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