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<div class="twikiMiddleContainer"><div class="twikiMain"><div class="twikiSearchResults"><div class="twikiSearchResultsHeader">&nbsp;<tt><b>&lt;&lt;O&gt;&gt;</b></tt>&nbsp; Difference Topic
		<b><a href="../../view/Cinelerra/ColorModel">ColorModel</a></b>
		(<a href="http://www.ftconsult.com/twiki/bin/view/Cinelerra/ColorModel?rev=r1.3">r1.3</a> - 29&nbsp;Dec&nbsp;2004 - <a class="twikiLink" href="../../view/Main/NathanKidd">NathanKidd</a>)</div>
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<table border="1" cellspacing="1" cellpadding="0">
<tr><th class="twikiFirstCol" bgcolor="#99CCCC"> <strong>META TOPICPARENT</strong> </th><td colspan="2" bgcolor="#FFFFCC"> <a class="twikiLink" href="../../view/Cinelerra/SetFormat">SetFormat</a> </td></tr>
</table>
<h3><a name="Video_Color_Models"> </a><a name="Video_Color_Models_"> </a> Video <a class="twikiLink" href="../../view/Cinelerra/ColorModel">Color Models</a> </h3>
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<ul>
<li> <code><b>RGBA8888</b></code> uses <font color="#ff0000"> Red </font>, <font color="#008000">Green </font>, <font color="#000080">Blue </font>, and Alpha with 8 bits per channel.
</li>
</ul>
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<tr><td bgcolor="#D0FFD0" class="twikiDiffChangedHeader" colspan ="9"><b> Changed: </b></td></tr>
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<h4><a name="Selecting_the_best_color_model_f"> </a> Selecting the best color model for your projevt </h4>
</td></tr>
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<h4><a name="Selecting_the_best_color_model_f"> </a> Selecting the best color model for your project </h4>
</td></tr>
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<td class="twikiDiffUnchangedText">
<img src="../../../pub/TWiki/TWikiDocGraphics/warning.gif" border="0" alt="ALERT!" width="16" height="16" /> When working on <strong>Cinelerra</strong> the <a class="twikiLink" href="../../view/Cinelerra/SetFormat">selection</a> of an internal <a class="twikiLink" href="../../view/Cinelerra/ColorModel">ColorModel</a> determines how accurate and fast the effects are. It is very important to <a class="twikiLink" href="../../view/Cinelerra/SetFormat">select</a> the <a class="twikiLink" href="../../view/Cinelerra/ColorMode">ColorMode</a> best suited for your purposes, below is some information regarding Cinelerras handling of various video <a class="twikiLink" href="../../view/Cinelerra/ColorModel">ColorModels</a> 
<p />
<ul>
<li> <span class="twikiNewLink" style="background : #FFFFCE;"><font color="#0000FF">YUV</font><a href="http://www.ftconsult.com/twiki/bin/edit/Cinelerra/YUV?topicparent=Cinelerra.ColorModel"><sup>?</sup></a></span> <a class="twikiLink" href="../../view/Cinelerra/ColorModel">ColorModels</a> are usually faster than <span class="twikiNewLink" style="background : #FFFFCE;"><font color="#0000FF">RGB</font><a href="http://www.ftconsult.com/twiki/bin/edit/Cinelerra/RGB?topicparent=Cinelerra.ColorModel"><sup>?</sup></a></span> <a class="twikiLink" href="../../view/Cinelerra/ColorModel">ColorModels</a> when using compressed footage. They also destroy fewer colors than <span class="twikiNewLink" style="background : #FFFFCE;"><font color="#0000FF">RGB</font><a href="http://www.ftconsult.com/twiki/bin/edit/Cinelerra/RGB?topicparent=Cinelerra.ColorModel"><sup>?</sup></a></span> <a class="twikiLink" href="../../view/Cinelerra/ColorModel">ColorModels</a>.
