上回我们学会了怎么计算级别（H.264 级别（Level）、DPB 与 MaxDpbMbs 详解）。但是每次手工计算就太麻烦了，我们希望有一款工具能完成这些运算。最好该工具还能跨平台使用。
<!DOCTYPE html PUBLIC "-//W3C//Dtd XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/Dtd/xhtml1-transitional.dtd"> <html> <head> <title>H.264 Level Calculator</title> <meta content="text/html; charset=utf-8" http-equiv="Content-Type"> <script type="text/javascript"> // var var tblLevels = [ {Level:"1", MaxDpbMbs:396, MaxSecondMbs:1485, MaxFrameMbs:99} ,{Level:"1b", MaxDpbMbs:396, MaxSecondMbs:1485, MaxFrameMbs:99} ,{Level:"1.1", MaxDpbMbs:900, MaxSecondMbs:3000, MaxFrameMbs:396} ,{Level:"1.2", MaxDpbMbs:2376, MaxSecondMbs:6000, MaxFrameMbs:396} ,{Level:"1.3", MaxDpbMbs:2376, MaxSecondMbs:11880, MaxFrameMbs:396} ,{Level:"2", MaxDpbMbs:2376, MaxSecondMbs:11880, MaxFrameMbs:396} ,{Level:"2.1", MaxDpbMbs:4752, MaxSecondMbs:19800, MaxFrameMbs:792} ,{Level:"2.2", MaxDpbMbs:8100, MaxSecondMbs:20250, MaxFrameMbs:1620} ,{Level:"3", MaxDpbMbs:8100, MaxSecondMbs:40500, MaxFrameMbs:1620} ,{Level:"3.1", MaxDpbMbs:18000, MaxSecondMbs:108000, MaxFrameMbs:3600} ,{Level:"3.2", MaxDpbMbs:20480, MaxSecondMbs:216000, MaxFrameMbs:5120} ,{Level:"4", MaxDpbMbs:32768, MaxSecondMbs:245760, MaxFrameMbs:8192} ,{Level:"4.1", MaxDpbMbs:32768, MaxSecondMbs:245760, MaxFrameMbs:8192} ,{Level:"4.2", MaxDpbMbs:34816, MaxSecondMbs:522240, MaxFrameMbs:8704} ,{Level:"5", MaxDpbMbs:110400, MaxSecondMbs:589824, MaxFrameMbs:22080} ,{Level:"5.1", MaxDpbMbs:184320, MaxSecondMbs:983040, MaxFrameMbs:36864} ]; // 取得命名对象 function getRef(id) { if (document.getElementById) return document.getElementById(id); // DOM if (document.all) return document.all[id]; // IE4 if (document.layers) return document.layers[id]; // Netscape4 return null; } // 取得控件文本。支持 input。 function getCtlText(ctl) { if (null==ctl) return; return ctl.value; } function input_onchange() { // in var nwidth = Number(getCtlText(getRef("txtwidth"))); var nheight = Number(getCtlText(getRef("txtheight"))); var nfps = Number(getCtlText(getRef("txtfps"))); var nref = Number(getCtlText(getRef("txtref"))); var nlevel = getRef("txtLevel").selectedIndex; // out var txtolevel = getRef("txtolevel"); var txtoframeMbs = getRef("txtoframeMbs"); var txtosecondMbs = getRef("txtosecondMbs"); var txtoDpbMbs = getRef("txtoDpbMbs"); var txtofps = getRef("txtofps"); var txtoref = getRef("txtoref"); // debug //txtolevel.value = txtolevel.value + "."; //txtolevel.value = nwidth + ", " + nheight + ", " + nfps + ", "+ nref + ", " + nlevel; //txtolevel.value = tblLevels[nlevel % tblLevels.length].Level; // 计算level var frameMbs = Math.ceil(nwidth/16) * Math.ceil(nheight/16); // 计算每帧宏块数 var secondMbs = frameMbs * nfps; // 计算每秒宏块数 var DpbMbs = frameMbs * nref; // 计算DPB宏块数 var idx = NaN; // 匹配的级别 var bOK = false; // 是否找到匹配的级别。 