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,
);