</li>
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<ul>
<li> Some effects, like <span class="twikiNewLink" style="background : #FFFFCE;"><font color="#0000FF">VideoFade</font><a href="http://www.ftconsult.com/twiki/bin/edit/Cinelerra/VideoFade?topicparent=Cinelerra.ColorModel"><sup>?</sup></a></span>, work around the need for <span class="twikiNewLink" style="background : #FFFFCE;"><font color="#0000FF">AlphaChannels</font><a href="http://www.ftconsult.com/twiki/bin/edit/Cinelerra/AlphaChannels?topicparent=Cinelerra.ColorModel"><sup>?</sup></a></span> while other effects, like <a class="twikiLink" href="../../view/Cinelerra/VideoChromaKey">VideoChromaKey</a>, require an <span class="twikiNewLink" style="background : #FFFFCE;"><font color="#0000FF">AlphaChannel</font><a href="http://www.ftconsult.com/twiki/bin/edit/Cinelerra/AlphaChannel?topicparent=Cinelerra.ColorModel"><sup>?</sup></a></span> to do anything, so it's a good idea to try the effect without <span class="twikiNewLink" style="background : #FFFFCE;"><font color="#0000FF">AlphaChannels</font><a href="http://www.ftconsult.com/twiki/bin/edit/Cinelerra/AlphaChannels?topicparent=Cinelerra.ColorModel"><sup>?</sup></a></span>.
</li>
</ul>
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<li> If footage stored as JPEG or MPEG is processed many times in <span class="twikiNewLink" style="background : #FFFFCE;"><font color="#0000FF">RGB</font><a href="http://www.ftconsult.com/twiki/bin/edit/Cinelerra/RGB?topicparent=Cinelerra.ColorModel"><sup>?</sup></a></span>, the colors will fade while they won't if processed in <span class="twikiNewLink" style="background : #FFFFCE;"><font color="#0000FF">YUV</font><a href="http://www.ftconsult.com/twiki/bin/edit/Cinelerra/YUV?topicparent=Cinelerra.ColorModel"><sup>?</sup></a></span>.
</li>
</ul>
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<tr><td bgcolor="#ccccff" class="twikiDiffAddedMarker" valign="top" width="1%">&gt;<br />&gt;</td>
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<ul>
<li> If footage stored as JPEG or MPEG is processed many times in <span class="twikiNewLink" style="background : #FFFFCE;"><font color="#0000FF">RGB</font><a href="http://www.ftconsult.com/twiki/bin/edit/Cinelerra/RGB?topicparent=Cinelerra.ColorModel"><sup>?</sup></a></span>, the colors will fade, while they won't if processed in <span class="twikiNewLink" style="background : #FFFFCE;"><font color="#0000FF">YUV</font><a href="http://www.ftconsult.com/twiki/bin/edit/Cinelerra/YUV?topicparent=Cinelerra.ColorModel"><sup>?</sup></a></span>.
</li>
</ul>
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<td class="twikiDiffUnchangedText">
<p />
<h3><a name="Other_resources"> </a> Other resources </h3>
</td></tr>

</table></div><div class="twikiSearchResults"><div class="twikiSearchResultsHeader">&nbsp;<tt><b>&lt;&lt;O&gt;&gt;</b></tt>&nbsp; Difference Topic
		<b><a href="../../view/Cinelerra/ColorModel">ColorModel</a></b>
		(<a href="http://www.ftconsult.com/twiki/bin/view/Cinelerra/ColorModel?rev=r1.2">r1.2</a> - 12&nbsp;Jan&nbsp;2004 - <a class="twikiLink" href="../../view/Main/AlexFerrer">AlexFerrer</a>)</div>
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<tr><th class="twikiFirstCol" bgcolor="#99CCCC"> <strong>META TOPICPARENT</strong> </th><td colspan="2" bgcolor="#FFFFCC"> <a class="twikiLink" href="../../view/Cinelerra/SetFormat">SetFormat</a> </td></tr>
</table>
<h3><a name="Video_Color_Models"> </a><a name="Video_Color_Models_"> </a> Video <a class="twikiLink" href="../../view/Cinelerra/ColorModel">Color Models</a> </h3>
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<h4><a name="Selecting_the_best_color_model_f"> </a> Selecting the best color model for your projevt </h4>
<img src="../../../pub/TWiki/TWikiDocGraphics/warning.gif" border="0" alt="ALERT!" width="16" height="16" /> When working on <strong>Cinelerra</strong> the <a class="twikiLink" href="../../view/Cinelerra/SetFormat">selection</a> of an internal <a class="twikiLink" href="../../view/Cinelerra/ColorModel">ColorModel</a> determines how accurate and fast the effects are. It is very important to <a class="twikiLink" href="../../view/Cinelerra/SetFormat">select</a> the <a class="twikiLink" href="../../view/Cinelerra/ColorMode">ColorMode</a> best suited for your purposes, below is some information regarding Cinelerras handling of various video <a class="twikiLink" href="../../view/Cinelerra/ColorModel">ColorModels</a> 
</td></tr>
<tr><td bgcolor="#D0FFD0" class="twikiDiffChangedHeader" colspan ="9"><b> Changed: </b></td></tr>
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<ul>
<li> <span class="twikiNewLink" style="background : #FFFFCE;"><font color="#0000FF">YUV</font><a href="http://www.ftconsult.com/twiki/bin/edit/Cinelerra/YUV?topicparent=Cinelerra.ColorModel"><sup>?</sup></a></span> colormodels are usually faster than <span class="twikiNewLink" style="background : #FFFFCE;"><font color="#0000FF">RGB</font><a href="http://www.ftconsult.com/twiki/bin/edit/Cinelerra/RGB?topicparent=Cinelerra.ColorModel"><sup>?</sup></a></span> <a class="twikiLink" href="../../view/Cinelerra/ColorModel">ColorModels</a> when using compressed footage. They also destroy fewer colors than <span class="twikiNewLink" style="background : #FFFFCE;"><font color="#0000FF">RGB</font><a href="http://www.ftconsult.com/twiki/bin/edit/Cinelerra/RGB?topicparent=Cinelerra.ColorModel"><sup>?</sup></a></span> colormodels.
