_feature_data) {
+      /* skip segment feature mode */
+      if (!gst_bit_reader_skip (reader, 1))
+        goto error;
+
+      for (i = 0; i < 4; i++) {
+        /* quantizer update */
+        if (!gst_bit_reader_get_bits_uint8 (reader, &tmp8, 1))
+          goto error;
+
+        if (tmp8 != 0) {
+          /* skip quantizer value (7 bits) and sign (1 bit) */
+          if (!gst_bit_reader_skip (reader, 8))
+            goto error;
+        }
+      }
+
+      for (i = 0; i < 4; i++) {
+        /* loop filter update */
+        if (!gst_bit_reader_get_bits_uint8 (reader, &tmp8, 1))
+          goto error;
+
+        if (tmp8 != 0) {
+          /* skip lf update value (6 bits) and sign (1 bit) */
+          if (!gst_bit_reader_skip (reader, 7))
+            goto error;
+        }
+      }
+    }
+
+    if (update_mb_segmentation_map) {
+      for (i = 0; i < 3; i++) {
+        /* segment prob update */
+        if (!gst_bit_reader_get_bits_uint8 (reader, &tmp8, 1))
+          goto error;
+
+        if (tmp8 != 0) {
+          /* skip segment prob */
+          if (!gst_bit_reader_skip (reader, 8))
+            goto error;
+        }
+      }
+    }
+  }
+
+  /* skip filter type (1 bit), loop filter level (6 bits) and
+   * sharpness level (3 bits) */
+  if (!gst_bit_reader_skip (reader, 10))
+    goto error;
+
+  /* loop_filter_adj_enabled */
+  if (!gst_bit_reader_get_bits_uint8 (reader, &tmp8, 1))
+    goto error;
+
+  if (tmp8 != 0) {
+    /* loop filter adj enabled */
+
+    /* mode_ref_lf_delta_update */
+    if (!gst_bit_reader_get_bits_uint8 (reader, &tmp8, 1))
+      goto error;
+
+    if (tmp8 != 0) {
+      /* mode_ref_lf_data_update */
+      int i;
+
+      for (i = 0; i < 8; i++) {
+        /* 8 updates, 1 bit indicate whether there is one and if follow by a
+         * 7 bit update */
+        if (!gst_bit_reader_get_bits_uint8 (reader, &tmp8, 1))
+          goto error;
+
+        if (tmp8 != 0) {
+          /* skip delta magnitude (6 bits) and sign (1 bit) */
+          if (!gst_bit_reader_skip (reader, 7))
+            goto error;
+        }
+      }
+    }
+  }
+
+  if (!gst_bit_reader_get_bits_uint8 (reader, &tmp8, 2))
+    goto error;
+
+  self->n_partitions = partitions = 1 << tmp8;
+
+  /* Check if things are still sensible */
+  if (header_size + (partitions - 1) * 3 >= GST_BUFFER_SIZE (buffer))
+    goto error;
+
+  /* partition data is right after the frame header */
+  data = GST_BUFFER_DATA (buffer) + header_size;
+
+  self->partition_offset[0] = header_size + (partitions - 1) * 3;
+
+  /* Include partition data in the header for RTP purposes */
+  self->header_size = self->partition_offset[0];
+
+  for (i = 0; i < (partitions - 1); i++) {
+    guint size = (data[2] << 16 | data[1] << 8 | data[0]);
+
+    data += 3;
+    self->partition_size[i] = size;
+    self->partition_offset[i + 1] = self->partition_offset[i] + size;
+  }
+
+  /* Check that our partition offsets and sizes don't go outsize the buffer
+   * size. */
+  if (self->partition_offset[i] >= GST_BUFFER_SIZE (buffer))
+    goto error;
+
