1/* 2 * RTMP packet utilities 3 * Copyright (c) 2009 Kostya Shishkov 4 * 5 * This file is part of FFmpeg. 6 * 7 * FFmpeg is free software; you can redistribute it and/or 8 * modify it under the terms of the GNU Lesser General Public 9 * License as published by the Free Software Foundation; either 10 * version 2.1 of the License, or (at your option) any later version. 11 * 12 * FFmpeg is distributed in the hope that it will be useful, 13 * but WITHOUT ANY WARRANTY; without even the implied warranty of 14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 15 * Lesser General Public License for more details. 16 * 17 * You should have received a copy of the GNU Lesser General Public 18 * License along with FFmpeg; if not, write to the Free Software 19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 20 */ 21 22#ifndef AVFORMAT_RTMPPKT_H 23#define AVFORMAT_RTMPPKT_H 24 25#include "avformat.h" 26 27/** maximum possible number of different RTMP channels */ 28#define RTMP_CHANNELS 65599 29 30/** 31 * channels used to for RTMP packets with different purposes (i.e. data, network 32 * control, remote procedure calls, etc.) 33 */ 34enum RTMPChannel { 35 RTMP_NETWORK_CHANNEL = 2, ///< channel for network-related messages (bandwidth report, ping, etc) 36 RTMP_SYSTEM_CHANNEL, ///< channel for sending server control messages 37 RTMP_SOURCE_CHANNEL, ///< channel for sending a/v to server 38 RTMP_VIDEO_CHANNEL = 8, ///< channel for video data 39 RTMP_AUDIO_CHANNEL, ///< channel for audio data 40}; 41 42/** 43 * known RTMP packet types 44 */ 45typedef enum RTMPPacketType { 46 RTMP_PT_CHUNK_SIZE = 1, ///< chunk size change 47 RTMP_PT_BYTES_READ = 3, ///< number of bytes read 48 RTMP_PT_PING, ///< ping 49 RTMP_PT_SERVER_BW, ///< server bandwidth 50 RTMP_PT_CLIENT_BW, ///< client bandwidth 51 RTMP_PT_AUDIO = 8, ///< audio packet 52 RTMP_PT_VIDEO, ///< video packet 53 RTMP_PT_FLEX_STREAM = 15, ///< Flex shared stream 54 RTMP_PT_FLEX_OBJECT, ///< Flex shared object 55 RTMP_PT_FLEX_MESSAGE, ///< Flex shared message 56 RTMP_PT_NOTIFY, ///< some notification 57 RTMP_PT_SHARED_OBJ, ///< shared object 58 RTMP_PT_INVOKE, ///< invoke some stream action 59 RTMP_PT_METADATA = 22, ///< FLV metadata 60} RTMPPacketType; 61 62/** 63 * possible RTMP packet header sizes 64 */ 65enum RTMPPacketSize { 66 RTMP_PS_TWELVEBYTES = 0, ///< packet has 12-byte header 67 RTMP_PS_EIGHTBYTES, ///< packet has 8-byte header 68 RTMP_PS_FOURBYTES, ///< packet has 4-byte header 69 RTMP_PS_ONEBYTE ///< packet is really a next chunk of a packet 70}; 71 72/** 73 * structure for holding RTMP packets 74 */ 75typedef struct RTMPPacket { 76 int channel_id; ///< RTMP channel ID (nothing to do with audio/video channels though) 77 RTMPPacketType type; ///< packet payload type 78 uint32_t timestamp; ///< packet full timestamp 79 uint32_t ts_delta; ///< timestamp increment to the previous one in milliseconds (latter only for media packets) 80 uint32_t extra; ///< probably an additional channel ID used during streaming data 81 uint8_t *data; ///< packet payload 82 int data_size; ///< packet payload size 83} RTMPPacket; 84 85/** 86 * Creates new RTMP packet with given attributes. 87 * 88 * @param pkt packet 89 * @param channel_id packet channel ID 90 * @param type packet type 91 * @param timestamp packet timestamp 92 * @param size packet size 93 * @return zero on success, negative value otherwise 94 */ 95int ff_rtmp_packet_create(RTMPPacket *pkt, int channel_id, RTMPPacketType type, 96 int timestamp, int size); 97 98/** 99 * Frees RTMP packet. 100 * 101 * @param pkt packet 102 */ 103void ff_rtmp_packet_destroy(RTMPPacket *pkt); 104 105/** 106 * Reads RTMP packet sent by the server. 