文件列表:

dirac-0.5.0\aclocal.m4 (248917, 2004-12-02)
dirac-0.5.0\AUTHORS (662, 2004-11-26)
dirac-0.5.0\ChangeLog (82088, 2004-12-01)
dirac-0.5.0\config.guess (43632, 2004-12-02)
dirac-0.5.0\config.sub (31175, 2004-12-02)
dirac-0.5.0\configure (702341, 2004-12-02)
dirac-0.5.0\configure.ac (9571, 2004-11-26)
dirac-0.5.0\COPYING (70940, 2004-03-12)
dirac-0.5.0\decoder\decmain.cpp (10853, 2004-11-25)
dirac-0.5.0\decoder\Makefile.am (436, 2004-11-22)
dirac-0.5.0\decoder\Makefile.in (15809, 2004-12-02)
dirac-0.5.0\depcomp (15205, 2004-12-02)
dirac-0.5.0\dirac.pc.in (302, 2004-11-22)
dirac-0.5.0\doc\algorithm\Makefile.am (284, 2004-11-22)
dirac-0.5.0\doc\algorithm\Makefile.in (10957, 2004-12-02)
dirac-0.5.0\doc\api\dirac_api.doxygen (36868, 2004-08-19)
dirac-0.5.0\doc\api\dirac_api_foot.html (347, 2004-08-19)
dirac-0.5.0\doc\api\dirac_api_head.html (460, 2004-05-27)
dirac-0.5.0\doc\api\Makefile.am (468, 2004-11-22)
dirac-0.5.0\doc\api\Makefile.in (11169, 2004-12-02)
dirac-0.5.0\doc\dirac_bitstream.txt (3231, 2004-08-26)
dirac-0.5.0\doc\dirac_doc_howto.txt (1528, 2004-03-22)
dirac-0.5.0\doc\faq.htm (11918, 2004-08-19)
dirac-0.5.0\doc\Makefile.am (720, 2004-11-22)
dirac-0.5.0\doc\Makefile.in (16607, 2004-12-02)
dirac-0.5.0\doc\programmers\Makefile.am (483, 2004-11-22)
dirac-0.5.0\doc\programmers\Makefile.in (11231, 2004-12-02)
dirac-0.5.0\doc\programmers\programmers_guide.aux (1540, 2004-12-02)
dirac-0.5.0\doc\programmers\programmers_guide.tex (21050, 2004-05-27)
dirac-0.5.0\encoder\encmain.cpp (22412, 2004-11-25)
dirac-0.5.0\encoder\Makefile.am (482, 2004-11-22)
dirac-0.5.0\encoder\Makefile.in (15912, 2004-12-02)
dirac-0.5.0\INSTALL (7834, 2004-11-22)
dirac-0.5.0\install-sh (9212, 2004-12-02)
dirac-0.5.0\libdirac_common\arith_codec.h (21894, 2004-11-29)
dirac-0.5.0\libdirac_common\arrays.h (14731, 2004-11-29)
dirac-0.5.0\libdirac_common\band_codec.cpp (16627, 2004-11-22)
dirac-0.5.0\libdirac_common\band_codec.h (10323, 2004-11-29)
dirac-0.5.0\libdirac_common\bit_manager.cpp (10765, 2004-11-22)
dirac-0.5.0\libdirac_common\bit_manager.h (17344, 2004-11-29)
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README for the Dirac video codec ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ by Thomas Davies, BBC R&D (dirac@rd.bbc.co.uk) 1. Executive Summary ~~~~~~~~~~~~~~~~~~~~ Dirac is an open source video codec. It uses a traditional hybrid video codec architecture, but with the wavelet transform instead of the usual block transforms. Motion compensation uses overlapped blocks to reduce block artefacts that would upset the transform coding stage. Dirac can code just about any size of video, from streaming up to HD and beyond, although certain presets are defined for different applications and standards. These cover the parameters that need to be set for the encoder to work, such as block sizes and temporal prediction structures, which must otherwise be set by hand. Dirac is intended to develop into real coding and decoding software, capable of plugging into video processing applications and media players that need compression. It is intended to develop into a simple set of reliable but effective coding tools that work over a wide variety of content and formats, using well-understood compression techniques, in a clear and accessible software structure. It is not intended as a demonstration or reference coder. 2. Documentation ~~~~~~~~~~~~~~~~ A user guide and a guide to the software is in progress. More details on running the codec can be found at http://dirac.sourceforge.net/ 3. Building and installing ~~~~~~~~~~~~~~~~~~~~~~~~~~ GNU/Linux, Unix, MacOS X, Cygwin, Mingw --------------------------------------- ./configure --enable-debug (to enable extra debug compile options) OR ./configure --enable-profile (to enable the g++ profiling flag -pg) OR ./configure --enable-debug --enable-profile (to enable extra debug compile options and profiling options) OR ./configure By default, both shared and static libraries are built. To build all-static libraries use ./configure --disable-shared To build shared libraries only use ./configure --disable-static make make install The INSTALL file documents arguments to ./configure such as --prefix=/usr/local (specify the installation location prefix). MSYS and