--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gst_plugins_good/gst/law/mulaw-encode.c	Fri Apr 16 15:15:52 2010 +0300
@@ -0,0 +1,299 @@
+/* GStreamer
+ * Copyright (C) <1999> Erik Walthinsen <omega@cse.ogi.edu>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ */
+/**
+ * SECTION:element-mulawenc
+ *
+ * This element encode mulaw audio. Mulaw coding is also known as G.711.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+#include <gst/gst.h>
+#include "mulaw-encode.h"
+#include "mulaw-conversion.h"
+
+extern GstStaticPadTemplate mulaw_enc_src_factory;
+extern GstStaticPadTemplate mulaw_enc_sink_factory;
+
+/* Stereo signals and args */
+enum
+{
+  /* FILL ME */
+  LAST_SIGNAL
+};
+
+enum
+{
+  ARG_0
+};
+
+static void gst_mulawenc_class_init (GstMuLawEncClass * klass);
+static void gst_mulawenc_base_init (GstMuLawEncClass * klass);
+static void gst_mulawenc_init (GstMuLawEnc * mulawenc);
+
+static GstFlowReturn gst_mulawenc_chain (GstPad * pad, GstBuffer * buffer);
+
+static GstElementClass *parent_class = NULL;
+
+/*static guint gst_stereo_signals[LAST_SIGNAL] = { 0 }; */
+
+static GstCaps *
+mulawenc_getcaps (GstPad * pad)
+{
+  GstMuLawEnc *mulawenc;
+  GstPad *otherpad;
+  GstCaps *othercaps, *result;
+  const GstCaps *templ;
+  gchar *name;
+  gint i;
+
+  mulawenc = GST_MULAWENC (GST_PAD_PARENT (pad));
+
+  /* figure out the name of the caps we are going to return */
+  if (pad == mulawenc->srcpad) {
+    name = "audio/x-mulaw";
+    otherpad = mulawenc->sinkpad;
+  } else {
+    name = "audio/x-raw-int";
+    otherpad = mulawenc->srcpad;
+  }
+  /* get caps from the peer, this can return NULL when there is no peer */
+  othercaps = gst_pad_peer_get_caps (otherpad);
+
+  /* get the template caps to make sure we return something acceptable */
+  templ = gst_pad_get_pad_template_caps (pad);
+
+  if (othercaps) {
+    /* there was a peer */
+    othercaps = gst_caps_make_writable (othercaps);
+
+    /* go through the caps and remove the fields we don't want */
+    for (i = 0; i < gst_caps_get_size (othercaps); i++) {
+      GstStructure *structure;
+
+      structure = gst_caps_get_structure (othercaps, i);
+
+      /* adjust the name */
+      gst_structure_set_name (structure, name);
+
+      if (pad == mulawenc->srcpad) {
+        /* remove the fields we don't want */
+        gst_structure_remove_fields (structure, "width", "depth", "endianness",
+            "signed", NULL);
+      } else {
+        /* add fixed fields */
+        gst_structure_set (structure, "width", G_TYPE_INT, 16,
+            "depth", G_TYPE_INT, 16,
+            "endianness", G_TYPE_INT, G_BYTE_ORDER,
+            "signed", G_TYPE_BOOLEAN, TRUE, NULL);
+      }
+    }
+    /* filter against the allowed caps of the pad to return our result */
+    result = gst_caps_intersect (othercaps, templ);
+    gst_caps_unref (othercaps);
+  } else {
+    /* there was no peer, return the template caps */
+    result = gst_caps_copy (templ);
+  }
+  return result;
+}
+
+static gboolean
+mulawenc_setcaps (GstPad * pad, GstCaps * caps)
+{
+  GstMuLawEnc *mulawenc;
+  GstPad *otherpad;
+  GstStructure *structure;
+  GstCaps *base_caps;
+
+  mulawenc = GST_MULAWENC (gst_pad_get_parent (pad));
+
+  structure = gst_caps_get_structure (caps, 0);
+  gst_structure_get_int (structure, "channels", &mulawenc->channels);
+  gst_structure_get_int (structure, "rate", &mulawenc->rate);
+
+  if (pad == mulawenc->sinkpad) {
+    otherpad = mulawenc->srcpad;
+  } else {
+    otherpad = mulawenc->sinkpad;
+  }
+  base_caps = gst_caps_copy (gst_pad_get_pad_template_caps (otherpad));
+
+  structure = gst_caps_get_structure (base_caps, 0);
+  gst_structure_set (structure, "rate", G_TYPE_INT, mulawenc->rate, NULL);
+  gst_structure_set (structure, "channels", G_TYPE_INT, mulawenc->channels,
+      NULL);
+
+  gst_pad_set_caps (otherpad, base_caps);
+
+  gst_object_unref (mulawenc);
+  gst_caps_unref (base_caps);
+
+  return TRUE;
+}
+
+GType
+gst_mulawenc_get_type (void)
+{
+  static GType mulawenc_type = 0;
+
+  if (!mulawenc_type) {
+    static const GTypeInfo mulawenc_info = {
