added new element to add Xing headers to MP3 files (this allows decoder to figure out the length of VBR files)

Original commit message from CVS:
2006-03-11  Christophe Fergeau  <teuf@gnome.org>

Reviewed by: Tim-Philipp Müller  <tim at centricular dot net>

* configure.ac:
* gst/xingheader/Makefile.am:
* gst/xingheader/gstxingmux.c:
* gst/xingheader/gstxingmux.h: added new element to add Xing headers
to MP3 files (this allows decoder to figure out the length of VBR
files)

ChangeLog

@@ -1,3 +1,14 @@
+2006-03-11  Christophe Fergeau  <teuf@gnome.org>
+
+	Reviewed by: Tim-Philipp Müller  <tim at centricular dot net>
+
+	* configure.ac:
+	* gst/xingheader/Makefile.am:
+	* gst/xingheader/gstxingmux.c: 
+	* gst/xingheader/gstxingmux.h: added new element to add Xing headers
+	to MP3 files (this allows decoder to figure out the length of VBR
+	files) 
+
 2006-03-11  Christophe Fergeau  <teuf@gnome.org>
 	
 	Patch by: Alex Lancaster

configure.ac

@@ -285,6 +285,7 @@ GST_PLUGINS_ALL="\
 		freeze \
 		speed   \
 		qtdemux \
+		xingheader \
 		tta     \
                 "
 
@@ -730,6 +731,7 @@ gst/modplug/libmodplug/Makefile
 gst/speed/Makefile
 gst/qtdemux/Makefile
 gst/tta/Makefile
+gst/xingheader/Makefile
 sys/Makefile
 sys/glsink/Makefile
 sys/ximagesrc/Makefile

gst/xingheader/Makefile.am

@@ -0,0 +1,12 @@
+
+plugin_LTLIBRARIES = libgstxingheader.la
+
+libgstxingheader_la_SOURCES = gstxingmux.c
+libgstxingheader_la_CFLAGS = $(GST_CFLAGS)
+libgstxingheader_la_LDFLAGS = $(GST_PLUGIN_LDFLAGS)
+
+
+noinst_HEADERS = gstxingmux.h
+
+AM_CFLAGS = $(GST_CFLAGS)
+LIBS = $(GST_LIBS) $(LAME_LIBS)