Microsoft Visual C++ ----------------------------- Download and install the no-cost Microsoft C++ compiler from http://msdn.microsoft.com/visualc/vctoolkit2003/ Download and install MSYS (the MinGW Minimal SYStem), MSYS-1.0.10.exe, from http://www.mingw.org/download.shtml. An MSYS icon will be available on the desktop. Click on the MSYS icon on the desktop to open a MSYS shell window. Create a .profile file to set up the environment variables required. vi .profile Include the following three lines in the .profile file. export PATH=/c/Program\ Files/Microsoft\ Visual\ C++\ Toolkit\ 2003/bin:$PATH export INCLUDE=/c/Program\ Files/Microsoft\ Visual\ C++\ Toolkit\ 2003/include export LIB=/c/Program\ Files/Microsoft\ Visual\ C++\ Toolkit\ 2003/lib (Replace /c/Program\ Files/Microsoft\ Visual\ C++\ Toolkit\ 2003/ with the location where VC++ 2003 is installed if necessary) Exit from the MSYS shell and click on the MSYS icon on the desktop to open a new MSYS shell window for the .profile to take effect. Change directory to the directory where Dirac was unpacked. By default only the dynamic libraries are built. ./configure CXX=cl --enable-debug (to enable extra debug compile options) OR ./configure CXX=cl --disable-shared (to build static libraries) OR ./configure CXX=cl make make install The INSTALL file documents arguments to ./configure such as --prefix=/usr/local (specify the installation location prefix). Microsoft Visual C++ .NET 2003 ------------------------------ The MS VC++ .NET 2003 solution and project files are in win32/VS2003 directory. Double-click on the solution file, dirac.sln, in the win32/VS2003 directory. The target 'Everything' builds the codec libraries and utilities. Four build-types are supported Debug - builds unoptimised encoder and decoder dlls with debug symbols Release - builds optimised encoder and decoder dlls Static-Debug - builds unoptimised encoder and decoder static libraries with debug symbols Static-Release - builds optimised encoder and decoder static libraries Static libraries are created in the win32/VS2003/lib/ directory. Encoder and Decoder dlls and import libraries, encoder and decoder apps are created in the win32/VS2003/bin/ directory. The "C" public API is exported using the _declspec(dllexport) mechanism. Conversion utilites are created in the win32/VS2003/utils/conversion/ directory. Only static versions are built. Instrumentation utility is created in the win32/VS2003/utils/instrumentation/ directory. Only static versions are built. 4. Running the example programs ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 4.1 Command-line parameters At the moment there is a simple command-line parser class which is used in all the executables. The general procedure for running a program is to type: prog_name - flag_val ... param1 param2 ... In other words, options are prefixed by a dash; some options take values, while others are boolean options that enable specific features. For example: When running the encoder, the -qf options requires a numeric argument specifying the "quality factor" for encoding. The -verbose option enables detailed output and does not require an argument. Running any program without arguments will display a list of parameters and options. 4.2 File formats The example coder and decoder use a temporary file format which consists of raw 8-bit planar YUV data together with a header file. This means that data is stored bytewise, with a frame of Y followed by a frame of U followed by a frame of V, all scanned in the usual raster order. Other file formats are supported by means of conversion utilities that may be found in the subdirectory util/conversion. These will convert to and from raw RGB format, and support all the standard raw YUV formats as well as bitmaps. Raw RGB can be obtained as an output from standard conversion utilities such as ImageMagick. Once a raw YUV file has been made, in order to run the codec, a header must be constructed. The header records such picture information as: the picture dimensions, which are taken to be those of the luminance or Y component, and other metadata. The other metadata consists of the chroma format, the frame rate in Hertz, a flag indicating interlace and, if interlace, a flag indicating