ffmpeg/libavformat/rtmppkt.h
Josh Allmann d4aef99780 rtmp: Follow Flash player numbering for channels.
Channel 4 is typically used by the Flash player to transmit
audio, channel 6 for video, and various stream-specific invokes
get sent over channel 8, which is designated the source channel.

This more closely matches the behavior of the Flash player,
including the transmission of play requests over channel 8.

Signed-off-by: Martin Storsjö <martin@martin.st>
2013-09-17 11:03:36 +03:00

296 lines
9.3 KiB
C

/*
* RTMP packet utilities
* Copyright (c) 2009 Konstantin Shishkov
*
* This file is part of Libav.
*
* Libav 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.
*
* Libav 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 Libav; 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_delta; ///< 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 size; ///< packet payload size
} 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)
* @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);
/**
* 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 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, 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)
* @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);
/**
* 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);
/**
* @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);
/**
* 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 */