gstreamer/gst/law/mulaw-decode.c
2011-12-09 10:50:18 +01:00

316 lines
8.5 KiB
C

/* 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.
*/
/**
* SECTION:element-mulawdec
*
* This element decodes 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-decode.h"
#include "mulaw-conversion.h"
extern GstStaticPadTemplate mulaw_dec_src_factory;
extern GstStaticPadTemplate mulaw_dec_sink_factory;
/* Stereo signals and args */
enum
{
/* FILL ME */
LAST_SIGNAL
};
enum
{
ARG_0
};
static GstStateChangeReturn
gst_mulawdec_change_state (GstElement * element, GstStateChange transition);
static gboolean gst_mulawdec_event (GstPad * pad, GstObject * parent,
GstEvent * event);
static GstFlowReturn gst_mulawdec_chain (GstPad * pad, GstObject * parent,
GstBuffer * buffer);
#define gst_mulawdec_parent_class parent_class
G_DEFINE_TYPE (GstMuLawDec, gst_mulawdec, GST_TYPE_ELEMENT);
static gboolean
mulawdec_setcaps (GstMuLawDec * mulawdec, GstCaps * caps)
{
GstStructure *structure;
int rate, channels;
gboolean ret;
GstCaps *outcaps;
structure = gst_caps_get_structure (caps, 0);
ret = gst_structure_get_int (structure, "rate", &rate);
ret = ret && gst_structure_get_int (structure, "channels", &channels);
if (!ret)
return FALSE;
outcaps = gst_caps_new_simple ("audio/x-raw",
"format", G_TYPE_STRING, GST_AUDIO_NE (S16),
"rate", G_TYPE_INT, rate, "channels", G_TYPE_INT, channels, NULL);
ret = gst_pad_set_caps (mulawdec->srcpad, outcaps);
gst_caps_unref (outcaps);
if (ret) {
GST_DEBUG_OBJECT (mulawdec, "rate=%d, channels=%d", rate, channels);
mulawdec->rate = rate;
mulawdec->channels = channels;
}
return ret;
}
static GstCaps *
mulawdec_getcaps (GstPad * pad, GstCaps * filter)
{
GstMuLawDec *mulawdec;
GstPad *otherpad;
GstCaps *othercaps, *result;
const GstCaps *templ;
const gchar *name;
gint i;
mulawdec = GST_MULAWDEC (GST_PAD_PARENT (pad));
/* figure out the name of the caps we are going to return */
if (pad == mulawdec->srcpad) {
name = "audio/x-raw";
otherpad = mulawdec->sinkpad;
} else {
name = "audio/x-mulaw";
otherpad = mulawdec->srcpad;
}
/* get caps from the peer, this can return NULL when there is no peer */
othercaps = gst_pad_peer_query_caps (otherpad, NULL);
/* get the template caps to make sure we return something acceptable */
templ = gst_pad_get_pad_template_caps (pad);
if (othercaps) {
/* there was a peer */
othercaps = gst_caps_make_writable (othercaps);
/* go through the caps and remove the fields we don't want */
for (i = 0; i < gst_caps_get_size (othercaps); i++) {
GstStructure *structure;
structure = gst_caps_get_structure (othercaps, i);
/* adjust the name */
gst_structure_set_name (structure, name);
if (pad == mulawdec->sinkpad) {
/* remove the fields we don't want */
gst_structure_remove_fields (structure, "format", NULL);
} else {
/* add fixed fields */
gst_structure_set (structure, "format", G_TYPE_STRING,
GST_AUDIO_NE (S16), NULL);
}
}
/* filter against the allowed caps of the pad to return our result */
result = gst_caps_intersect (othercaps, templ);
gst_caps_unref (othercaps);
} else {
/* there was no peer, return the template caps */
result = gst_caps_copy (templ);
}
if (filter && result) {
GstCaps *temp;
temp = gst_caps_intersect (result, filter);
gst_caps_unref (result);
result = temp;
}
return result;
}
static gboolean
gst_mulawdec_query (GstPad * pad, GstObject * parent, GstQuery * query)
{
gboolean res;
switch (GST_QUERY_TYPE (query)) {
case GST_QUERY_CAPS:
{
GstCaps *filter, *caps;
gst_query_parse_caps (query, &filter);
caps = mulawdec_getcaps (pad, filter);
gst_query_set_caps_result (query, caps);
