/* GStreamer
- * Copyright (C) <1999> Erik Walthinsen <omega@cse.ogi.edu>
+ * Copyright (C) 1999 Erik Walthinsen <omega@cse.ogi.edu>
+ * PCM - A-Law conversion
+ * Copyright (C) 2000 by Abramo Bagnara <abramo@alsa-project.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.
+ * 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
* Boston, MA 02111-1307, USA.
*/
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
#include <gst/gst.h>
#include "alaw-encode.h"
-#include "mulaw-conversion.h"
-#include "alaw-conversion.h"
extern GstPadTemplate *alawenc_src_template, *alawenc_sink_template;
+/* elementfactory information */
+static GstElementDetails alawenc_details = {
+ "PCM to A Law conversion",
+ "Codec/Encoder/Audio",
+ "Convert 16bit PCM to 8bit A law",
+ "Zaheer Merali <zaheer@bellworldwide.net>"
+};
/* Stereo signals and args */
-enum {
+enum
+{
/* FILL ME */
LAST_SIGNAL
};
-enum {
+enum
+{
ARG_0
};
-static void gst_alawenc_class_init (GstALawEncClass *klass);
-static void gst_alawenc_init (GstALawEnc *alawenc);
+static void gst_alawenc_class_init (GstALawEncClass * klass);
+static void gst_alawenc_base_init (GstALawEncClass * klass);
+static void gst_alawenc_init (GstALawEnc * alawenc);
-static void gst_alawenc_set_property (GObject *object, guint prop_id, const GValue *value, GParamSpec *pspec);
-static void gst_alawenc_get_property (GObject *object, guint prop_id, GValue *value, GParamSpec *pspec);
+static void gst_alawenc_set_property (GObject * object, guint prop_id,
+ const GValue * value, GParamSpec * pspec);
+static void gst_alawenc_get_property (GObject * object, guint prop_id,
+ GValue * value, GParamSpec * pspec);
-static void gst_alawenc_chain (GstPad *pad, GstBuffer *buf);
+static void gst_alawenc_chain (GstPad * pad, GstData * _data);
+/*
+ * s16_to_alaw() - Convert a 16-bit linear PCM value to 8-bit A-law
+ *
+ * s16_to_alaw() accepts an 16-bit integer and encodes it as A-law data.
+ *
+ * Linear Input Code Compressed Code
+ * ------------------------ ---------------
+ * 0000000wxyza 000wxyz
+ * 0000001wxyza 001wxyz
+ * 000001wxyzab 010wxyz
+ * 00001wxyzabc 011wxyz
+ * 0001wxyzabcd 100wxyz
+ * 001wxyzabcde 101wxyz
+ * 01wxyzabcdef 110wxyz
+ * 1wxyzabcdefg 111wxyz
+ *
+ * For further information see John C. Bellamy's Digital Telephony, 1982,
+ * John Wiley & Sons, pps 98-111 and 472-476.
+ */
-static GstElementClass *parent_class = NULL;
-/*static guint gst_stereo_signals[LAST_SIGNAL] = { 0 }; */
+static inline gint
+val_seg (gint val)
+{
+ gint r = 1;
-/*
-static GstPadNegotiateReturn
-alawenc_negotiate_sink (GstPad *pad, GstCaps **caps, gint counter)
+ val >>= 8;
+ if (val & 0xf0) {
+ val >>= 4;
+ r += 4;
+ }
+ if (val & 0x0c) {
+ val >>= 2;
+ r += 2;
+ }
+ if (val & 0x02)
+ r += 1;
+ return r;
+}
+
+static guint8
+s16_to_alaw (gint pcm_val)
{
- GstCaps* tempcaps;
-
- GstALawEnc* alawenc=GST_ALAWENC (GST_OBJECT_PARENT (pad));
-
- if (*caps==NULL)
- return GST_PAD_NEGOTIATE_FAIL;
-
- tempcaps = gst_caps_copy(*caps);
-
- gst_caps_set(tempcaps,"format",GST_PROPS_STRING("int"));
- gst_caps_set(tempcaps,"law",GST_PROPS_INT(2));
- gst_caps_set(tempcaps,"depth",GST_PROPS_INT(8));
- gst_caps_set(tempcaps,"width",GST_PROPS_INT(8));
- gst_caps_set(tempcaps,"signed",GST_PROPS_BOOLEAN(FALSE));
-
- if (gst_pad_try_set_caps (alawenc->srcpad, tempcaps) > 0)
