libavformat/rdt.c File Reference

Realmedia RTSP protocol (RDT) support. More...

#include "avformat.h"
#include "libavutil/avstring.h"
#include "rtpdec.h"
#include "rdt.h"
#include "libavutil/base64.h"
#include "libavutil/md5.h"
#include "rm.h"
#include "internal.h"
#include "avio_internal.h"
#include "libavcodec/get_bits.h"

Go to the source code of this file.

Data Structures

struct RDTDemuxContext

struct PayloadContext

RTP/H264 specific private data. More...

Defines

#define XOR_TABLE_SIZE 37

#define RDT_HANDLER(n, s, t)

Functions

RDTDemuxContext * ff_rdt_parse_open (AVFormatContext *ic, int first_stream_of_set_idx, void *priv_data, RTPDynamicProtocolHandler *handler)

Allocate and init the RDT parsing context.

void ff_rdt_parse_close (RDTDemuxContext *s)

void ff_rdt_calc_response_and_checksum (char response[41], char chksum[9], const char *challenge)

Calculate the response (RealChallenge2 in the RTSP header) to the challenge (RealChallenge1 in the RTSP header from the Real/Helix server), which is used as some sort of client validation.

static int rdt_load_mdpr (PayloadContext *rdt, AVStream *st, int rule_nr)

int ff_rdt_parse_header (const uint8_t *buf, int len, int *pset_id, int *pseq_no, int *pstream_id, int *pis_keyframe, uint32_t *ptimestamp)

Actual data handling.

static int rdt_parse_packet (AVFormatContext *ctx, PayloadContext *rdt, AVStream *st, AVPacket *pkt, uint32_t *timestamp, const uint8_t *buf, int len, int flags)

int ff_rdt_parse_packet (RDTDemuxContext *s, AVPacket *pkt, uint8_t **bufptr, int len)

Parse RDT-style packet data (header + media data).

void ff_rdt_subscribe_rule (char *cmd, int size, int stream_nr, int rule_nr)

Add subscription information to Subscribe parameter string.

static unsigned char * rdt_parse_b64buf (unsigned int *target_len, const char *p)

static int rdt_parse_sdp_line (AVFormatContext *s, int st_index, PayloadContext *rdt, const char *line)

static void real_parse_asm_rule (AVStream *st, const char *p, const char *end)

static AVStream * add_dstream (AVFormatContext *s, AVStream *orig_st)

static void real_parse_asm_rulebook (AVFormatContext *s, AVStream *orig_st, const char *p)

void ff_real_parse_sdp_a_line (AVFormatContext *s, int stream_index, const char *line)

Parse a server-related SDP line.

static PayloadContext * rdt_new_context (void)

static void rdt_free_context (PayloadContext *rdt)

RDT_HANDLER (live_video,"x-pn-multirate-realvideo-live", AVMEDIA_TYPE_VIDEO)

RDT_HANDLER (live_audio,"x-pn-multirate-realaudio-live", AVMEDIA_TYPE_AUDIO)

RDT_HANDLER (video,"x-pn-realvideo", AVMEDIA_TYPE_VIDEO)

RDT_HANDLER (audio,"x-pn-realaudio", AVMEDIA_TYPE_AUDIO)

void av_register_rdt_dynamic_payload_handlers (void)

Register RDT-related dynamic payload handlers with our cache.

Detailed Description

Realmedia RTSP protocol (RDT) support.

Author:: Ronald S. Bultje <rbultje@ronald.bitfreak.net>

Definition in file rdt.c.

Define Documentation

#define RDT_HANDLER	(	n,
		s,
		t	)

Value:

static RTPDynamicProtocolHandler ff_rdt_ ## n ## _handler = { \
    .enc_name         = s, \
    .codec_type       = t, \
    .codec_id         = CODEC_ID_NONE, \
    .parse_sdp_a_line = rdt_parse_sdp_line, \
    .alloc            = rdt_new_context, \
    .free             = rdt_free_context, \
    .parse_packet     = rdt_parse_packet \
}

Definition at line 553 of file rdt.c.

