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/* GStreamer plugin for forward error correction
* Copyright (C) 2017 Pexip
*
* 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 Street, Fifth Floor, Boston, MA 02110-1301 USA
*
* Author: Mikhail Fludkov <misha@pexip.com>
*/
#ifndef __RTP_ULPFEC_COMMON_H__
#define __RTP_ULPFEC_COMMON_H__
#include <gst/gst.h>
#include <gst/rtp/rtp.h>
G_BEGIN_DECLS
#define GST_WARNING_RTP_PACKET(obj, name, pkt) rtp_ulpfec_log_rtppacket (GST_CAT_DEFAULT, GST_LEVEL_WARNING, obj, name, pkt)
#define GST_LOG_RTP_PACKET(obj, name, pkt) rtp_ulpfec_log_rtppacket (GST_CAT_DEFAULT, GST_LEVEL_LOG, obj, name, pkt)
#define GST_DEBUG_RTP_PACKET(obj, name, pkt) rtp_ulpfec_log_rtppacket (GST_CAT_DEFAULT, GST_LEVEL_DEBUG, obj, name, pkt)
#define GST_INFO_RTP_PACKET(obj, name, pkt) rtp_ulpfec_log_rtppacket (GST_CAT_DEFAULT, GST_LEVEL_INFO, obj, name, pkt)
#define GST_WARNING_FEC_PACKET(obj, pkt) rtp_ulpfec_log_fec_packet (GST_CAT_DEFAULT, GST_LEVEL_WARNING, obj, pkt)
#define GST_DEBUG_FEC_PACKET(obj, pkt) rtp_ulpfec_log_fec_packet (GST_CAT_DEFAULT, GST_LEVEL_DEBUG, obj, pkt)
#define GST_INFO_FEC_PACKET(obj, pkt) rtp_ulpfec_log_fec_packet (GST_CAT_DEFAULT, GST_LEVEL_INFO, obj, pkt)
#define RTP_ULPFEC_PROTECTED_PACKETS_MAX(L) ((L) ? 48 : 16)
#define RTP_ULPFEC_SEQ_BASE_OFFSET_MAX(L) (RTP_ULPFEC_PROTECTED_PACKETS_MAX(L) - 1)
/**
* RtpUlpFecMapInfo: Helper wrapper around GstRTPBuffer
*
* @rtp: mapped RTP buffer
**/
typedef struct {
// FIXME: it used to contain more fields now we are left with only GstRTPBuffer.
// it will be nice to use it directly
GstRTPBuffer rtp;
} RtpUlpFecMapInfo;
/* FIXME: parse/write these properly instead of relying in packed structs */
#ifdef _MSC_VER
#pragma pack(push, 1)
#define ATTRIBUTE_PACKED
#else
#define ATTRIBUTE_PACKED __attribute__ ((packed))
#endif
/* RFC 5109 */
/*
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|E|L|P|X| CC |M| PT recovery | SN base |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| TS recovery |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| length recovery |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 3: FEC Header Format
*/
#if G_BYTE_ORDER == G_LITTLE_ENDIAN
typedef struct {
guint8 CC:4;
guint8 X:1;
guint8 P:1;
guint8 L:1;
guint8 E:1;
guint8 pt:7;
guint8 M:1;
guint16 seq;
guint32 timestamp;
guint16 len;
} ATTRIBUTE_PACKED RtpUlpFecHeader;
#else
typedef struct {
guint8 E:1;
guint8 L:1;
guint8 P:1;
guint8 X:1;
guint8 CC:4;
guint8 M:1;
guint8 pt:7;
guint16 seq;
guint32 timestamp;
guint16 len;
} ATTRIBUTE_PACKED RtpUlpFecHeader;
#endif
/*
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Protection Length | mask |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| mask cont. (present only when L = 1) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 4: ULP Level Header Format
*/
typedef struct
{
guint16 protection_len;
guint16 mask;
guint32 mask_continued;
} ATTRIBUTE_PACKED RtpUlpFecLevelHeader;
#ifdef _MSC_VER
#pragma pack(pop)
#else
#undef ATTRIBUTE_PACKED
#endif
gboolean rtp_ulpfec_map_info_map (GstBuffer *buffer, RtpUlpFecMapInfo *info);
void rtp_ulpfec_map_info_unmap (RtpUlpFecMapInfo *info);
void rtp_buffer_to_ulpfec_bitstring (GstRTPBuffer *rtp, GArray *dst_arr,
gboolean fec_buffer, gboolean fec_mask_long);
GstBuffer * rtp_ulpfec_bitstring_to_media_rtp_buffer (GArray *arr,
gboolean fec_mask_long, guint32 ssrc, guint16 seq);
GstBuffer * rtp_ulpfec_bitstring_to_fec_rtp_buffer (GArray *arr, guint16 seq_base, gboolean fec_mask_long,
guint64 fec_mask, gboolean marker, guint8 pt, guint16 seq,
guint32 timestamp, guint32 ssrc);
#ifndef GST_DISABLE_GST_DEBUG
void rtp_ulpfec_log_rtppacket (GstDebugCategory * cat, GstDebugLevel level,
gpointer object, const gchar *name,
GstRTPBuffer *rtp);
void rtp_ulpfec_log_fec_packet (GstDebugCategory * cat, GstDebugLevel level,
gpointer object, GstRTPBuffer *fecrtp);
#else
#define rtp_ulpfec_log_rtppacket(cat,level,obj,name,rtp) /* NOOP */
#define rtp_ulpfec_log_fec_packet(cat,level,obj,fecrtp) /* NOOP */
#endif
RtpUlpFecHeader * rtp_ulpfec_buffer_get_fechdr (GstRTPBuffer *rtp);
guint rtp_ulpfec_get_headers_len (gboolean fec_mask_long);
guint16 rtp_ulpfec_hdr_get_protection_len (RtpUlpFecHeader const *fec_hdr);
guint64 rtp_ulpfec_packet_mask_from_seqnum (guint16 seq, guint16 fec_seq_base, gboolean fec_mask_long);
guint64 rtp_ulpfec_buffer_get_mask (GstRTPBuffer *rtp);
guint16 rtp_ulpfec_buffer_get_seq_base (GstRTPBuffer *rtp);
gboolean rtp_ulpfec_mask_is_long (guint64 mask);
gboolean rtp_ulpfec_buffer_is_valid (GstRTPBuffer * rtp);
G_END_DECLS
#endif
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