gst/xingheader/gstxingmux.c

@@ -0,0 +1,380 @@
+/*
+ * (c) 2006 Christophe Fergeau  <teuf@gnome.org>
+ *
+ * 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.
+ */
+
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <string.h>
+#include "gstxingmux.h"
+
+GST_DEBUG_CATEGORY_STATIC (xing_mux_debug);
+#define GST_CAT_DEFAULT xing_mux_debug
+
+GST_BOILERPLATE (GstXingMux, gst_xing_mux, GstElement, GST_TYPE_ELEMENT);
+
+/* Xing Header stuff */
+struct _GstXingMuxPriv
+{
+  guint64 duration;
+  guint64 byte_count;
+  GList *seek_table;
+  gboolean flush;
+};
+
+#define GST_XING_FRAME_FIELD   (1 << 0)
+#define GST_XING_BYTES_FIELD   (1 << 1)
+#define GST_XING_TOC_FIELD     (1 << 2)
+#define GST_XING_QUALITY_FIELD (1 << 3)
+
+static const int XING_FRAME_SIZE = 418;
+
+static GstStateChangeReturn
+gst_xing_mux_change_state (GstElement * element, GstStateChange transition);
+static GstFlowReturn gst_xing_mux_chain (GstPad * pad, GstBuffer * buffer);
+static gboolean gst_xing_mux_sink_event (GstPad * pad, GstEvent * event);
+
+
+static void
+gst_xing_mux_finalize (GObject * obj)
+{
+  GstXingMux *xing = GST_XING_MUX (obj);
+
+  g_free (xing->priv);
+  xing->priv = NULL;
+  G_OBJECT_CLASS (parent_class)->finalize (obj);
+}
+
+
+static GstStaticPadTemplate gst_xing_mux_sink_template =
+GST_STATIC_PAD_TEMPLATE ("sink",
+    GST_PAD_SINK,
+    GST_PAD_ALWAYS,
+    GST_STATIC_CAPS ("audio/mpeg, "
+        "mpegversion = (int) 1, " "layer = (int) 3"));
+
+
+static GstStaticPadTemplate gst_xing_mux_src_template =
+GST_STATIC_PAD_TEMPLATE ("src",
+    GST_PAD_SRC,
+    GST_PAD_ALWAYS,
+    GST_STATIC_CAPS ("audio/mpeg, "
+        "mpegversion = (int) 1, " "layer = (int) 3"));
+
+
+static void
+gst_xing_mux_base_init (gpointer g_class)
+{
+  GstElementClass *element_class = GST_ELEMENT_CLASS (g_class);
+
+  static GstElementDetails gst_xing_mux_details = {
+    "MP3 Xing Muxer",
+    "Formatter/Metadata",
+    "Adds a Xing header to the beginning of a VBR MP3 file",
+    "Christophe Fergeau <teuf@gnome.org>"
+  };
+
+
+  gst_element_class_add_pad_template (element_class,
+      gst_static_pad_template_get (&gst_xing_mux_src_template));
+  gst_element_class_add_pad_template (element_class,
+      gst_static_pad_template_get (&gst_xing_mux_sink_template));
+  gst_element_class_set_details (element_class, &gst_xing_mux_details);
+}
+
+static void
+gst_xing_mux_class_init (GstXingMuxClass * klass)
+{
+  GObjectClass *gobject_class;
+  GstElementClass *gstelement_class;
+
+  gobject_class = (GObjectClass *) klass;
+  gstelement_class = (GstElementClass *) klass;
+
+  gobject_class->finalize = GST_DEBUG_FUNCPTR (gst_xing_mux_finalize);
+  gstelement_class->change_state =
+      GST_DEBUG_FUNCPTR (gst_xing_mux_change_state);
+}
+
+static void
+xing_set_flush (GstXingMux * xing, gboolean flush)
+{
+  if (xing->priv == NULL) {
+    return;
+  }
+  xing->priv->flush = flush;
+}
+
+static void
+gst_xing_mux_init (GstXingMux * xing, GstXingMuxClass * xingmux_class)
+{
+  GstElementClass *klass = GST_ELEMENT_CLASS (xingmux_class);
+
+  /* pad through which data comes in to the element */
+  xing->sinkpad =
+      gst_pad_new_from_template (gst_element_class_get_pad_template (klass,
+          "sink"), "sink");
+  gst_pad_set_setcaps_function (xing->sinkpad,
+      GST_DEBUG_FUNCPTR (gst_pad_proxy_setcaps));
+  gst_pad_set_chain_function (xing->sinkpad,
+      GST_DEBUG_FUNCPTR (gst_xing_mux_chain));
+  gst_pad_set_event_function (xing->sinkpad,
+      GST_DEBUG_FUNCPTR (gst_xing_mux_sink_event));
+  gst_element_add_pad (GST_ELEMENT (xing), xing->sinkpad);
+
+  /* pad through which data goes out of the element */
+  xing->srcpad =
+      gst_pad_new_from_template (gst_element_class_get_pad_template (klass,
+          "src"), "src");
+  gst_element_add_pad (GST_ELEMENT (xing), xing->srcpad);
+
+  xing->priv = g_malloc0 (sizeof (GstXingMuxPriv));
+  xing_set_flush (xing, TRUE);
+  xing->priv->duration = GST_CLOCK_TIME_NONE;
+
+}
+
+G_GNUC_UNUSED static void
+xing_update_data (GstXingMux * xing, gint bytes, guint64 duration)
+{
+  if (xing->priv == NULL) {
+    return;
+  }
+  xing->priv->byte_count += bytes;
+
+  if (duration == GST_CLOCK_TIME_NONE) {
+    return;
+  }
+  if (xing->priv->duration == GST_CLOCK_TIME_NONE) {
+    xing->priv->duration = duration;
+  } else {
+    xing->priv->duration += duration;
+  }
+}
+
+static GstBuffer *
+xing_generate_header (GstXingMux * xing)
+{
+  guint32 xing_flags;
+  GstBuffer *header;
+  guint32 *data;
+
+  /* Dummy header that we will stick at the beginning of our frame
+   *
+   * 0xffe => synchronization bits
+   * 0x1b  => 11010b (11b == MPEG1 | 01b == Layer III | 0b == no CRC)
+   * 0x9   => 128kbps
+   * 0x00  => 00b == 44100 Hz | 0b == no padding | 0b == private bit
+   * 0x44  => 0010b 0010b (00b == stereo | 10b == (unused) mode extension)
+   *                      (0b == no copyright bit | 0b == original bit)
+   *                      (00b == no emphasis)
+   *
+   * Such a frame (MPEG1 Layer III) contains 1152 samples, its size is thus:
+   * (1152*(128000/8))/44100 = 417.96
+   * 