+  self->partition_size[i] = GST_BUFFER_SIZE (buffer)
+      - self->partition_offset[i];
+
+  self->partition_offset[i + 1] = GST_BUFFER_SIZE (buffer);
+
+  gst_bit_reader_free (reader);
+  return TRUE;
+
+error:
+  GST_DEBUG ("Failed to parse frame");
+  gst_bit_reader_free (reader);
+  return FALSE;
+}
+
+static guint
+gst_rtp_vp8_fit_partitions (GstRtpVP8Pay * self, gint first, gsize available)
+{
+  guint num = 0;
+  int i;
+
+  g_assert (first < self->n_partitions);
+
+  if (first < 0) {
+    if (self->header_size > available)
+      return 0;
+
+    available -= self->header_size;
+    num++;
+    first = 0;
+  }
+
+  for (i = first;
+      i < self->n_partitions && self->partition_size[i] < available; i++) {
+    num++;
+    available -= self->partition_size[i];
+  }
+
+  return num;
+}
+
+static GstBuffer *
+gst_rtp_vp8_create_sub (GstRtpVP8Pay * self,
+    GstBuffer * buffer, gint current, guint num)
+{
+  guint offset = 0;
+  guint size;
+
+  if (current >= 0) {
+    offset = self->partition_offset[current];
+  }
+
+  size = self->partition_offset[current + num] - offset;
+
+  return gst_buffer_create_sub (buffer, offset, size);
+}
+
+
+static guint
+gst_rtp_vp8_payload_next (GstRtpVP8Pay * self,
+    GstBufferListIterator * it, gint first, GstBuffer * buffer)
+{
+  guint num;
+  GstBuffer *header;
+  GstBuffer *sub;
+  gboolean mark;
+  gsize available = gst_rtp_vp8_calc_payload_len (GST_BASE_RTP_PAYLOAD (self));
+
+  g_assert (first < 8);
+
+  /* How many partitions can we fit */
+  num = gst_rtp_vp8_fit_partitions (self, first, available);
+
+  if (num > 0) {
+    mark = (first + num == self->n_partitions);
+    /* whole set of partitions, payload them and done */
+    header = gst_rtp_vp8_create_header_buffer (first == -1, mark,
+        FI_FRAG_UNFRAGMENTED, buffer);
+    sub = gst_rtp_vp8_create_sub (self, buffer, first, num);
+
+    gst_buffer_list_iterator_add_group (it);
+    gst_buffer_list_iterator_add (it, header);
+    gst_buffer_list_iterator_add (it, sub);
+  } else {
+    /* Fragmented packets */
+    guint left;
+    guint offset;
+
+    if (first >= 0) {
+      offset = self->partition_offset[first];
+      left = self->partition_size[first];
+    } else {
+      offset = 0;
+      left = self->header_size;
+    }
+
+    header = gst_rtp_vp8_create_header_buffer (first == -1, FALSE,
+        FI_FRAG_START, buffer);
+    sub = gst_buffer_create_sub (buffer, offset, available);
+    offset += available;
+
+    gst_buffer_list_iterator_add_group (it);
+    gst_buffer_list_iterator_add (it, header);
+    gst_buffer_list_iterator_add (it, sub);
+
+    left -= available;
+
+    for (; left > available; left -= available) {
+      header = gst_rtp_vp8_create_header_buffer (first == -1, FALSE,
+          FI_FRAG_MIDDLE, buffer);
+
+      sub = gst_buffer_create_sub (buffer, offset, available);
+      offset += available;
+
+      gst_buffer_list_iterator_add_group (it);
+      gst_buffer_list_iterator_add (it, header);
+      gst_buffer_list_iterator_add (it, sub);
+    }
+
+    mark = (first + 1 == self->n_partitions);
+