- {
- return GST_PAD_NEGOTIATE_AGREE;
+ gint seg;
+ guint8 mask;
+ guint8 aval;
+
+ if (pcm_val >= 0) {
+ mask = 0xD5;
+ } else {
+ mask = 0x55;
+ pcm_val = -pcm_val;
+ if (pcm_val > 0x7fff)
+ pcm_val = 0x7fff;
}
+
+ if (pcm_val < 256)
+ aval = pcm_val >> 4;
else {
- gst_caps_unref (tempcaps);
- return GST_PAD_NEGOTIATE_FAIL;
+ /* Convert the scaled magnitude to segment number. */
+ seg = val_seg (pcm_val);
+ aval = (seg << 4) | ((pcm_val >> (seg + 3)) & 0x0f);
}
-}
-*/
+ return aval ^ mask;
+}
+
+static GstElementClass *parent_class = NULL;
+
+/*static guint gst_stereo_signals[LAST_SIGNAL] = { 0 }; */
+
+static GstPadLinkReturn
+alawenc_link (GstPad * pad, const GstCaps * caps)
+{
+ GstCaps *tempcaps;
+ gint rate, channels;
+ GstStructure *structure;
+ gboolean ret;
+
+ GstALawEnc *alawenc = GST_ALAWENC (GST_OBJECT_PARENT (pad));
+
+ structure = gst_caps_get_structure (caps, 0);
+
+ ret = gst_structure_get_int (structure, "rate", &rate);
+ ret &= gst_structure_get_int (structure, "channels", &channels);
+
+ if (!ret)
+ return GST_PAD_LINK_REFUSED;
+
+ tempcaps = gst_caps_new_simple ("audio/x-alaw",
+ "depth", G_TYPE_INT, 8,
+ "width", G_TYPE_INT, 8,
+ "signed", G_TYPE_BOOLEAN, FALSE,
+ "rate", G_TYPE_INT, rate, "channels", G_TYPE_INT, channels, NULL);
+
+ return gst_pad_try_set_caps (alawenc->srcpad, tempcaps);
+}
GType
-gst_alawenc_get_type(void) {
+gst_alawenc_get_type (void)
+{
static GType alawenc_type = 0;
if (!alawenc_type) {
static const GTypeInfo alawenc_info = {
- sizeof(GstALawEncClass), NULL,
+ sizeof (GstALawEncClass),
+ (GBaseInitFunc) gst_alawenc_base_init,
NULL,
- (GClassInitFunc)gst_alawenc_class_init,
+ (GClassInitFunc) gst_alawenc_class_init,
NULL,
NULL,
- sizeof(GstALawEnc),
+ sizeof (GstALawEnc),
0,
- (GInstanceInitFunc)gst_alawenc_init,
+ (GInstanceInitFunc) gst_alawenc_init,
};
- alawenc_type = g_type_register_static(GST_TYPE_ELEMENT, "GstALawEnc", &alawenc_info, 0);
+ alawenc_type =
+ g_type_register_static (GST_TYPE_ELEMENT, "GstALawEnc", &alawenc_info,
+ 0);
}
return alawenc_type;
}
static void
-gst_alawenc_class_init (GstALawEncClass *klass)
+gst_alawenc_base_init (GstALawEncClass * klass)
+{
+ GstElementClass *element_class = GST_ELEMENT_CLASS (klass);
+
+ gst_element_class_add_pad_template (element_class, alawenc_src_template);
+ gst_element_class_add_pad_template (element_class, alawenc_sink_template);
+ gst_element_class_set_details (element_class, &alawenc_details);
+}
+
+static void
+gst_alawenc_class_init (GstALawEncClass * klass)
{
GObjectClass *gobject_class;
GstElementClass *gstelement_class;
- gobject_class = (GObjectClass*)klass;
- gstelement_class = (GstElementClass*)klass;
+ gobject_class = (GObjectClass *) klass;
+ gstelement_class = (GstElementClass *) klass;
- parent_class = g_type_class_ref(GST_TYPE_ELEMENT);
+ parent_class = g_type_class_ref (GST_TYPE_ELEMENT);
gobject_class->set_property = gst_alawenc_set_property;
gobject_class->get_property = gst_alawenc_get_property;
}
static void
-gst_alawenc_init (GstALawEnc *alawenc)
+gst_alawenc_init (GstALawEnc * alawenc)
{
- alawenc->sinkpad = gst_pad_new_from_template(alawenc_sink_template,"sink");
- alawenc->srcpad = gst_pad_new_from_template(alawenc_src_template,"src");
- /*gst_pad_set_negotiate_function(alawenc->sinkpad, alawenc_negotiate_sink);*/
