gstsbcenc.c

实现bluez蓝牙profile需要的库

/*
 *
 *  BlueZ - Bluetooth protocol stack for Linux
 *
 *  Copyright (C) 2004-2007  Marcel Holtmann <[e-mail]>
 *
 *
 *  This library is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU Lesser 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
 *  Lesser General Public License for more details.
 *
 *  You should have received a copy of the GNU Lesser General Public
 *  License along with this library; if not, write to the Free Software
 *  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 *
 */

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <string.h>

#include "gstsbcenc.h"

GST_DEBUG_CATEGORY_STATIC(sbc_enc_debug);
#define GST_CAT_DEFAULT sbc_enc_debug

#define GST_TYPE_SBC_MODE (gst_sbc_mode_get_type())

static GType gst_sbc_mode_get_type(void)
{
	static GType sbc_mode_type = 0;
	static GEnumValue sbc_modes[] = {
		{  0, "Auto",		"auto"		},
		{  1, "Mono",		"mono"		},
		{  2, "Dual Channel",	"dual"		},
		{  3, "Stereo",		"stereo"	},
		{  4, "Joint Stereo",	"joint"		},
		{ -1, NULL, NULL}
	};

	if (!sbc_mode_type)
		sbc_mode_type = g_enum_register_static("GstSbcMode", sbc_modes);

	return sbc_mode_type;
}

enum {
	PROP_0,
	PROP_MODE,
};

GST_BOILERPLATE(GstSbcEnc, gst_sbc_enc, GstElement, GST_TYPE_ELEMENT);

static const GstElementDetails sbc_enc_details =
	GST_ELEMENT_DETAILS("Bluetooth SBC encoder",
				"Codec/Encoder/Audio",
				"Encode a SBC audio stream",
				"Marcel Holtmann <[e-mail]>");

static GstStaticPadTemplate sbc_enc_sink_factory =
	GST_STATIC_PAD_TEMPLATE("sink", GST_PAD_SINK, GST_PAD_ALWAYS,
		GST_STATIC_CAPS("audio/x-raw-int, "
				"rate = (int) { 16000, 32000, 44100, 48000 }, "
				"channels = (int) [ 1, 2 ], "
				"endianness = (int) LITTLE_ENDIAN, "
				"signed = (boolean) true, "
				"width = (int) 16, "
				"depth = (int) 16"));

static GstStaticPadTemplate sbc_enc_src_factory =
	GST_STATIC_PAD_TEMPLATE("src", GST_PAD_SRC, GST_PAD_ALWAYS,
		GST_STATIC_CAPS("audio/x-sbc, "
				"rate = (int) { 16000, 32000, 44100, 48000 }, "
				"channels = (int) [ 1, 2 ], "
				"mode = (string) { mono, dual, stereo, joint }, "
				"blocks = (int) { 4, 8, 12, 16 }, "
				"subbands = (int) { 4, 8 }, "
				"allocation = (string) { snr, loudness }"));

static GstFlowReturn sbc_enc_chain(GstPad *pad, GstBuffer *buffer)
{
	GstSbcEnc *enc = GST_SBC_ENC(gst_pad_get_parent(pad));
	GstFlowReturn res = GST_FLOW_OK;
	GstStructure *structure;
	gint rate, channels;
	guint size, offset = 0;
	guint8 *data;

	data = GST_BUFFER_DATA(buffer);
	size = GST_BUFFER_SIZE(buffer);

	structure = gst_caps_get_structure(GST_PAD_CAPS(pad), 0);
	gst_structure_get_int(structure, "rate", &rate);
	gst_structure_get_int(structure, "channels", &channels);

	enc->sbc.rate = rate;
	enc->sbc.channels = channels;
	enc->sbc.subbands = 8;
	enc->sbc.joint = 0;

	while (offset < size) {
		GstBuffer *output;
		GstCaps *caps;
		int consumed;

		consumed = sbc_encode(&enc->sbc, data + offset, size - offset);
		if (consumed <= 0)
			break;

		caps = GST_PAD_CAPS(enc->srcpad);