#define XOR_TABLE_SIZE 37

Referenced by ff_rdt_calc_response_and_checksum().

Function Documentation

static AVStream* add_dstream	(	AVFormatContext *	s,
		AVStream *	orig_st
	)			`[static]`

Definition at line 458 of file rdt.c.

Referenced by real_parse_asm_rulebook().

void av_register_rdt_dynamic_payload_handlers ( void )

Register RDT-related dynamic payload handlers with our cache.

Definition at line 569 of file rdt.c.

Referenced by av_register_all().

void ff_rdt_calc_response_and_checksum	(	char	response[41],
		char	chksum[9],
		const char *	challenge
	)

Calculate the response (RealChallenge2 in the RTSP header) to the challenge (RealChallenge1 in the RTSP header from the Real/Helix server), which is used as some sort of client validation.

Parameters:

	response	pointer to response buffer, it should be at least 41 bytes (40 data + 1 zero) bytes long.
	chksum	pointer to buffer containing a checksum of the response, it should be at least 9 (8 data + 1 zero) bytes long.
	challenge	pointer to the RealChallenge1 value provided by the server.

Definition at line 94 of file rdt.c.

void ff_rdt_parse_close ( RDTDemuxContext * s )

Definition at line 78 of file rdt.c.

Referenced by ff_rtsp_undo_setup().

int ff_rdt_parse_header	(	const uint8_t *	buf,
		int	len,
		int *	pset_id,
		int *	pseq_no,
		int *	pstream_id,
		int *	pis_keyframe,
		uint32_t *	ptimestamp
	)

Actual data handling.

Parse RDT-style packet header.

return 0 on packet, no more left, 1 on packet, 1 on partial packet...

Layout of the header (in bits): 1: len_included Flag indicating whether this header includes a length field; this can be used to concatenate multiple RDT packets in a single UDP/TCP data frame and is used to precede RDT data by stream status packets 1: need_reliable Flag indicating whether this header includes a "reliable sequence number"; these are apparently sequence numbers of data packets alone. For data packets, this flag is always set, according to the Real documentation [1] 5: set_id ID of a set of streams of identical content, possibly with different codecs or bitrates 1: is_reliable Flag set for certain streams deemed less tolerable for packet loss 16: seq_no Packet sequence number; if >=0xFF00, this is a non-data packet containing stream status info, the second byte indicates the type of status packet (see wireshark docs / source code [2]) if (len_included) { 16: packet_len } else { packet_len = remainder of UDP/TCP frame } 1: is_back_to_back Back-to-Back flag; used for timing, set for one in every 10 packets, according to the Real documentation [1] 1: is_slow_data Slow-data flag; currently unused, according to Real docs [1] 5: stream_id ID of the stream within this particular set of streams 1: is_no_keyframe Non-keyframe flag (unset if packet belongs to a keyframe) 32: timestamp (PTS) if (set_id == 0x1F) { 16: set_id (extended set-of-streams ID; see set_id) } if (need_reliable) { 16: reliable_seq_no Reliable sequence number (see need_reliable) } if (stream_id == 0x3F) { 16: stream_id (extended stream ID; see stream_id) } [1] https://protocol.helixcommunity.org/files/2005/devdocs/RDT_Feature_Level_20.txt [2] http://www.wireshark.org/docs/dfref/r/rdt.html and http://anonsvn.wireshark.org/viewvc/trunk/epan/dissectors/packet-rdt.c

Definition at line 190 of file rdt.c.

Referenced by ff_rdt_parse_packet(), and ff_rtsp_tcp_read_packet().

RDTDemuxContext* ff_rdt_parse_open	(	AVFormatContext *	ic,
		int	first_stream_of_set_idx,
		void *	priv_data,
		RTPDynamicProtocolHandler *	handler
	)

Allocate and init the RDT parsing context.

