Utility functions [I/O and Muxing/Demuxing Library]

Miscellaneous utility functions related to both muxing and demuxing (or neither). More...

Modules
	RIFF FourCCs
	Get the tables mapping RIFF FourCCs to libavcodec AVCodecIDs.
Functions
void	av_hex_dump (FILE *f, const uint8_t *buf, int size)
	Send a nice hexadecimal dump of a buffer to the specified file stream.
void	av_hex_dump_log (void *avcl, int level, const uint8_t *buf, int size)
	Send a nice hexadecimal dump of a buffer to the log.
void	av_pkt_dump2 (FILE *f, AVPacket *pkt, int dump_payload, AVStream *st)
	Send a nice dump of a packet to the specified file stream.
void	av_pkt_dump_log2 (void *avcl, int level, AVPacket *pkt, int dump_payload, AVStream *st)
	Send a nice dump of a packet to the log.
enum AVCodecID	av_codec_get_id (const struct AVCodecTag *const *tags, unsigned int tag)
	Get the AVCodecID for the given codec tag tag.
unsigned int	av_codec_get_tag (const struct AVCodecTag *const *tags, enum AVCodecID id)
	Get the codec tag for the given codec id id.
int	av_find_default_stream_index (AVFormatContext *s)
int	av_index_search_timestamp (AVStream *st, int64_t timestamp, int flags)
	Get the index for a specific timestamp.
int	av_add_index_entry (AVStream *st, int64_t pos, int64_t timestamp, int size, int distance, int flags)
	Add an index entry into a sorted list.
void	av_url_split (char *proto, int proto_size, char *authorization, int authorization_size, char *hostname, int hostname_size, int *port_ptr, char *path, int path_size, const char *url)
	Split a URL string into components.
void	av_dump_format (AVFormatContext *ic, int index, const char *url, int is_output)
int	av_get_frame_filename (char *buf, int buf_size, const char *path, int number)
	Return in 'buf' the path with 'd' replaced by a number.
int	av_filename_number_test (const char *filename)
	Check whether filename actually is a numbered sequence generator.
int	av_sdp_create (AVFormatContext *ac[], int n_files, char *buf, int size)
	Generate an SDP for an RTP session.
int	av_match_ext (const char *filename, const char *extensions)
	Return a positive value if the given filename has one of the given extensions, 0 otherwise.
int	avformat_query_codec (AVOutputFormat *ofmt, enum AVCodecID codec_id, int std_compliance)
	Test if the given container can store a codec.

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Detailed Description

Miscellaneous utility functions related to both muxing and demuxing (or neither).

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Function Documentation

void av_hex_dump	(	FILE *	f,
		const uint8_t *	buf,
		int	size
	)

Send a nice hexadecimal dump of a buffer to the specified file stream.

Parameters:

	f	The file stream pointer where the dump should be sent to.
	buf	buffer
	size	buffer size

See also:

av_hex_dump_log, av_pkt_dump2, av_pkt_dump_log2

void av_hex_dump_log	(	void *	avcl,
		int	level,
		const uint8_t *	buf,
		int	size
	)

Send a nice hexadecimal dump of a buffer to the log.

Parameters:

	avcl	A pointer to an arbitrary struct of which the first field is a pointer to an AVClass struct.
	level	The importance level of the message, lower values signifying higher importance.
	buf	buffer
	size	buffer size

See also:

av_hex_dump, av_pkt_dump2, av_pkt_dump_log2

void av_pkt_dump2	(	FILE *	f,
		AVPacket *	pkt,
		int	dump_payload,
		AVStream *	st
	)

Send a nice dump of a packet to the specified file stream.

Parameters:

	f	The file stream pointer where the dump should be sent to.
	pkt	packet to dump
	dump_payload	True if the payload must be displayed, too.
	st	AVStream that the packet belongs to

void av_pkt_dump_log2	(	void *	avcl,
		int	level,
		AVPacket *	pkt,
		int	dump_payload,
		AVStream *	st
	)

Send a nice dump of a packet to the log.

Parameters:

	avcl	A pointer to an arbitrary struct of which the first field is a pointer to an AVClass struct.
	level	The importance level of the message, lower values signifying higher importance.
	pkt	packet to dump
	dump_payload	True if the payload must be displayed, too.
	st	AVStream that the packet belongs to

enum AVCodecID av_codec_get_id	(	const struct AVCodecTag *const *	tags,
		unsigned int	tag
	)

Get the AVCodecID for the given codec tag tag.

