/*
* RTMP packet utilities
* Copyright (c) 2009 Konstantin Shishkov
*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#ifndef AVFORMAT_RTMPPKT_H
#define AVFORMAT_RTMPPKT_H
#include "libavcodec/bytestream.h"
#include "avformat.h"
#include "url.h"
/** maximum possible number of different RTMP channels */
#define RTMP_CHANNELS 65599
/**
* channels used to for RTMP packets with different purposes (i.e. data, network
* control, remote procedure calls, etc.)
*/
enum RTMPChannel {
RTMP_NETWORK_CHANNEL = 2, ///< channel for network-related messages (bandwidth report, ping, etc)
RTMP_SYSTEM_CHANNEL, ///< channel for sending server control messages
RTMP_AUDIO_CHANNEL, ///< channel for audio data
RTMP_VIDEO_CHANNEL = 6, ///< channel for video data
RTMP_SOURCE_CHANNEL = 8, ///< channel for a/v invokes
};
/**
* known RTMP packet types
*/
typedef enum RTMPPacketType {
RTMP_PT_CHUNK_SIZE = 1, ///< chunk size change
RTMP_PT_BYTES_READ = 3, ///< number of bytes read
RTMP_PT_PING, ///< ping
RTMP_PT_SERVER_BW, ///< server bandwidth
RTMP_PT_CLIENT_BW, ///< client bandwidth
RTMP_PT_AUDIO = 8, ///< audio packet
RTMP_PT_VIDEO, ///< video packet
RTMP_PT_FLEX_STREAM = 15, ///< Flex shared stream
RTMP_PT_FLEX_OBJECT, ///< Flex shared object
RTMP_PT_FLEX_MESSAGE, ///< Flex shared message
RTMP_PT_NOTIFY, ///< some notification
RTMP_PT_SHARED_OBJ, ///< shared object
RTMP_PT_INVOKE, ///< invoke some stream action
RTMP_PT_METADATA = 22, ///< FLV metadata
} RTMPPacketType;
/**
* possible RTMP packet header sizes
*/
enum RTMPPacketSize {
RTMP_PS_TWELVEBYTES = 0, ///< packet has 12-byte header
RTMP_PS_EIGHTBYTES, ///< packet has 8-byte header
RTMP_PS_FOURBYTES, ///< packet has 4-byte header
RTMP_PS_ONEBYTE ///< packet is really a next chunk of a packet
};
/**
* structure for holding RTMP packets
*/
typedef struct RTMPPacket {
int channel_id; ///< RTMP channel ID (nothing to do with audio/video channels though)
RTMPPacketType type; ///< packet payload type
uint32_t timestamp; ///< packet full timestamp
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.
uint32_t extra; ///< probably an additional channel ID used during streaming data
uint8_t *data; ///< packet payload
int size; ///< packet payload size
int offset; ///< amount of data read so far
int read; ///< amount read, including headers
} RTMPPacket;
/**
* Create new RTMP packet with given attributes.
*
* @param pkt packet
* @param channel_id packet channel ID
* @param type packet type
* @param timestamp packet timestamp
* @param size packet size
* @return zero on success, negative value otherwise
*/
int ff_rtmp_packet_create(RTMPPacket *pkt, int channel_id, RTMPPacketType type,
int timestamp, int size);
/**
* Free RTMP packet.
*
* @param pkt packet
*/
void ff_rtmp_packet_destroy(RTMPPacket *pkt);
/**
* Read RTMP packet sent by the server.
*
* @param h reader context
* @param p packet
* @param chunk_size current chunk size
* @param prev_pkt previously read packet headers for all channels
* (may be needed for restoring incomplete packet header)
* @param nb_prev_pkt number of allocated elements in prev_pkt
* @return number of bytes read on success, negative value otherwise
*/
int ff_rtmp_packet_read(URLContext *h, RTMPPacket *p,
int chunk_size, RTMPPacket **prev_pkt,
int *nb_prev_pkt);
/**
* Read internal RTMP packet sent by the server.
*
* @param h reader context
* @param p packet
* @param chunk_size current chunk size
* @param prev_pkt previously read packet headers for all channels
* (may be needed for restoring incomplete packet header)
* @param nb_prev_pkt number of allocated elements in prev_pkt
* @param c the first byte already read
* @return number of bytes read on success, negative value otherwise
*/
int ff_rtmp_packet_read_internal(URLContext *h, RTMPPacket *p, int chunk_size,
RTMPPacket **prev_pkt, int *nb_prev_pkt,
uint8_t c);
/**
* Send RTMP packet to the server.
*
* @param h reader context
* @param p packet to send
* @param chunk_size current chunk size
* @param prev_pkt previously sent packet headers for all channels
* (may be used for packet header compressing)
* @param nb_prev_pkt number of allocated elements in prev_pkt
* @return number of bytes written on success, negative value otherwise
*/
int ff_rtmp_packet_write(URLContext *h, RTMPPacket *p,
int chunk_size, RTMPPacket **prev_pkt,
int *nb_prev_pkt);
/**
* Print information and contents of RTMP packet.
