sndfile: rewrite sndfile for 1.0

Add a sfdec for a start. Instead of a source plugin, this is a demuxer/decoder combination. This makes it work with auto-plugging.

5 files changed, 604 insertions, 82 deletions

diff --git a/ext/sndfile/Makefile.am b/ext/sndfile/Makefile.am
index f7dde8a7f..c0135cc3a 100644
--- a/ext/sndfile/Makefile.am
+++ b/ext/sndfile/Makefile.am
@@ -1,10 +1,9 @@
-
 plugin_LTLIBRARIES = libgstsndfile.la
 
-libgstsndfile_la_SOURCES = gstsf.c gstsfsrc.c gstsfsink.c
+libgstsndfile_la_SOURCES = gstsf.c gstsfdec.c
 libgstsndfile_la_CFLAGS = $(GST_PLUGINS_BAD_CFLAGS) $(GST_PLUGINS_BASE_CFLAGS) $(GST_BASE_CFLAGS) $(GST_CFLAGS) $(SNDFILE_CFLAGS)
-libgstsndfile_la_LIBADD = $(GST_BASE_LIBS) $(GST_LIBS) $(SNDFILE_LIBS)
+libgstsndfile_la_LIBADD = $(GST_PLUGINS_BASE_LIBS) $(GST_BASE_LIBS) $(GST_LIBS) $(SNDFILE_LIBS)
 libgstsndfile_la_LDFLAGS = $(GST_PLUGIN_LDFLAGS)
 libgstsndfile_la_LIBTOOLFLAGS = $(GST_PLUGIN_LIBTOOLFLAGS)
 
-noinst_HEADERS = gstsf.h gstsfsrc.h gstsfsink.h
+noinst_HEADERS = gstsf.h gstsfdec.h
diff --git a/ext/sndfile/gstsf.c b/ext/sndfile/gstsf.c
index e71b18884..a8f1c61bc 100644
--- a/ext/sndfile/gstsf.c
+++ b/ext/sndfile/gstsf.c
@@ -27,79 +27,86 @@
 
 #include "gstsf.h"
 