whether the interlace is top-field first. The chroma format setting records whether the video is sampled 4:4:4, 4:2:2, 4:1:1 or 4:2:0, and is essential. The frame rate setting is used to calculate bit-rate for the encoder, and display rate for the decoder, and if omitted a rate of 12Hz is assumed. The header file is made using the make_header tool in subdirectory picheader/make_header. It's in text format so can also be edited manually. Example. Compress an image sequence of 100 frames of 352x288 video in tiff format. Step 1. Use your favourite conversion routine to produce a single raw RGB file of all the data. If your routine converts frame-by-frame then you will need to concatenate the output. Step 2. Convert from RGB to the YUV format of your choice. For example, to do 420, type RGBtoYUV420 file.yuv 352 288 100 Note that this uses stdin and stdout to read and write the data. Step 3. Make the appropriate header to accompany the raw data file: make_header -xl 720 -yl 576 -cformat format420 -framerate 25 -interlace file This writes file.hdr with the corresponding parameters. Step 4. Run the encoder. This will produce a locally decoded output in the same format. Step 5. Convert back to RGB. YUV420toRGB file.rgb 352 288 100 Step 6. Use your favourite conversion utility to convert to the format of your choice. You can also use the transcode utility to convert data to and from Dirac's native formats (see http://zebra.fh-weingarten.de/~transcode/): This example uses a 720x576x50 DV source, and transcodes to 720x576 YUV in 4:2:0 chroma format. Cascading codecs (DV + Dirac) is generally a bad idea - use this only if you don't have any other source of uncompressed video. transcode -i source.dv -x auto,null --dv_yuy2_mode -k -V -y raw,null -o file.avi tcextract -i test.avi -x rgb > file.yuv make_header -xl 720 -yl 576 -cformat format420 -framerate 25 -interlace file Viewing and playback utilities for uncompressed video include MPlayer and ImageMagick's display command. Continuing the 352x288 4:2:0 example above, to display a single frame of raw YUV with ImageMagick use the following (use to see subsequent frames): display -size 352x288 test.yuv Raw YUV 420 data can also be played back in MPlayer - use the following MPlayer command: mplayer -fps 15 -rawvideo on:size=1520***:w=352:h=288 test.yuv (at the time of writing MPlayer could not playback 4:2:2 or 4:4:4 YUV data) 4.3 Encoding There are a large number of parameters that can be used to run the encoder, all of which are listed below, and which are set using the same conventions as for make_header. However, things are simplified by using presets for different applications. These set such things as block sizes and overlaps for motion estimation and compensation (the codec used overlapped blocks), and psychovisual weighting. They also define the context in which other parameters like quality factors, operate. The presets are: CIF : for CIF video SD576 : for standard definition video HD720 : for 1280x720 High Definition progressive video HD1080 : for 1920/1440x1080 High Definition progressive video [not yet supported] The other useful parameter is the quality factor qf. This is a number from 0 to 10. The higher the number, the better the quality. The encoder attempts to adapt the encoding process to produce constant quality across the sequence. (Due to variations in the content, it may not exactly achieve this.) Simple coding example. Code an SD sequence to high quality. Solution. dirac_encoder -SD576 -qf 9 test test_out will read test.yuv and test.hdr as input, and output a compressed bitstream test_out.drc as well as locally-decoded files test_out.yuv and test_out.hdr. Other parameters. verbose : turn on verbosity (if you don't, you won't see the final bitrate!) start : code from this frame number stop : code up until this frame number L1_sep : the separation between L1 frames (frames that are predicted but also used as reference frames, like P frames in MPEG-2) num_L1 : the number of L1 frames before the next intra frame xblen : the width of blocks used for motion compensation yblen : the height of blocks used for motion compensation xbsep : the horizontal separation between blocks. Always

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