var i; if (!isNaN(frameMbs)) { // 查找第一个匹配的级别 for(i=0; i<tblLevels.length; ++i) { // 判断每帧宏块数 bOK = tblLevels[i].MaxFrameMbs >= frameMbs; // 判断每秒宏块数 if (bOK && !isNaN(nfps) && nfps>0 ) { bOK = tblLevels[i].MaxSecondMbs >= secondMbs; } // 判断DPB宏块数 if (bOK && !isNaN(nref) && nref>0 ) { bOK = tblLevels[i].MaxDpbMbs >= DpbMbs; } if (bOK) { idx = i; break } } } txtolevel.value = isNaN(idx)?NaN:tblLevels[idx].Level; txtoframeMbs.value = frameMbs; txtosecondMbs.value = secondMbs; txtoDpbMbs.value = DpbMbs; // 根据level约束计算fps/ref var ofps = NaN; // 帧数 var oref = NaN; // 参考帧数 if (!isNaN(nlevel) && nlevel>=0 && nlevel<tblLevels.length) { ofps = tblLevels[nlevel].MaxSecondMbs / frameMbs; oref = Math.min(16, tblLevels[nlevel].MaxDpbMbs / frameMbs); } txtofps.value = ofps; txtoref.value = oref; } function oninit() { // 启动时计算一次 input_onchange(); } </script> </head> <body onload='oninit()'> <h1>H.264 Level Calculator（H.264级别计算器）</h1> <p><span title='作者'>Author</span>: <a href='http://www.cnblogs.com/zyl910/'>zyl910</a></p> <form> <table id="tblview" border="1" cellSpacing="1" cellPadding="1"> <tr> <th></th> <th>计算level</th> <th>根据level约束计算fps/ref</th> </tr> <tr> <th>in</th> <td> width（宽度）:<input id="txtwidth" value='1280' onchange='input_onchange()' /><br /> height（高度）:<input id="txtheight" value='720' onchange='input_onchange()' /><br /> fps（帧率）:<input id="txtfps" value='24' onchange='input_onchange()' /><br /> ref（参考帧数）:<input id="txtref" value='3' onchange='input_onchange()' /><br /> </td> <td>level（级别）:<select id="txtLevel" onchange='input_onchange()'> <option value='1'>1</option> <option value='1b'>1b</option> <option value='1.1'>1.1</option> <option value='1.2'>1.2</option> <option value='1.3'>1.3</option> <option value='2'>2</option> <option value='2.1'>2.1</option> <option value='2.2'>2.2</option> <option value='3'>3</option> <option value='3.1' selected>3.1</option> <option value='3.2'>3.2</option> <option value='4'>4</option> <option value='4.1'>4.1</option> <option value='4.2'>4.2</option> <option value='5'>5</option> <option value='5.1'>5.1</option> </select> </td> </tr> <tr> <th>out</th> <td> level（级别）:<input id="txtolevel" NAME="txtolevel" readonly /><br /> frameMbs（每帧宏块）:<input id="txtoframeMbs" NAME="txtoframeMbs" readonly /><br /> secondMbs（每秒宏块）:<input id="txtosecondMbs" NAME="txtosecondMbs" readonly /><br /> DpbMbs（DPB宏块）:<input id="txtoDpbMbs" NAME="txtoDpbMbs" readonly /><br /> </td> <td> fps（帧率）:<input id="txtofps" NAME="txtofps" readonly /><br /> ref（参考帧数）:<input id="txtoref" NAME="txtoref" readonly /><br /> </td> </tr> </table> </form> <p>Browser compatible: IE, FireFox, Chrome, Maxthon3...</p> <hr /> <h3>Appendix A: Level Table</h3> <table border="1" cellspacing="1" cellpadding="1" ID="tblref1"><colgroup> <col width="59" /> <col span="2" width="69" /> <col width="71" /> <col span="2" width="68" /> <col width="74" /> <col width="218" /></colgroup> <tbody> <tr> <td rowspan="2" width="59" height="54">Level</td> <td colspan="2" width="138">Max macroblocks</td> <td colspan="4" width="281">Max video bit rate (kbit/s)</td> <td rowspan="2" width="218">Examples for high resolution @ frame rate (max