</li>
</ul>
</td></tr>
<tr><td bgcolor="#ccccff" class="twikiDiffAddedMarker" valign="top" width="1%">&gt;<br />&gt;</td>
<td class="twikiDiffAddedText">
<ul>
<li> <span class="twikiNewLink" style="background : #FFFFCE;"><font color="#0000FF">YUV</font><a href="http://www.ftconsult.com/twiki/bin/edit/Cinelerra/YUV?topicparent=Cinelerra.ColorModel"><sup>?</sup></a></span> <a class="twikiLink" href="../../view/Cinelerra/ColorModel">ColorModels</a> are usually faster than <span class="twikiNewLink" style="background : #FFFFCE;"><font color="#0000FF">RGB</font><a href="http://www.ftconsult.com/twiki/bin/edit/Cinelerra/RGB?topicparent=Cinelerra.ColorModel"><sup>?</sup></a></span> <a class="twikiLink" href="../../view/Cinelerra/ColorModel">ColorModels</a> when using compressed footage. They also destroy fewer colors than <span class="twikiNewLink" style="background : #FFFFCE;"><font color="#0000FF">RGB</font><a href="http://www.ftconsult.com/twiki/bin/edit/Cinelerra/RGB?topicparent=Cinelerra.ColorModel"><sup>?</sup></a></span> <a class="twikiLink" href="../../view/Cinelerra/ColorModel">ColorModels</a>.
</li>
</ul>
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<tr><td valign="top" bgcolor="#ffffff" class="twikiDiffUnchangedText" width="1%"><br /></td>
<td class="twikiDiffUnchangedText">

</td></tr>
<tr><td bgcolor="#D0FFD0" class="twikiDiffChangedHeader" colspan ="9"><b> Changed: </b></td></tr>
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<ul>
<li> Four channel <span class="twikiNewLink" style="background : #FFFFCE;"><font color="#0000FF">colormodel</font><a href="http://www.ftconsult.com/twiki/bin/edit/Cinelerra/Colormodel?topicparent=Cinelerra.ColorModel"><sup>?</sup></a></span>s are notoriously slower than three channel <a class="twikiLink" href="../../view/Cinelerra/ColorModel">ColorModels</a>, with the slowest being RGBA16161616.   
</li>
</ul>
</td></tr>
<tr><td bgcolor="#ccccff" class="twikiDiffAddedMarker" valign="top" width="1%">&gt;<br />&gt;</td>
<td class="twikiDiffAddedText">
<ul>
<li> Four channel <a class="twikiLink" href="../../view/Cinelerra/ColorModel">ColorModels</a> are notoriously slower than three channel <a class="twikiLink" href="../../view/Cinelerra/ColorModel">ColorModels</a>, with the slowest being RGBA16161616.   
</li>
</ul>
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<tr><td valign="top" bgcolor="#ffffff" class="twikiDiffUnchangedText" width="1%"><br /></td>
<td class="twikiDiffUnchangedText">
<p />
When effects are processed, media files are decompressed into an internal <a class="twikiLink" href="../../view/Cinelerra/ColorModel">ColorModel</a> first and then converted to the <a class="twikiLink" href="../../view/Cinelerra/ColorModel">ColorModel</a> format of the output device.