+/* sf formats */
 
-GType
-gst_sf_major_types_get_type (void)
+GstCaps *
+gst_sf_create_audio_template_caps (void)
 {
-  static GType sf_major_types_type = 0;
-  static GEnumValue *sf_major_types = NULL;
-
-  if (!sf_major_types_type) {
-    SF_FORMAT_INFO format_info;
-    int k, count;
-
-    sf_command (NULL, SFC_GET_FORMAT_MAJOR_COUNT, &count, sizeof (int));
-
-    sf_major_types = g_new0 (GEnumValue, count + 1);
-
-    for (k = 0; k < count; k++) {
-      format_info.format = k;
-      sf_command (NULL, SFC_GET_FORMAT_MAJOR, &format_info,
-          sizeof (format_info));
-      sf_major_types[k].value = format_info.format;
-      sf_major_types[k].value_name = g_strdup (format_info.name);
-      sf_major_types[k].value_nick = g_strdup (format_info.extension);
-
-      /* Irritatingly enough, there exist major_types with the same extension. Let's
-         just hope that sndfile gives us the list in alphabetical order, as it
-         currently does. */
-      if (k > 0
-          && strcmp (sf_major_types[k].value_nick,
-              sf_major_types[k - 1].value_nick) == 0) {
-        g_free ((gchar *) sf_major_types[k].value_nick);
-        sf_major_types[k].value_nick =
-            g_strconcat (sf_major_types[k - 1].value_nick, "-",
-            sf_major_types[k].value_name, NULL);
-        g_strcanon ((gchar *) sf_major_types[k].value_nick,
-            G_CSET_A_2_Z G_CSET_a_2_z G_CSET_DIGITS "-", '-');
-      }
+  GstCaps *caps = gst_caps_new_empty ();
+  SF_FORMAT_INFO format_info;
+  const gchar *fmt;
+  gint k, count;
+
+  sf_command (NULL, SFC_GET_FORMAT_MAJOR_COUNT, &count, sizeof (gint));
+
+  for (k = 0; k < count; k++) {
+    format_info.format = k;
+    sf_command (NULL, SFC_GET_FORMAT_MAJOR, &format_info, sizeof (format_info));
+
+    switch (format_info.format) {
+      case SF_FORMAT_AIFF:     /* Apple/SGI AIFF format */
+        fmt = "audio/x-aiff";
+        break;
+      case SF_FORMAT_AU:       /* Sun/NeXT AU format */
+        fmt = "audio/x-au";
+        break;
+      case SF_FORMAT_FLAC:     /* FLAC lossless file format */
+        fmt = "audio/x-flac";
+        break;
+      case SF_FORMAT_IRCAM:    /* Berkeley/IRCAM/CARL */
+        fmt = "audio/x-ircam";
+        break;
+      case SF_FORMAT_NIST:     /* Sphere NIST format. */
+        fmt = "audio/x-nist";
+        break;
+      case SF_FORMAT_OGG:      /* Xiph OGG container */
+        fmt = "audio/ogg";
+        break;
+      case SF_FORMAT_PAF:      /* Ensoniq PARIS file format. */
+        fmt = "audio/x-paris";
+        break;
+      case SF_FORMAT_RAW:      /* RAW PCM data. */
+        fmt = "audio/x-raw";
+        break;
+      case SF_FORMAT_SDS:      /* Midi Sample Dump Standard */
+        fmt = "audio/x-sds";
+        break;
+      case SF_FORMAT_SVX:      /* Amiga IFF / SVX8 / SV16 format. */
+        fmt = "audio/x-svx";
+        break;
+      case SF_FORMAT_VOC:      /* VOC files. */
+        fmt = "audio/x-voc";
+        break;
+      case SF_FORMAT_WAV:      /* Microsoft WAV format */
+      case SF_FORMAT_WAVEX:    /* MS WAVE with WAVEFORMATEX */
+        fmt = "audio/x-wav";
+        break;
+      case SF_FORMAT_W64:      /* Sonic Foundry's 64 bit RIFF/WAV */
+        fmt = "audio/x-w64";
+        break;
+      case SF_FORMAT_XI:       /* Fasttracker 2 Extended Instrument */
+        fmt = "audio/x-xi";
+        break;
+      case SF_FORMAT_RF64:     /* RF64 WAV file */
+      case SF_FORMAT_MAT4:     /* Matlab (tm) V4.2 / GNU Octave 2.0 */
+      case SF_FORMAT_MAT5:     /* Matlab (tm) V5.0 / GNU Octave 2.1 */
+      case SF_FORMAT_PVF:      /* Portable Voice Format */
+      case SF_FORMAT_HTK:      /* HMM Tool Kit format */
+      case SF_FORMAT_AVR:      /* Audio Visual Research */
+      case SF_FORMAT_SD2:      /* Sound Designer 2 */
+      case SF_FORMAT_CAF:      /* Core Audio File format */
+      case SF_FORMAT_WVE:      /* Psion WVE format */
+      case SF_FORMAT_MPC2K:    /* Akai MPC 2000 sampler */
+      default:
+        fmt = NULL;
+        GST_WARNING ("format 0x%x: '%s' is not mapped", format_info.format,
+            format_info.name);
     }
-
-    sf_major_types_type =
-        g_enum_register_static ("GstSndfileMajorTypes", sf_major_types);
-  }
-  return sf_major_types_type;
-}
-
-GType
-gst_sf_minor_types_get_type (void)
-{
-  static GType sf_minor_types_type = 0;
-  static GEnumValue *sf_minor_types = NULL;
-
-  if (!sf_minor_types_type) {
-    SF_FORMAT_INFO format_info;
-    int k, count;
-
-    sf_command (NULL, SFC_GET_FORMAT_SUBTYPE_COUNT, &count, sizeof (int));
-
-    sf_minor_types = g_new0 (GEnumValue, count + 1);
-
-    for (k = 0; k < count; k++) {
-      format_info.format = k;
-      sf_command (NULL, SFC_GET_FORMAT_SUBTYPE, &format_info,
-          sizeof (format_info));
-      sf_minor_types[k].value = format_info.format;
-      sf_minor_types[k].value_name = g_strdup (format_info.name);
-      sf_minor_types[k].value_nick = g_ascii_strdown (format_info.name, -1);
-      g_strcanon ((gchar *) sf_minor_types[k].value_nick,
-          G_CSET_a_2_z G_CSET_DIGITS "-", '-');
+    if (fmt != NULL) {
+      gst_caps_append_structure (caps, gst_structure_new_empty (fmt));
     }
-
-    sf_minor_types_type =
-        g_enum_register_static ("GstSndfileMinorTypes", sf_minor_types);
   }
-  return sf_minor_types_type;
+  return gst_caps_simplify (caps);
 }
 
