uvgrtp-base/include/uvgrtp/frame.hh

#pragma once

#include "util.hh"

#ifdef _WIN32
#include <winsock2.h>
#include <windows.h>
#include <ws2def.h>
#else
#include <netinet/in.h>
#endif

#include <string>
#include <vector>

/* https://stackoverflow.com/questions/1537964/visual-c-equivalent-of-gccs-attribute-packed  */
#if defined(__MINGW32__) || defined(__MINGW64__) || defined(__GNUC__) || defined(__linux__)
#define PACK(__Declaration__) __Declaration__ __attribute__((__packed__))
#else
#define PACK(__Declaration__) __pragma(pack(push, 1)) __Declaration__ __pragma(pack(pop))
#endif

namespace uvgrtp {
    namespace frame {

        enum RTCP_FRAME_TYPE {
            RTCP_FT_SR    = 200, /* Sender report */
            RTCP_FT_RR    = 201, /* Receiver report */
            RTCP_FT_SDES  = 202, /* Source description */
            RTCP_FT_BYE   = 203, /* Goodbye */
            RTCP_FT_APP   = 204, /* Application-specific message */
            RTCP_FT_RTPFB = 205, /* Transport layer FB message */
            RTCP_FT_PSFB  = 206  /* Payload-specific FB message */
        };

        enum RTCP_PSFB_FMT {
            RTCP_PSFB_PLI     = 1,  /* Picture Loss Indication (PLI), defined in RFC 4585 */
            RTCP_PSFB_SLI     = 2,  /* Slice Loss Indication (SLI), defined in RFC 4585 */
            RTCP_PSFB_RPSI    = 3,  /* Reference Picture Selection Indication (RPSI), defined in RFC 4585 */
            RTCP_PSFB_FIR     = 4,  /* Full Intra Request (FIR), defined in RFC 5154 */
            RTCP_PSFB_TSTR    = 5,  /* Temporal-Spatial Trade-off Request (TSTR), defined in RFC 5154 */
            RTCP_PSFB_AFB     = 15  /* Application Layer FB (AFB), defined in RFC 4585 */
        };

        enum RTCP_RTPFB_FMT {
            RTCP_RTPFB_NACK   = 1 /* Generic NACK, defined in RFC 4585 section 6.2 */
        };

        PACK(struct rtp_header {
            uint8_t version:2;
            uint8_t padding:1;
            uint8_t ext:1;
            uint8_t cc:4;
            uint8_t marker:1;
            uint8_t payload:7;
            uint16_t seq = 0;
            uint32_t timestamp = 0;
            uint32_t ssrc = 0;
        });

        PACK(struct ext_header {
            uint16_t type = 0;
            uint16_t len = 0;
            uint8_t *data = nullptr;
        });

        /** \brief See <a href="https://www.rfc-editor.org/rfc/rfc3550#section-5" target="_blank">RFC 3550 section 5</a> */
        struct rtp_frame {
            struct rtp_header header;
            uint32_t *csrc = nullptr;
            struct ext_header *ext = nullptr;

            size_t padding_len = 0; /* non-zero if frame is padded */

            /** \brief Length of the packet payload in bytes added by uvgRTP to help process the frame
            *
            *   \details payload_len = total length - header length - padding length (if padded) 
            */
            size_t payload_len = 0; 
            uint8_t* payload = nullptr;

            /// \cond DO_NOT_DOCUMENT
            uint8_t *dgram = nullptr;      /* pointer to the UDP datagram (for internal use only) */
            size_t   dgram_size = 0;       /* size of the UDP datagram */
            /// \endcond
        };

        /** \brief Header of for all RTCP packets defined in <a href="https://www.rfc-editor.org/rfc/rfc3550#section-6" target="_blank">RFC 3550 section 6</a> */
        struct rtcp_header {
            /** \brief  This field identifies the version of RTP. The version defined by
             * RFC 3550 is two (2).  */
            uint8_t version = 0;
            /** \brief Does this packet contain padding at the end */
            uint8_t padding = 0;
            union {
                /** \brief Source count or report count. Alternative to pkt_subtype. */
                uint8_t count = 0;   
                /** \brief Subtype in APP packets. Alternative to count */
                uint8_t pkt_subtype; 
                /** \brief Feedback message type (FMT), specified in RFC 5104 section 4.3. Alternative to count and pkt_subtype */
                uint8_t fmt;
            };
            /** \brief Identifies the RTCP packet type */
            uint8_t pkt_type = 0;
            /** \brief Length of the whole message measured in 32-bit words */
            uint16_t length = 0;
        };

        /** \brief See <a href="https://www.rfc-editor.org/rfc/rfc3550#section-6.4.1" target="_blank">RFC 3550 section 6.4.1</a> */
        struct rtcp_sender_info {
            /** \brief NTP timestamp, most significant word */
            uint32_t ntp_msw = 0;
            /** \brief NTP timestamp, least significant word */
            uint32_t ntp_lsw = 0;
            /** \brief RTP timestamp corresponding to this NTP timestamp */
            uint32_t rtp_ts = 0;
            uint32_t pkt_cnt = 0;
            /** \brief Also known as octet count*/
            uint32_t byte_cnt = 0;
        };

