gstsbcutil.c

这是Linux环境下的蓝牙源代码

/*
 *
 *  BlueZ - Bluetooth protocol stack for Linux
 *
 *  Copyright (C) 2004-2008  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 <math.h>
#include "gstsbcutil.h"

/*
 * Selects one rate from a list of possible rates
 * TODO - use a better approach to this (it is selecting the last element)
 */
gint gst_sbc_select_rate_from_list(const GValue *value)
{
	guint size = gst_value_list_get_size(value);
	return g_value_get_int(gst_value_list_get_value(value, size-1));
}

/*
 * Selects one number of channels option from a range of possible numbers
 * TODO - use a better approach to this (it is selecting the maximum value)
 */
gint gst_sbc_select_channels_from_range(const GValue *value)
{
	return gst_value_get_int_range_max(value);
}

/*
 * Selects one number of blocks from a list of possible blocks
 * TODO - use a better approach to this (it is selecting the last element)
 */
gint gst_sbc_select_blocks_from_list(const GValue *value)
{
	guint size = gst_value_list_get_size(value);
	return g_value_get_int(gst_value_list_get_value(value, size-1));
}

/*
 * Selects one number of subbands from a list
 * TODO - use a better approach to this (it is selecting the last element)
 */
gint gst_sbc_select_subbands_from_list(const GValue *value)
{
	guint size = gst_value_list_get_size(value);
	return g_value_get_int(gst_value_list_get_value(value, size-1));
}

/*
 * Selects one bitpool option from a range
 * TODO - use a better approach to this (it is selecting the maximum value)
 */
gint gst_sbc_select_bitpool_from_range(const GValue *value)
{
	return gst_value_get_int_range_max(value);
}

/*
 * Selects one allocation mode from the ones on the list
 * TODO - use a better approach
 */
const gchar *gst_sbc_get_allocation_from_list(const GValue *value)
{
	guint size = gst_value_list_get_size(value);
	return g_value_get_string(gst_value_list_get_value(value, size-1));
}

/*
 * Selects one mode from the ones on the list
 */
const gchar *gst_sbc_get_mode_from_list(const GValue *list, gint channels)
{
	int i;
	const GValue *value;
	const gchar *aux;
	gboolean joint, stereo, dual, mono;

	joint = stereo = dual = mono = FALSE;
	guint size = gst_value_list_get_size(list);

	for (i = 0; i < size; i++) {
		value = gst_value_list_get_value(list, i);
		aux = g_value_get_string(value);
		if (strcmp("joint", aux) == 0)
			joint = TRUE;
		else if (strcmp("stereo", aux) == 0)
			stereo = TRUE;
		else if (strcmp("dual", aux) == 0)
			dual = TRUE;
		else if (strcmp("mono", aux) == 0)
			mono = TRUE;
	}

	if (channels == 1 && mono)
		return "mono";
	else if (channels == 2) {
		if (joint)
			return "joint";
		else if (stereo)
			return "stereo";
		else if (dual)
			return "dual";
	}

	return NULL;
}

gint gst_sbc_parse_rate_from_sbc(gint frequency)
{
	switch (frequency) {
	case SBC_FREQ_16000:
		return 16000;
	case SBC_FREQ_32000:
		return 32000;
	case SBC_FREQ_44100:
		return 44100;
	case SBC_FREQ_48000:
		return 48000;
	default:
		return 0;
	}
}

gint gst_sbc_parse_rate_to_sbc(gint rate)
{
	switch (rate) {
	case 16000:
		return SBC_FREQ_16000;
	case 32000:
		return SBC_FREQ_32000;
	case 44100:
		return SBC_FREQ_44100;
	case 48000:
		return SBC_FREQ_48000;
	default:
		return -1;
	}
}

gint gst_sbc_get_channel_number(gint mode)
{
	switch (mode) {
	case SBC_MODE_JOINT_STEREO:
	case SBC_MODE_STEREO:
	case SBC_MODE_DUAL_CHANNEL:
		return 2;
	case SBC_MODE_MONO:
		return 1;
	default:
		return 0;
	}
}

gint gst_sbc_parse_subbands_from_sbc(gint subbands)
{
	switch (subbands) {
	case SBC_SB_4:
		return 4;
	case SBC_SB_8:
		return 8;
	default:
		return 0;
	}
}

gint gst_sbc_parse_subbands_to_sbc(gint subbands)
{
	switch (subbands) {
	case 4:
		return SBC_SB_4;
	case 8:
		return SBC_SB_8;
	default:
		return -1;
	}
}

gint gst_sbc_parse_blocks_from_sbc(gint blocks)
{
	switch (blocks) {
	case SBC_BLK_4:
		return 4;
	case SBC_BLK_8:
		return 8;
	case SBC_BLK_12:
		return 12;
	case SBC_BLK_16:
		return 16;
	default:
		return 0;
	}
}

gint gst_sbc_parse_blocks_to_sbc(gint blocks)
{
	switch (blocks) {
	case 4:
		return SBC_BLK_4;
	case 8:
		return SBC_BLK_8;
	case 12:
		return SBC_BLK_12;
	case 16:
		return SBC_BLK_16;
	default:
		return -1;
	}
}