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<tr><td bgcolor="#D0FFD0" class="twikiDiffChangedHeader" colspan ="9"><b> Changed: </b></td></tr>
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<ul>
<li> To do effects which involve <span class="twikiNewLink" style="background : #FFFFCE;"><font color="#0000FF">alpha channels</font><a href="http://www.ftconsult.com/twiki/bin/edit/Cinelerra/AlphaChannels?topicparent=Cinelerra.ColorModel"><sup>?</sup></a></span>, a <a class="twikiLink" href="../../view/Cinelerra/ColorModel">ColorModel</a> with an <span class="twikiNewLink" style="background : #FFFFCE;"><font color="#0000FF">alpha channel</font><a href="http://www.ftconsult.com/twiki/bin/edit/Cinelerra/AlphaChannel?topicparent=Cinelerra.ColorModel"><sup>?</sup></a></span> <code><b>must be selected.</b></code> (<em>i.e.</em> RGBA8888, YUVA8888, RGBA16161616 &amp; YUVA16161616.)
</li>
</ul>
</td></tr>
<tr><td bgcolor="#ccccff" class="twikiDiffAddedMarker" valign="top" width="1%">&gt;<br />&gt;</td>
<td class="twikiDiffAddedText">
<ul>
<li> To do effects which involve <span class="twikiNewLink" style="background : #FFFFCE;"><font color="#0000FF">AlphaChannels</font><a href="http://www.ftconsult.com/twiki/bin/edit/Cinelerra/AlphaChannels?topicparent=Cinelerra.ColorModel"><sup>?</sup></a></span>, a <a class="twikiLink" href="../../view/Cinelerra/ColorModel">ColorModel</a> with an <span class="twikiNewLink" style="background : #FFFFCE;"><font color="#0000FF">AlphaChannel</font><a href="http://www.ftconsult.com/twiki/bin/edit/Cinelerra/AlphaChannel?topicparent=Cinelerra.ColorModel"><sup>?</sup></a></span> <code><b>must be selected.</b></code> (<em>i.e.</em> RGBA8888, YUVA8888, RGBA16161616 &amp; YUVA16161616.)
</li>
</ul>
</td></tr>
<tr><td valign="top" bgcolor="#ffffff" class="twikiDiffUnchangedText" width="1%"><br /></td>
<td class="twikiDiffUnchangedText">

</td></tr>
<tr><td bgcolor="#D0FFD0" class="twikiDiffChangedHeader" colspan ="9"><b> Changed: </b></td></tr>
<tr><td bgcolor="#ff9999" class="twikiDiffDeletedMarker" valign="top" width="1%">&lt;<br />&lt;</td>
<td class="twikiDiffDeletedText">
<ul>
<li> Some effects, like <span class="twikiNewLink" style="background : #FFFFCE;"><font color="#0000FF">VideoFade</font><a href="http://www.ftconsult.com/twiki/bin/edit/Cinelerra/VideoFade?topicparent=Cinelerra.ColorModel"><sup>?</sup></a></span>, work around the need for <span class="twikiNewLink" style="background : #FFFFCE;"><font color="#0000FF">alpha channels</font><a href="http://www.ftconsult.com/twiki/bin/edit/Cinelerra/AlphaChannels?topicparent=Cinelerra.ColorModel"><sup>?</sup></a></span> while other effects, like <a class="twikiLink" href="../../view/Cinelerra/VideoChromaKey">VideoChromaKey</a>, require an <span class="twikiNewLink" style="background : #FFFFCE;"><font color="#0000FF">alpha channel</font><a href="http://www.ftconsult.com/twiki/bin/edit/Cinelerra/AlphaChannel?topicparent=Cinelerra.ColorModel"><sup>?</sup></a></span> to do anything, so it's a good idea to try the effect without <span class="twikiNewLink" style="background : #FFFFCE;"><font color="#0000FF">alpha channels</font><a href="http://www.ftconsult.com/twiki/bin/edit/Cinelerra/AlphaChannels?topicparent=Cinelerra.ColorModel"><sup>?</sup></a></span>.