If no codec id is found returns AV_CODEC_ID_NONE.

Parameters:

tags

list of supported codec_id-codec_tag pairs, as stored in AVInputFormat.codec_tag and AVOutputFormat.codec_tag

unsigned int av_codec_get_tag	(	const struct AVCodecTag *const *	tags,
		enum AVCodecID	id
	)

Get the codec tag for the given codec id id.

If no codec tag is found returns 0.

Parameters:

tags

list of supported codec_id-codec_tag pairs, as stored in AVInputFormat.codec_tag and AVOutputFormat.codec_tag

int av_find_default_stream_index

(

AVFormatContext *

s

)

int av_index_search_timestamp	(	AVStream *	st,
		int64_t	timestamp,
		int	flags
	)

Get the index for a specific timestamp.

Parameters:

flags

if AVSEEK_FLAG_BACKWARD then the returned index will correspond to the timestamp which is <= the requested one, if backward is 0, then it will be >= if AVSEEK_FLAG_ANY seek to any frame, only keyframes otherwise

Returns:

< 0 if no such timestamp could be found

int av_add_index_entry	(	AVStream *	st,
		int64_t	pos,
		int64_t	timestamp,
		int	size,
		int	distance,
		int	flags
	)

Add an index entry into a sorted list.

Update the entry if the list already contains it.

Parameters:

timestamp

timestamp in the time base of the given stream

void av_url_split	(	char *	proto,
		int	proto_size,
		char *	authorization,
		int	authorization_size,
		char *	hostname,
		int	hostname_size,
		int *	port_ptr,
		char *	path,
		int	path_size,
		const char *	url
	)

Split a URL string into components.

The pointers to buffers for storing individual components may be null, in order to ignore that component. Buffers for components not found are set to empty strings. If the port is not found, it is set to a negative value.

Parameters:

	proto	the buffer for the protocol
	proto_size	the size of the proto buffer
	authorization	the buffer for the authorization
	authorization_size	the size of the authorization buffer
	hostname	the buffer for the host name
	hostname_size	the size of the hostname buffer
	port_ptr	a pointer to store the port number in
	path	the buffer for the path
	path_size	the size of the path buffer
	url	the URL to split

void av_dump_format	(	AVFormatContext *	ic,
		int	index,
		const char *	url,
		int	is_output
	)

int av_get_frame_filename	(	char *	buf,
		int	buf_size,
		const char *	path,
		int	number
	)

Return in 'buf' the path with 'd' replaced by a number.

Also handles the '0nd' format where 'n' is the total number of digits and '%'.

Parameters:

	buf	destination buffer
	buf_size	destination buffer size
	path	numbered sequence string
	number	frame number

Returns:

0 if OK, -1 on format error

int av_filename_number_test

(

const char *

filename

)

Check whether filename actually is a numbered sequence generator.

Parameters:

filename

possible numbered sequence string

Returns:

1 if a valid numbered sequence string, 0 otherwise

int av_sdp_create	(	AVFormatContext *	ac[],
		int	n_files,
		char *	buf,
		int	size
	)

Generate an SDP for an RTP session.

Note, this overwrites the id values of AVStreams in the muxer contexts for getting unique dynamic payload types.

Parameters:

	ac	array of AVFormatContexts describing the RTP streams. If the array is composed by only one context, such context can contain multiple AVStreams (one AVStream per RTP stream). Otherwise, all the contexts in the array (an AVCodecContext per RTP stream) must contain only one AVStream.
	n_files	number of AVCodecContexts contained in ac
	buf	buffer where the SDP will be stored (must be allocated by the caller)
	size	the size of the buffer

Returns:

0 if OK, AVERROR_xxx on error

int av_match_ext	(	const char *	filename,
		const char *	extensions
	)

Return a positive value if the given filename has one of the given extensions, 0 otherwise.

Parameters:

extensions

a comma-separated list of filename extensions

int avformat_query_codec	(	AVOutputFormat *	ofmt,
		enum AVCodecID	codec_id,
		int	std_compliance
	)

Test if the given container can store a codec.

Parameters:

std_compliance

standards compliance level, one of FF_COMPLIANCE_*

Returns:

1 if codec with ID codec_id can be stored in ofmt, 0 if it cannot. A negative number if this information is not available.