107 * 108 * @param h reader context 109 * @param p packet 110 * @param chunk_size current chunk size 111 * @param prev_pkt previously read packet headers for all channels 112 * (may be needed for restoring incomplete packet header) 113 * @return number of bytes read on success, negative value otherwise 114 */ 115int ff_rtmp_packet_read(URLContext *h, RTMPPacket *p, 116 int chunk_size, RTMPPacket *prev_pkt); 117 118/** 119 * Sends RTMP packet to the server. 120 * 121 * @param h reader context 122 * @param p packet to send 123 * @param chunk_size current chunk size 124 * @param prev_pkt previously sent packet headers for all channels 125 * (may be used for packet header compressing) 126 * @return number of bytes written on success, negative value otherwise 127 */ 128int ff_rtmp_packet_write(URLContext *h, RTMPPacket *p, 129 int chunk_size, RTMPPacket *prev_pkt); 130 131/** 132 * Prints information and contents of RTMP packet. 133 * 134 * @param h output context 135 * @param p packet to dump 136 */ 137void ff_rtmp_packet_dump(void *ctx, RTMPPacket *p); 138 139/** 140 * @defgroup amffuncs functions used to work with AMF format (which is also used in .flv) 141 * @see amf_* funcs in libavformat/flvdec.c 142 * @{ 143 */ 144 145/** 146 * Calculates number of bytes taken by first AMF entry in data. 147 * 148 * @param data input data 149 * @param data_end input buffer end 150 * @return number of bytes used by first AMF entry 151 */ 152int ff_amf_tag_size(const uint8_t *data, const uint8_t *data_end); 153 154/** 155 * Retrieves value of given AMF object field in string form. 156 * 157 * @param data AMF object data 158 * @param data_end input buffer end 159 * @param name name of field to retrieve 160 * @param dst buffer for storing result 161 * @param dst_size output buffer size 162 * @return 0 if search and retrieval succeeded, negative value otherwise 163 */ 164int ff_amf_get_field_value(const uint8_t *data, const uint8_t *data_end, 165 const uint8_t *name, uint8_t *dst, int dst_size); 166 167/** 168 * Writes boolean value in AMF format to buffer. 169 * 170 * @param dst pointer to the input buffer (will be modified) 171 * @param val value to write 172 */ 173void ff_amf_write_bool(uint8_t **dst, int val); 174 175/** 176 * Writes number in AMF format to buffer. 177 * 178 * @param dst pointer to the input buffer (will be modified) 179 * @param num value to write 180 */ 181void ff_amf_write_number(uint8_t **dst, double num); 182 183/** 184 * Writes string in AMF format to buffer. 185 * 186 * @param dst pointer to the input buffer (will be modified) 187 * @param str string to write 188 */ 189void ff_amf_write_string(uint8_t **dst, const char *str); 190 191/** 192 * Writes AMF NULL value to buffer. 193 * 194 * @param dst pointer to the input buffer (will be modified) 195 */ 196void ff_amf_write_null(uint8_t **dst); 197 198/** 199 * Writes marker for AMF object to buffer. 200 * 201 * @param dst pointer to the input buffer (will be modified) 202 */ 203void ff_amf_write_object_start(uint8_t **dst); 204 205/** 206 * Writes string used as field name in AMF object to buffer. 207 * 208 * @param dst pointer to the input buffer (will be modified) 209 * @param str string to write 210 */ 211void ff_amf_write_field_name(uint8_t **dst, const char *str); 212 213/** 214 * Writes marker for end of AMF object to buffer. 215 * 216 * @param dst pointer to the input buffer (will be modified) 217 */ 218void ff_amf_write_object_end(uint8_t **dst); 219 220/** @} */ // AMF funcs 221 222#endif /* AVFORMAT_RTMPPKT_H */ 223