gstreamer/gst/law/alaw-decode.c
Ronald S. Bultje 920ad8773b gst/law/: Fix capsnego in all four, remove the unused property functions and simplify the chain functions slightly. I...
Original commit message from CVS:
* gst/law/alaw-decode.c: (alawdec_getcaps), (alawdec_link),
(gst_alawdec_base_init), (gst_alawdec_class_init),
(gst_alawdec_init), (gst_alawdec_chain):
* gst/law/alaw-encode.c: (alawenc_getcaps), (alawenc_link),
(gst_alawenc_base_init), (gst_alawenc_class_init),
(gst_alawenc_init), (gst_alawenc_chain):
* gst/law/mulaw-decode.c: (mulawdec_getcaps), (mulawdec_link),
(gst_mulawdec_base_init), (gst_mulawdec_class_init),
(gst_mulawdec_init), (gst_mulawdec_chain):
* gst/law/mulaw-encode.c: (mulawenc_getcaps), (mulawenc_link),
(gst_mulawenc_base_init), (gst_mulawenc_class_init),
(gst_mulawenc_init), (gst_mulawenc_chain):
Fix capsnego in all four, remove the unused property functions and
simplify the chain functions slightly. I guess we could use macros
or something similar for those, since the code is so similar, but
I'm currently too lazy...
2004-03-26 01:56:11 +00:00

237 lines
6.8 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;
/* 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_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 GstCaps *
alawdec_getcaps (GstPad * pad)
{
GstALawDec *alawdec = GST_ALAWDEC (gst_pad_get_parent (pad));
GstPad *otherpad;
GstCaps *base_caps, *othercaps;
GstStructure *structure;
const GValue *rate, *chans;
if (pad == alawdec->sinkpad) {
otherpad = alawdec->srcpad;
base_caps = gst_caps_new_simple ("audio/x-mulaw", NULL);
} else {
otherpad = alawdec->sinkpad;
base_caps = gst_caps_new_simple ("audio/x-raw-int",
"width", G_TYPE_INT, 16, "depth", G_TYPE_INT, 16,
"endianness", G_TYPE_INT, G_BYTE_ORDER, NULL);
}
othercaps = gst_pad_get_allowed_caps (otherpad);
/* Not fully correct, but usually, all structures in a caps have
* the same samplerate and channels range. */
structure = gst_caps_get_structure (othercaps, 0);
rate = gst_structure_get_value (structure, "rate");
chans = gst_structure_get_value (structure, "channels");
if (!rate || !chans)
return gst_caps_new_empty ();
/* Set the samplerate/channels on the to-be-returned caps */
structure = gst_caps_get_structure (base_caps, 0);
gst_structure_set_value (structure, "rate", rate);
gst_structure_set_value (structure, "channels", chans);
gst_caps_free (othercaps);
return base_caps;
}
static GstPadLinkReturn
alawdec_link (GstPad * pad, const GstCaps * caps)
{
GstALawDec *alawdec = GST_ALAWDEC (gst_pad_get_parent (pad));
GstPad *otherpad;
GstStructure *structure;
const GValue *rate, *chans;
GstCaps *base_caps;
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 GST_PAD_LINK_REFUSED;
if (pad == alawdec->srcpad) {
otherpad = alawdec->sinkpad;
base_caps = gst_caps_new_simple ("audio/x-mulaw", NULL);
} else {
otherpad = alawdec->srcpad;
base_caps = gst_caps_new_simple ("audio/x-raw-int",
"width", G_TYPE_INT, 16, "depth", G_TYPE_INT, 16,
"endianness", G_TYPE_INT, G_BYTE_ORDER, NULL);
}
structure = gst_caps_get_structure (base_caps, 0);
gst_structure_set_value (structure, "rate", rate);
gst_structure_set_value (structure, "channels", chans);
return gst_pad_try_set_caps (otherpad, base_caps);
}
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);
GstElementDetails alawdec_details = {
"A Law to PCM conversion",
"Codec/Decoder/Audio",
"Convert 8bit A law to 16bit PCM",
"Zaheer Merali <zaheer@bellworldwide.net>"
};
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)
{
parent_class = g_type_class_ref (GST_TYPE_ELEMENT);
}
static void
gst_alawdec_init (GstALawDec * alawdec)
{
alawdec->sinkpad = gst_pad_new_from_template (alawdec_sink_template, "sink");
gst_pad_set_link_function (alawdec->sinkpad, alawdec_link);
gst_pad_set_getcaps_function (alawdec->sinkpad, alawdec_getcaps);
gst_pad_set_chain_function (alawdec->sinkpad, gst_alawdec_chain);
gst_element_add_pad (GST_ELEMENT (alawdec), alawdec->sinkpad);
alawdec->srcpad = gst_pad_new_from_template (alawdec_src_template, "src");
gst_pad_set_link_function (alawdec->srcpad, alawdec_link);
gst_pad_set_getcaps_function (alawdec->srcpad, alawdec_getcaps);
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_and_alloc (GST_BUFFER_SIZE (buf) * 2);
GST_BUFFER_TIMESTAMP (outbuf) = GST_BUFFER_TIMESTAMP (buf);
GST_BUFFER_DURATION (outbuf) = GST_BUFFER_DURATION (buf);
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));
}