1 files changed, 211 insertions, 0 deletions
diff --git a/gst/law/mulaw-encode.c b/gst/law/mulaw-encode.c
new file mode 100644
index 0000000..ed943af
--- /dev/null
+++ b/gst/law/mulaw-encode.c
@@ -0,0 +1,211 @@
+/* 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., 51 Franklin St, Fifth Floor,
+ * Boston, MA 02110-1301, 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 <gst/audio/audio.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 gboolean gst_mulawenc_start (GstAudioEncoder * audioenc);
+static gboolean gst_mulawenc_set_format (GstAudioEncoder * enc,
+    GstAudioInfo * info);
+static GstFlowReturn gst_mulawenc_handle_frame (GstAudioEncoder * enc,
+    GstBuffer * buffer);
+static void gst_mulawenc_set_tags (GstMuLawEnc * mulawenc);
+
+
+#define gst_mulawenc_parent_class parent_class
+G_DEFINE_TYPE (GstMuLawEnc, gst_mulawenc, GST_TYPE_AUDIO_ENCODER);
+
+/*static guint gst_stereo_signals[LAST_SIGNAL] = { 0 }; */
+
+static gboolean
+gst_mulawenc_start (GstAudioEncoder * audioenc)
+{
+  GstMuLawEnc *mulawenc = GST_MULAWENC (audioenc);
+
+  mulawenc->channels = 0;
+  mulawenc->rate = 0;
+
+  return TRUE;
+}
+
+
+static void
+gst_mulawenc_set_tags (GstMuLawEnc * mulawenc)
+{
+  GstTagList *taglist;
+  guint bitrate;
+
+  /* bitrate of mulaw is 8 bits/sample * sample rate * number of channels */
+  bitrate = 8 * mulawenc->rate * mulawenc->channels;
+
+  taglist = gst_tag_list_new_empty ();
+  gst_tag_list_add (taglist, GST_TAG_MERGE_REPLACE,
+      GST_TAG_MAXIMUM_BITRATE, bitrate, NULL);
+  gst_tag_list_add (taglist, GST_TAG_MERGE_REPLACE,
+      GST_TAG_MINIMUM_BITRATE, bitrate, NULL);
+  gst_tag_list_add (taglist, GST_TAG_MERGE_REPLACE,
+      GST_TAG_BITRATE, bitrate, NULL);
+
+  gst_audio_encoder_merge_tags (GST_AUDIO_ENCODER (mulawenc),
+      taglist, GST_TAG_MERGE_REPLACE);
+
+  gst_tag_list_unref (taglist);
+}
+
+
+static gboolean
+gst_mulawenc_set_format (GstAudioEncoder * audioenc, GstAudioInfo * info)
+{
+  GstCaps *base_caps;
+  GstStructure *structure;
+  GstMuLawEnc *mulawenc = GST_MULAWENC (audioenc);
+  gboolean ret;
+
+  mulawenc->rate = info->rate;
+  mulawenc->channels = info->channels;
+
+  base_caps =
+      gst_pad_get_pad_template_caps (GST_AUDIO_ENCODER_SRC_PAD (audioenc));
+  g_assert (base_caps);
+  base_caps = gst_caps_make_writable (base_caps);
+  g_assert (base_caps);
+
+  structure = gst_caps_get_structure (base_caps, 0);
+  g_assert (structure);
+  gst_structure_set (structure, "rate", G_TYPE_INT, mulawenc->rate, NULL);
+  gst_structure_set (structure, "channels", G_TYPE_INT, mulawenc->channels,
+      NULL);
+
+  gst_mulawenc_set_tags (mulawenc);
+
+  ret = gst_audio_encoder_set_output_format (audioenc, base_caps);
+  gst_caps_unref (base_caps);
+
+  return ret;
+}
+
+static GstFlowReturn
+gst_mulawenc_handle_frame (GstAudioEncoder * audioenc, GstBuffer * buffer)
+{
+  GstMuLawEnc *mulawenc;
+  GstMapInfo inmap, outmap;
+  gint16 *linear_data;
+  gsize linear_size;
+  guint8 *mulaw_data;
+  guint mulaw_size;
+  GstBuffer *outbuf;
+  GstFlowReturn ret;
+
+  if (!buffer) {
+    ret = GST_FLOW_OK;
+    goto done;
+  }
+
+  mulawenc = GST_MULAWENC (audioenc);
+
+  if (!mulawenc->rate || !mulawenc->channels)
+    goto not_negotiated;
+
+  gst_buffer_map (buffer, &inmap, GST_MAP_READ);
+  linear_data = (gint16 *) inmap.data;
+  linear_size = inmap.size;
+
+  mulaw_size = linear_size / 2;
+
+  outbuf = gst_audio_encoder_allocate_output_buffer (audioenc, mulaw_size);
+
+  g_assert (outbuf);
+
+  gst_buffer_map (outbuf, &outmap, GST_MAP_WRITE);
+  mulaw_data = outmap.data;
+
+  mulaw_encode (linear_data, mulaw_data, mulaw_size);
+
+  gst_buffer_unmap (outbuf, &outmap);
+  gst_buffer_unmap (buffer, &inmap);
+
+  ret = gst_audio_encoder_finish_frame (audioenc, outbuf, -1);
+
+done:
+
+  return ret;
+
+not_negotiated:
+  {
+    GST_DEBUG_OBJECT (mulawenc, "no format negotiated");
+    ret = GST_FLOW_NOT_NEGOTIATED;
+    goto done;
+  }
+}
+
+
+
+static void
+gst_mulawenc_class_init (GstMuLawEncClass * klass)
+{
+  GstElementClass *element_class = GST_ELEMENT_CLASS (klass);
+  GstAudioEncoderClass *audio_encoder_class = GST_AUDIO_ENCODER_CLASS (klass);
+
+  audio_encoder_class->start = GST_DEBUG_FUNCPTR (gst_mulawenc_start);
+  audio_encoder_class->set_format = GST_DEBUG_FUNCPTR (gst_mulawenc_set_format);
+  audio_encoder_class->handle_frame =
+      GST_DEBUG_FUNCPTR (gst_mulawenc_handle_frame);
+
+  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_static_metadata (element_class, "Mu Law audio encoder",
+      "Codec/Encoder/Audio",
+      "Convert 16bit PCM to 8bit mu law",
+      "Zaheer Abbas Merali <zaheerabbas at merali dot org>");
+}
+
+static void
+gst_mulawenc_init (GstMuLawEnc * mulawenc)
+{
+
+}