Libav libavformat HOWTO - Revision history

Lu zero at 02:43, 16 November 2011

2011-11-16T02:43:25Z

← Older revision		Revision as of 19:43, 15 November 2011
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	: ''This page will hold information on how libavformat is structured an how to add demuxer and protocols to it''		: ''This page will hold information on how libavformat is structured an how to add demuxer and protocols to it''
	: ''please make this page more complete if you can, thanks''		: ''please make this page more complete if you can, thanks''

			Libavformat provides means to retrieve codec data and stream metadata from container formats and network streams.

			Demuxers let the application access or store the codec data and metadata within a container format providing at least timing information.

			Protocols let you access container formats through any kind of storage or delivery system, being that a filesystem access (e.g. pipe, file), a low level network protocol (tcp, udp) or a application level protocol (rtmp, http, tls)

			In general (TODO: make a diagram out of it)

			Protocol -> Demuxer -> Encoded data with timing information (video frames, audio samples, timed metadata) -> Decoders -> Raw data with timing information -> Output

			Input -> Raw data with timing information -> Encoders -> Coded data with timing information -> Muxer -> Protocol

	== Demuxer structure ==		== Demuxer structure ==
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	== Introducing a new demuxer or a new protocol ==		== Introducing a new demuxer or a new protocol ==

	A demuxer let the application access the codec data and metadata stored within a container, a muxer let you store codec data and metadata using the container format chosen, a protocol provides an I/O abstraction to network or system storage.

	In order to make available the new demuxer you have to edit '''libavformat/allformats.c''' and '''libavformat/Makefile'''.
			In order to make available the new demuxer or the new protocol you have to edit '''libavformat/allformats.c''' and '''libavformat/Makefile'''.
	The former holds a list of available demuxers and protocol and is parsed by configure to generate build system		The former holds a list of available demuxers and protocol and is parsed by configure to generate build system
	variables for it, the latter ~~keeps~~ the actual build directives.		variables for it, the latter contains the actual build directives.

	=== libavformat/Makefile ===		=== libavformat/Makefile ===
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	The macro will add ff_'''name'''_protocol to the available protocols.		The macro will add ff_'''name'''_protocol to the available protocols.

	~~== Introducing a new protocol ==~~

	Protocols let you access container formats through any kind of storage or delivery system, being that a filesystem access (e.g. pipe, file), a low level network protocol (tcp, udp) or a application level protocol (rtmp, http, tls)

	~~=== libavformat/Makefile ===~~

	~~=== libavformat/allformats.c ===~~

	== Example code ==		== Example code ==

Lu zero at 02:34, 16 November 2011

2011-11-16T02:34:25Z

← Older revision		Revision as of 19:34, 15 November 2011
Line 1:		Line 1:

			: ''This page will hold information on how libavformat is structured an how to add demuxer and protocols to it''
	: ''please make this page more complete if you can, thanks''		: ''please make this page more complete if you can, thanks''

Lu zero at 02:33, 16 November 2011

2011-11-16T02:33:14Z

← Older revision		Revision as of 19:33, 15 November 2011
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	: ''please make this page more complete if you can, thanks''		: ''please make this page more complete if you can, thanks''

	== ~~Introducing a new demuxer~~ ==		== Demuxer structure ==

	A demuxer let the application access the codec data and metadata stored within a container, a muxer let you store codec data and metadata using the container format chosen.		== Protocol structure ==

			== Introducing a new demuxer or a new protocol ==

			A demuxer let the application access the codec data and metadata stored within a container, a muxer let you store codec data and metadata using the container format chosen, a protocol provides an I/O abstraction to network or system storage.

	In order to make available the new demuxer you have to edit '''libavformat/allformats.c''' and '''libavformat/Makefile'''.		In order to make available the new demuxer you have to edit '''libavformat/allformats.c''' and '''libavformat/Makefile'''.
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	=== libavformat/Makefile ===		=== libavformat/Makefile ===

			==== Demuxer specific ====

	The convention regarding the file structure is to use, for a format named '''name''', '''name'''enc.c for muxer code and '''name'''dec.c for demuxer code, common code should go in '''name'''.c		The convention regarding the file structure is to use, for a format named '''name''', '''name'''enc.c for muxer code and '''name'''dec.c for demuxer code, common code should go in '''name'''.c
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	OBJS-$(CONFIG_NAME_DEMUXER) += namedec.o name.o		OBJS-$(CONFIG_NAME_DEMUXER) += namedec.o name.o

	to the Makefile in order to build ~~the additional code~~.		to the Makefile in order to build.

	=== ~~libavformat/allformats.c~~ ===		==== Protocol specific ====

	~~In order~~ to ~~add~~ a demuxer:		The convention regarding the file structure is to use use directly the protocol name, so for a protocol named '''name''', '''name'''.c.
	~~REGISTER_DEMUXER(NAME,~~ '''name''')		If the protocol is tightly bound to a specific demuxer or could be mismatched is advised to use '''name'''proto.c (e.g. rtmpproto.c)

	~~In order to add a muxer:~~		Add
	~~REGISTER_MUXER~~(~~NAME, '''name'''~~)		OBJS-$(CONFIG_NAME_PROTOCOL) += nameproto.o

	In order to ~~add muxer and demuxer in a single line:~~		to the Makefile in order to build.
	~~REGISTER_MUXDEMU(NAME, '''name''')~~

	~~The macro will register ff_'''name'''_demuxer or~~/~~and ff_'''name'''_muxer to the available formats~~.		=== libavformat/allformats.c ===

	Modifying allformats.c will trigger a build system warning:		Modifying allformats.c will trigger a build system warning:
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	In order to build the new code. Make sure you properly edited Makefile and allformats.c .		In order to build the new code. Make sure you properly edited Makefile and allformats.c .

