2 * RTMP packet utilities
3 * Copyright (c) 2009 Konstantin Shishkov
5 * This file is part of FFmpeg.
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.
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.
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
22 #ifndef AVFORMAT_RTMPPKT_H
23 #define AVFORMAT_RTMPPKT_H
25 #include "libavcodec/bytestream.h"
29 /** maximum possible number of different RTMP channels */
30 #define RTMP_CHANNELS 65599
33 * channels used to for RTMP packets with different purposes (i.e. data, network
34 * control, remote procedure calls, etc.)
37 RTMP_NETWORK_CHANNEL = 2, ///< channel for network-related messages (bandwidth report, ping, etc)
38 RTMP_SYSTEM_CHANNEL, ///< channel for sending server control messages
39 RTMP_AUDIO_CHANNEL, ///< channel for audio data
40 RTMP_VIDEO_CHANNEL = 6, ///< channel for video data
41 RTMP_SOURCE_CHANNEL = 8, ///< channel for a/v invokes
45 * known RTMP packet types
47 typedef enum RTMPPacketType {
48 RTMP_PT_CHUNK_SIZE = 1, ///< chunk size change
49 RTMP_PT_BYTES_READ = 3, ///< number of bytes read
50 RTMP_PT_PING, ///< ping
51 RTMP_PT_SERVER_BW, ///< server bandwidth
52 RTMP_PT_CLIENT_BW, ///< client bandwidth
53 RTMP_PT_AUDIO = 8, ///< audio packet
54 RTMP_PT_VIDEO, ///< video packet
55 RTMP_PT_FLEX_STREAM = 15, ///< Flex shared stream
56 RTMP_PT_FLEX_OBJECT, ///< Flex shared object
57 RTMP_PT_FLEX_MESSAGE, ///< Flex shared message
58 RTMP_PT_NOTIFY, ///< some notification
59 RTMP_PT_SHARED_OBJ, ///< shared object
60 RTMP_PT_INVOKE, ///< invoke some stream action
61 RTMP_PT_METADATA = 22, ///< FLV metadata
65 * possible RTMP packet header sizes
68 RTMP_PS_TWELVEBYTES = 0, ///< packet has 12-byte header
69 RTMP_PS_EIGHTBYTES, ///< packet has 8-byte header
70 RTMP_PS_FOURBYTES, ///< packet has 4-byte header
71 RTMP_PS_ONEBYTE ///< packet is really a next chunk of a packet
75 * structure for holding RTMP packets
77 typedef struct RTMPPacket {
78 int channel_id; ///< RTMP channel ID (nothing to do with audio/video channels though)
79 RTMPPacketType type; ///< packet payload type
80 uint32_t timestamp; ///< packet full timestamp
81 uint32_t ts_field; ///< 24-bit timestamp or increment to the previous one, in milliseconds (latter only for media packets). Clipped to a maximum of 0xFFFFFF, indicating an extended timestamp field.
82 uint32_t extra; ///< probably an additional channel ID used during streaming data
83 uint8_t *data; ///< packet payload
84 int size; ///< packet payload size
85 int offset; ///< amount of data read so far
86 int read; ///< amount read, including headers
90 * Create new RTMP packet with given attributes.
93 * @param channel_id packet channel ID
94 * @param type packet type
95 * @param timestamp packet timestamp
96 * @param size packet size
97 * @return zero on success, negative value otherwise
99 int ff_rtmp_packet_create(RTMPPacket *pkt, int channel_id, RTMPPacketType type,
100 int timestamp, int size);
107 void ff_rtmp_packet_destroy(RTMPPacket *pkt);
110 * Read RTMP packet sent by the server.
112 * @param h reader context
114 * @param chunk_size current chunk size
115 * @param prev_pkt previously read packet headers for all channels
116 * (may be needed for restoring incomplete packet header)
117 * @param nb_prev_pkt number of allocated elements in prev_pkt
118 * @return number of bytes read on success, negative value otherwise
120 int ff_rtmp_packet_read(URLContext *h, RTMPPacket *p,
121 int chunk_size, RTMPPacket **prev_pkt,
124 * Read internal RTMP packet sent by the server.
126 * @param h reader context
128 * @param chunk_size current chunk size
129 * @param prev_pkt previously read packet headers for all channels
130 * (may be needed for restoring incomplete packet header)
131 * @param nb_prev_pkt number of allocated elements in prev_pkt
132 * @param c the first byte already read
133 * @return number of bytes read on success, negative value otherwise
135 int ff_rtmp_packet_read_internal(URLContext *h, RTMPPacket *p, int chunk_size,
136 RTMPPacket **prev_pkt, int *nb_prev_pkt,
140 * Send RTMP packet to the server.
142 * @param h reader context
143 * @param p packet to send
144 * @param chunk_size current chunk size
145 * @param prev_pkt previously sent packet headers for all channels
146 * (may be used for packet header compressing)
147 * @param nb_prev_pkt number of allocated elements in prev_pkt
148 * @return number of bytes written on success, negative value otherwise
150 int ff_rtmp_packet_write(URLContext *h, RTMPPacket *p,
151 int chunk_size, RTMPPacket **prev_pkt,
155 * Print information and contents of RTMP packet.