*
* @param ctx output context
* @param p packet to dump
*/
void ff_rtmp_packet_dump(void *ctx, RTMPPacket *p);
/**
* Enlarge the prev_pkt array to fit the given channel
*
* @param prev_pkt array with previously sent packet headers
* @param nb_prev_pkt number of allocated elements in prev_pkt
* @param channel the channel number that needs to be allocated
*/
int ff_rtmp_check_alloc_array(RTMPPacket **prev_pkt, int *nb_prev_pkt,
int channel);
/**
* @name Functions used to work with the AMF format (which is also used in .flv)
* @see amf_* funcs in libavformat/flvdec.c
* @{
*/
/**
* Calculate number of bytes taken by first AMF entry in data.
*
* @param data input data
* @param data_end input buffer end
* @return number of bytes used by first AMF entry
*/
int ff_amf_tag_size(const uint8_t *data, const uint8_t *data_end);
/**
* Retrieve value of given AMF object field in string form.
*
* @param data AMF object data
* @param data_end input buffer end
* @param name name of field to retrieve
* @param dst buffer for storing result
* @param dst_size output buffer size
* @return 0 if search and retrieval succeeded, negative value otherwise
*/
int ff_amf_get_field_value(const uint8_t *data, const uint8_t *data_end,
const uint8_t *name, uint8_t *dst, int dst_size);
/**
* Write boolean value in AMF format to buffer.
*
* @param dst pointer to the input buffer (will be modified)
* @param val value to write
*/
void ff_amf_write_bool(uint8_t **dst, int val);
/**
* Write number in AMF format to buffer.
*
* @param dst pointer to the input buffer (will be modified)
* @param num value to write
*/
void ff_amf_write_number(uint8_t **dst, double num);
/**
* Write string in AMF format to buffer.
*
* @param dst pointer to the input buffer (will be modified)
* @param str string to write
*/
void ff_amf_write_string(uint8_t **dst, const char *str);
/**
* Write a string consisting of two parts in AMF format to a buffer.
*
* @param dst pointer to the input buffer (will be modified)
* @param str1 first string to write, may be null
* @param str2 second string to write, may be null
*/
void ff_amf_write_string2(uint8_t **dst, const char *str1, const char *str2);
/**
* Write AMF NULL value to buffer.
*
* @param dst pointer to the input buffer (will be modified)
*/
void ff_amf_write_null(uint8_t **dst);
/**
* Write marker for AMF object to buffer.
*
* @param dst pointer to the input buffer (will be modified)
*/
void ff_amf_write_object_start(uint8_t **dst);
/**
* Write string used as field name in AMF object to buffer.
*
* @param dst pointer to the input buffer (will be modified)
* @param str string to write
*/
void ff_amf_write_field_name(uint8_t **dst, const char *str);
/**
* Write marker for end of AMF object to buffer.
*
* @param dst pointer to the input buffer (will be modified)
*/
void ff_amf_write_object_end(uint8_t **dst);
/**
* Read AMF boolean value.
*
*@param[in,out] gbc GetByteContext initialized with AMF-formatted data
*@param[out] val 0 or 1
*@return 0 on success or an AVERROR code on failure
*/
int ff_amf_read_bool(GetByteContext *gbc, int *val);
/**
* Read AMF number value.
*
*@param[in,out] gbc GetByteContext initialized with AMF-formatted data
*@param[out] val read value
*@return 0 on success or an AVERROR code on failure
*/
int ff_amf_read_number(GetByteContext *gbc, double *val);
/**
* Get AMF string value.
*
* This function behaves the same as ff_amf_read_string except that
* it does not expect the AMF type prepended to the actual data.
* Appends a trailing null byte to output string in order to
* ease later parsing.
*
*@param[in,out] gbc GetByteContext initialized with AMF-formatted data
*@param[out] str read string
*@param[in] strsize buffer size available to store the read string
*@param[out] length read string length
*@return 0 on success or an AVERROR code on failure
*/
int ff_amf_get_string(GetByteContext *bc, uint8_t *str,
int strsize, int *length);
/**
* Read AMF string value.
*
* Appends a trailing null byte to output string in order to
* ease later parsing.
*
*@param[in,out] gbc GetByteContext initialized with AMF-formatted data
*@param[out] str read string
*@param[in] strsize buffer size available to store the read string
*@param[out] length read string length
*@return 0 on success or an AVERROR code on failure
*/
int ff_amf_read_string(GetByteContext *gbc, uint8_t *str,
int strsize, int *length);
/**
* Read AMF NULL value.
*
*@param[in,out] gbc GetByteContext initialized with AMF-formatted data
*@return 0 on success or an AVERROR code on failure
*/
int ff_amf_read_null(GetByteContext *gbc);
/**
* Match AMF string with a NULL-terminated string.
*
* @return 0 if the strings do not match.
*/
int ff_amf_match_string(const uint8_t *data, int size, const char *str);
/** @} */ // AMF funcs
#endif /* AVFORMAT_RTMPPKT_H */