const gchar *gst_sbc_parse_mode_from_sbc(gint mode)
{
	switch (mode) {
	case SBC_MODE_MONO:
		return "mono";
	case SBC_MODE_DUAL_CHANNEL:
		return "dual";
	case SBC_MODE_STEREO:
		return "stereo";
	case SBC_MODE_JOINT_STEREO:
	case SBC_MODE_AUTO:
		return "joint";
	default:
		return NULL;
	}
}

gint gst_sbc_parse_mode_to_sbc(const gchar *mode)
{
	if (g_ascii_strcasecmp(mode, "joint") == 0)
		return SBC_MODE_JOINT_STEREO;
	else if (g_ascii_strcasecmp(mode, "stereo") == 0)
		return SBC_MODE_STEREO;
	else if (g_ascii_strcasecmp(mode, "dual") == 0)
		return SBC_MODE_DUAL_CHANNEL;
	else if (g_ascii_strcasecmp(mode, "mono") == 0)
		return SBC_MODE_MONO;
	else if (g_ascii_strcasecmp(mode, "auto") == 0)
		return SBC_MODE_JOINT_STEREO;
	else
		return -1;
}

const gchar *gst_sbc_parse_allocation_from_sbc(gint alloc)
{
	switch (alloc) {
	case SBC_AM_LOUDNESS:
		return "loudness";
	case SBC_AM_SNR:
		return "snr";
	case SBC_AM_AUTO:
		return "loudness";
	default:
		return NULL;
	}
}

gint gst_sbc_parse_allocation_to_sbc(const gchar *allocation)
{
	if (g_ascii_strcasecmp(allocation, "loudness") == 0)
		return SBC_AM_LOUDNESS;
	else if (g_ascii_strcasecmp(allocation, "snr") == 0)
		return SBC_AM_SNR;
	else
		return SBC_AM_LOUDNESS;
}

GstCaps* gst_sbc_parse_caps_from_sbc(sbc_t *sbc)
{
	GstCaps *caps;
	const gchar *mode_str;
	const gchar *allocation_str;

	mode_str = gst_sbc_parse_mode_from_sbc(sbc->mode);
	allocation_str = gst_sbc_parse_allocation_from_sbc(sbc->allocation);
	caps = gst_caps_new_simple("audio/x-sbc",
				"rate", G_TYPE_INT,
				gst_sbc_parse_rate_from_sbc(sbc->frequency),
				"channels", G_TYPE_INT,
				gst_sbc_get_channel_number(sbc->mode),
				"mode", G_TYPE_STRING, mode_str,
				"subbands", G_TYPE_INT,
				gst_sbc_parse_subbands_from_sbc(sbc->subbands),
				"blocks", G_TYPE_INT,
				gst_sbc_parse_blocks_from_sbc(sbc->blocks),
				"allocation", G_TYPE_STRING, allocation_str,
				"bitpool", G_TYPE_INT, sbc->bitpool,
				NULL);

	return caps;
}

/*
 * Given a GstCaps, this will return a fixed GstCaps on sucessfull conversion.
 * If an error occurs, it will return NULL and error_message will contain the
 * error message.
 *
 * error_message must be passed NULL, if an error occurs, the caller has the
 * ownership of the error_message, it must be freed after use.
 */
GstCaps* gst_sbc_util_caps_fixate(GstCaps *caps, gchar** error_message)
{
	GstCaps *result;
	GstStructure *structure;
	const GValue *value;
	gboolean error = FALSE;
	gint temp, rate, channels, blocks, subbands, bitpool;
	const gchar* allocation = NULL;
	const gchar* mode = NULL;

	g_assert(*error_message == NULL);

	structure = gst_caps_get_structure(caps, 0);

	if (!gst_structure_has_field(structure, "rate")) {
		error = TRUE;
		*error_message = g_strdup("no rate");
		goto error;
	} else {
		value = gst_structure_get_value(structure, "rate");
		if (GST_VALUE_HOLDS_LIST(value))
			temp = gst_sbc_select_rate_from_list(value);
		else
			temp = g_value_get_int(value);
		rate = temp;
	}

	if (!gst_structure_has_field(structure, "channels")) {
		error = TRUE;
		*error_message = g_strdup("no channels");
		goto error;
	} else {
		value = gst_structure_get_value(structure, "channels");
		if (GST_VALUE_HOLDS_INT_RANGE(value))
			temp = gst_sbc_select_channels_from_range(value);
		else
			temp = g_value_get_int(value);
		channels = temp;
	}

	if (!gst_structure_has_field(structure, "blocks")) {
		error = TRUE;
		*error_message = g_strdup("no blocks.");
		goto error;
	} else {
		value = gst_structure_get_value(structure, "blocks");
		if (GST_VALUE_HOLDS_LIST(value))
			temp = gst_sbc_select_blocks_from_list(value);
		else
			temp = g_value_get_int(value);
		blocks = temp;
	}

