diff -ruN ffmpeg.orig/doc/patents.txt ffmpeg/doc/patents.txt

--- ffmpeg.orig/doc/patents.txt	1970-01-01 03:00:00 +0300

+++ ffmpeg/doc/patents.txt	2005-04-08 00:47:38 +0400

@@ -0,0 +1,88 @@

+

+The MP3 audio coding format

+===========================

+

+   Much has already been said about MP3 and the huge patent portfolio of

+the MPEG members, especially the Fraunhofer institute. Eric Scheirer's

+MPEG, Patents, and Audio Coding FAQ [1.1] is an attempt to "inject

+some sanity in what is becoming an increasingly heated discussion

+about patent rights surrounding MPEG technology, especially for audio

+compression". It also has a few words about other patented products

+covered in this document.

+

+[1.1] http://web.media.mit.edu/~eds/mpeg-patents-faq

+

+

+The AAC audio coding format

+===========================

+

+   Dolby's AAC (Advanced Audio Coding) is covered by patents owned by

+Dolby Laboratories, AT&T Laboratories, Fraunhofer Institute and Sony

+Corp.

+

+   The FAAC project was threatened by the AAC license consortium. Press

+report about how "an opensource project was closed down due to pressures

+from the AAC license consortium which requires a lumpsum payment of

+10,000 USD plus a per-copy payment of 1.35 USD, thus effectively banning

+free software implementations. The policies surrounding AAC also harm

+interoperability [2.2]." This was related by Heise [2.3] and FFII has

+a page about the Dolby threat [2.1] as well as additional information

+about MPEG-related patents [2.4].

+

+   The author stopped distributing the FAAC binaries, but still provides

+full source code and CVS access. To my knowledge he has not been

+threatened again. I also read on a web forum [2.5] that Cisco's lawyers

+claim that their LGPL distribution of AAC software in MPEG4IP is

+completely legal and that Dolby cannot forbid such distribution.

+

+[2.1] http://swpat.ffii.org/patents/effects/dolby/index.en.html

+[2.2] http://www.xiph.org/archives/vorbis-dev/200011/0286.html

+[2.3] http://www.heise.de/newsticker/data/vza-20.11.00-000/

+[2.4] http://swpat.ffii.org/patents/effects/mpeg/index.en.html

+[2.5] http://www.hydrogenaudio.org/index.php?showtopic=310&

+

+

+The ASF file encapsulation format

+=================================

+

+   Microsoft obtained a patent on the ASF (Active Stream Format) audio

+file format on March 21, 2000:

+

+  | United States Patent 6,041,345 Levi , et al. March 21, 2000

+  |

+  | Active stream format for holding multiple media streams

+  |

+  |  Abstract An active stream format is defined and adopted for a

+  | logical structure that encapsulates multiple data streams. The data

+  | streams may be of different media. The data of the data streams

+  | is partitioned into packets that are suitable for transmission

+  | over a transport medium. The packets may include error correcting

+  | information. The packets may also include clock licenses for

+  | dictating the advancement of a clock when the data streams are

+  | rendered. The format of ASF facilitates flexibility and choice

+  | of packet size and in specifying maximum bit rate at which data

+  | may be rendered. Error concealment strategies may be employed in

+  | the packetization of data to distribute portions of samples to

+  | multiple packets. Property information may be replicated and stored

+  | in separate packets to enhance its error tolerance. The format

+  | facilitates dynamic definition of media types and the packetization

+  | of data in such dynamically defined data types within the format.

+

+   This patent is rumoured to have been enforced at least once, though

+only through what I'd call non-hostile intimidation. Avery Lee, the

+VirtualDub author, removed ASF support from his software after a phone

+call from a Microsoft employee that he relates in his 5/12/2000 news

+[3.1].

+

+   However I could not find evidence of an official threat: all I could

+find on the web seemed to be interpretations of the VirtualDub author's

+article, for instance on Advogato [3.2], CPT [3.3] or FFII [3.4]. Avery

+Lee states that the phone call was from a programmer, not from the

+legal department. There does not seem to be an official statement from

+Microsoft.

+

+[3.1] http://web.archive.org/web/20000817222620/http://www.geocities.com/virtualdub/virtualdub_news.html

+[3.2] http://www.advogato.com/article/101.html

+[3.3] http://www.cptech.org/ip/business/software/audio.html

+[3.4] http://swpat.ffii.org/patents/effects/asf/index.en.html

+

diff -ruN ffmpeg.orig/doc/README.ALT ffmpeg/doc/README.ALT

--- ffmpeg.orig/doc/README.ALT	1970-01-01 03:00:00 +0300

+++ ffmpeg/doc/README.ALT	2005-04-08 00:55:46 +0400

@@ -0,0 +1,42 @@

+Notes for the ALT Linux ffmpeg packages

+=======================================

+(Copied from Debian package notes)

+

+ The license for the whole work is the GPL, not the LGPL, because GPL-only

+parts of ffmpeg were activated. If you need LGPL versions of the libraries,

+please contact me.

+

+

+Linking code against ffmpeg

+===========================

+

+ To compile code against the ffmpeg libraries, use `ffmpeg-config --cflags`:

+

+   gcc `ffmpeg-config --cflags` -c code.c -o code.o

+

+ To link it afterwards, use `ffmpeg-config --libs avcodec`:

+

+   gcc code.o -o code `ffmpeg-config --libs avcodec` -lotherlibs

+

+ Accepted arguments for --libs are "avcodec", "avformat" and "postproc". If

+you are linking a plugin for an application with one of these libraries, use

+the --plugin-libs flag instead of --libs.

+

+

+Summary of the patent issues with ffmpeg

+========================================

+

+   The only patents related to ffmpeg which seem to be enforced against open

+source software cover the following codec technologies and file formats:

+

+   * MP3 encoding

+   * AAC decoding and encoding

+   * the ASF file format

+

+   I did not activate MP3 encoding (through LAME) in libavcodec, nor AAC

+support (through FAAC/FAAD). However, since I have found no real enforcement

+of the mysterious ASF file format patents, I did not deactivate ASF support in

+libavformat. See more details in the patents.txt file.

+

+

+ -- Sam Hocevar <sam@zoy.org>  Fri, 16 Jul 2004 12:47:27 +0200