gstreamer/gst/law/alaw-decode.c
David Schleef ce51f6173c Merge CAPS branch
Original commit message from CVS:
Merge CAPS branch
2003-12-22 01:47:09 +00:00

233 lines
6.3 KiB
C

/* GStreamer
* 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 2.1 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
* 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 <gst/gst.h>
#include "alaw-decode.h"
extern GstPadTemplate *alawdec_src_template, *alawdec_sink_template;
/* elementfactory information */
static GstElementDetails alawdec_details = {
"A Law to PCM conversion",
"Codec/Decoder/Audio",
"Convert 8bit A law to 16bit PCM",
"Zaheer Merali <zaheer@bellworldwide.net>"
};
/* Stereo signals and args */
enum {
/* FILL ME */
LAST_SIGNAL
};
enum {
ARG_0
};
static void gst_alawdec_class_init (GstALawDecClass *klass);
static void gst_alawdec_base_init (GstALawDecClass *klass);
static void gst_alawdec_init (GstALawDec *alawdec);
static void gst_alawdec_set_property (GObject *object, guint prop_id, const GValue *value, GParamSpec *pspec);
static void gst_alawdec_get_property (GObject *object, guint prop_id, GValue *value, GParamSpec *pspec);
static void gst_alawdec_chain (GstPad *pad, GstData *_data);
static GstElementClass *parent_class = NULL;
/*static guint gst_stereo_signals[LAST_SIGNAL] = { 0 }; */
/*
* alaw_to_s16() - Convert an A-law value to 16-bit linear PCM
*
*/
static gint alaw_to_s16(guint8 a_val)
{
gint t;
gint seg;
a_val ^= 0x55;
t = a_val & 0x7f;
if (t < 16)
t = (t << 4) + 8;
else {
seg = (t >> 4) & 0x07;
t = ((t & 0x0f) << 4) + 0x108;
t <<= seg -1;
}
return ((a_val & 0x80) ? t : -t);
}
static GstPadLinkReturn
alawdec_link (GstPad *pad, const GstCaps *caps)
{
GstCaps* tempcaps;
gint rate, channels;
GstStructure *structure;
gboolean ret;
GstALawDec* alawdec = GST_ALAWDEC (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-raw-int",
"depth", G_TYPE_INT, 16,
"width", G_TYPE_INT, 16,
"signed", G_TYPE_BOOLEAN, TRUE,
"endianness", G_TYPE_INT, G_BYTE_ORDER,
"rate", G_TYPE_INT, rate,
"channels", G_TYPE_INT, channels,
NULL);
return gst_pad_try_set_caps (alawdec->srcpad, tempcaps);
}
GType
gst_alawdec_get_type(void) {
static GType alawdec_type = 0;
if (!alawdec_type) {
static const GTypeInfo alawdec_info = {
sizeof(GstALawDecClass),
(GBaseInitFunc)gst_alawdec_base_init,
NULL,
(GClassInitFunc)gst_alawdec_class_init,
NULL,
NULL,
sizeof(GstALawDec),
0,
(GInstanceInitFunc)gst_alawdec_init,
};
alawdec_type = g_type_register_static(GST_TYPE_ELEMENT, "GstALawDec", &alawdec_info, 0);
}
return alawdec_type;
}
static void
gst_alawdec_base_init (GstALawDecClass *klass)
{
GstElementClass *element_class = GST_ELEMENT_CLASS (klass);
gst_element_class_add_pad_template (element_class, alawdec_src_template);
gst_element_class_add_pad_template (element_class, alawdec_sink_template);
gst_element_class_set_details (element_class, &alawdec_details);
}
static void
gst_alawdec_class_init (GstALawDecClass *klass)
{
GObjectClass *gobject_class;
GstElementClass *gstelement_class;
gobject_class = (GObjectClass*)klass;
gstelement_class = (GstElementClass*)klass;
parent_class = g_type_class_ref(GST_TYPE_ELEMENT);
gobject_class->set_property = gst_alawdec_set_property;
gobject_class->get_property = gst_alawdec_get_property;
}
static void
gst_alawdec_init (GstALawDec *alawdec)
{
alawdec->sinkpad = gst_pad_new_from_template(alawdec_sink_template,"sink");
alawdec->srcpad = gst_pad_new_from_template(alawdec_src_template,"src");
gst_pad_set_link_function(alawdec->sinkpad, alawdec_link);
gst_element_add_pad(GST_ELEMENT(alawdec),alawdec->sinkpad);
gst_pad_set_chain_function(alawdec->sinkpad,gst_alawdec_chain);
gst_element_add_pad(GST_ELEMENT(alawdec),alawdec->srcpad);
}
static void
gst_alawdec_chain (GstPad *pad,GstData *_data)
{
GstBuffer *buf = GST_BUFFER (_data);
GstALawDec *alawdec;
gint16 *linear_data;
guint8 *alaw_data;
GstBuffer* outbuf;
gint i;
g_return_if_fail(pad != NULL);
g_return_if_fail(GST_IS_PAD(pad));
g_return_if_fail(buf != NULL);
alawdec = GST_ALAWDEC(GST_OBJECT_PARENT (pad));
g_return_if_fail(alawdec != NULL);
g_return_if_fail(GST_IS_ALAWDEC(alawdec));
alaw_data = (guint8 *)GST_BUFFER_DATA(buf);
outbuf=gst_buffer_new();
GST_BUFFER_DATA(outbuf) = (gchar*)g_new(gint16,GST_BUFFER_SIZE(buf));
GST_BUFFER_SIZE(outbuf) = GST_BUFFER_SIZE(buf)*2;
linear_data = (gint16*)GST_BUFFER_DATA(outbuf);
for (i = 0; i < GST_BUFFER_SIZE(buf); i++) {
*linear_data = alaw_to_s16 (*alaw_data);
linear_data++;
alaw_data++;
}
gst_buffer_unref(buf);
gst_pad_push(alawdec->srcpad,GST_DATA (outbuf));
}
static void
gst_alawdec_set_property (GObject *object, guint prop_id, const GValue *value, GParamSpec *pspec)
{
GstALawDec *alawdec;
/* it's not null if we got it, but it might not be ours */
g_return_if_fail(GST_IS_ALAWDEC(object));
alawdec = GST_ALAWDEC(object);
switch (prop_id) {
default:
break;
}
}
static void
gst_alawdec_get_property (GObject *object, guint prop_id, GValue *value, GParamSpec *pspec)
{
GstALawDec *alawdec;
/* it's not null if we got it, but it might not be ours */
g_return_if_fail(GST_IS_ALAWDEC(object));
alawdec = GST_ALAWDEC(object);
switch (prop_id) {
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}