</li>
</ul>
</td></tr>
<tr><td bgcolor="#ccccff" class="twikiDiffAddedMarker" valign="top" width="1%">&gt;<br />&gt;</td>
<td class="twikiDiffAddedText">
<ul>
<li> Some effects, like <span class="twikiNewLink" style="background : #FFFFCE;"><font color="#0000FF">VideoFade</font><a href="http://www.ftconsult.com/twiki/bin/edit/Cinelerra/VideoFade?topicparent=Cinelerra.ColorModel"><sup>?</sup></a></span>, work around the need for <span class="twikiNewLink" style="background : #FFFFCE;"><font color="#0000FF">AlphaChannels</font><a href="http://www.ftconsult.com/twiki/bin/edit/Cinelerra/AlphaChannels?topicparent=Cinelerra.ColorModel"><sup>?</sup></a></span> while other effects, like <a class="twikiLink" href="../../view/Cinelerra/VideoChromaKey">VideoChromaKey</a>, require an <span class="twikiNewLink" style="background : #FFFFCE;"><font color="#0000FF">AlphaChannel</font><a href="http://www.ftconsult.com/twiki/bin/edit/Cinelerra/AlphaChannel?topicparent=Cinelerra.ColorModel"><sup>?</sup></a></span> to do anything, so it's a good idea to try the effect without <span class="twikiNewLink" style="background : #FFFFCE;"><font color="#0000FF">AlphaChannels</font><a href="http://www.ftconsult.com/twiki/bin/edit/Cinelerra/AlphaChannels?topicparent=Cinelerra.ColorModel"><sup>?</sup></a></span>.
</li>
</ul>
</td></tr>
<tr><td valign="top" bgcolor="#ffffff" class="twikiDiffUnchangedText" width="1%"><br /></td>
<td class="twikiDiffUnchangedText">
<p />
<ul>
<li> If footage stored as JPEG or MPEG is processed many times in <span class="twikiNewLink" style="background : #FFFFCE;"><font color="#0000FF">RGB</font><a href="http://www.ftconsult.com/twiki/bin/edit/Cinelerra/RGB?topicparent=Cinelerra.ColorModel"><sup>?</sup></a></span>, the colors will fade while they won't if processed in <span class="twikiNewLink" style="background : #FFFFCE;"><font color="#0000FF">YUV</font><a href="http://www.ftconsult.com/twiki/bin/edit/Cinelerra/YUV?topicparent=Cinelerra.ColorModel"><sup>?</sup></a></span>.
</li>
</ul>
</td></tr>
<tr><td bgcolor="#D0FFD0" class="twikiDiffAddedHeader" colspan ="9"><b> Added:   </b>
</td></tr>
<tr><td bgcolor="#ccccff" class="twikiDiffAddedMarker" valign="top" width="1%">&gt;<br />&gt;</td>
<td class="twikiDiffAddedText">
<h3><a name="Other_resources"> </a> Other resources </h3>
<p />
<ul>
<li> Alpha Channel info <a href="http://en2.wikipedia.org/wiki/Alpha_channel" target="_top">http://en2.wikipedia.org/wiki/Alpha_channel</a>
</li>
<li> Color model there is info on wikipedia at <a href="http://en2.wikipedia.org/wiki/Color_model" target="_top">http://en2.wikipedia.org/wiki/Color_model</a> or a more in depth description at <a href="http://lea.hamradio.si/~s51kq/V-CIV.HTM" target="_top">http://lea.hamradio.si/~s51kq/V-CIV.HTM</a>
</li>
</ul>
</td></tr>
<tr><td valign="top" bgcolor="#ffffff" class="twikiDiffUnchangedText" width="1%"><br /></td>
<td class="twikiDiffUnchangedText">
<p />
-- <a class="twikiLink" href="../../view/Main/AlexFerrer">AlexFerrer</a> - 12 Jan 2004
<hr />
</td></tr>

</table></div><div class="twikiSearchResults"><div class="twikiSearchResultsHeader">&nbsp;<tt><b>&lt;&lt;O&gt;&gt;</b></tt>&nbsp; Difference Topic
		<b><a href="../../view/Cinelerra/ColorModel">ColorModel</a></b>
		(<a href="http://www.ftconsult.com/twiki/bin/view/Cinelerra/ColorModel?rev=r1.1">r1.1</a> - 12&nbsp;Jan&nbsp;2004 - <a class="twikiLink" href="../../view/Main/AlexFerrer">AlexFerrer</a>)</div>
<table class="twikiDiffTable" width="100%" cellspacing="0">
<tr bgcolor="#eeeeee" class="twikiDiffLineNumberHeader"><th align="left" colspan="9">Line: 1 to 1</th></tr>