 static gboolean
@@ -112,12 +119,8 @@ plugin_init (GstPlugin * plugin)
   bind_textdomain_codeset (GETTEXT_PACKAGE, "UTF-8");
 #endif /* ENABLE_NLS */
 
-  if (!gst_element_register (plugin, "sfsink", GST_RANK_NONE,
-          gst_sf_sink_get_type ()))
-    return FALSE;
-
-  if (!gst_element_register (plugin, "sfsrc", GST_RANK_NONE,
-          gst_sf_src_get_type ()))
+  if (!gst_element_register (plugin, "sfdec", GST_RANK_MARGINAL,
+          gst_sf_dec_get_type ()))
     return FALSE;
 
   return TRUE;
@@ -126,5 +129,5 @@ plugin_init (GstPlugin * plugin)
 GST_PLUGIN_DEFINE (GST_VERSION_MAJOR,
     GST_VERSION_MINOR,
     sndfile,
-    "use libsndfile to read and write audio from and to files",
+    "use libsndfile to read and write various audio formats",
     plugin_init, VERSION, "LGPL", GST_PACKAGE_NAME, GST_PACKAGE_ORIGIN)
diff --git a/ext/sndfile/gstsf.h b/ext/sndfile/gstsf.h
index 0b12f656a..71584569f 100644
--- a/ext/sndfile/gstsf.h
+++ b/ext/sndfile/gstsf.h
@@ -28,6 +28,7 @@
 
 G_BEGIN_DECLS
 
+GstCaps *gst_sf_create_audio_template_caps (void);
 
 #define GST_TYPE_SF_MAJOR_TYPES (gst_sf_major_types_get_type())
 #define GST_TYPE_SF_MINOR_TYPES (gst_sf_minor_types_get_type())
@@ -35,9 +36,7 @@ G_BEGIN_DECLS
 GType gst_sf_major_types_get_type (void);
 GType gst_sf_minor_types_get_type (void);
 
-GType gst_sf_sink_get_type (void);
-GType gst_sf_src_get_type (void);
-
+GType gst_sf_dec_get_type (void);
 
