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| 1 ------------------------------------------------------------------------- | |
| 2 The Xiph.org Foundation's libtheora 1.2 | |
| 3 ------------------------------------------------------------------------- | |
| 4 | |
| 5 *** What is Theora? | |
| 6 | |
| 7 Theora is Xiph.Org's first publicly released video codec, intended | |
| 8 for use within the Foundation's Ogg multimedia streaming system. | |
| 9 Theora is derived directly from On2's VP3 codec, adds new features | |
| 10 while allow it a longer useful lifetime as an competitive codec. | |
| 11 | |
| 12 The 1.0 release decoder supported all the new features, but the | |
| 13 encoder is nearly identical to the VP3 code. | |
| 14 | |
| 15 The 1.1 release featured a completely rewritten encoder, offering | |
| 16 better performance and compression, and making more complete use | |
| 17 of the format's feature set. | |
| 18 | |
| 19 The 1.2 release features significant additional improvements in | |
| 20 compression and performance. Files produced by newer encoders can | |
| 21 be decoded by earlier releases. | |
| 22 | |
| 23 *** Where is Theora? | |
| 24 | |
| 25 Theora's main site is www.theora.org. Theora and related libraries | |
| 26 can be gotten from www.theora.org or the main Xiph.Org site at | |
| 27 www.xiph.org. Development source is kept in an open subversion | |
| 28 repository, see http://theora.org/svn/ for instructions. | |
| 29 | |
| 30 ------------------------------------------------------------------------- | |
| 31 Getting started with the code | |
| 32 ------------------------------------------------------------------------- | |
| 33 | |
| 34 *** What do I need to build the source? | |
| 35 | |
| 36 Requirements summary: | |
| 37 | |
| 38 For libtheora: | |
| 39 | |
| 40 libogg 1.1 or newer. | |
| 41 | |
| 42 For example encoder: | |
| 43 | |
| 44 as above, | |
| 45 | |
| 46 libvorbis and libvorbisenc 1.0.1 or newer. | |
| 47 (libvorbis 1.3.1 or newer for 5.1 audio) | |
| 48 | |
| 49 For creating a source distribution package: | |
| 50 | |
| 51 as above, | |
| 52 | |
| 53 Doxygen to build the API documentation, | |
| 54 pdflatex and fig2dev to build the format specification | |
| 55 (transfig package in Ubuntu). | |
| 56 | |
| 57 For the player only: | |
| 58 | |
| 59 as above, | |
| 60 | |
| 61 SDL (Simple Direct media Layer) libraries and headers, | |
| 62 OSS audio driver and development headers. | |
| 63 | |
| 64 The provided build system is the GNU automake/autoconf system, and | |
| 65 the main library, libtheora, should already build smoothly on any | |
| 66 system. Failure of libtheora to build on a GNU-enabled system is | |
| 67 considered a bug; please report problems to theora-dev@xiph.org. | |
| 68 | |
| 69 Windows build support is included in the win32 directory. | |
| 70 | |
| 71 Project files for Apple XCode are included in the macosx directory. | |
| 72 | |
| 73 There is also a more limited scons build. | |
| 74 | |
| 75 *** How do I use the sample encoder? | |
| 76 | |
| 77 The sample encoder takes raw video in YUV4MPEG2 format, as used by | |
| 78 lavtools, mjpeg-tools and other packages. The encoder expects audio, | |
| 79 if any, in a separate wave WAV file. Try 'encoder_example -h' for a | |
| 80 complete list of options. | |
| 81 | |
| 82 An easy way to get raw video and audio files is to use MPlayer as an | |
| 83 export utility. The options " -ao pcm -vo yuv4mpeg " will export a | |
| 84 wav file named audiodump.wav and a YUV video file in the correct | |
| 85 format for encoder_example as stream.yuv. Be careful when exporting | |
| 86 video alone; MPlayer may drop frames to 'keep up' with the audio | |
| 87 timer. The example encoder can't properly synchronize input audio and | |
| 88 video file that aren't in sync to begin with. | |
| 89 | |
| 90 The encoder will also take video or audio on stdin if '-' is specified | |
| 91 as the input file name. | |
| 92 | |
| 93 There is also a 'png2theora' example which accepts a set of image | |
| 94 files in that format. | |
| 95 | |
| 96 *** How do I use the sample player? | |
| 97 | |
| 98 The sample player takes an Ogg file on standard in; the file may be | |
| 99 audio alone, video alone or video with audio. | |
| 100 | |
| 101 *** What other tools are available? | |
| 102 | |
| 103 The programs in the examples directory are intended as tutorial source | |
| 104 for developers using the library. As such they sacrifice features and | |
| 105 robustness in the interests of comprehension and should not be | |
| 106 considered serious applications. | |
| 107 | |
| 108 If you're wanting to just use theora, consider the programs linked | |
| 109 from http://www.theora.org/. There is playback support in a number | |
| 110 of common free players, and plugins for major media frameworks. | |
| 111 Jan Gerber's ffmpeg2theora is an excellent encoding front end. | |
| 112 | |
| 113 ------------------------------------------------------------------------- | |
| 114 Troubleshooting the build process | |
| 115 ------------------------------------------------------------------------- | |
| 116 | |
| 117 *** Compile error, such as: | |
| 118 | |
| 119 encoder_internal.h:664: parse error before `ogg_uint16_t' | |
| 120 | |
| 121 This means you have version of libogg prior to 1.1. A *complete* new Ogg | |
| 122 install, libs and headers is needed. | |
| 123 | |
| 124 Also be sure that there aren't multiple copies of Ogg installed in | |
| 125 /usr and /usr/local; an older one might be first on the search path | |
| 126 for libs and headers. | |
| 127 | |
| 128 *** Link error, such as: | |
| 129 | |
| 130 undefined reference to `oggpackB_stream' | |
| 131 | |
| 132 See above; you need libogg 1.1 or later. | |
| 133 | |
| 134 *** Link error, such as: | |
| 135 | |
| 136 undefined reference to `vorbis_granule_time' | |
| 137 | |
| 138 You need libvorbis and libvorbisenc from the 1.0.1 release or later. | |
| 139 | |
| 140 *** Link error, such as: | |
| 141 | |
| 142 /usr/lib/libSDL.a(SDL_esdaudio.lo): In function `ESD_OpenAudio': | |
| 143 SDL_esdaudio.lo(.text+0x25d): undefined reference to `esd_play_stream' | |
| 144 | |
| 145 Be sure to use an SDL that's built to work with OSS. If you use an | |
| 146 SDL that is also built with ESD and/or ALSA support, it will try to | |
| 147 suck in all those extra libraries at link time too. That will only | |
| 148 work if the extra libraries are also installed. | |
| 149 | |
| 150 *** Link warning, such as: | |
| 151 | |
| 152 libtool: link: warning: library `/usr/lib/libogg.la' was moved. | |
| 153 libtool: link: warning: library `/usr/lib/libogg.la' was moved. | |
| 154 | |
| 155 Re-run theora/autogen.sh after an Ogg or Vorbis rebuild/reinstall | |
| 156 |