+   * There are also 32 bytes (ie 8 32 bits values) to skip after the header 
+   * for such frames
+   */
+  const guint8 mp3_header[4] = { 0xff, 0xfb, 0x90, 0x44 };
+  const int SIDE_INFO_SIZE = 32 / sizeof (guint32);
+
+  header = gst_buffer_new_and_alloc (XING_FRAME_SIZE);
+
+  data = (guint32 *) GST_BUFFER_DATA (header);
+  memset (data, 0, XING_FRAME_SIZE);
+  memcpy (data, mp3_header, 4);
+  memcpy (&data[8 + 1], "Xing", 4);
+
+  xing_flags = 0;
+  if (xing->priv->duration != GST_CLOCK_TIME_NONE) {
+    guint number_of_frames;
+
+    /* The Xing Header contains a NumberOfFrames field, which verifies to:
+     * Duration = NumberOfFrames *SamplesPerFrame/SamplingRate
+     * SamplesPerFrame and SamplingRate are values for the current frame, 
+     * ie 1152 and 44100 in our case.
+     */
+    number_of_frames = (44100 * xing->priv->duration / GST_SECOND) / 1152;
+    data[SIDE_INFO_SIZE + 3] = GUINT32_TO_BE (number_of_frames);
+
+    xing_flags |= GST_XING_FRAME_FIELD;
+  }
+
+  if (xing->priv->byte_count != 0) {
+    xing_flags |= GST_XING_BYTES_FIELD;
+    data[SIDE_INFO_SIZE + 4] = GUINT32_TO_BE (xing->priv->byte_count);
+  }
+
+  /* Un-#ifdef when it's implemented :) xing code in VbrTag.c looks like
+   * it could be stolen
+   */
+#if 0
+  if (xing->priv->seek_table != NULL) {
+    GList *it;
+
+    xing_flags |= GST_XING_TOC_FIELD;
+    for (it = xing->priv->seek_table; it != NULL; it = it->next) {
+      /* do something */
+    }
+  }
+#endif
+
+  data[SIDE_INFO_SIZE + 2] = GUINT32_TO_BE (xing_flags);
+  gst_buffer_set_caps (header, GST_PAD_CAPS (xing->srcpad));
+  //  gst_util_dump_mem ((guchar *)data, XING_FRAME_SIZE);
+  return header;
+}
+
+static gboolean
+xing_ready_to_flush (GstXingMux * xing)
+{
+  if (xing->priv == NULL) {
+    return FALSE;
+  }
+  return xing->priv->flush;
+}
+
+static void
+xing_push_header (GstXingMux * xing)
+{
+  GstBuffer *header;
+  GstEvent *event;
+
+  event = gst_event_new_new_segment (FALSE, 1.0, GST_FORMAT_BYTES,
+      0, GST_CLOCK_TIME_NONE, 0);
+
+  gst_pad_push_event (xing->srcpad, event);
+
+  header = xing_generate_header (xing);
+  xing_set_flush (xing, FALSE);
+  GST_INFO ("Writing real Xing header to beginning of stream");
+  gst_pad_push (xing->srcpad, header);
+}
+
+static GstFlowReturn
+gst_xing_mux_chain (GstPad * pad, GstBuffer * buffer)
+{
+  GstXingMux *xing = GST_XING_MUX (GST_OBJECT_PARENT (pad));
+
+  xing_update_data (xing, GST_BUFFER_SIZE (buffer),
+      GST_BUFFER_DURATION (buffer));
+
+  if (xing_ready_to_flush (xing)) {
+    GST_INFO ("Writing empty Xing header to stream");
+    gst_pad_push (xing->srcpad, xing_generate_header (xing));
+    xing_set_flush (xing, FALSE);
+  }
+
+  return gst_pad_push (xing->srcpad, buffer);
+}
+
+static gboolean
+gst_xing_mux_sink_event (GstPad * pad, GstEvent * event)
+{
+  GstXingMux *xing;
+  gboolean result;
+
+  xing = GST_XING_MUX (gst_pad_get_parent (pad));
+  result = FALSE;
+
+  switch (GST_EVENT_TYPE (event)) {
+    case GST_EVENT_NEWSEGMENT:
+    {
+      gboolean update;
+      gdouble rate;
+      GstFormat format;
+      gint64 value, end_value, base;
+
+      gst_event_parse_new_segment (event, &update, &rate, &format,
+          &value, &end_value, &base);
+      gst_event_unref (event);
+      if (format == GST_FORMAT_BYTES && gst_pad_is_linked (xing->srcpad)) {
+        GstEvent *new_event;
+
+        GST_INFO ("Adjusting NEW_SEGMENT event by %d", XING_FRAME_SIZE);
+        value += XING_FRAME_SIZE;
+        if (end_value != -1) {
+          end_value += XING_FRAME_SIZE;
+        }
+
+        new_event = gst_event_new_new_segment (update, rate, format,
+            value, end_value, base);
+        result = gst_pad_push_event (xing->srcpad, new_event);
+      } else {
+        result = FALSE;
+      }
+    }
+      break;
+
+    case GST_EVENT_EOS:
+      GST_DEBUG_OBJECT (xing, "handling EOS event");
+      xing_push_header (xing);
+      result = gst_pad_push_event (xing->srcpad, event);
+      break;
+    default:
+      result = gst_pad_event_default (pad, event);
+      break;
+  }
+  gst_object_unref (GST_OBJECT (xing));
+
+  return result;
+}
+
+
+static GstStateChangeReturn
+gst_xing_mux_change_state (GstElement * element, GstStateChange transition)
+{
+  GstXingMux *xing;
+  GstStateChangeReturn result;
+
+  xing = GST_XING_MUX (element);
+
+  result = GST_ELEMENT_CLASS (parent_class)->change_state (element, transition);
+
+  switch (transition) {
+    case GST_STATE_CHANGE_PAUSED_TO_READY:
+      memset (xing->priv, 0, sizeof (GstXingMuxPriv));
+      xing_set_flush (xing, TRUE);
+      break;
+    default:
+      break;
+  }
+
+  return result;
+}
+
+
+static gboolean
+plugin_init (GstPlugin * plugin)
+{
+  if (!gst_element_register (plugin, "xingmux", GST_RANK_NONE,
+          GST_TYPE_XING_MUX))
+    return FALSE;
+
+  GST_DEBUG_CATEGORY_INIT (xing_mux_debug, "xingmux", 0, "Xing Header Muxer");
+
+  return TRUE;
+}
+
+GST_PLUGIN_DEFINE (GST_VERSION_MAJOR,
+    GST_VERSION_MINOR,
+    "xingheader",
+    "Add a xing header to mp3 encoded data",
+    plugin_init, VERSION, "LGPL", GST_PACKAGE, GST_ORIGIN)

