[7d1142d8] | 1 | <sect2>
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| 2 | <title>Contents</title>
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| 3 |
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| 4 | <para>The <application>XviD</application> core package contains the <filename
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| 5 | class="libraryfile">libxvidcore</filename> library and the
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| 6 | appendant header files. The library itself provides functions to encode
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| 7 | and decode most MPEG-4 video data.</para>
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| 8 |
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| 9 | <para>Following features of MPEG-4 are supported:</para>
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| 10 | <para><emphasis>I, P Frame encoding</emphasis></para>
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| 11 | <para>I-Frames are image frames, while P-Frames are Pattern Frames.
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| 12 | Image Frames contain full images. P-Frames contain patterns of what changes in
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| 13 | the image, thusly saving a lot of space.</para>
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| 14 | <para><emphasis>PMVFast and EPZS with diamond a sqare pattern motion
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| 15 | estimation</emphasis></para>
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| 16 | <para>Fast Motion detection that can refer a square or diamond
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| 17 | shaped pattern to different directions.</para>
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| 18 | <para><emphasis>inter4v mode</emphasis></para>
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| 19 | <para>Fast interpolation ability.</para>
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| 20 | <para><emphasis>fullpixel and halfpixel precision</emphasis></para>
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| 21 | <para>Even halfpixel movements can be encoded. Better precision
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| 22 | results in better compression at better quality.</para>
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| 23 | <para><emphasis>both MPEG-4 and H263 quantizations</emphasis></para>
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| 24 | <para>MPEG-4 is the standard DivX was derived from. H263 is a
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| 25 | slightly changed subset of that standard made by Microsoft. Quantization
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| 26 | means to map the quantity of color values to numbers.</para>
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| 27 | <para><emphasis>custom quant matrices</emphasis></para>
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| 28 | <para>The quantization can be done using custom matrices,
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| 29 | possibly giving better results if the matrix is made to suit the video
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| 30 | data. Every normal user should be fine with the default matrix that comes
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| 31 | with <application>XviD</application>.</para>
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| 32 | <para><emphasis>Adaptive quantization / Luminance masking</emphasis></para>
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| 33 | <para>Qantization and Luminance masking are variant, depending
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| 34 | on the input material, therefore providing better results on dark or very
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| 35 | contrasting images.</para>
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| 36 |
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| 37 | </sect2>
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| 38 |
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