<tr><td bgcolor="#D0FFD0" class="twikiDiffAddedHeader" colspan ="9"><b> Added:   </b>
</td></tr>
<tr><td bgcolor="#ccccff" class="twikiDiffAddedMarker" valign="top" width="1%">&gt;<br />&gt;</td>
<td class="twikiDiffAddedText">
<table border="1" cellspacing="1" cellpadding="0">
<tr><th class="twikiFirstCol" bgcolor="#99CCCC"> <strong>META TOPICPARENT</strong> </th><td colspan="2" bgcolor="#FFFFCC"> <a class="twikiLink" href="../../view/Cinelerra/SetFormat">SetFormat</a> </td></tr>
</table>
<h3><a name="Video_Color_Models"> </a><a name="Video_Color_Models_"> </a> Video <a class="twikiLink" href="../../view/Cinelerra/ColorModel">Color Models</a> </h3>
<p />
<img src="../../../pub/TWiki/TWikiDocGraphics/pencil.gif" border="0" alt="REFACTOR" width="16" height="16" /> [Basic description of color models goes here ]
<p />
<h3><a name="Color_Models_in_Cinelerra"> </a> Color Models in Cinelerra </h3>
Color models are very important for video playback. When video is stored on disk, it is stored in one <a class="twikiLink" href="../../view/Cinelerra/ColorModel">ColorModel</a>, (<em>normally compressed using a <span class="twikiNewLink" style="background : #FFFFCE;"><font color="#0000FF">YUV</font><a href="http://www.ftconsult.com/twiki/bin/edit/Cinelerra/YUV?topicparent=Cinelerra.ColorModel"><sup>?</sup></a></span> derivative.</em>) When played back, <strong>Cinelerra</strong> decompresses it from the file format directly into the format of the output device.
<p />
<strong>Cinelerra</strong> <a class="twikiLink" href="../../view/Cinelerra/ColorModel">ColorModels</a> are described using a certain packing order of components and a certain number of bits for each component. The packing order is printed on the left and the bit allocation is printed on the right.
<p />
<ul>
<li> <code><b>RGBA8888</b></code> uses <font color="#ff0000"> Red </font>, <font color="#008000">Green </font>, <font color="#000080">Blue </font>, and Alpha with 8 bits per channel.
</li>
</ul>
<p />
<h4><a name="Selecting_the_best_color_model_f"> </a> Selecting the best color model for your projevt </h4>
<img src="../../../pub/TWiki/TWikiDocGraphics/warning.gif" border="0" alt="ALERT!" width="16" height="16" /> When working on <strong>Cinelerra</strong> the <a class="twikiLink" href="../../view/Cinelerra/SetFormat">selection</a> of an internal <a class="twikiLink" href="../../view/Cinelerra/ColorModel">ColorModel</a> determines how accurate and fast the effects are. It is very important to <a class="twikiLink" href="../../view/Cinelerra/SetFormat">select</a> the <a class="twikiLink" href="../../view/Cinelerra/ColorMode">ColorMode</a> best suited for your purposes, below is some information regarding Cinelerras handling of various video <a class="twikiLink" href="../../view/Cinelerra/ColorModel">ColorModels</a> 
<p />
<ul>
<li> <span class="twikiNewLink" style="background : #FFFFCE;"><font color="#0000FF">YUV</font><a href="http://www.ftconsult.com/twiki/bin/edit/Cinelerra/YUV?topicparent=Cinelerra.ColorModel"><sup>?</sup></a></span> colormodels are usually faster than <span class="twikiNewLink" style="background : #FFFFCE;"><font color="#0000FF">RGB</font><a href="http://www.ftconsult.com/twiki/bin/edit/Cinelerra/RGB?topicparent=Cinelerra.ColorModel"><sup>?</sup></a></span> <a class="twikiLink" href="../../view/Cinelerra/ColorModel">ColorModels</a> when using compressed footage. They also destroy fewer colors than <span class="twikiNewLink" style="background : #FFFFCE;"><font color="#0000FF">RGB</font><a href="http://www.ftconsult.com/twiki/bin/edit/Cinelerra/RGB?topicparent=Cinelerra.ColorModel"><sup>?</sup></a></span> colormodels.