			==== Demuxer specific ====

			In order to add a demuxer:
			REGISTER_DEMUXER(NAME, '''name''')

			In order to add a muxer:
			REGISTER_MUXER(NAME, '''name''')

			In order to add muxer and demuxer in a single line:
			REGISTER_MUXDEMU(NAME, '''name''')

			The macro will add ff_'''name'''_demuxer or/and ff_'''name'''_muxer to the available formats.

			==== Protocol specific ====

			In order to add a protoco:
			REGISTER_PROTOCOL(NAME, '''name''')

			The macro will add ff_'''name'''_protocol to the available protocols.

	== Introducing a new protocol ==		== Introducing a new protocol ==

Lu zero at 02:18, 16 November 2011

2011-11-16T02:18:52Z

← Older revision		Revision as of 19:18, 15 November 2011
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	[[Category:Libav Tutorials]]		[[Category:Libav Tutorials]]
	[[Category:Tutorials]]		[[Category:Tutorials]]
			[[Category:Work In Progress]]

Lu zero: /* Introducing a new demuxer */

2011-11-15T03:26:57Z

Introducing a new demuxer

← Older revision		Revision as of 20:26, 14 November 2011
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	== Introducing a new demuxer ==		== Introducing a new demuxer ==

	In order to make available the new demuxer you have to edit libavformat/allformats.c and libavformat/Makefile.		A demuxer let the application access the codec data and metadata stored within a container, a muxer let you store codec data and metadata using the container format chosen.

			In order to make available the new demuxer you have to edit '''libavformat/allformats.c''' and '''libavformat/Makefile'''.
	The former holds a list of available demuxers and protocol and is parsed by configure to generate build system		The former holds a list of available demuxers and protocol and is parsed by configure to generate build system
	variables for it, the latter keeps the actual build directives.		variables for it, the latter keeps the actual build directives.

Lu zero at 03:24, 15 November 2011

2011-11-15T03:24:59Z

← Older revision		Revision as of 20:24, 14 November 2011
Line 41:		Line 41:

	In order to build the new code. Make sure you properly edited Makefile and allformats.c .		In order to build the new code. Make sure you properly edited Makefile and allformats.c .

			== Introducing a new protocol ==

			Protocols let you access container formats through any kind of storage or delivery system, being that a filesystem access (e.g. pipe, file), a low level network protocol (tcp, udp) or a application level protocol (rtmp, http, tls)

			=== libavformat/Makefile ===

			=== libavformat/allformats.c ===

	== Example code ==		== Example code ==

Lu zero: /* wiring in the demuxer */

2011-11-15T03:21:43Z

wiring in the demuxer

← Older revision		Revision as of 20:21, 14 November 2011
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	: ''please make this page more complete if you can, thanks''		: ''please make this page more complete if you can, thanks''

	== ~~wiring in the~~ demuxer ==		== Introducing a new demuxer ==

	In order to make available the new demuxer you have to edit libavformat/allformats.c and libavformat/Makefile.		In order to make available the new demuxer you have to edit libavformat/allformats.c and libavformat/Makefile.

Lu zero: /* libavformat/allformats.c */

2011-11-15T03:21:05Z

libavformat/allformats.c

← Older revision		Revision as of 20:21, 14 November 2011
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	In order to add a demuxer:		In order to add a demuxer:
	REGISTER_DEMUXER(~~DEMUXERNAME~~, ~~demuxername~~)		REGISTER_DEMUXER(NAME, '''name''')

	In order to add a muxer:		In order to add a muxer:
	REGISTER_MUXER(~~MUXERNAME~~, ~~muxername~~)		REGISTER_MUXER(NAME, '''name''')

	In order to add muxer and demuxer in a single line:		In order to add muxer and demuxer in a single line:
	REGISTER_MUXDEMU(NAME, name)		REGISTER_MUXDEMU(NAME, '''name''')

	The macro will register ~~ff_name_demuxer~~ or/and ~~ff_name_muxer~~ to the available formats.		The macro will register ff_'''name'''_demuxer or/and ff_'''name'''_muxer to the available formats.

	Modifying allformats.c will trigger a build system warning:		Modifying allformats.c will trigger a build system warning:

Lu zero: /* libavformat/Makefile */

2011-11-15T03:20:04Z

libavformat/Makefile

← Older revision		Revision as of 20:20, 14 November 2011
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	=== libavformat/Makefile ===		=== libavformat/Makefile ===

	The convention regarding the file structure is to use 'name'enc.c for muxer code and 'name'dec.c for demuxer code,		The convention regarding the file structure is to use, for a format named '''name''', '''name'''enc.c for muxer code and '''name'''dec.c for demuxer code, common code should go in '''name'''.c
	common code should go in name.c

	Add		Add

Lu zero: Libav demuxer HOWTO moved to Libav libavformat HOWTO: Broaden the scope of the howto a little

2011-11-15T03:17:46Z

Libav demuxer HOWTO moved to Libav libavformat HOWTO: Broaden the scope of the howto a little

← Older revision	Revision as of 20:17, 14 November 2011
(No difference)