diff --git a/CHANGES b/CHANGES index 2b9f8e6972ee57fd5ef113596faa108a0a571c77..1180fbfa3b34b072abcc6cf5db8995f507568d33 100644 --- a/CHANGES +++ b/CHANGES @@ -213,6 +213,11 @@ bridge_t38 several esoteric issues that can occur when channels are removed from a bridge after completing a T.38 fax. +Codecs +------------------ + * Added format attribute negotiation for the VP8 video codec. Format attribute + negotiation is provided by the res_format_attr_vp8 module. + ConfBridge ------------------ * A new "timeout" user profile option has been added. This configures the number diff --git a/res/res_format_attr_vp8.c b/res/res_format_attr_vp8.c new file mode 100644 index 0000000000000000000000000000000000000000..777239aaea92fd9ae0b9e6c7d509425d06064a59 --- /dev/null +++ b/res/res_format_attr_vp8.c @@ -0,0 +1,228 @@ +/* + * Asterisk -- An open source telephony toolkit. + * + * Copyright (C) 2015, Alexander Traud + * + * Alexander Traud <pabstraud@compuserve.com> + * + * 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 VP8 format attribute interface + * + * \author Alexander Traud <pabstraud@compuserve.com> + * + * \note http://tools.ietf.org/html/draft-ietf-payload-vp8 + */ + +/*** MODULEINFO + <support_level>core</support_level> + ***/ + +#include "asterisk.h" + +ASTERISK_REGISTER_FILE() + +#include "asterisk/module.h" +#include "asterisk/format.h" +#include "asterisk/logger.h" /* for ast_log, LOG_WARNING */ +#include "asterisk/strings.h" /* for ast_str_append */ +#include "asterisk/utils.h" /* for MIN, ast_malloc, ast_free */ + +struct vp8_attr { + unsigned int maximum_frame_rate; + unsigned int maximum_frame_size; +}; + +static struct vp8_attr default_vp8_attr = { + .maximum_frame_rate = UINT_MAX, + .maximum_frame_size = UINT_MAX, +}; + +static void vp8_destroy(struct ast_format *format) +{ + struct vp8_attr *attr = ast_format_get_attribute_data(format); + + ast_free(attr); +} + +static int vp8_clone(const struct ast_format *src, struct ast_format *dst) +{ + struct vp8_attr *original = ast_format_get_attribute_data(src); + struct vp8_attr *attr = ast_malloc(sizeof(*attr)); + + if (!attr) { + return -1; + } + + if (original) { + *attr = *original; + } else { + *attr = default_vp8_attr; + } + + ast_format_set_attribute_data(dst, attr); + + return 0; +} + +static struct ast_format *vp8_parse_sdp_fmtp(const struct ast_format *format, const char *attributes) +{ + struct ast_format *cloned; + struct vp8_attr *attr; + const char *kvp; + unsigned int val; + + cloned = ast_format_clone(format); + if (!cloned) { + return NULL; + } + attr = ast_format_get_attribute_data(cloned); + + if ((kvp = strstr(attributes, "max-fr")) && sscanf(kvp, "max-fr=%30u", &val) == 1) { + attr->maximum_frame_rate = val; + } else { + attr->maximum_frame_rate = UINT_MAX; + } + + if ((kvp = strstr(attributes, "max-fs")) && sscanf(kvp, "max-fs=%30u", &val) == 1) { + attr->maximum_frame_size = val; + } else { + attr->maximum_frame_size = UINT_MAX; + } + + return cloned; +} + +static void vp8_generate_sdp_fmtp(const struct ast_format *format, unsigned int payload, struct ast_str **str) +{ + struct vp8_attr *attr = ast_format_get_attribute_data(format); + int added = 0; + + if (!attr) { + /* + * (Only) cached formats do not have attribute data assigned because + * they were created before this attribute module was registered. + * Therefore, we assume the default attribute values here. + */ + attr = &default_vp8_attr; + } + + if (UINT_MAX != attr->maximum_frame_rate) { + 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, "max-fr=%u", attr->maximum_frame_rate); + } + + if (UINT_MAX != attr->maximum_frame_size) { + 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, "max-fs=%u", attr->maximum_frame_size); + } + + if (added) { + ast_str_append(str, 0, "\r\n"); + } +} + +static struct ast_format *vp8_getjoint(const struct ast_format *format1, const struct ast_format *format2) +{ + struct vp8_attr *attr1 = ast_format_get_attribute_data(format1); + struct vp8_attr *attr2 = ast_format_get_attribute_data(format2); + struct ast_format *jointformat; + struct vp8_attr *attr_res; + + if (!attr1) { + attr1 = &default_vp8_attr; + } + + if (!attr2) { + attr2 = &default_vp8_attr; + } + + jointformat = ast_format_clone(format1); + if (!jointformat) { + return NULL; + } + attr_res = ast_format_get_attribute_data(jointformat); + + attr_res->maximum_frame_rate = MIN(attr1->maximum_frame_rate, attr2->maximum_frame_rate); + attr_res->maximum_frame_size = MIN(attr1->maximum_frame_size, attr2->maximum_frame_size); + + return jointformat; +} + +static struct ast_format *vp8_set(const struct ast_format *format, const char *name, const char *value) +{ + struct ast_format *cloned; + struct vp8_attr *attr; + unsigned int val; + + if (sscanf(value, "%30u", &val) != 1) { + ast_log(LOG_WARNING, "Unknown value '%s' for attribute type '%s'\n", + value, name); + return NULL; + } + + cloned = ast_format_clone(format); + if (!cloned) { + return NULL; + } + attr = ast_format_get_attribute_data(cloned); + + if (!strcasecmp(name, "maximum_frame_rate")) { + attr->maximum_frame_rate = val; + } else if (!strcasecmp(name, "maximum_frame_size")) { + attr->maximum_frame_size = val; + } else { + ast_log(LOG_WARNING, "unknown attribute type %s\n", name); + } + + return cloned; +} + +static struct ast_format_interface vp8_interface = { + .format_destroy = vp8_destroy, + .format_clone = vp8_clone, + .format_get_joint = vp8_getjoint, + .format_attribute_set = vp8_set, + .format_parse_sdp_fmtp = vp8_parse_sdp_fmtp, + .format_generate_sdp_fmtp = vp8_generate_sdp_fmtp, +}; + +static int load_module(void) +{ + if (ast_format_interface_register("vp8", &vp8_interface)) { + return AST_MODULE_LOAD_DECLINE; + } + + return AST_MODULE_LOAD_SUCCESS; +} + +static int unload_module(void) +{ + return 0; +} + +AST_MODULE_INFO(ASTERISK_GPL_KEY, AST_MODFLAG_LOAD_ORDER, "VP8 Format Attribute Module", + .support_level = AST_MODULE_SUPPORT_CORE, + .load = load_module, + .unload = unload_module, + .load_pri = AST_MODPRI_CHANNEL_DEPEND, +);