</li>
</ul>
<p />
<ul>
<li> Four channel <span class="twikiNewLink" style="background : #FFFFCE;"><font color="#0000FF">colormodel</font><a href="http://www.ftconsult.com/twiki/bin/edit/Cinelerra/Colormodel?topicparent=Cinelerra.ColorModel"><sup>?</sup></a></span>s are notoriously slower than three channel <a class="twikiLink" href="../../view/Cinelerra/ColorModel">ColorModels</a>, with the slowest being RGBA16161616.   
</li>
</ul>
<p />
When effects are processed, media files are decompressed into an internal <a class="twikiLink" href="../../view/Cinelerra/ColorModel">ColorModel</a> first and then converted to the <a class="twikiLink" href="../../view/Cinelerra/ColorModel">ColorModel</a> format of the output device.
<p />
<ul>
<li> To do effects which involve <span class="twikiNewLink" style="background : #FFFFCE;"><font color="#0000FF">alpha channels</font><a href="http://www.ftconsult.com/twiki/bin/edit/Cinelerra/AlphaChannels?topicparent=Cinelerra.ColorModel"><sup>?</sup></a></span>, a <a class="twikiLink" href="../../view/Cinelerra/ColorModel">ColorModel</a> with an <span class="twikiNewLink" style="background : #FFFFCE;"><font color="#0000FF">alpha channel</font><a href="http://www.ftconsult.com/twiki/bin/edit/Cinelerra/AlphaChannel?topicparent=Cinelerra.ColorModel"><sup>?</sup></a></span> <code><b>must be selected.</b></code> (<em>i.e.</em> RGBA8888, YUVA8888, RGBA16161616 &amp; YUVA16161616.)
</li>
</ul>
<p />
<ul>
<li> Some effects, like <span class="twikiNewLink" style="background : #FFFFCE;"><font color="#0000FF">VideoFade</font><a href="http://www.ftconsult.com/twiki/bin/edit/Cinelerra/VideoFade?topicparent=Cinelerra.ColorModel"><sup>?</sup></a></span>, work around the need for <span class="twikiNewLink" style="background : #FFFFCE;"><font color="#0000FF">alpha channels</font><a href="http://www.ftconsult.com/twiki/bin/edit/Cinelerra/AlphaChannels?topicparent=Cinelerra.ColorModel"><sup>?</sup></a></span> while other effects, like <a class="twikiLink" href="../../view/Cinelerra/VideoChromaKey">VideoChromaKey</a>, require an <span class="twikiNewLink" style="background : #FFFFCE;"><font color="#0000FF">alpha channel</font><a href="http://www.ftconsult.com/twiki/bin/edit/Cinelerra/AlphaChannel?topicparent=Cinelerra.ColorModel"><sup>?</sup></a></span> to do anything, so it's a good idea to try the effect without <span class="twikiNewLink" style="background : #FFFFCE;"><font color="#0000FF">alpha channels</font><a href="http://www.ftconsult.com/twiki/bin/edit/Cinelerra/AlphaChannels?topicparent=Cinelerra.ColorModel"><sup>?</sup></a></span>.
</li>
</ul>
<p />
<ul>
<li> If footage stored as JPEG or MPEG is processed many times in <span class="twikiNewLink" style="background : #FFFFCE;"><font color="#0000FF">RGB</font><a href="http://www.ftconsult.com/twiki/bin/edit/Cinelerra/RGB?topicparent=Cinelerra.ColorModel"><sup>?</sup></a></span>, the colors will fade while they won't if processed in <span class="twikiNewLink" style="background : #FFFFCE;"><font color="#0000FF">YUV</font><a href="http://www.ftconsult.com/twiki/bin/edit/Cinelerra/YUV?topicparent=Cinelerra.ColorModel"><sup>?</sup></a></span>.
</li>
</ul>
<p />
<p />
-- <a class="twikiLink" href="../../view/Main/AlexFerrer">AlexFerrer</a> - 12 Jan 2004
<hr />
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<tr><th class="twikiFirstCol" bgcolor="#99CCCC"> <strong>META TOPICMOVED</strong> </th><td bgcolor="#FFFFCC"> <span class="twikiNewLink" style="background : #FFFFCE;"><font color="#0000FF">AlexFerrer</font><a href="http://www.ftconsult.com/twiki/bin/edit/Cinelerra/AlexFerrer?topicparent=Cinelerra.ColorModel"><sup>?</sup></a></span> </td><td bgcolor="#FFFFCC"> date="1073926624" from="Cinelerra.ColorModels" to="Cinelerra.ColorModel" </td></tr>
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