 G_END_DECLS
 
diff --git a/ext/sndfile/gstsfdec.c b/ext/sndfile/gstsfdec.c
new file mode 100644
index 000000000..95e48f996
--- /dev/null
+++ b/ext/sndfile/gstsfdec.c
@@ -0,0 +1,448 @@
+/* GStreamer libsndfile plugin
+ * Copyright (C) 2013 Stefan Sauer <ensonic@users.sf.net>
+ *
+ * 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 self 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 <gst/gst-i18n-plugin.h>
+
+#include "gstsfdec.h"
+#include <gst/audio/audio.h>
+
+enum
+{
+  PROP_0,
+  PROP_LOCATION
+};
+
+#define FORMATS \
+    "{ "GST_AUDIO_NE (F32)", "GST_AUDIO_NE (S32)", "GST_AUDIO_NE (S16)" }"
+
+static GstStaticPadTemplate sf_dec_src_factory = GST_STATIC_PAD_TEMPLATE ("src",
+    GST_PAD_SRC,
+    GST_PAD_ALWAYS,
+    GST_STATIC_CAPS ("audio/x-raw, "
+        "format = (string) " FORMATS ", "
+        "layout = (string) interleaved, "
+        "rate = (int) [ 1, MAX ], " "channels = (int) [ 1, MAX ]"));
+
+GST_DEBUG_CATEGORY_STATIC (gst_sf_dec_debug);
+#define GST_CAT_DEFAULT gst_sf_dec_debug
+
+#define DEFAULT_BUFFER_FRAMES	(256)
+
+static GstStateChangeReturn gst_sf_dec_change_state (GstElement * element,
+    GstStateChange transition);
+
+static gboolean gst_sf_dec_sink_activate (GstPad * pad, GstObject * parent);
+static gboolean gst_sf_dec_sink_activate_mode (GstPad * sinkpad,
+    GstObject * parent, GstPadMode mode, gboolean active);
+static void gst_sf_dec_loop (GstPad * pad);
+
+static gboolean gst_sf_dec_start (GstSFDec * bsrc);
+static gboolean gst_sf_dec_stop (GstSFDec * bsrc);
+
+#define _do_init \
+    GST_DEBUG_CATEGORY_INIT (gst_sf_dec_debug, "sfdec", 0, "sfdec element");
+#define gst_sf_dec_parent_class parent_class
+G_DEFINE_TYPE_WITH_CODE (GstSFDec, gst_sf_dec, GST_TYPE_ELEMENT, _do_init);
+
+/* sf virtual io */
+
+static sf_count_t
+gst_sf_vio_get_filelen (void *user_data)
+{
+  GstElement *element = GST_ELEMENT (user_data);
+  gint64 dur;
+
+  if (gst_element_query_duration (element, GST_FORMAT_BYTES, &dur)) {
+    return (sf_count_t) dur;
+  }
+  GST_WARNING_OBJECT (element, "query_duration failed");
+  return -1;
+}
+
+static sf_count_t
+gst_sf_vio_tell (void *user_data)
+{
+  GstSFDec *self = GST_SF_DEC (user_data);
+  return self->pos;
+}
+
+static sf_count_t
+gst_sf_vio_seek (sf_count_t offset, int whence, void *user_data)
+{
+  GstSFDec *self = GST_SF_DEC (user_data);
+
+  switch (whence) {
+    case SEEK_CUR:
+      self->pos += offset;
+      break;
+    case SEEK_SET:
+      self->pos = offset;
+      break;
+    case SEEK_END:
+      self->pos = gst_sf_vio_get_filelen (user_data) - offset;
+      break;
+  }
+  return (sf_count_t) self->pos;
+}
+
+static sf_count_t
+gst_sf_vio_read (void *ptr, sf_count_t count, void *user_data)
+{
+  GstSFDec *self = GST_SF_DEC (user_data);
+  GstBuffer *buffer = gst_buffer_new_wrapped_full (0, ptr, count, 0, count,
+      ptr, NULL);
+
+  if (gst_pad_pull_range (self->sinkpad, self->pos, count, &buffer) ==
+      GST_FLOW_OK) {
+    GST_DEBUG_OBJECT (self, "read %d bytes @ pos %" G_GUINT64_FORMAT,
+        (gint) count, self->pos);
+    self->pos += count;
+    return count;
+  }
+  GST_WARNING_OBJECT (self, "read failed");
+  return 0;
+}
+
+static sf_count_t
+gst_sf_vio_write (const void *ptr, sf_count_t count, void *user_data)
+{
+  GstSFDec *self = GST_SF_DEC (user_data);
