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FFmpeg/libavformat/rtmppkt.h

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/*
* RTMP packet utilities
* Copyright (c) 2009 Kostya 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 "avformat.h"
/** maximum possible number of different RTMP channels */
#define RTMP_CHANNELS 64
/**
* 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_VIDEO_CHANNEL = 8, ///< channel for video data
RTMP_AUDIO_CHANNEL, ///< channel for audio data
};
/**
* 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 {
uint8_t channel_id; ///< RTMP channel ID (nothing to do with audio/video channels though)
RTMPPacketType type; ///< packet payload type
uint32_t timestamp; ///< packet full timestamp or timestamp increment to the previous one in milliseconds (latter only for media packets)
uint32_t extra; ///< probably an additional channel ID used during streaming data
uint8_t *data; ///< packet payload
int data_size; ///< packet payload size
} RTMPPacket;
/**
* Creates 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);
/**
* Frees RTMP packet.
*
* @param pkt packet
*/
void ff_rtmp_packet_destroy(RTMPPacket *pkt);
/**
* Reads 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)
* @return zero on success, negative value otherwise
*/
int ff_rtmp_packet_read(URLContext *h, RTMPPacket *p,
int chunk_size, RTMPPacket *prev_pkt);
/**
* Sends 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)
* @return zero on success, negative value otherwise
*/
int ff_rtmp_packet_write(URLContext *h, RTMPPacket *p,
int chunk_size, RTMPPacket *prev_pkt);
/**
* @defgroup amffuncs functions used to work with AMF format (which is also used in .flv)
* @see amf_* funcs in libavformat/flvdec.c
* @{
*/
/**
* Calculates 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);
/**
* Retrieves 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);
/**
* Writes 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);
/**
* Writes 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);
/**
* Writes 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);
/**
* Writes AMF NULL value to buffer.
*
* @param dst pointer to the input buffer (will be modified)
*/
void ff_amf_write_null(uint8_t **dst);
/**
* Writes 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);
/**
* Writes 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);
/**
* Writes 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);
/** @} */ // AMF funcs
#endif /* AVFORMAT_RTMPPKT_H */