res_format_attr_h263.c

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/*
 * Asterisk -- An open source telephony toolkit.
 *
 * Copyright (C) 2012, Digium, Inc.
 *
 * Joshua Colp <[email protected]>
 *
 * See http://www.asterisk.org for more information about
 * the Asterisk project. Please do not directly contact
 * any of the maintainers of this project for assistance;
 * the project provides a web site, mailing lists and IRC
 * channels for your use.
 *
 * This program is free software, distributed under the terms of
 * the GNU General Public License Version 2. See the LICENSE file
 * at the top of the source tree.
 *
 */

/*! \file
 *
 * \brief H.263 Format Attribute Module
 *
 * \author\verbatim Joshua Colp <[email protected]> \endverbatim
 *
 * This is a format attribute module for the H.263 codec.
 * \ingroup applications
 */

/*** MODULEINFO
 <support_level>core</support_level>
 ***/

#include "asterisk.h"

#include <ctype.h> /* for toupper */

#include "asterisk/module.h"
#include "asterisk/format.h"
#include "asterisk/strings.h" /* for ast_str_append */
#include "asterisk/utils.h" /* for ast_strip */

/*! \brief Value that indicates an attribute is actually unset */
#define H263_ATTR_KEY_UNSET UINT8_MAX

struct h263_attr {
 unsigned int SQCIF; /*!< Minimum picture interval for SQCIF resolution */
 unsigned int QCIF; /*!< Minimum picture interval for QCIF resolution */
 unsigned int CIF; /*!< Minimum picture interval for CIF resolution */
 unsigned int CIF4; /*!< Minimum picture interval for CIF4 resolution */
 unsigned int CIF16; /*!< Minimum picture interval for CIF16 resolution */
 unsigned int VGA; /*!< Minimum picture interval for VGA resolution */
 unsigned int CUSTOM_XMAX; /*!< Custom resolution (Xmax) */
 unsigned int CUSTOM_YMAX; /*!< Custom resolution (Ymax) */
 unsigned int CUSTOM_MPI; /*!< Custom resolution (MPI) */
 unsigned int CPCF; /*!< Custom Picture Clock Frequency */
 unsigned int CPCF_2;
 unsigned int CPCF_3;
 unsigned int CPCF_4;
 unsigned int CPCF_5;
 unsigned int CPCF_6;
 unsigned int CPCF_7;
 unsigned int CPCF_MPI;
 unsigned int F; /*!< F annex support */
 unsigned int I; /*!< I annex support */
 unsigned int J; /*!< J annex support */
 unsigned int T; /*!< T annex support */
 unsigned int K; /*!< K annex support */
 unsigned int N; /*!< N annex support */
 unsigned int P_SUB1; /*!< Reference picture resampling (sub mode 1) */
 unsigned int P_SUB2; /*!< Reference picture resampling (sub mode 2) */
 unsigned int P_SUB3; /*!< Reference picture resampling (sub mode 3) */
 unsigned int P_SUB4; /*!< Reference picture resampling (sub mode 4) */
 unsigned int PAR_WIDTH; /*!< Pixel aspect ratio (width) */
 unsigned int PAR_HEIGHT; /*!< Pixel aspect ratio (height) */
 unsigned int BPP; /*!< Bits per picture maximum */
 unsigned int HRD; /*!< Hypothetical reference decoder status */
 unsigned int MaxBR; /*!< Vendor Specific: CounterPath Bria (Solo) */
};

static void h263_destroy(struct ast_format *format)
{
 struct h263_attr *attr = ast_format_get_attribute_data(format);

 ast_free(attr);
}

static int h263_clone(const struct ast_format *src, struct ast_format *dst)
{
 struct h263_attr *original = ast_format_get_attribute_data(src);
 struct h263_attr *attr = ast_calloc(1, sizeof(*attr));

 if (!attr) {
 return -1;
 }

 if (original) {
 *attr = *original;
 }

 ast_format_set_attribute_data(dst, attr);

 return 0;
}

static enum ast_format_cmp_res h263_cmp(const struct ast_format *format1, const struct ast_format *format2)
{
 struct h263_attr *attr1 = ast_format_get_attribute_data(format1);
 struct h263_attr *attr2 = ast_format_get_attribute_data(format2);

 if (!attr1 || !attr2 || (attr1 && attr2 && !memcmp(attr1, attr2, sizeof(*attr1)))) {
 return AST_FORMAT_CMP_EQUAL;
 }
 return AST_FORMAT_CMP_NOT_EQUAL;
}