Parameters:

	ic	the containing RTSP demuxer context
	first_stream_of_set_idx	index to the first AVStream in the RTSP demuxer context's ic->streams array that is part of this particular stream's set of streams (with identical content)
	priv_data	private data of the payload data handler context
	handler	pointer to the parse_packet() payload parsing function

Returns:: a newly allocated RDTDemuxContext. Free with ff_rdt_parse_close().

Definition at line 55 of file rdt.c.

Referenced by rtsp_open_transport_ctx().

int ff_rdt_parse_packet	(	RDTDemuxContext *	s,
		AVPacket *	pkt,
		uint8_t **	buf,
		int	len
	)

Parse RDT-style packet data (header + media data).

Usage similar to rtp_parse_packet().

< Should not be used if buf is NULL, but should be set to the timestamp of the packet returned....

Definition at line 335 of file rdt.c.

void ff_rdt_subscribe_rule	(	char *	cmd,
		int	size,
		int	stream_nr,
		int	rule_nr
	)

Add subscription information to Subscribe parameter string.

Parameters:

	cmd	string to write the subscription information into.
	size	size of cmd.
	stream_nr	stream number.
	rule_nr	rule number to conform to.

Definition at line 384 of file rdt.c.

Referenced by rtsp_read_packet().

void ff_real_parse_sdp_a_line	(	AVFormatContext *	s,
		int	stream_index,
		const char *	buf
	)

Parse a server-related SDP line.

Parameters:

	s	the RTSP AVFormatContext
	stream_index	the index of the first stream in the set represented by the SDP m= line (in s->streams)
	buf	the SDP line

Definition at line 513 of file rdt.c.

static void rdt_free_context ( PayloadContext * rdt ) [static]

Definition at line 537 of file rdt.c.

RDT_HANDLER	(	audio	,
		"x-pn-realaudio"	,
		AVMEDIA_TYPE_AUDIO
	)

RDT_HANDLER	(	video	,
		"x-pn-realvideo"	,
		AVMEDIA_TYPE_VIDEO
	)

RDT_HANDLER	(	live_audio	,
		"x-pn-multirate-realaudio-live"	,
		AVMEDIA_TYPE_AUDIO
	)

RDT_HANDLER	(	live_video	,
		"x-pn-multirate-realvideo-live"	,
		AVMEDIA_TYPE_VIDEO
	)

static int rdt_load_mdpr	(	PayloadContext *	rdt,
		AVStream *	st,
		int	rule_nr
	)			`[static]`

Layout of the MLTI chunk: 4: MLTI 2: number of streams Then for each stream ([number_of_streams] times): 2: mdpr index 2: number of mdpr chunks Then for each mdpr chunk ([number_of_mdpr_chunks] times): 4: size [size]: data we skip MDPR chunks until we reach the one of the stream we're interested in, and forward that ([size]+[data]) to the RM demuxer to parse the stream-specific header data.

Definition at line 132 of file rdt.c.

Referenced by rdt_parse_sdp_line().

static PayloadContext* rdt_new_context ( void ) [static]

Definition at line 523 of file rdt.c.

static unsigned char* rdt_parse_b64buf	(	unsigned int *	target_len,
		const char *	p
	)			`[static]`

Definition at line 392 of file rdt.c.

Referenced by rdt_parse_sdp_line().

static int rdt_parse_packet	(	AVFormatContext *	ctx,
		PayloadContext *	rdt,
		AVStream *	st,
		AVPacket *	pkt,
		uint32_t *	timestamp,
		const uint8_t *	buf,
		int	len,
		int	flags
	)			`[static]`

Definition at line 294 of file rdt.c.

static int rdt_parse_sdp_line	(	AVFormatContext *	s,
		int	st_index,
		PayloadContext *	rdt,
		const char *	line
	)			`[static]`

Definition at line 407 of file rdt.c.

static void real_parse_asm_rule	(	AVStream *	st,
		const char *	p,
		const char *	end
	)			`[static]`

Definition at line 445 of file rdt.c.

