From 0ebf5bdf043a27fd3dfb7f92e0cb63d88954c44d Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Fri, 19 Apr 2024 03:47:29 +0200 Subject: Adding upstream version 115.8.0esr. Signed-off-by: Daniel Baumann --- media/libtheora/README.md | 148 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 148 insertions(+) create mode 100644 media/libtheora/README.md (limited to 'media/libtheora/README.md') diff --git a/media/libtheora/README.md b/media/libtheora/README.md new file mode 100644 index 0000000000..b136f7114c --- /dev/null +++ b/media/libtheora/README.md @@ -0,0 +1,148 @@ +# Xiph.org Foundation's libtheora + +### What is Theora? + +Theora was Xiph.Org's first publicly released video codec, intended +for use within the Foundation's Ogg multimedia streaming system. +Theora is derived directly from On2's VP3 codec, adds new features +while allowing it a longer useful lifetime. + +The 1.0 release decoder supported all the new features, but the +encoder is nearly identical to the VP3 code. + +The 1.1 release featured a completely rewritten encoder, offering +better performance and compression, and making more complete use +of the format's feature set. + +The 1.2 release features significant additional improvements in +compression and performance. Files produced by newer encoders can +be decoded by earlier releases. + +### Where is Theora? + +Theora's main site is https://www.theora.org. Releases of Theora +and related libraries can be found on the +[download page](https://www.theora.org/downloads/) or the +[main Xiph.Org site](https://xiph.org/downloads/). + +Development source is kept at https://gitlab.xiph.org/xiph/theora. + +## Getting started with the code + +### What do I need to build the source? + +Requirements summary: + +For libtheora: + +* libogg 1.1 or newer. + +For example encoder: + +* as above, +* libvorbis and libvorbisenc 1.0.1 or newer. + (libvorbis 1.3.1 or newer for 5.1 audio) + +For creating a source distribution package: + +* as above, +* Doxygen to build the API documentation, +* pdflatex and fig2dev to build the format specification + (transfig package in Ubuntu). + +For the player only: + +* as above, +* SDL (Simple Direct media Layer) libraries and headers, +* OSS audio driver and development headers. + +The provided build system is the GNU automake/autoconf system, and +the main library, libtheora, should already build smoothly on any +system. Failure of libtheora to build on a GNU-enabled system is +considered a bug; please report problems to theora-dev@xiph.org. + +Windows build support is included in the win32 directory. + +Project files for Apple XCode are included in the macosx directory. + +There is also a more limited scons build. + +### How do I use the sample encoder? + +The sample encoder takes raw video in YUV4MPEG2 format, as used by +lavtools, mjpeg-tools and other packages. The encoder expects audio, +if any, in a separate wave WAV file. Try 'encoder_example -h' for a +complete list of options. + +An easy way to get raw video and audio files is to use MPlayer as an +export utility. The options " -ao pcm -vo yuv4mpeg " will export a +wav file named audiodump.wav and a YUV video file in the correct +format for encoder_example as stream.yuv. Be careful when exporting +video alone; MPlayer may drop frames to 'keep up' with the audio +timer. The example encoder can't properly synchronize input audio and +video file that aren't in sync to begin with. + +The encoder will also take video or audio on stdin if '-' is specified +as the input file name. + +There is also a 'png2theora' example which accepts a set of image +files in that format. + +### How do I use the sample player? + +The sample player takes an Ogg file on standard in; the file may be +audio alone, video alone or video with audio. + +### What other tools are available? + +The programs in the examples directory are intended as tutorial source +for developers using the library. As such they sacrifice features and +robustness in the interests of comprehension and should not be +considered serious applications. + +If you're wanting to just use theora, consider the programs linked +from https://www.theora.org/. There is playback support in a number +of common free players, and plugins for major media frameworks. +Jan Gerber's ffmpeg2theora is an excellent encoding front end. + +## Troubleshooting the build process + +### Compile error, such as: + +encoder_internal.h:664: parse error before `ogg_uint16_t` + +This means you have version of libogg prior to 1.1. A *complete* new Ogg +install, libs and headers is needed. + +Also be sure that there aren't multiple copies of Ogg installed in +/usr and /usr/local; an older one might be first on the search path +for libs and headers. + +### Link error, such as: + +undefined reference to `oggpackB_stream` + +See above; you need libogg 1.1 or later. + +### Link error, such as: + +undefined reference to `vorbis_granule_time` + +You need libvorbis and libvorbisenc from the 1.0.1 release or later. + +### Link error, such as: + +/usr/lib/libSDL.a(SDL_esdaudio.lo): In function `ESD_OpenAudio`: +SDL_esdaudio.lo(.text+0x25d): undefined reference to `esd_play_stream` + +Be sure to use an SDL that's built to work with OSS. If you use an +SDL that is also built with ESD and/or ALSA support, it will try to +suck in all those extra libraries at link time too. That will only +work if the extra libraries are also installed. + +### Link warning, such as: + +libtool: link: warning: library `/usr/lib/libogg.la` was moved. +libtool: link: warning: library `/usr/lib/libogg.la` was moved. + +Re-run theora/autogen.sh after an Ogg or Vorbis rebuild/reinstall -- cgit v1.2.3