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