1 /* 2 * Copyright (c) 2012 The WebRTC project authors. All Rights Reserved. 3 * 4 * Use of this source code is governed by a BSD-style license 5 * that can be found in the LICENSE file in the root of the source 6 * tree. An additional intellectual property rights grant can be found 7 * in the file PATENTS. All contributing project authors may 8 * be found in the AUTHORS file in the root of the source tree. 9 */ 10 11 #ifndef WEBRTC_MODULES_RTP_RTCP_SOURCE_FORWARD_ERROR_CORRECTION_INTERNAL_H_ 12 #define WEBRTC_MODULES_RTP_RTCP_SOURCE_FORWARD_ERROR_CORRECTION_INTERNAL_H_ 13 14 #include "webrtc/modules/rtp_rtcp/source/forward_error_correction.h" 15 #include "webrtc/typedefs.h" 16 17 namespace webrtc { 18 19 // Packet mask size in bytes (L bit is set). 20 static const int kMaskSizeLBitSet = 6; 21 // Packet mask size in bytes (L bit is cleared). 22 static const int kMaskSizeLBitClear = 2; 23 24 namespace internal { 25 26 class PacketMaskTable { 27 public: 28 PacketMaskTable(FecMaskType fec_mask_type, int num_media_packets); ~PacketMaskTable()29 ~PacketMaskTable() {} fec_mask_type()30 FecMaskType fec_mask_type() const { return fec_mask_type_; } fec_packet_mask_table()31 const uint8_t*** fec_packet_mask_table() const { 32 return fec_packet_mask_table_; 33 } 34 35 private: 36 FecMaskType InitMaskType(FecMaskType fec_mask_type, int num_media_packets); 37 const uint8_t*** InitMaskTable(FecMaskType fec_mask_type_); 38 const FecMaskType fec_mask_type_; 39 const uint8_t*** fec_packet_mask_table_; 40 }; 41 42 // Returns an array of packet masks. The mask of a single FEC packet 43 // corresponds to a number of mask bytes. The mask indicates which 44 // media packets should be protected by the FEC packet. 45 46 // \param[in] num_media_packets The number of media packets to protect. 47 // [1, max_media_packets]. 48 // \param[in] num_fec_packets The number of FEC packets which will 49 // be generated. [1, num_media_packets]. 50 // \param[in] num_imp_packets The number of important packets. 51 // [0, num_media_packets]. 52 // num_imp_packets = 0 is the equal 53 // protection scenario. 54 // \param[in] use_unequal_protection Enables unequal protection: allocates 55 // more protection to the num_imp_packets. 56 // \param[in] mask_table An instance of the |PacketMaskTable| 57 // class, which contains the type of FEC 58 // packet mask used, and a pointer to the 59 // corresponding packet masks. 60 // \param[out] packet_mask A pointer to hold the packet mask array, 61 // of size: num_fec_packets * 62 // "number of mask bytes". 63 void GeneratePacketMasks(int num_media_packets, int num_fec_packets, 64 int num_imp_packets, bool use_unequal_protection, 65 const PacketMaskTable& mask_table, 66 uint8_t* packet_mask); 67 68 } // namespace internal 69 } // namespace webrtc 70 #endif // WEBRTC_MODULES_RTP_RTCP_SOURCE_FORWARD_ERROR_CORRECTION_INTERNAL_H_ 71