		res = gst_pad_alloc_buffer_and_set_caps(enc->srcpad,
						GST_BUFFER_OFFSET_NONE,
						enc->sbc.len, caps, &output);

		if (res != GST_FLOW_OK)
			goto done;

		memcpy(GST_BUFFER_DATA(output), enc->sbc.data, enc->sbc.len);

		res = gst_pad_push(enc->srcpad, output);
		if (res != GST_FLOW_OK)
			goto done;

		offset += consumed;
	}

	if (offset < size)
		res = GST_FLOW_ERROR;

done:
	gst_buffer_unref(buffer);
	gst_object_unref(enc);

	return res;
}

static GstStateChangeReturn sbc_enc_change_state(GstElement *element,
						GstStateChange transition)
{
	GstSbcEnc *enc = GST_SBC_ENC(element);

	switch (transition) {
	case GST_STATE_CHANGE_READY_TO_PAUSED:
		GST_DEBUG("Setup subband codec");
		sbc_init(&enc->sbc, 0);
		break;

	case GST_STATE_CHANGE_PAUSED_TO_READY:
		GST_DEBUG("Finish subband codec");
		sbc_finish(&enc->sbc);
		break;

	default:
		break;
	}

	return parent_class->change_state(element, transition);
}

static void gst_sbc_enc_base_init(gpointer g_class)
{
	GstElementClass *element_class = GST_ELEMENT_CLASS(g_class);

	gst_element_class_add_pad_template(element_class,
		gst_static_pad_template_get(&sbc_enc_sink_factory));

	gst_element_class_add_pad_template(element_class,
		gst_static_pad_template_get(&sbc_enc_src_factory));

	gst_element_class_set_details(element_class, &sbc_enc_details);
}

static void gst_sbc_enc_set_property(GObject *object, guint prop_id,
					const GValue *value, GParamSpec *pspec)
{
	GstSbcEnc *enc = GST_SBC_ENC(object);

	switch (prop_id) {
	case PROP_MODE:
		enc->mode = g_value_get_enum(value);
		break;

	default:
		G_OBJECT_WARN_INVALID_PROPERTY_ID(object, prop_id, pspec);
		break;
	}
}

static void gst_sbc_enc_get_property(GObject *object, guint prop_id,
					GValue *value, GParamSpec *pspec)
{
	GstSbcEnc *enc = GST_SBC_ENC(object);

	switch (prop_id) {
	case PROP_MODE:
		g_value_set_enum(value, enc->mode);
		break;

	default:
		G_OBJECT_WARN_INVALID_PROPERTY_ID(object, prop_id, pspec);
		break;
	}
}

static void gst_sbc_enc_class_init(GstSbcEncClass *klass)
{
	GObjectClass *object_class = G_OBJECT_CLASS(klass);
	GstElementClass *element_class = GST_ELEMENT_CLASS(klass);

	parent_class = g_type_class_peek_parent(klass);

	object_class->set_property = GST_DEBUG_FUNCPTR(gst_sbc_enc_set_property);
	object_class->get_property = GST_DEBUG_FUNCPTR(gst_sbc_enc_get_property);

	element_class->change_state = GST_DEBUG_FUNCPTR(sbc_enc_change_state);

	g_object_class_install_property(object_class, PROP_MODE,
			g_param_spec_enum("mode", "Mode", "Encoding mode",
				GST_TYPE_SBC_MODE, 0, G_PARAM_READWRITE));

	GST_DEBUG_CATEGORY_INIT(sbc_enc_debug, "sbcenc", 0,
						"SBC encoding element");
}

static void gst_sbc_enc_init(GstSbcEnc *self, GstSbcEncClass *klass)
{
	self->sinkpad = gst_pad_new_from_static_template(&sbc_enc_sink_factory, "sink");
	gst_element_add_pad(GST_ELEMENT(self), self->sinkpad);

	self->srcpad = gst_pad_new_from_static_template(&sbc_enc_src_factory, "src");
	gst_pad_set_chain_function(self->sinkpad, GST_DEBUG_FUNCPTR(sbc_enc_chain));
	gst_element_add_pad(GST_ELEMENT(self), self->srcpad);
}