#define DETERMINE_JOINT(joint, attr1, attr2, field) (joint->field = (attr1 && attr1->field) ? attr1->field : (attr2 && attr2->field) ? attr2->field : 0)

static struct ast_format *h263_getjoint(const struct ast_format *format1, const struct ast_format *format2)
{
 struct ast_format *cloned;
 struct h263_attr *attr, *attr1, *attr2;

 cloned = ast_format_clone(format1);
 if (!cloned) {
 return NULL;
 }
 attr = ast_format_get_attribute_data(cloned);

 attr1 = ast_format_get_attribute_data(format1);
 attr2 = ast_format_get_attribute_data(format2);

 DETERMINE_JOINT(attr, attr1, attr2, SQCIF);
 DETERMINE_JOINT(attr, attr1, attr2, QCIF);
 DETERMINE_JOINT(attr, attr1, attr2, CIF);
 DETERMINE_JOINT(attr, attr1, attr2, CIF4);
 DETERMINE_JOINT(attr, attr1, attr2, CIF16);
 DETERMINE_JOINT(attr, attr1, attr2, VGA);
 DETERMINE_JOINT(attr, attr1, attr2, CUSTOM_XMAX);
 DETERMINE_JOINT(attr, attr1, attr2, CUSTOM_YMAX);
 DETERMINE_JOINT(attr, attr1, attr2, CUSTOM_MPI);
 DETERMINE_JOINT(attr, attr1, attr2, CPCF);
 DETERMINE_JOINT(attr, attr1, attr2, CPCF_2);
 DETERMINE_JOINT(attr, attr1, attr2, CPCF_3);
 DETERMINE_JOINT(attr, attr1, attr2, CPCF_4);
 DETERMINE_JOINT(attr, attr1, attr2, CPCF_5);
 DETERMINE_JOINT(attr, attr1, attr2, CPCF_6);
 DETERMINE_JOINT(attr, attr1, attr2, CPCF_7);
 DETERMINE_JOINT(attr, attr1, attr2, CPCF_MPI);
 DETERMINE_JOINT(attr, attr1, attr2, F);
 DETERMINE_JOINT(attr, attr1, attr2, I);
 DETERMINE_JOINT(attr, attr1, attr2, J);
 DETERMINE_JOINT(attr, attr1, attr2, T);
 DETERMINE_JOINT(attr, attr1, attr2, K);
 DETERMINE_JOINT(attr, attr1, attr2, N);
 DETERMINE_JOINT(attr, attr1, attr2, P_SUB1);
 DETERMINE_JOINT(attr, attr1, attr2, P_SUB2);
 DETERMINE_JOINT(attr, attr1, attr2, P_SUB3);
 DETERMINE_JOINT(attr, attr1, attr2, P_SUB4);
 DETERMINE_JOINT(attr, attr1, attr2, PAR_WIDTH);
 DETERMINE_JOINT(attr, attr1, attr2, PAR_HEIGHT);
 DETERMINE_JOINT(attr, attr1, attr2, BPP);
 DETERMINE_JOINT(attr, attr1, attr2, HRD);
 DETERMINE_JOINT(attr, attr1, attr2, MaxBR);

 return cloned;
}

static struct ast_format *h263_parse_sdp_fmtp(const struct ast_format *format, const char *attributes)
{
 char *attribs = ast_strdupa(attributes), *attrib;
 struct ast_format *cloned;
 struct h263_attr *attr;

 cloned = ast_format_clone(format);
 if (!cloned) {
 return NULL;
 }
 attr = ast_format_get_attribute_data(cloned);

 /* upper-case everything, so we are case-insensitive */
 for (attrib = attribs; *attrib; ++attrib) {
 *attrib = toupper(*attrib);
 } /* based on channels/chan_sip.c:process_a_sdp_image() */

 attr->BPP = H263_ATTR_KEY_UNSET;
 attr->MaxBR = H263_ATTR_KEY_UNSET;
 attr->PAR_WIDTH = H263_ATTR_KEY_UNSET;
 attr->PAR_HEIGHT = H263_ATTR_KEY_UNSET;

 while ((attrib = strsep(&attribs, ";"))) {
 unsigned int val, val2 = 0, val3 = 0, val4 = 0, val5 = 0, val6 = 0, val7 = 0, val8 = 0;

 attrib = ast_strip(attrib);