+  GstBuffer *buffer = gst_buffer_new_wrapped (g_memdup (ptr, count), count);
+
+  if (gst_pad_push (self->srcpad, buffer) == GST_FLOW_OK) {
+    return count;
+  }
+  GST_WARNING_OBJECT (self, "write failed");
+  return 0;
+}
+
+SF_VIRTUAL_IO gst_sf_vio = {
+  &gst_sf_vio_get_filelen,
+  &gst_sf_vio_seek,
+  &gst_sf_vio_read,
+  &gst_sf_vio_write,
+  &gst_sf_vio_tell,
+};
+
+
+static void
+gst_sf_dec_class_init (GstSFDecClass * klass)
+{
+  GstElementClass *gstelement_class;
+
+  gstelement_class = GST_ELEMENT_CLASS (klass);
+  gstelement_class->change_state = GST_DEBUG_FUNCPTR (gst_sf_dec_change_state);
+
+  gst_element_class_set_static_metadata (gstelement_class, "Sndfile decoder",
+      "Demuxer/Audio",
+      "Read audio streams using libsndfile",
+      "Stefan Sauer <ensonic@user.sf.net>");
+
+  gst_element_class_add_pad_template (gstelement_class,
+      gst_static_pad_template_get (&sf_dec_src_factory));
+
+  gst_element_class_add_pad_template (gstelement_class,
+      gst_pad_template_new ("sink", GST_PAD_SINK, GST_PAD_ALWAYS,
+          gst_sf_create_audio_template_caps ()));
+
+}
+
+static void
+gst_sf_dec_init (GstSFDec * self)
+{
+  self->sinkpad = gst_pad_new_from_template (gst_element_class_get_pad_template
+      (GST_ELEMENT_GET_CLASS (self), "sink"), "sink");
+  gst_pad_set_activate_function (self->sinkpad,
+      GST_DEBUG_FUNCPTR (gst_sf_dec_sink_activate));
+  gst_pad_set_activatemode_function (self->sinkpad,
+      GST_DEBUG_FUNCPTR (gst_sf_dec_sink_activate_mode));
+  gst_element_add_pad (GST_ELEMENT (self), self->sinkpad);
+
+  self->srcpad = gst_pad_new_from_static_template (&sf_dec_src_factory, "src");
+  /* TODO(ensonic): event + query functions */
+  gst_element_add_pad (GST_ELEMENT (self), self->srcpad);
+}
+
+static GstStateChangeReturn
+gst_sf_dec_change_state (GstElement * element, GstStateChange transition)
+{
+  GstStateChangeReturn ret;
+  GstSFDec *self = GST_SF_DEC (element);
+
+  switch (transition) {
+    case GST_STATE_CHANGE_READY_TO_PAUSED:
+      gst_sf_dec_start (self);
+      break;
+    default:
+      break;
+  }
+
+  ret = GST_ELEMENT_CLASS (parent_class)->change_state (element, transition);
+
+  switch (transition) {
+    case GST_STATE_CHANGE_PAUSED_TO_READY:
+      gst_sf_dec_stop (self);
+      break;
+    default:
+      break;
+  }
+  return ret;
+}
+
+static gboolean
+gst_sf_dec_start (GstSFDec * self)
+{
+  self->file = NULL;
+
+  return TRUE;
+}
+
+static gboolean
+gst_sf_dec_stop (GstSFDec * self)
+{
+  int err = 0;
+
+  g_return_val_if_fail (self->file != NULL, FALSE);
+
+  GST_INFO_OBJECT (self, "Closing sndfile stream");
+
+  if ((err = sf_close (self->file)))
+    goto close_failed;
+
+  self->file = NULL;
+  self->offset = 0;
+  self->channels = 0;
+  self->rate = 0;
+
+  return TRUE;
+
+close_failed:
+  {
+    GST_ELEMENT_ERROR (self, RESOURCE, CLOSE,
+        ("Could not close sndfile stream."),
+        ("soundfile error: %s", sf_error_number (err)));
+    return FALSE;
+  }
+}
+
+static gboolean
+gst_sf_dec_sink_activate (GstPad * sinkpad, GstObject * parent)
+{
+  GstQuery *query;
+  gboolean pull_mode;
+
+  query = gst_query_new_scheduling ();
+
+  if (!gst_pad_peer_query (sinkpad, query)) {
+    gst_query_unref (query);
+    goto activate_push;
+  }
+
+  pull_mode = gst_query_has_scheduling_mode_with_flags (query,
+      GST_PAD_MODE_PULL, GST_SCHEDULING_FLAG_SEEKABLE);
