libavformat/rtpdec_qdm2.c File Reference

RTP support for the QDM2 payload (todo: wiki). More...

#include <string.h>
#include "libavutil/intreadwrite.h"
#include "libavcodec/avcodec.h"
#include "rtp.h"
#include "rtpdec.h"
#include "rtpdec_formats.h"

Go to the source code of this file.

Data Structures
struct	PayloadContext
	Structure listing useful vars to parse RTP packet payload. More...
Functions
static int	qdm2_parse_config (PayloadContext *qdm, AVStream *st, const uint8_t *buf, const uint8_t *end)
	Parse configuration (basically the codec-specific extradata) from an RTP config subpacket (starts with 0xff).
static int	qdm2_parse_subpacket (PayloadContext *qdm, AVStream *st, const uint8_t *buf, const uint8_t *end)
	Parse a single subpacket.
static int	qdm2_restore_block (PayloadContext *qdm, AVStream *st, AVPacket *pkt)
	Add a superblock header around a set of subpackets.
static int	qdm2_parse_packet (AVFormatContext *s, PayloadContext *qdm, AVStream *st, AVPacket *pkt, uint32_t *timestamp, const uint8_t *buf, int len, int flags)
	return 0 on packet, no more left, 1 on packet, -1 on partial packet.
static PayloadContext *	qdm2_extradata_new (void)
static void	qdm2_extradata_free (PayloadContext *qdm)
Variables
RTPDynamicProtocolHandler	ff_qdm2_dynamic_handler

---

Detailed Description

RTP support for the QDM2 payload (todo: wiki).

Author:

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

Definition in file rtpdec_qdm2.c.

---

Function Documentation

static void qdm2_extradata_free

(

PayloadContext *

qdm

)

[static]

Definition at line 305 of file rtpdec_qdm2.c.

static PayloadContext* qdm2_extradata_new

(

void

)

[static]

Definition at line 300 of file rtpdec_qdm2.c.

static int qdm2_parse_config	(	PayloadContext *	qdm,
		AVStream *	st,
		const uint8_t *	buf,
		const uint8_t *	end
	)			[static]

Parse configuration (basically the codec-specific extradata) from an RTP config subpacket (starts with 0xff).

Layout of the config subpacket (in bytes): 1: 0xFF <- config ID then an array { 1: size <- of the current item 1: item type <- 0 .. 4 size-2: data <- data depends on the item type }

Item 0 implies the end of the config subpacket, and has no data. Item 1 implies a stream configuration without extradata. Item 2 max. nr. of subpackets per superblock Item 3 superblock type for the stream Item 4 implies a stream configuration with extradata (size >= 0x1c).

Returns:

<0 on error, otherwise the number of bytes parsed from the input buffer.

< subpackets per block

Definition at line 75 of file rtpdec_qdm2.c.

Referenced by qdm2_parse_packet().

static int qdm2_parse_packet	(	AVFormatContext *	s,
		PayloadContext *	qdm,
		AVStream *	st,
		AVPacket *	pkt,
		uint32_t *	timestamp,
		const uint8_t *	buf,
		int	len,
		int	flags
	)			[static]

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

..

Definition at line 237 of file rtpdec_qdm2.c.

static int qdm2_parse_subpacket	(	PayloadContext *	qdm,
		AVStream *	st,
		const uint8_t *	buf,
		const uint8_t *	end
	)			[static]

Parse a single subpacket.

We store this subpacket in an intermediate buffer (position depends on the ID (byte[0]). When called, at least 4 bytes are available for reading (see qdm2_parse_packet()).

Layout of a single subpacket (RTP packets commonly contain multiple such subpackets) - length in bytes: 1: ordering ID <- 0 .. 0x7F 1: subpacket type <- 0 .. 0x7F; value & 0x80 means subpacket length = 2 bytes, else 1 byte 1/2: subpacket length <- length of the data following the flags/length fields if (subpacket type & 0x7F) == 0x7F 1: subpacket type, higher bits size: subpacket data

The subpackets come in randomly, and should be encapsulated into 1 or more superblocks (containing qdm->subpkts_per_block subpackets each) per RTP packet, in order of ascending "ordering ID", see qdm2_restore_block().

Returns:

<0 on error, otherwise the number of bytes parsed from the input buffer.

Definition at line 152 of file rtpdec_qdm2.c.

Referenced by qdm2_parse_packet().

static int qdm2_restore_block	(	PayloadContext *	qdm,
		AVStream *	st,
		AVPacket *	pkt
	)			[static]

Add a superblock header around a set of subpackets.

Returns:

<0 on error, else 0.

Definition at line 186 of file rtpdec_qdm2.c.

Referenced by qdm2_parse_packet().

---

Variable Documentation

RTPDynamicProtocolHandler ff_qdm2_dynamic_handler

Initial value:

 {
    .enc_name         = "X-QDM",
    .codec_type       = AVMEDIA_TYPE_AUDIO,
    .codec_id         = CODEC_ID_NONE,
    .alloc            = qdm2_extradata_new,
    .free             = qdm2_extradata_free,
    .parse_packet     = qdm2_parse_packet,
}

Definition at line 310 of file rtpdec_qdm2.c.

Referenced by av_register_rtp_dynamic_payload_handlers().