+    header = gst_rtp_vp8_create_header_buffer (first == -1, mark,
+        FI_FRAG_END, buffer);
+    sub = gst_buffer_create_sub (buffer, offset, left);
+
+    gst_buffer_list_iterator_add_group (it);
+    gst_buffer_list_iterator_add (it, header);
+    gst_buffer_list_iterator_add (it, sub);
+
+    return 1;
+  }
+
+  return num;
+}
+
+
+static GstFlowReturn
+gst_rtp_vp8_pay_handle_buffer (GstBaseRTPPayload * payload, GstBuffer * buffer)
+{
+  GstRtpVP8Pay *self = GST_RTP_VP8_PAY (payload);
+  GstFlowReturn ret;
+  GstBufferList *list;
+  GstBufferListIterator *it;
+  gint current;
+
+  if (G_UNLIKELY (!gst_rtp_vp8_pay_parse_frame (self, buffer))) {
+    /* FIXME throw flow error */
+    g_message ("Failed to parse frame");
+    return GST_FLOW_ERROR;
+  }
+
+  list = gst_buffer_list_new ();
+  it = gst_buffer_list_iterate (list);
+
+  for (current = -1; current < self->n_partitions;) {
+    guint n;
+
+    n = gst_rtp_vp8_payload_next (self, it, current, buffer);
+    current += n;
+  }
+
+  ret = gst_basertppayload_push_list (payload, list);
+  gst_buffer_list_iterator_free (it);
+
+  return ret;
+}
+
+static gboolean
+gst_rtp_vp8_pay_set_caps (GstBaseRTPPayload * payload, GstCaps * caps)
+{
+  gst_basertppayload_set_options (payload, "video", TRUE,
+      "VP8-DRAFT-0-3-2", 90000);
+  return gst_basertppayload_set_outcaps (payload, NULL);
+}
+
+gboolean
+gst_rtp_vp8_pay_plugin_init (GstPlugin * plugin)
+{
+  return gst_element_register (plugin, "rtpvp8pay",
+      GST_RANK_MARGINAL, GST_TYPE_RTP_VP8_PAY);
+}

gst/rtpvp8/gstrtpvp8pay.h

@@ -0,0 +1,65 @@
+/*
+ * gst-rtp-vp8-pay.h - Header for GstRtpVP8Pay
+ * Copyright (C) 2011 Sjoerd Simons <sjoerd@luon.net>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ */
+
+#ifndef __GST_RTP_VP8_PAY_H__
+#define __GST_RTP_VP8_PAY_H__
+
+#include <glib-object.h>
+#include <gst/base/gstadapter.h>
+#include <gst/rtp/gstbasertppayload.h>
+
+G_BEGIN_DECLS typedef struct _GstRtpVP8Pay GstRtpVP8Pay;
+typedef struct _GstRtpVP8PayClass GstRtpVP8PayClass;
+
+struct _GstRtpVP8PayClass
+{
+  GstBaseRTPPayloadClass parent_class;
+};
+
+struct _GstRtpVP8Pay
+{
+  GstBaseRTPPayload parent;
+  gboolean is_keyframe;
+  gint n_partitions;
+  guint header_size;
+  /* Add the end offset for easier implementation */
+  guint partition_offset[9];
+  guint partition_size[8];
+};
+
+GType gst_rtp_vp8_pay_get_type (void);
+
+/* TYPE MACROS */
+#define GST_TYPE_RTP_VP8_PAY \
+  (gst_rtp_vp8_pay_get_type())
+#define GST_RTP_VP8_PAY(obj) \
+  (G_TYPE_CHECK_INSTANCE_CAST((obj), GST_TYPE_RTP_VP8_PAY, GstRtpVP8Pay))
+#define GST_RTP_VP8_PAY_CLASS(klass) \
+  (G_TYPE_CHECK_CLASS_CAST((klass), GST_TYPE_RTP_VP8_PAY, GstRtpVP8PayClass))
+#define GST_IS_RTP_VP8_PAY(obj) \
+  (G_TYPE_CHECK_INSTANCE_TYPE((obj), GST_TYPE_RTP_VP8_PAY))
+#define GST_IS_RTP_VP8_PAY_CLASS(klass) \
+  (G_TYPE_CHECK_CLASS_TYPE((klass), GST_TYPE_RTP_VP8_PAY))
+#define GST_RTP_VP8_PAY_GET_CLASS(obj) \
+  (G_TYPE_INSTANCE_GET_CLASS ((obj), GST_TYPE_RTP_VP8_PAY, GstRtpVP8PayClass))
+
+gboolean gst_rtp_vp8_pay_plugin_init (GstPlugin * plugin);
+
+G_END_DECLS
+#endif /* #ifndef __GST_RTP_VP8_PAY_H__ */