 if (sscanf(attrib, "SQCIF=%30u", &val) == 1) {
 attr->SQCIF = val;
 } else if (strcmp(attrib, "SQCIF") == 0) {
 attr->SQCIF = 1;
 } else if (sscanf(attrib, "QCIF=%30u", &val) == 1) {
 attr->QCIF = val;
 } else if (strcmp(attrib, "QCIF") == 0) {
 attr->QCIF = 1;
 } else if (sscanf(attrib, "CIF=%30u", &val) == 1) {
 attr->CIF = val;
 } else if (strcmp(attrib, "CIF") == 0) {
 attr->CIF = 1;
 } else if (sscanf(attrib, "CIF4=%30u", &val) == 1) {
 attr->CIF4 = val;
 } else if (strcmp(attrib, "CIF4") == 0) {
 attr->CIF4 = 1;
 } else if (sscanf(attrib, "CIF16=%30u", &val) == 1) {
 attr->CIF16 = val;
 } else if (strcmp(attrib, "CIF16") == 0) {
 attr->CIF16 = 1;
 } else if (sscanf(attrib, "VGA=%30u", &val) == 1) {
 attr->VGA = val;
 } else if (strcmp(attrib, "VGA") == 0) {
 attr->VGA = 1;
 } else if (sscanf(attrib, "CUSTOM=%30u,%30u,%30u", &val, &val2, &val3) == 3) {
 attr->CUSTOM_XMAX = val;
 attr->CUSTOM_YMAX = val2;
 attr->CUSTOM_MPI = val3;
 } else if (sscanf(attrib, "CPCF=%30u,%30u,%30u,%30u,%30u,%30u,%30u,%30u",
 &val, &val2, &val3, &val4, &val5, &val6, &val7, &val8) == 8) {
 attr->CPCF = val;
 attr->CPCF_2 = val2;
 attr->CPCF_3 = val3;
 attr->CPCF_4 = val4;
 attr->CPCF_5 = val5;
 attr->CPCF_6 = val6;
 attr->CPCF_7 = val7;
 attr->CPCF_MPI = val8;
 } else if (sscanf(attrib, "F=%30u", &val) == 1) {
 attr->F = val;
 } else if (sscanf(attrib, "I=%30u", &val) == 1) {
 attr->I = val;
 } else if (sscanf(attrib, "J=%30u", &val) == 1) {
 attr->J = val;
 } else if (sscanf(attrib, "T=%30u", &val) == 1) {
 attr->T = val;
 } else if (sscanf(attrib, "K=%30u", &val) == 1) {
 attr->K = val;
 } else if (sscanf(attrib, "N=%30u", &val) == 1) {
 attr->N = val;
 } else if (sscanf(attrib, "PAR=%30u:%30u", &val, &val2) == 2) {
 attr->PAR_WIDTH = val;
 attr->PAR_HEIGHT = val2;
 } else if (sscanf(attrib, "BPP=%30u", &val) == 1) {
 attr->BPP = val;
 } else if (sscanf(attrib, "HRD=%30u", &val) == 1) {
 attr->HRD = val;
 } else if (sscanf(attrib, "P=%30u,%30u,%30u,%30u", &val, &val2, &val3, &val4) > 0) {
 attr->P_SUB1 = val;
 attr->P_SUB2 = val2;
 attr->P_SUB3 = val3;
 attr->P_SUB4 = val4;
 } else if (sscanf(attrib, "MAXBR=%30u", &val) == 1) {
 attr->MaxBR = val;
 }
 }

 return cloned;
}

#define APPEND_IF_NOT_H263_UNSET(field, str, name) do { \
 if (field != H263_ATTR_KEY_UNSET) { \
 if (added) { \
 ast_str_append(str, 0, ";"); \
 } else if (0 < ast_str_append(str, 0, "a=fmtp:%u ", payload)) { \
 added = 1; \
 } \
 ast_str_append(str, 0, "%s=%u", name, field); \
 } \
} while (0)

#define APPEND_IF_NONZERO(field, str, name) do { \
 if (field) { \
 if (added) { \
 ast_str_append(str, 0, ";"); \
 } else if (0 < ast_str_append(str, 0, "a=fmtp:%u ", payload)) { \
 added = 1; \
 } \
 ast_str_append(str, 0, "%s=%u", name, field); \
 } \
} while (0)

static void h263_generate_sdp_fmtp(const struct ast_format *format, unsigned int payload, struct ast_str **str)
{
 struct h263_attr *attr = ast_format_get_attribute_data(format);
 int added = 0;

 if (!attr) {
 return;
 }

 if (attr->CPCF) {
 if (added) {
 ast_str_append(str, 0, ";");
 } else if (0 < ast_str_append(str, 0, "a=fmtp:%u ", payload)) {
 added = 1;
 }
 ast_str_append(str, 0, "CPCF=%u,%u,%u,%u,%u,%u,%u,%u", attr->CPCF, attr->CPCF_2, attr->CPCF_3,
 attr->CPCF_4, attr->CPCF_5, attr->CPCF_6, attr->CPCF_7, attr->CPCF_MPI);
 }