+  gst_query_unref (query);
+
+  if (!pull_mode)
+    goto activate_push;
+
+  GST_DEBUG_OBJECT (sinkpad, "activating pull");
+  return gst_pad_activate_mode (sinkpad, GST_PAD_MODE_PULL, TRUE);
+
+activate_push:
+  {
+    GST_DEBUG_OBJECT (sinkpad, "activating push");
+    return gst_pad_activate_mode (sinkpad, GST_PAD_MODE_PUSH, TRUE);
+  }
+}
+
+static gboolean
+gst_sf_dec_sink_activate_mode (GstPad * sinkpad, GstObject * parent,
+    GstPadMode mode, gboolean active)
+{
+  gboolean res;
+
+  switch (mode) {
+    case GST_PAD_MODE_PUSH:
+      res = FALSE;              /* no push support */
+      break;
+    case GST_PAD_MODE_PULL:
+      if (active) {
+        /* if we have a scheduler we can start the task */
+        res = gst_pad_start_task (sinkpad, (GstTaskFunction) gst_sf_dec_loop,
+            sinkpad, NULL);
+      } else {
+        res = gst_pad_stop_task (sinkpad);
+      }
+      break;
+    default:
+      res = FALSE;
+      break;
+  }
+  return res;
+}
+
+static gboolean
+gst_sf_dec_open_file (GstSFDec * self)
+{
+  SF_INFO info;
+  GstCaps *caps;
+  GstStructure *s;
+  GstSegment seg;
+  gint width;
+  const gchar *format;
+  gchar *stream_id;
+
+  GST_DEBUG_OBJECT (self, "opening the stream");
+  info.format = 0;
+  self->file = sf_open_virtual (&gst_sf_vio, SFM_READ, &info, self);
+  if (!self->file)
+    goto open_failed;
+
+  stream_id =
+      gst_pad_create_stream_id (self->srcpad, GST_ELEMENT_CAST (self), NULL);
+  gst_pad_push_event (self->srcpad, gst_event_new_stream_start (stream_id));
+  g_free (stream_id);
+
+  self->channels = info.channels;
+  self->rate = info.samplerate;
+  /* TODO(ensonic): do something with info.seekable? */
+  /* TODO(ensonic): calculate duration info.frames */
+
+  /* negotiate srcpad caps */
+  if ((caps = gst_pad_get_allowed_caps (self->srcpad)) == NULL) {
+    caps = gst_pad_get_pad_template_caps (self->srcpad);
+  }
+  caps = gst_caps_make_writable (caps);
+  GST_DEBUG_OBJECT (self, "allowed caps %" GST_PTR_FORMAT, caps);
+
+  s = gst_caps_get_structure (caps, 0);
+  gst_structure_set (s,
+      "channels", G_TYPE_INT, self->channels,
+      "rate", G_TYPE_INT, self->rate, NULL);
+
+  if (!gst_structure_fixate_field_string (s, "format", GST_AUDIO_NE (S16)))
+    GST_WARNING_OBJECT (self, "Failed to fixate format to S16NE");
+
+  caps = gst_caps_fixate (caps);
+
+  GST_DEBUG_OBJECT (self, "fixated caps %" GST_PTR_FORMAT, caps);
+
+  /* configure to output the negotiated format */
+  s = gst_caps_get_structure (caps, 0);
+  format = gst_structure_get_string (s, "format");
+  if (g_str_equal (format, GST_AUDIO_NE (S32))) {
+    self->reader = (GstSFReader) sf_readf_int;
+    width = 32;
+  } else if (g_str_equal (format, GST_AUDIO_NE (S16))) {
+    self->reader = (GstSFReader) sf_readf_short;
+    width = 16;
+  } else {
+    self->reader = (GstSFReader) sf_readf_float;
+    width = 32;
+  }
+  self->bytes_per_frame = width * self->channels / 8;
+
+  gst_pad_set_caps (self->srcpad, caps);
+  gst_caps_unref (caps);
+
+  gst_segment_init (&seg, GST_FORMAT_TIME);
+  /* TODO: calculate seg.stop = song_length; */
+  gst_pad_push_event (self->srcpad, gst_event_new_segment (&seg));
+
+  return TRUE;
+
+open_failed:
+  {
+    GST_ELEMENT_ERROR (self, RESOURCE, OPEN_READ,
+        (_("Could not open sndfile stream for reading.")),