157 * @param ctx output context
158 * @param p packet to dump
160 void ff_rtmp_packet_dump(void *ctx, RTMPPacket *p);
163 * Enlarge the prev_pkt array to fit the given channel
165 * @param prev_pkt array with previously sent packet headers
166 * @param nb_prev_pkt number of allocated elements in prev_pkt
167 * @param channel the channel number that needs to be allocated
169 int ff_rtmp_check_alloc_array(RTMPPacket **prev_pkt, int *nb_prev_pkt,
173 * @name Functions used to work with the AMF format (which is also used in .flv)
174 * @see amf_* funcs in libavformat/flvdec.c
179 * Calculate number of bytes taken by first AMF entry in data.
181 * @param data input data
182 * @param data_end input buffer end
183 * @return number of bytes used by first AMF entry
185 int ff_amf_tag_size(const uint8_t *data, const uint8_t *data_end);
188 * Retrieve value of given AMF object field in string form.
190 * @param data AMF object data
191 * @param data_end input buffer end
192 * @param name name of field to retrieve
193 * @param dst buffer for storing result
194 * @param dst_size output buffer size
195 * @return 0 if search and retrieval succeeded, negative value otherwise
197 int ff_amf_get_field_value(const uint8_t *data, const uint8_t *data_end,
198 const uint8_t *name, uint8_t *dst, int dst_size);
201 * Write boolean value in AMF format to buffer.
203 * @param dst pointer to the input buffer (will be modified)
204 * @param val value to write
206 void ff_amf_write_bool(uint8_t **dst, int val);
209 * Write number in AMF format to buffer.
211 * @param dst pointer to the input buffer (will be modified)
212 * @param num value to write
214 void ff_amf_write_number(uint8_t **dst, double num);
217 * Write string in AMF format to buffer.
219 * @param dst pointer to the input buffer (will be modified)
220 * @param str string to write
222 void ff_amf_write_string(uint8_t **dst, const char *str);
225 * Write a string consisting of two parts in AMF format to a buffer.
227 * @param dst pointer to the input buffer (will be modified)
228 * @param str1 first string to write, may be null
229 * @param str2 second string to write, may be null
231 void ff_amf_write_string2(uint8_t **dst, const char *str1, const char *str2);
234 * Write AMF NULL value to buffer.
236 * @param dst pointer to the input buffer (will be modified)
238 void ff_amf_write_null(uint8_t **dst);
241 * Write marker for AMF object to buffer.
243 * @param dst pointer to the input buffer (will be modified)
245 void ff_amf_write_object_start(uint8_t **dst);
248 * Write string used as field name in AMF object to buffer.
250 * @param dst pointer to the input buffer (will be modified)
251 * @param str string to write
253 void ff_amf_write_field_name(uint8_t **dst, const char *str);
256 * Write marker for end of AMF object to buffer.
258 * @param dst pointer to the input buffer (will be modified)
260 void ff_amf_write_object_end(uint8_t **dst);
263 * Read AMF boolean value.
265 *@param[in,out] gbc GetByteContext initialized with AMF-formatted data
266 *@param[out] val 0 or 1
267 *@return 0 on success or an AVERROR code on failure
269 int ff_amf_read_bool(GetByteContext *gbc, int *val);
272 * Read AMF number value.
274 *@param[in,out] gbc GetByteContext initialized with AMF-formatted data
275 *@param[out] val read value
276 *@return 0 on success or an AVERROR code on failure
278 int ff_amf_read_number(GetByteContext *gbc, double *val);
281 * Get AMF string value.
283 * This function behaves the same as ff_amf_read_string except that
284 * it does not expect the AMF type prepended to the actual data.
285 * Appends a trailing null byte to output string in order to
286 * ease later parsing.
288 *@param[in,out] gbc GetByteContext initialized with AMF-formatted data
289 *@param[out] str read string
290 *@param[in] strsize buffer size available to store the read string
291 *@param[out] length read string length
292 *@return 0 on success or an AVERROR code on failure
294 int ff_amf_get_string(GetByteContext *bc, uint8_t *str,
295 int strsize, int *length);
298 * Read AMF string value.
300 * Appends a trailing null byte to output string in order to
301 * ease later parsing.
303 *@param[in,out] gbc GetByteContext initialized with AMF-formatted data
304 *@param[out] str read string
305 *@param[in] strsize buffer size available to store the read string
306 *@param[out] length read string length
307 *@return 0 on success or an AVERROR code on failure
309 int ff_amf_read_string(GetByteContext *gbc, uint8_t *str,
310 int strsize, int *length);
313 * Read AMF NULL value.
315 *@param[in,out] gbc GetByteContext initialized with AMF-formatted data
316 *@return 0 on success or an AVERROR code on failure
318 int ff_amf_read_null(GetByteContext *gbc);
321 * Match AMF string with a NULL-terminated string.
323 * @return 0 if the strings do not match.
326 int ff_amf_match_string(const uint8_t *data, int size, const char *str);
328 /** @} */ // AMF funcs
330 #endif /* AVFORMAT_RTMPPKT_H */