gst_caps_unref (caps);
res = TRUE;
break;
}
default:
res = gst_pad_query_default (pad, parent, query);
break;
}
return res;
}
static void
gst_mulawdec_class_init (GstMuLawDecClass * klass)
{
GstElementClass *element_class = (GstElementClass *) klass;
gst_element_class_add_pad_template (element_class,
gst_static_pad_template_get (&mulaw_dec_src_factory));
gst_element_class_add_pad_template (element_class,
gst_static_pad_template_get (&mulaw_dec_sink_factory));
gst_element_class_set_details_simple (element_class, "Mu Law audio decoder",
"Codec/Decoder/Audio",
"Convert 8bit mu law to 16bit PCM",
"Zaheer Abbas Merali <zaheerabbas at merali dot org>");
element_class->change_state = GST_DEBUG_FUNCPTR (gst_mulawdec_change_state);
}
static void
gst_mulawdec_init (GstMuLawDec * mulawdec)
{
mulawdec->sinkpad =
gst_pad_new_from_static_template (&mulaw_dec_sink_factory, "sink");
gst_pad_set_query_function (mulawdec->sinkpad, gst_mulawdec_query);
gst_pad_set_event_function (mulawdec->sinkpad, gst_mulawdec_event);
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_static_template (&mulaw_dec_src_factory, "src");
gst_pad_set_query_function (mulawdec->srcpad, gst_mulawdec_query);
gst_element_add_pad (GST_ELEMENT (mulawdec), mulawdec->srcpad);
}
static gboolean
gst_mulawdec_event (GstPad * pad, GstObject * parent, GstEvent * event)
{
GstMuLawDec *mulawdec;
gboolean res;
mulawdec = GST_MULAWDEC (parent);
switch (GST_EVENT_TYPE (event)) {
case GST_EVENT_CAPS:
{
GstCaps *caps;
gst_event_parse_caps (event, &caps);
mulawdec_setcaps (mulawdec, caps);
gst_event_unref (event);
res = TRUE;
break;
}
default:
res = gst_pad_event_default (pad, parent, event);
break;
}
return res;
}
static GstFlowReturn
gst_mulawdec_chain (GstPad * pad, GstObject * parent, GstBuffer * buffer)
{
GstMuLawDec *mulawdec;
gint16 *linear_data;
guint8 *mulaw_data;
gsize mulaw_size, linear_size;
GstBuffer *outbuf;
GstFlowReturn ret;
mulawdec = GST_MULAWDEC (parent);
if (G_UNLIKELY (mulawdec->rate == 0))
goto not_negotiated;
mulaw_data = gst_buffer_map (buffer, &mulaw_size, NULL, GST_MAP_READ);
linear_size = mulaw_size * 2;
outbuf = gst_buffer_new_allocate (NULL, linear_size, 0);
linear_data = gst_buffer_map (outbuf, NULL, NULL, GST_MAP_WRITE);
/* copy discont flag */
if (GST_BUFFER_FLAG_IS_SET (buffer, GST_BUFFER_FLAG_DISCONT))
GST_BUFFER_FLAG_SET (outbuf, GST_BUFFER_FLAG_DISCONT);
GST_BUFFER_TIMESTAMP (outbuf) = GST_BUFFER_TIMESTAMP (buffer);
if (GST_BUFFER_DURATION (outbuf) == GST_CLOCK_TIME_NONE)
GST_BUFFER_DURATION (outbuf) = gst_util_uint64_scale_int (GST_SECOND,
linear_size, 2 * mulawdec->rate * mulawdec->channels);
else
GST_BUFFER_DURATION (outbuf) = GST_BUFFER_DURATION (buffer);
mulaw_decode (mulaw_data, linear_data, mulaw_size);
gst_buffer_unmap (outbuf, linear_data, -1);
gst_buffer_unmap (buffer, mulaw_data, -1);
gst_buffer_unref (buffer);
ret = gst_pad_push (mulawdec->srcpad, outbuf);
return ret;
/* ERRORS */
not_negotiated:
{
GST_WARNING_OBJECT (mulawdec, "no input format set: not-negotiated");
gst_buffer_unref (buffer);
return GST_FLOW_NOT_NEGOTIATED;
}
}
static GstStateChangeReturn
gst_mulawdec_change_state (GstElement * element, GstStateChange transition)
{
GstStateChangeReturn ret;
GstMuLawDec *dec = GST_MULAWDEC (element);
switch (transition) {
default:
break;
}
ret = GST_ELEMENT_CLASS (parent_class)->change_state (element, transition);
if (ret != GST_STATE_CHANGE_SUCCESS)
return ret;
switch (transition) {
case GST_STATE_CHANGE_PAUSED_TO_READY:
dec->rate = 0;
dec->channels = 0;
break;
default:
break;
}
return ret;
}