Referenced by real_parse_asm_rulebook().

static void real_parse_asm_rulebook	(	AVFormatContext *	s,
		AVStream *	orig_st,
		const char *	p
	)			`[static]`

The ASMRuleBook contains a list of comma-separated strings per rule, and each rule is separated by a ;. The last one also has a ; at the end so we can use it as delimiter. Every rule occurs twice, once for when the RTSP packet header marker is set and once for if it isn't. We only read the first because we don't care much (that's what the "odd" variable is for). Each rule contains a set of one or more statements, optionally preceeded by a single condition. If there's a condition, the rule starts with a '#'. Multiple conditions are merged between brackets, so there are never multiple conditions spread out over separate statements. Generally, these conditions are bitrate limits (min/max) for multi-bitrate streams.

Definition at line 472 of file rdt.c.

Referenced by ff_real_parse_sdp_a_line().


Data Structures
struct	RDTDemuxContext
struct	PayloadContext
	RTP/H264 specific private data. More...
Defines
#define	XOR_TABLE_SIZE 37
#define	RDT_HANDLER(n, s, t)
Functions
RDTDemuxContext *	ff_rdt_parse_open (AVFormatContext ic, int first_stream_of_set_idx, void priv_data, RTPDynamicProtocolHandler *handler)
	Allocate and init the RDT parsing context.
void	ff_rdt_parse_close (RDTDemuxContext *s)
void	ff_rdt_calc_response_and_checksum (char response[41], char chksum[9], const char *challenge)
	Calculate the response (RealChallenge2 in the RTSP header) to the challenge (RealChallenge1 in the RTSP header from the Real/Helix server), which is used as some sort of client validation.
static int	rdt_load_mdpr (PayloadContext rdt, AVStream st, int rule_nr)
int	ff_rdt_parse_header (const uint8_t buf, int len, int pset_id, int pseq_no, int pstream_id, int pis_keyframe, uint32_t ptimestamp)
	Actual data handling.
static int	rdt_parse_packet (AVFormatContext ctx, PayloadContext rdt, AVStream st, AVPacket pkt, uint32_t timestamp, const uint8_t buf, int len, int flags)
int	ff_rdt_parse_packet (RDTDemuxContext s, AVPacket pkt, uint8_t **bufptr, int len)
	Parse RDT-style packet data (header + media data).
void	ff_rdt_subscribe_rule (char *cmd, int size, int stream_nr, int rule_nr)
	Add subscription information to Subscribe parameter string.
static unsigned char *	rdt_parse_b64buf (unsigned int target_len, const char p)
static int	rdt_parse_sdp_line (AVFormatContext s, int st_index, PayloadContext rdt, const char *line)
static void	real_parse_asm_rule (AVStream st, const char p, const char *end)
static AVStream *	add_dstream (AVFormatContext s, AVStream orig_st)
static void	real_parse_asm_rulebook (AVFormatContext s, AVStream orig_st, const char *p)
void	ff_real_parse_sdp_a_line (AVFormatContext s, int stream_index, const char line)
	Parse a server-related SDP line.
static PayloadContext *	rdt_new_context (void)
static void	rdt_free_context (PayloadContext *rdt)
	RDT_HANDLER (live_video,"x-pn-multirate-realvideo-live", AVMEDIA_TYPE_VIDEO)
	RDT_HANDLER (live_audio,"x-pn-multirate-realaudio-live", AVMEDIA_TYPE_AUDIO)
	RDT_HANDLER (video,"x-pn-realvideo", AVMEDIA_TYPE_VIDEO)
	RDT_HANDLER (audio,"x-pn-realaudio", AVMEDIA_TYPE_AUDIO)
void	av_register_rdt_dynamic_payload_handlers (void)
	Register RDT-related dynamic payload handlers with our cache.