	if (!gst_structure_has_field(structure, "subbands")) {
		error = TRUE;
		*error_message = g_strdup("no subbands");
		goto error;
	} else {
		value = gst_structure_get_value(structure, "subbands");
		if (GST_VALUE_HOLDS_LIST(value))
			temp = gst_sbc_select_subbands_from_list(value);
		else
			temp = g_value_get_int(value);
		subbands = temp;
	}

	if (!gst_structure_has_field(structure, "bitpool")) {
		error = TRUE;
		*error_message = g_strdup("no bitpool");
		goto error;
	} else {
		value = gst_structure_get_value(structure, "bitpool");
		if (GST_VALUE_HOLDS_INT_RANGE(value))
			temp = gst_sbc_select_bitpool_from_range(value);
		else
			temp = g_value_get_int(value);
		bitpool = temp;
	}

	if (!gst_structure_has_field(structure, "allocation")) {
		error = TRUE;
		*error_message = g_strdup("no allocation");
		goto error;
	} else {
		value = gst_structure_get_value(structure, "allocation");
		if (GST_VALUE_HOLDS_LIST(value))
			allocation = gst_sbc_get_allocation_from_list(value);
		else
			allocation = g_value_get_string(value);
	}

	if (!gst_structure_has_field(structure, "mode")) {
		error = TRUE;
		*error_message = g_strdup("no mode");
		goto error;
	} else {
		value = gst_structure_get_value(structure, "mode");
		if (GST_VALUE_HOLDS_LIST(value)) {
			mode = gst_sbc_get_mode_from_list(value, channels);
		} else
			mode = g_value_get_string(value);
	}

	/* perform validation
	 * if channels is 1, we must have channel mode = mono
	 * if channels is 2, we can't have channel mode = mono */
	if ( (channels == 1 && (strcmp(mode, "mono") != 0) ) ||
			( channels == 2 && ( strcmp(mode, "mono") == 0))) {
		*error_message = g_strdup_printf("Invalid combination of "
					"channels (%d) and channel mode (%s)",
					channels, mode);
		error = TRUE;
	}

error:
	if (error)
		return NULL;

	result = gst_caps_new_simple("audio/x-sbc",
					"rate", G_TYPE_INT, rate,
					"channels", G_TYPE_INT, channels,
					"mode", G_TYPE_STRING, mode,
					"blocks", G_TYPE_INT, blocks,
					"subbands", G_TYPE_INT, subbands,
					"allocation", G_TYPE_STRING, allocation,
					"bitpool", G_TYPE_INT, bitpool,
					NULL);

	return result;
}

/**
 * Sets the int field_value to the  param "field" on the structure.
 * value is used to do the operation, it must be a uninitialized (zero-filled)
 * GValue, it will be left unitialized at the end of the function.
 */
void gst_sbc_util_set_structure_int_param(GstStructure *structure,
			const gchar* field, gint field_value,
			GValue *value)
{
	value = g_value_init(value, G_TYPE_INT);
	g_value_set_int(value, field_value);
	gst_structure_set_value(structure, field, value);
	g_value_unset(value);
}

/**
 * Sets the string field_value to the  param "field" on the structure.
 * value is used to do the operation, it must be a uninitialized (zero-filled)
 * GValue, it will be left unitialized at the end of the function.
 */
void gst_sbc_util_set_structure_string_param(GstStructure *structure,
			const gchar* field, const gchar* field_value,
			GValue *value)
{
	value = g_value_init(value, G_TYPE_STRING);
	g_value_set_string(value, field_value);
	gst_structure_set_value(structure, field, value);
	g_value_unset(value);
}

gboolean gst_sbc_util_fill_sbc_params(sbc_t *sbc, GstCaps *caps)
{
	GstStructure *structure;
	gint rate, channels, subbands, blocks, bitpool;
	const gchar* mode;
	const gchar* allocation;

	g_assert(gst_caps_is_fixed(caps));

	structure = gst_caps_get_structure(caps, 0);

	if (!gst_structure_get_int(structure, "rate", &rate))
		return FALSE;
	if (!gst_structure_get_int(structure, "channels", &channels))
		return FALSE;
	if (!gst_structure_get_int(structure, "subbands", &subbands))
		return FALSE;
	if (!gst_structure_get_int(structure, "blocks", &blocks))
		return FALSE;
	if (!gst_structure_get_int(structure, "bitpool", &bitpool))
		return FALSE;

	if (!(mode = gst_structure_get_string(structure, "mode")))
		return FALSE;
	if (!(allocation = gst_structure_get_string(structure, "allocation")))
		return FALSE;

	if (channels == 1 && strcmp(mode, "mono") != 0)
		return FALSE;

	sbc->frequency = gst_sbc_parse_rate_to_sbc(rate);
	sbc->blocks = gst_sbc_parse_blocks_to_sbc(blocks);
	sbc->subbands = gst_sbc_parse_subbands_to_sbc(subbands);
	sbc->bitpool = bitpool;
	sbc->mode = gst_sbc_parse_mode_to_sbc(mode);
	sbc->allocation = gst_sbc_parse_allocation_to_sbc(allocation);

	return TRUE;
}