1/* 2 * RTMP packet utilities 3 * Copyright (c) 2009 Kostya Shishkov 4 * 5 * This file is part of Libav. 6 * 7 * Libav 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 * Libav 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 Libav; 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#include "url.h" 27 28/** maximum possible number of different RTMP channels */ 29#define RTMP_CHANNELS 65599 30 31/** 32 * channels used to for RTMP packets with different purposes (i.e. data, network 33 * control, remote procedure calls, etc.) 34 */ 35enum RTMPChannel { 36 RTMP_NETWORK_CHANNEL = 2, ///< channel for network-related messages (bandwidth report, ping, etc) 37 RTMP_SYSTEM_CHANNEL, ///< channel for sending server control messages 38 RTMP_SOURCE_CHANNEL, ///< channel for sending a/v to server 39 RTMP_VIDEO_CHANNEL = 8, ///< channel for video data 40 RTMP_AUDIO_CHANNEL, ///< channel for audio data 41}; 42 43/** 44 * known RTMP packet types 45 */ 46typedef enum RTMPPacketType { 47 RTMP_PT_CHUNK_SIZE = 1, ///< chunk size change 48 RTMP_PT_BYTES_READ = 3, ///< number of bytes read 49 RTMP_PT_PING, ///< ping 50 RTMP_PT_SERVER_BW, ///< server bandwidth 51 RTMP_PT_CLIENT_BW, ///< client bandwidth 52 RTMP_PT_AUDIO = 8, ///< audio packet 53 RTMP_PT_VIDEO, ///< video packet 54 RTMP_PT_FLEX_STREAM = 15, ///< Flex shared stream 55 RTMP_PT_FLEX_OBJECT, ///< Flex shared object 56 RTMP_PT_FLEX_MESSAGE, ///< Flex shared message 57 RTMP_PT_NOTIFY, ///< some notification 58 RTMP_PT_SHARED_OBJ, ///< shared object 59 RTMP_PT_INVOKE, ///< invoke some stream action 60 RTMP_PT_METADATA = 22, ///< FLV metadata 61} RTMPPacketType; 62 63/** 64 * possible RTMP packet header sizes 65 */ 66enum RTMPPacketSize { 67 RTMP_PS_TWELVEBYTES = 0, ///< packet has 12-byte header 68 RTMP_PS_EIGHTBYTES, ///< packet has 8-byte header 69 RTMP_PS_FOURBYTES, ///< packet has 4-byte header 70 RTMP_PS_ONEBYTE ///< packet is really a next chunk of a packet 71}; 72 73/** 74 * structure for holding RTMP packets 75 */ 76typedef struct RTMPPacket { 77 int channel_id; ///< RTMP channel ID (nothing to do with audio/video channels though) 78 RTMPPacketType type; ///< packet payload type 79 uint32_t timestamp; ///< packet full timestamp 80 uint32_t ts_delta; ///< timestamp increment to the previous one in milliseconds (latter only for media packets) 81 uint32_t extra; ///< probably an additional channel ID used during streaming data 82 uint8_t *data; ///< packet payload 83 int data_size; ///< packet payload size 84} RTMPPacket; 85 86/** 87 * Create new RTMP packet with given attributes. 88 * 89 * @param pkt packet 90 * @param channel_id packet channel ID 91 * @param type packet type 92 * @param timestamp packet timestamp 93 * @param size packet size 94 * @return zero on success, negative value otherwise 95 */ 96int ff_rtmp_packet_create(RTMPPacket *pkt, int channel_id, RTMPPacketType type, 97 int timestamp, int size); 98 99/** 100 * Free RTMP packet. 101 * 102 * @param pkt packet 103 */ 104void ff_rtmp_packet_destroy(RTMPPacket *pkt); 105 106/** 107 * Read RTMP packet sent by the server. 108 * 109 * @param h reader context 110 * @param p packet 111 * @param chunk_size current chunk size 112 * @param prev_pkt previously read packet headers for all channels 113 * (may be needed for restoring incomplete packet header) 114 * @return number of bytes read on success, negative value otherwise 115 */ 116int ff_rtmp_packet_read(URLContext *h, RTMPPacket *p, 117 int chunk_size, RTMPPacket *prev_pkt); 118 119/** 120 * Send RTMP packet to the server. 121 * 122 * @param h reader context 123 * @param p packet to send 124 * @param chunk_size current chunk size 125 * @param prev_pkt previously sent packet headers for all channels 126 * (may be used for packet header compressing) 127 * @return number of bytes written on success, negative value otherwise 128 */ 129int ff_rtmp_packet_write(URLContext *h, RTMPPacket *p, 130 int chunk_size, RTMPPacket *prev_pkt); 131 132/** 133 * Print information and contents of RTMP packet. 134 * 135 * @param ctx output context 136 * @param p packet to dump 137 */ 138void ff_rtmp_packet_dump(void *ctx, RTMPPacket *p); 139 140/** 141 * @name Functions used to work with the AMF format (which is also used in .flv) 142 * @see amf_* funcs in libavformat/flvdec.c 143 * @{ 144 */ 145 146/** 147 * Calculate number of bytes taken by first AMF entry in data. 148 * 149 * @param data input data 150 * @param data_end input buffer end 151 * @return number of bytes used by first AMF entry 152 */ 153int ff_amf_tag_size(const uint8_t *data, const uint8_t *data_end); 154 155/** 156 * Retrieve value of given AMF object field in string form. 157 * 158 * @param data AMF object data 159 * @param data_end input buffer end 160 * @param name name of field to retrieve 161 * @param dst buffer for storing result 162 * @param dst_size output buffer size 163 * @return 0 if search and retrieval succeeded, negative value otherwise 164 */ 165int ff_amf_get_field_value(const uint8_t *data, const uint8_t *data_end, 166 const uint8_t *name, uint8_t *dst, int dst_size); 167 168/** 169 * Write boolean value in AMF format to buffer. 170 * 171 * @param dst pointer to the input buffer (will be modified) 172 * @param val value to write 173 */ 174void ff_amf_write_bool(uint8_t **dst, int val); 175 176/** 177 * Write number in AMF format to buffer. 178 * 179 * @param dst pointer to the input buffer (will be modified) 180 * @param num value to write 181 */ 182void ff_amf_write_number(uint8_t **dst, double num); 183 184/** 185 * Write string in AMF format to buffer. 186 * 187 * @param dst pointer to the input buffer (will be modified) 188 * @param str string to write 189 */ 190void ff_amf_write_string(uint8_t **dst, const char *str); 191 192/** 193 * Write AMF NULL value to buffer. 194 * 195 * @param dst pointer to the input buffer (will be modified) 196 */ 197void ff_amf_write_null(uint8_t **dst); 198 199/** 200 * Write marker for AMF object to buffer. 201 * 202 * @param dst pointer to the input buffer (will be modified) 203 */ 204void ff_amf_write_object_start(uint8_t **dst); 205 206/** 207 * Write string used as field name in AMF object to buffer. 208 * 209 * @param dst pointer to the input buffer (will be modified) 210 * @param str string to write 211 */ 212void ff_amf_write_field_name(uint8_t **dst, const char *str); 213 214/** 215 * Write marker for end of AMF object to buffer. 216 * 217 * @param dst pointer to the input buffer (will be modified) 218 */ 219void ff_amf_write_object_end(uint8_t **dst); 220 221/** @} */ // AMF funcs 222 223#endif /* AVFORMAT_RTMPPKT_H */ 224