gst/xingheader/gstxingmux.h

@@ -0,0 +1,52 @@
+/*
+ * (c) 2006 Christophe Fergeau  <teuf@gnome.org>
+ *
+ * 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.
+ */
+
+#include <gst/gst.h>
+
+typedef struct _GstXingMuxPriv GstXingMuxPriv;
+
+/* Definition of structure storing data for this element. */
+typedef struct _GstXingMux {
+  GstElement element;
+
+  GstPad *sinkpad, *srcpad;
+  
+  GstXingMuxPriv *priv;
+
+} GstXingMux;
+
+/* Standard definition defining a class for this element. */
+typedef struct _GstXingMuxClass {
+  GstElementClass parent_class;
+} GstXingMuxClass;
+
+/* Standard macros for defining types for this element.  */
+#define GST_TYPE_XING_MUX \
+  (gst_xing_mux_get_type())
+#define GST_XING_MUX(obj) \
+  (G_TYPE_CHECK_INSTANCE_CAST((obj),GST_TYPE_XING_MUX,GstXingMux))
+#define GST_XING_MUX_CLASS(klass) \
+  (G_TYPE_CHECK_CLASS_CAST((klass),GST_TYPE_XING_MUX,GstXingMuxClass))
+#define GST_IS_XING_MUX(obj) \
+  (G_TYPE_CHECK_INSTANCE_TYPE((obj),GST_TYPE_XING_MUX))
+#define GST_IS_XING_MUX_CLASS(obj) \
+  (G_TYPE_CHECK_CLASS_TYPE((klass),GST_TYPE_XING_MUX))
+
+/* Standard function returning type information. */
+GType gst_my_filter_get_type (void);