+      sizeof (GstMuLawEncClass),
+      (GBaseInitFunc) gst_mulawenc_base_init,
+      NULL,
+      (GClassInitFunc) gst_mulawenc_class_init,
+      NULL,
+      NULL,
+      sizeof (GstMuLawEnc),
+      0,
+      (GInstanceInitFunc) gst_mulawenc_init,
+    };
+
+    mulawenc_type =
+        g_type_register_static (GST_TYPE_ELEMENT, "GstMuLawEnc", &mulawenc_info,
+        0);
+  }
+  return mulawenc_type;
+}
+
+static void
+gst_mulawenc_base_init (GstMuLawEncClass * klass)
+{
+  GstElementClass *element_class = GST_ELEMENT_CLASS (klass);
+  const GstElementDetails mulawenc_details =
+      GST_ELEMENT_DETAILS ("Mu Law audio encoder",
+      "Codec/Encoder/Audio",
+      "Convert 16bit PCM to 8bit mu law",
+      "Zaheer Abbas Merali <zaheerabbas at merali dot org>");
+
+  gst_element_class_add_pad_template (element_class,
+      gst_static_pad_template_get (&mulaw_enc_src_factory));
+  gst_element_class_add_pad_template (element_class,
+      gst_static_pad_template_get (&mulaw_enc_sink_factory));
+  gst_element_class_set_details (element_class, &mulawenc_details);
+}
+
+static void
+gst_mulawenc_class_init (GstMuLawEncClass * klass)
+{
+  parent_class = g_type_class_peek_parent (klass);
+}
+
+static void
+gst_mulawenc_init (GstMuLawEnc * mulawenc)
+{
+  mulawenc->sinkpad =
+      gst_pad_new_from_static_template (&mulaw_enc_sink_factory, "sink");
+  gst_pad_set_setcaps_function (mulawenc->sinkpad, mulawenc_setcaps);
+  gst_pad_set_getcaps_function (mulawenc->sinkpad, mulawenc_getcaps);
+  gst_pad_set_chain_function (mulawenc->sinkpad, gst_mulawenc_chain);
+  gst_element_add_pad (GST_ELEMENT (mulawenc), mulawenc->sinkpad);
+
+  mulawenc->srcpad =
+      gst_pad_new_from_static_template (&mulaw_enc_src_factory, "src");
+  gst_pad_set_setcaps_function (mulawenc->srcpad, mulawenc_setcaps);
+  gst_pad_set_getcaps_function (mulawenc->srcpad, mulawenc_getcaps);
+  gst_pad_use_fixed_caps (mulawenc->srcpad);
+  gst_element_add_pad (GST_ELEMENT (mulawenc), mulawenc->srcpad);
+
+  /* init rest */
+  mulawenc->channels = 0;
+  mulawenc->rate = 0;
+}
+
+static GstFlowReturn
+gst_mulawenc_chain (GstPad * pad, GstBuffer * buffer)
+{
+  GstMuLawEnc *mulawenc;
+  gint16 *linear_data;
+  guint linear_size;
+  guint8 *mulaw_data;
+  guint mulaw_size;
+  GstBuffer *outbuf;
+  GstFlowReturn ret;
+  GstClockTime timestamp, duration;
+
+  mulawenc = GST_MULAWENC (gst_pad_get_parent (pad));
+
+  if (!mulawenc->rate || !mulawenc->channels)
+    goto not_negotiated;
+
+  linear_data = (gint16 *) GST_BUFFER_DATA (buffer);
+  linear_size = GST_BUFFER_SIZE (buffer);
+
+  mulaw_size = linear_size / 2;
+
+  timestamp = GST_BUFFER_TIMESTAMP (buffer);
+  duration = GST_BUFFER_DURATION (buffer);
+
+  ret = gst_pad_alloc_buffer_and_set_caps (mulawenc->srcpad,
+      GST_BUFFER_OFFSET_NONE, mulaw_size, GST_PAD_CAPS (mulawenc->srcpad),
+      &outbuf);
+  if (ret != GST_FLOW_OK)
+    goto alloc_failed;
+
+  if (duration == -1) {
+    duration = gst_util_uint64_scale_int (mulaw_size,
+        GST_SECOND, mulawenc->rate * mulawenc->channels);
+  }
+
+  if (GST_BUFFER_SIZE (outbuf) < mulaw_size) {
+    /* pad-alloc can suggest a smaller size */
+    gst_buffer_unref (outbuf);
+    outbuf = gst_buffer_new_and_alloc (mulaw_size);
+  }
+
+  mulaw_data = (guint8 *) GST_BUFFER_DATA (outbuf);
+
+  /* copy discont flag */
+  if (GST_BUFFER_FLAG_IS_SET (buffer, GST_BUFFER_FLAG_DISCONT))
+    GST_BUFFER_FLAG_SET (outbuf, GST_BUFFER_FLAG_DISCONT);
+
+  GST_BUFFER_TIMESTAMP (outbuf) = timestamp;
+  GST_BUFFER_DURATION (outbuf) = duration;
+
+  gst_buffer_set_caps (outbuf, GST_PAD_CAPS (mulawenc->srcpad));
+
+  mulaw_encode (linear_data, mulaw_data, mulaw_size);
+
+  gst_buffer_unref (buffer);
+
+  ret = gst_pad_push (mulawenc->srcpad, outbuf);
+
+done:
+  gst_object_unref (mulawenc);
+
+  return ret;
+
+not_negotiated:
+  {
+    GST_DEBUG_OBJECT (mulawenc, "no format negotiated");
+    ret = GST_FLOW_NOT_NEGOTIATED;
+    gst_buffer_unref (buffer);
+    goto done;
+  }
+alloc_failed:
+  {
+    GST_DEBUG_OBJECT (mulawenc, "pad alloc failed");
+    gst_buffer_unref (buffer);
+    goto done;
+  }
+}