        /** \brief See <a href="https://www.rfc-editor.org/rfc/rfc3550#section-6.4.1" target="_blank">RFC 3550 section 6.4.1</a> */
        struct rtcp_report_block {
            uint32_t ssrc = 0;
            uint8_t  fraction = 0;
            int32_t  lost = 0;
            uint32_t last_seq = 0;
            uint32_t jitter = 0;
            uint32_t lsr = 0;  /* last Sender Report */
            uint32_t dlsr = 0; /* delay since last Sender Report */
        };

        /** \brief See <a href="https://www.rfc-editor.org/rfc/rfc3550#section-6.4.2" target="_blank">RFC 3550 section 6.4.2</a> */
        struct rtcp_receiver_report {
            struct rtcp_header header;
            uint32_t ssrc = 0;
            std::vector<rtcp_report_block> report_blocks;
        };

        /** \brief See <a href="https://www.rfc-editor.org/rfc/rfc3550#section-6.4.1" target="_blank">RFC 3550 section 6.4.1</a> */
        struct rtcp_sender_report {
            struct rtcp_header header;
            uint32_t ssrc = 0;
            struct rtcp_sender_info sender_info;
            std::vector<rtcp_report_block> report_blocks;
        };

        /** \brief See <a href="https://www.rfc-editor.org/rfc/rfc3550#section-6.5" target="_blank">RFC 3550 section 6.5</a> */
        struct rtcp_sdes_item {
            uint8_t type = 0;
            uint8_t length = 0;
            uint8_t *data = nullptr;
        };

        /** \brief See <a href="https://www.rfc-editor.org/rfc/rfc3550#section-6.5" target="_blank">RFC 3550 section 6.5</a> */
        struct rtcp_sdes_chunk {
            uint32_t ssrc = 0;
            std::vector<rtcp_sdes_item> items;
        };

        /** \brief See <a href="https://www.rfc-editor.org/rfc/rfc3550#section-6.5" target="_blank">RFC 3550 section 6.5</a> */
        struct rtcp_sdes_packet {
            struct rtcp_header header;
            std::vector<rtcp_sdes_chunk> chunks;
        };

        /** \brief See <a href="https://www.rfc-editor.org/rfc/rfc3550#section-6.7" target="_blank">RFC 3550 section 6.7</a> */
        struct rtcp_app_packet {
            struct rtcp_header header;
            uint32_t ssrc = 0;
            uint8_t name[4] = {0};
            uint8_t *payload = nullptr;
            /** \brief Size of the payload in bytes. Added by uvgRTP to help process the payload. */
            size_t payload_len = 0;
        };

        /** \brief Full Intra Request, See RFC 5104 section 4.3.1 */
        struct rtcp_fir {
            uint32_t ssrc = 0;
            uint8_t seq = 0;
        };
        /** \brief Slice Loss Indication, See RFC 4585 section 6.3.2 */
        struct rtcp_sli {
            uint16_t first = 0;
            uint16_t num = 0;
            uint8_t picture_id = 0;
        };
        /** \brief Reference Picture Selection Indication, See RFC 4585 section 6.3.3 */
        struct rtcp_rpsi {
            uint8_t pb = 0;
            uint8_t pt = 0;
            uint8_t* str = nullptr;
        };

        /** \brief RTCP Feedback Control Information, See RFC 4585 section 6.1 */
        struct rtcp_fb_fci {

            union {
                rtcp_fir fir;
                rtcp_sli sli;
                rtcp_rpsi rpsi;
            };
        };

        /** \brief Feedback message. See RFC 4585 section 6.1 */
        struct rtcp_fb_packet {
            struct rtcp_header header;
            uint32_t sender_ssrc = 0;
            uint32_t media_ssrc = 0;
            std::vector<rtcp_fb_fci> items;
            /** \brief Size of the payload in bytes. Added by uvgRTP to help process the payload. */
            size_t payload_len = 0;
        };


        PACK(struct zrtp_frame {
            uint8_t version:4;
            uint16_t unused:12;
            uint16_t seq = 0;
            uint32_t magic = 0;
            uint32_t ssrc = 0;
            uint8_t payload[1];
        });

        /* Allocate an RTP frame
         *
         * First function allocates an empty RTP frame (no payload)
         *
         * Second allocates an RTP frame with payload of size "payload_len",
         *
         * Third allocate an RTP frame with payload of size "payload_len"
         * + probation zone of size "pz_size" * MAX_PAYLOAD
         *
         * Return pointer to frame on success
         * Return nullptr on error and set rtp_errno to:
         *    RTP_MEMORY_ERROR if allocation of memory failed */
        rtp_frame *alloc_rtp_frame();
        rtp_frame *alloc_rtp_frame(size_t payload_len);


        /* Deallocate RTP frame
         *
         * Return RTP_OK on successs
         * Return RTP_INVALID_VALUE if "frame" is nullptr */
        rtp_error_t dealloc_frame(uvgrtp::frame::rtp_frame *frame);


        /* Allocate ZRTP frame
         * Parameter "payload_size" defines the length of the frame
         *
         * Return pointer to frame on success
         * Return nullptr on error and set rtp_errno to:
         *    RTP_MEMORY_ERROR if allocation of memory failed
         *    RTP_INVALID_VALUE if "payload_size" is 0 */
        void* alloc_zrtp_frame(size_t payload_size);


        /* Deallocate ZRTP frame
         *
         * Return RTP_OK on successs
         * Return RTP_INVALID_VALUE if "frame" is nullptr */
        rtp_error_t dealloc_frame(uvgrtp::frame::zrtp_frame* frame);
    }
}

namespace uvg_rtp = uvgrtp;