+ alawenc->sinkpad = gst_pad_new_from_template (alawenc_sink_template, "sink");
+ alawenc->srcpad = gst_pad_new_from_template (alawenc_src_template, "src");
+ gst_pad_set_link_function (alawenc->sinkpad, alawenc_link);
- gst_element_add_pad(GST_ELEMENT(alawenc),alawenc->sinkpad);
- gst_pad_set_chain_function(alawenc->sinkpad,gst_alawenc_chain);
- gst_element_add_pad(GST_ELEMENT(alawenc),alawenc->srcpad);
+ gst_element_add_pad (GST_ELEMENT (alawenc), alawenc->sinkpad);
+ gst_pad_set_chain_function (alawenc->sinkpad, gst_alawenc_chain);
+ gst_element_add_pad (GST_ELEMENT (alawenc), alawenc->srcpad);
}
static void
-gst_alawenc_chain (GstPad *pad,GstBuffer *buf)
+gst_alawenc_chain (GstPad * pad, GstData * _data)
{
+ GstBuffer *buf = GST_BUFFER (_data);
GstALawEnc *alawenc;
gint16 *linear_data;
guint8 *alaw_data;
- GstBuffer* outbuf;
-
- g_return_if_fail(pad != NULL);
- g_return_if_fail(GST_IS_PAD(pad));
- g_return_if_fail(buf != NULL);
-
- alawenc = GST_ALAWENC(GST_OBJECT_PARENT (pad));
- g_return_if_fail(alawenc != NULL);
- g_return_if_fail(GST_IS_ALAWENC(alawenc));
-
- linear_data = (gint16 *)GST_BUFFER_DATA(buf);
- outbuf=gst_buffer_new();
- GST_BUFFER_DATA(outbuf) = (gchar*)g_new(gint16,GST_BUFFER_SIZE(buf)/4);
- GST_BUFFER_SIZE(outbuf) = GST_BUFFER_SIZE(buf)/2;
-
- alaw_data = (guint8*)GST_BUFFER_DATA(outbuf);
- mulaw_encode(linear_data,alaw_data,GST_BUFFER_SIZE(outbuf));
- isdn_audio_ulaw2alaw(alaw_data,GST_BUFFER_SIZE(outbuf));
- gst_buffer_unref(buf);
- gst_pad_push(alawenc->srcpad,outbuf);
+ GstBuffer *outbuf;
+ gint i;
+
+ g_return_if_fail (pad != NULL);
+ g_return_if_fail (GST_IS_PAD (pad));
+ g_return_if_fail (buf != NULL);
+
+ alawenc = GST_ALAWENC (GST_OBJECT_PARENT (pad));
+ g_return_if_fail (alawenc != NULL);
+ g_return_if_fail (GST_IS_ALAWENC (alawenc));
+
+ linear_data = (gint16 *) GST_BUFFER_DATA (buf);
+ outbuf = gst_buffer_new ();
+ GST_BUFFER_DATA (outbuf) =
+ (gchar *) g_new (guint8, GST_BUFFER_SIZE (buf) / 2);
+ GST_BUFFER_SIZE (outbuf) = GST_BUFFER_SIZE (buf) / 2;
+
+
+ alaw_data = (guint8 *) GST_BUFFER_DATA (outbuf);
+ for (i = 0; i < GST_BUFFER_SIZE (outbuf); i++) {
+ *alaw_data = s16_to_alaw (*linear_data);
+ alaw_data++;
+ linear_data++;
+ }
+ gst_buffer_unref (buf);
+ gst_pad_push (alawenc->srcpad, GST_DATA (outbuf));
}
static void
-gst_alawenc_set_property (GObject *object, guint prop_id, const GValue *value, GParamSpec *pspec)
+gst_alawenc_set_property (GObject * object, guint prop_id, const GValue * value,
+ GParamSpec * pspec)
{
GstALawEnc *alawenc;
/* it's not null if we got it, but it might not be ours */
- g_return_if_fail(GST_IS_ALAWENC(object));
- alawenc = GST_ALAWENC(object);
+ g_return_if_fail (GST_IS_ALAWENC (object));
+ alawenc = GST_ALAWENC (object);
switch (prop_id) {
default:
}
static void
-gst_alawenc_get_property (GObject *object, guint prop_id, GValue *value, GParamSpec *pspec)
+gst_alawenc_get_property (GObject * object, guint prop_id, GValue * value,
+ GParamSpec * pspec)
{
GstALawEnc *alawenc;
/* it's not null if we got it, but it might not be ours */
- g_return_if_fail(GST_IS_ALAWENC(object));
- alawenc = GST_ALAWENC(object);
+ g_return_if_fail (GST_IS_ALAWENC (object));
+ alawenc = GST_ALAWENC (object);
switch (prop_id) {
default:
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