 APPEND_IF_NONZERO(attr->CIF16, str, "CIF16");
 APPEND_IF_NONZERO(attr->CIF4, str, "CIF4");
 APPEND_IF_NONZERO(attr->VGA, str, "VGA");
 APPEND_IF_NONZERO(attr->CIF, str, "CIF");
 APPEND_IF_NONZERO(attr->QCIF, str, "QCIF");
 APPEND_IF_NONZERO(attr->SQCIF, str, "SQCIF");

 if (attr->CUSTOM_XMAX && attr->CUSTOM_YMAX && attr->CUSTOM_MPI) {
 if (added) {
 ast_str_append(str, 0, ";");
 } else if (0 < ast_str_append(str, 0, "a=fmtp:%u ", payload)) {
 added = 1;
 }
 ast_str_append(str, 0, "CUSTOM=%u,%u,%u", attr->CUSTOM_XMAX, attr->CUSTOM_YMAX, attr->CUSTOM_MPI);
 }

 APPEND_IF_NONZERO(attr->F, str, "F");
 APPEND_IF_NONZERO(attr->I, str, "I");
 APPEND_IF_NONZERO(attr->J, str, "J");
 APPEND_IF_NONZERO(attr->T, str, "T");
 APPEND_IF_NONZERO(attr->K, str, "K");
 APPEND_IF_NONZERO(attr->N, str, "N");

 if (attr->P_SUB1) {
 if (added) {
 ast_str_append(str, 0, ";");
 } else if (0 < ast_str_append(str, 0, "a=fmtp:%u ", payload)) {
 added = 1;
 }
 ast_str_append(str, 0, "P=%u", attr->P_SUB1);
 if (attr->P_SUB2) {
 ast_str_append(str, 0, ",%u", attr->P_SUB2);
 }
 if (attr->P_SUB3) {
 ast_str_append(str, 0, ",%u", attr->P_SUB3);
 }
 if (attr->P_SUB4) {
 ast_str_append(str, 0, ",%u", attr->P_SUB4);
 }
 }

 if (attr->PAR_WIDTH != H263_ATTR_KEY_UNSET && attr->PAR_HEIGHT != H263_ATTR_KEY_UNSET) {
 if (added) {
 ast_str_append(str, 0, ";");
 } else if (0 < ast_str_append(str, 0, "a=fmtp:%u ", payload)) {
 added = 1; \
 }
 ast_str_append(str, 0, "PAR=%u:%u", attr->PAR_WIDTH, attr->PAR_HEIGHT);
 }

 APPEND_IF_NOT_H263_UNSET(attr->BPP, str, "BPP");

 APPEND_IF_NONZERO(attr->HRD, str, "HRD");

 APPEND_IF_NOT_H263_UNSET(attr->MaxBR, str, "MaxBR");

 ast_str_append(str, 0, "\r\n");

 return;
}

static struct ast_format_interface h263_interface = {
 .format_destroy = h263_destroy,
 .format_clone = h263_clone,
 .format_cmp = h263_cmp,
 .format_get_joint = h263_getjoint,
 .format_parse_sdp_fmtp = h263_parse_sdp_fmtp,
 .format_generate_sdp_fmtp = h263_generate_sdp_fmtp,
};

static int unload_module(void)
{
 return 0;
}

static int load_module(void)
{
 if (ast_format_interface_register("h263", &h263_interface)) {
 return AST_MODULE_LOAD_DECLINE;
 }

 if (ast_format_interface_register("h263p", &h263_interface)) {
 return AST_MODULE_LOAD_DECLINE;
 }

 return AST_MODULE_LOAD_SUCCESS;
}

AST_MODULE_INFO(ASTERISK_GPL_KEY, AST_MODFLAG_DEFAULT, "H.263 Format Attribute Module",
 .support_level = AST_MODULE_SUPPORT_CORE,
 .load = load_module,
 .unload = unload_module,
);