FFmpeg demuxer HOWTO - Revision history

Fingolfin: /* libavformat/allformats.c */ Correct make target name

2011-04-08T09:43:37Z

libavformat/allformats.c: Correct make target name

← Older revision		Revision as of 02:43, 8 April 2011
Line 13:		Line 13:
	The macro will add the _demuxer or whatever is appropriate. '''Run configure in the top level directory and make clean, as config.h will be automatically modified'''.		The macro will add the _demuxer or whatever is appropriate. '''Run configure in the top level directory and make clean, as config.h will be automatically modified'''.

	make ~~dist-clean~~		make distclean
	./configure		./configure
	make		make


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

DonDiego: FFmpeg demuxer howto moved to FFmpeg demuxer HOWTO: Fix title spelling.

2010-07-08T13:48:19Z

FFmpeg demuxer howto moved to FFmpeg demuxer HOWTO: Fix title spelling.

← Older revision	Revision as of 06:48, 8 July 2010
(No difference)

DrV: libavformat/allformats.h no longer exists; macros in libavformat/allformats.c take care of the externs now

2008-12-15T05:01:05Z

libavformat/allformats.h no longer exists; macros in libavformat/allformats.c take care of the externs now

← Older revision		Revision as of 22:01, 14 December 2008
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	== registering the demuxer ==		== registering the demuxer ==

	~~=== libavformat/allformats.h ===~~

	~~Add for a demuxer:~~
	~~extern AVInputFormat demuxername_demuxer;~~

	~~Add for a muxer:~~
	~~extern AVOutputFormat muxername_muxer;~~

	~~Add these in the correct section, in 'alphabetical' order.~~

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

Crybaby: /* see also */ fix Category link

2007-06-03T20:34:50Z

Crybaby: /* libavformat/Makefile */

2007-06-01T13:24:32Z

libavformat/Makefile

← Older revision		Revision as of 06:24, 1 June 2007
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	=== libavformat/Makefile ===		=== libavformat/Makefile ===

	Add OBJS-$(CONFIG_DEMUXERNAME_DEMUXER) += filename.o		Add
			OBJS-$(CONFIG_DEMUXERNAME_DEMUXER) += filename.o

	== demuxer code ==		== demuxer code ==

Crybaby: try to clean up and wikify a bit.

2007-06-01T13:21:15Z

try to clean up and wikify a bit.

← Older revision		Revision as of 06:21, 1 June 2007
Line 5:		Line 5:
	=== libavformat/allformats.h ===		=== libavformat/allformats.h ===

	Add ~~"<code>~~extern AVInputFormat demuxername_demuxer~~</code>" or "<code>~~extern AVOutputFormat ~~demuxername</code>"~~ in the correct section, in alphabetical order.		Add for a demuxer:
			extern AVInputFormat demuxername_demuxer;

			Add for a muxer:
			extern AVOutputFormat muxername_muxer;

			Add these in the correct section, in 'alphabetical' order.

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

	Add ~~"<code>~~REGISTER_DEMUXER(DEMUXERNAME, demuxername)~~</code>".~~ The macro will add the _demuxer or whatever is appropriate. '''Run configure in the top level directory and make clean, as config.h will be automatically modified'''.		Add for a demuxer:
			REGISTER_DEMUXER(DEMUXERNAME, demuxername)

			For a muxer:
			REGISTER_MUXER(MUXERNAME, muxername)

			The macro will add the _demuxer or whatever is appropriate. '''Run configure in the top level directory and make clean, as config.h will be automatically modified'''.

			make dist-clean
			./configure
			make


	=== libavformat/Makefile ===		=== libavformat/Makefile ===
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	* [[FFmpeg programming conventions]]		* [[FFmpeg programming conventions]]

	[[Category:~~FFMPeg~~ Tutorials]]		[[Category:FFMpeg Tutorials]]
	[[Category:Tutorials]]		[[Category:Tutorials]]

Crybaby: /* see also */

2007-06-01T13:13:44Z

Gatoatigrado at 18:53, 7 April 2007

2007-04-07T18:53:53Z

New page

: ''please make this page more complete if you can, thanks''

== registering the demuxer ==

=== libavformat/allformats.h ===

Add "<code>extern AVInputFormat demuxername_demuxer</code>" or "<code>extern AVOutputFormat demuxername</code>" in the correct section, in alphabetical order.

=== libavformat/allformats.c ===

Add "<code>REGISTER_DEMUXER(DEMUXERNAME, demuxername)</code>". The macro will add the _demuxer or whatever is appropriate. '''Run configure in the top level directory and make clean, as config.h will be automatically modified'''.

=== libavformat/Makefile ===

Add OBJS-$(CONFIG_DEMUXERNAME_DEMUXER) += filename.o

== demuxer code ==

This section is merely an overview; please look at an actual demuxer to see how to do it.

=== demuxername_probe ===

The probe will be called by the framework; this is where you can detect if the file is your format. There should be no dependence on filename, in fact you probably can't even access it. Most video containers start with some constant sequence of bytes. If there are 4 bytes and they are always the same, and unique, then return AVPROBE_SCORE_MAX. Otherwise, return 0. If the format is mis-designed and doesn't have this, divide AVPROBE_SCORE_MAX by something (e.g. 2) to designate limited confidence that the file corresponds to your demuxer.

=== demuxername_read_header ===

Here you should get any header information, e.g. the frame width if it is video, the sample rate if it is audio, etc. You should also setup your streams (looking at examples usually explains most things, except perhaps [[presentation timestamp|timestamp]] information); set codec_type, codec_id, and possibly width, height, pix_fmt for video, and channels, sample_rate, bits_per_sample, and bit_rate for audio. return 0.

=== demuxername_read_packet ===

Most formats are split into blocks of audio and video. The read_packet function should set up pkt. This involves initializing the packet with av_new_packet, or, preferably, av_get_packet (which also takes the file stream as an argument). After you initialize the packet, you should set (in any order) pos and data (if you used av_new_packet), stream_index (to set which decoder, usually audio or video, to send the packet to, which corresponds to the order you initialized them in), and pts, the presentation timestamp.

== see also ==

* [[FFmpeg codec howto]]
* [[FFmpeg programming conventions]]

← Older revision		Revision as of 13:34, 3 June 2007
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	* [[FFmpeg programming conventions]]		* [[FFmpeg programming conventions]]

	[[Category:~~FFMpeg~~ Tutorials]]		[[Category:FFmpeg Tutorials]]
	[[Category:Tutorials]]		[[Category:Tutorials]]

← Older revision		Revision as of 06:13, 1 June 2007
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	* [[FFmpeg codec howto]]		* [[FFmpeg codec howto]]
	* [[FFmpeg programming conventions]]		* [[FFmpeg programming conventions]]

			[[Category:FFMPeg Tutorials]]
			[[Category:Tutorials]]