| /* 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 wraper around GstRTPBuffer |
| * |
| * @rtp: mapped RTP buffer |
| **/ |
| typedef struct { |
| // FIXME: it used to contain more fileds now we are left with only GstRTPBuffer. |
| // it will be nice to use it directly |
| GstRTPBuffer rtp; |
| } RtpUlpFecMapInfo; |
| |
| /* 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; |
| |
| 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 |