gstreamer/gst/law/mulaw-decode.c

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/* 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.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <gst/gst.h>
#include "mulaw-decode.h"
#include "mulaw-conversion.h"
extern GstPadTemplate *mulawdec_src_template, *mulawdec_sink_template;
/* Stereo signals and args */
enum
{
/* FILL ME */
LAST_SIGNAL
};
enum
{
ARG_0
};
static void gst_mulawdec_class_init (GstMuLawDecClass * klass);
static void gst_mulawdec_base_init (GstMuLawDecClass * klass);
static void gst_mulawdec_init (GstMuLawDec * mulawdec);
static GstFlowReturn gst_mulawdec_chain (GstPad * pad, GstBuffer * buffer);
static GstElementClass *parent_class = NULL;
/*static guint gst_stereo_signals[LAST_SIGNAL] = { 0 };*/
static GstCaps *
mulawdec_getcaps (GstPad * pad)
{
GstMuLawDec *mulawdec;
GstPad *otherpad;
GstCaps *base_caps, *othercaps;
mulawdec = GST_MULAWDEC (GST_PAD_PARENT (pad));
base_caps = gst_caps_copy (gst_pad_get_pad_template_caps (pad));
if (pad == mulawdec->sinkpad) {
otherpad = mulawdec->srcpad;
} else {
otherpad = mulawdec->sinkpad;
}
othercaps = gst_pad_peer_get_caps (otherpad);
if (othercaps) {
GstStructure *structure;
const GValue *orate, *ochans;
const GValue *rate, *chans;
GValue irate = { 0 }, ichans = {
0};
structure = gst_caps_get_structure (othercaps, 0);
orate = gst_structure_get_value (structure, "rate");
ochans = gst_structure_get_value (structure, "channels");
if (!orate || !ochans)
goto done;
structure = gst_caps_get_structure (base_caps, 0);
rate = gst_structure_get_value (structure, "rate");
chans = gst_structure_get_value (structure, "channels");
if (!rate || !chans)
goto done;
gst_value_intersect (&irate, orate, rate);
gst_value_intersect (&ichans, ochans, chans);
/* Set the samplerate/channels on the to-be-returned caps */
structure = gst_caps_get_structure (base_caps, 0);
gst_structure_set_value (structure, "rate", &irate);
gst_structure_set_value (structure, "channels", &ichans);
gst_caps_unref (othercaps);
}
done:
return base_caps;
}
static gboolean
mulawdec_setcaps (GstPad * pad, GstCaps * caps)
{
GstMuLawDec *mulawdec;
GstPad *otherpad;
GstStructure *structure;
const GValue *rate, *chans;
GstCaps *base_caps;
mulawdec = GST_MULAWDEC (GST_PAD_PARENT (pad));
structure = gst_caps_get_structure (caps, 0);
rate = gst_structure_get_value (structure, "rate");
chans = gst_structure_get_value (structure, "channels");
if (!rate || !chans)
return FALSE;
if (pad == mulawdec->srcpad) {
otherpad = mulawdec->sinkpad;
} else {
otherpad = mulawdec->srcpad;
}
base_caps = gst_caps_copy (gst_pad_get_pad_template_caps (otherpad));
structure = gst_caps_get_structure (base_caps, 0);
gst_structure_set_value (structure, "rate", rate);
gst_structure_set_value (structure, "channels", chans);
gst_pad_set_caps (otherpad, base_caps);
gst_caps_unref (base_caps);
return TRUE;
}
GType
gst_mulawdec_get_type (void)
{
static GType mulawdec_type = 0;
if (!mulawdec_type) {
static const GTypeInfo mulawdec_info = {
sizeof (GstMuLawDecClass),
(GBaseInitFunc) gst_mulawdec_base_init,
NULL,
(GClassInitFunc) gst_mulawdec_class_init,
NULL,
NULL,
sizeof (GstMuLawDec),
0,
(GInstanceInitFunc) gst_mulawdec_init,
};
mulawdec_type =
g_type_register_static (GST_TYPE_ELEMENT, "GstMuLawDec", &mulawdec_info,
0);
}
return mulawdec_type;
}
static void
gst_mulawdec_base_init (GstMuLawDecClass * klass)
{
GstElementClass *element_class = GST_ELEMENT_CLASS (klass);
GstElementDetails mulawdec_details = {
"Mu Law to PCM conversion",
"Codec/Decoder/Audio",
"Convert 8bit mu law to 16bit PCM",
"Zaheer Abbas Merali <zaheerabbas at merali dot org>"
};
gst_element_class_add_pad_template (element_class, mulawdec_src_template);
gst_element_class_add_pad_template (element_class, mulawdec_sink_template);
gst_element_class_set_details (element_class, &mulawdec_details);
}
static void
gst_mulawdec_class_init (GstMuLawDecClass * klass)
{
parent_class = g_type_class_ref (GST_TYPE_ELEMENT);
}
static void
gst_mulawdec_init (GstMuLawDec * mulawdec)
{
mulawdec->sinkpad =
gst_pad_new_from_template (mulawdec_sink_template, "sink");
gst_pad_set_setcaps_function (mulawdec->sinkpad, mulawdec_setcaps);
gst_pad_set_getcaps_function (mulawdec->sinkpad, mulawdec_getcaps);
gst_pad_set_chain_function (mulawdec->sinkpad, gst_mulawdec_chain);
gst_element_add_pad (GST_ELEMENT (mulawdec), mulawdec->sinkpad);
mulawdec->srcpad = gst_pad_new_from_template (mulawdec_src_template, "src");
gst_pad_set_setcaps_function (mulawdec->srcpad, mulawdec_setcaps);
gst_pad_set_getcaps_function (mulawdec->srcpad, mulawdec_getcaps);
gst_element_add_pad (GST_ELEMENT (mulawdec), mulawdec->srcpad);
}
static GstFlowReturn
gst_mulawdec_chain (GstPad * pad, GstBuffer * buffer)
{
GstMuLawDec *mulawdec;
gint16 *linear_data;
guint8 *mulaw_data;
GstBuffer *outbuf;
mulawdec = GST_MULAWDEC (GST_OBJECT_PARENT (pad));
mulaw_data = (guint8 *) GST_BUFFER_DATA (buffer);
outbuf = gst_buffer_new_and_alloc (GST_BUFFER_SIZE (buffer) * 2);
GST_BUFFER_TIMESTAMP (outbuf) = GST_BUFFER_TIMESTAMP (buffer);
GST_BUFFER_DURATION (outbuf) = GST_BUFFER_DURATION (buffer);
gst_buffer_set_caps (outbuf, GST_PAD_CAPS (mulawdec->srcpad));
linear_data = (gint16 *) GST_BUFFER_DATA (outbuf);
mulaw_decode (mulaw_data, linear_data, GST_BUFFER_SIZE (buffer));
gst_buffer_unref (buffer);
return gst_pad_push (mulawdec->srcpad, outbuf);
}