+        ("soundfile error: %s", sf_strerror (NULL)));
+    return FALSE;
+  }
+}
+
+static void
+gst_sf_dec_loop (GstPad * pad)
+{
+  GstSFDec *self = GST_SF_DEC (GST_PAD_PARENT (pad));
+  GstBuffer *buf;
+  GstMapInfo map;
+  GstFlowReturn flow;
+  sf_count_t bytes_read;
+  guint num_frames = 1024;      /* arbitrary */
+
+  if (G_UNLIKELY (!self->file)) {
+    /* not started yet */
+    if (!gst_sf_dec_open_file (self))
+      goto pause;
+  }
+
+  buf = gst_buffer_new_and_alloc (self->bytes_per_frame * num_frames);
+  gst_buffer_map (buf, &map, GST_MAP_WRITE);
+  bytes_read = self->reader (self->file, map.data, num_frames);
+  GST_DEBUG_OBJECT (self, "read %d / %d bytes = %d frames of audio",
+      (gint) bytes_read, (gint) map.size, num_frames);
+  gst_buffer_unmap (buf, &map);
+
+  if (G_UNLIKELY (bytes_read < 0))
+    goto could_not_read;
+
+  if (G_UNLIKELY (bytes_read == 0))
+    goto eos;
+
+  num_frames = bytes_read / self->bytes_per_frame;
+
+  GST_BUFFER_OFFSET (buf) = self->offset;
+  GST_BUFFER_TIMESTAMP (buf) = gst_util_uint64_scale_int (self->offset,
+      GST_SECOND, self->rate);
+  self->offset += num_frames;
+  GST_BUFFER_DURATION (buf) = gst_util_uint64_scale_int (self->offset,
+      GST_SECOND, self->rate) - GST_BUFFER_TIMESTAMP (buf);
+
+  flow = gst_pad_push (self->srcpad, buf);
+  if (flow != GST_FLOW_OK) {
+    GST_LOG_OBJECT (self, "pad push flow: %s", gst_flow_get_name (flow));
+    goto pause;
+  }
+
+  return;
+
+  /* ERROR */
+could_not_read:
+  {
+    GST_ELEMENT_ERROR (self, RESOURCE, READ, (NULL), GST_ERROR_SYSTEM);
+    gst_buffer_unref (buf);
+    goto pause;
+  }
+eos:
+  {
+    GST_DEBUG_OBJECT (self, "EOS");
+    gst_buffer_unref (buf);
+    gst_pad_push_event (self->srcpad, gst_event_new_eos ());
+    goto pause;
+  }
+pause:
+  {
+    GST_INFO_OBJECT (self, "Pausing");
+    gst_pad_pause_task (self->sinkpad);
+  }
+}
diff --git a/ext/sndfile/gstsfdec.h b/ext/sndfile/gstsfdec.h
new file mode 100644
index 000000000..a29e23a02
--- /dev/null
+++ b/ext/sndfile/gstsfdec.h
@@ -0,0 +1,73 @@
+/* GStreamer libsndfile plugin
+ * Copyright (C) 2013 Stefan Sauer <ensonic@users.sf.net>
+ *
+ * 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., 51 Franklin St, Fifth Floor,
+ * Boston, MA 02110-1301, USA.
+ */
+
+
+#ifndef __GST_SF_DEC_H__
+#define __GST_SF_DEC_H__
+
+
+#include "gstsf.h"
+#include <gst/base/gstbasesrc.h>
+
+
+G_BEGIN_DECLS
+
+
+#define GST_TYPE_SF_DEC \
+  (gst_sf_dec_get_type())
+#define GST_SF_DEC(obj) \
+  (G_TYPE_CHECK_INSTANCE_CAST((obj),GST_TYPE_SF_DEC,GstSFDec))
+#define GST_SF_DEC_CLASS(klass) \
+  (G_TYPE_CHECK_CLASS_CAST((klass),GST_TYPE_SF_DEC,GstSFDecClass))
+#define GST_IS_SF_DEC(obj) \
+  (G_TYPE_CHECK_INSTANCE_TYPE((obj),GST_TYPE_SF_DEC))
+#define GST_IS_SF_DEC_CLASS(klass) \
+  (G_TYPE_CHECK_CLASS_TYPE((klass),GST_TYPE_SF_DEC))
+
+typedef struct _GstSFDec GstSFDec;
+typedef struct _GstSFDecClass GstSFDecClass;
+
+typedef sf_count_t (*GstSFReader)(SNDFILE *f, void *data, sf_count_t nframes);
+
+struct _GstSFDec {
+  GstElement parent;
+
+  GstPad *sinkpad;
+  GstPad *srcpad;
+  
+  guint64 pos;
+
+  SNDFILE *file;
+  sf_count_t offset;
+  GstSFReader reader;
+  gint bytes_per_frame;
+
+  gint channels;
+  gint rate;
+};
+
+struct _GstSFDecClass {
+  GstElementClass parent_class;
+};
+
+
+G_END_DECLS
+
+
+#endif /* __GST_SF_DEC_H__ */