stored frames)</td> </tr> <tr> <td width="69">per second</td> <td width="69">per frame</td> <td width="71">BP, XP, MP</td> <td>HiP</td> <td>Hi10P</td> <td width="74">Hi422P, Hi444PP</td> </tr> <tr> <td height="36">1</td> <td align="right">1,485</td> <td align="right">99</td> <td align="right">64</td> <td align="right">80</td> <td align="right">192</td> <td align="right">256</td> <td width="218">128×96@30.9 (8)<br />176×144@15.0 (4)</td> </tr> <tr> <td height="36">1b</td> <td align="right">1,485</td> <td align="right">99</td> <td align="right">128</td> <td align="right">160</td> <td align="right">384</td> <td align="right">512</td> <td width="218">128×96@30.9 (8)<br />176×144@15.0 (4)</td> </tr> <tr> <td height="54">1.1</td> <td align="right">3,000</td> <td align="right">396</td> <td align="right">192</td> <td align="right">240</td> <td align="right">576</td> <td align="right">768</td> <td width="218">176×144@30.3 (9)<br />320×240@10.0 (3)<br />352×288@7.5 (2)</td> </tr> <tr> <td height="36">1.2</td> <td align="right">6,000</td> <td align="right">396</td> <td align="right">384</td> <td align="right">480</td> <td align="right">1,152</td> <td align="right">1,536</td> <td width="218">320×240@20.0 (7)<br />352×288@15.2 (6)</td> </tr> <tr> <td height="36">1.3</td> <td align="right">11,880</td> <td align="right">396</td> <td align="right">768</td> <td align="right">960</td> <td align="right">2,304</td> <td align="right">3,072</td> <td width="218">320×240@36.0 (7)<br />352×288@30.0 (6)</td> </tr> <tr> <td height="36">2</td> <td align="right">11,880</td> <td align="right">396</td> <td align="right">2,000</td> <td align="right">2,500</td> <td align="right">6,000</td> <td align="right">8,000</td> <td width="218">320×240@36.0 (7)<br />352×288@30.0 (6)</td> </tr> <tr> <td height="36">2.1</td> <td align="right">19,800</td> <td align="right">792</td> <td align="right">4,000</td> <td align="right">5,000</td> <td align="right">12,000</td> <td align="right">16,000</td> <td width="218">352×480@30.0 (7)<br />352×576@25.0 (6)</td> </tr> <tr> <td height="72">2.2</td> <td align="right">20,250</td> <td align="right">1,620</td> <td align="right">4,000</td> <td align="right">5,000</td> <td align="right">12,000</td> <td align="right">16,000</td> <td width="218">352×480@30.7(10)<br />352×576@25.6 (7)<br />720×480@15.0 (6)<br />720×576@12.5 (5)</td> </tr> <tr> <td height="72">3</td> <td align="right">40,500</td> <td align="right">1,620</td> <td align="right">10,000</td> <td align="right">12,500</td> <td align="right">30,000</td> <td align="right">40,000</td> <td width="218">352×480@61.4 (12)<br />352×576@51.1 (10)<br />720×480@30.0 (6)<br />720×576@25.0 (5)</td> </tr> <tr> <td height="54">3.1</td> <td align="right">108,000</td> <td align="right">3,600</td> <td align="right">14,000</td> <td align="right">17,500</td> <td align="right">42,000</td> <td align="right">56,000</td> <td width="218">720×480@80.0 (13)<br />720×576@66.7 (11)<br />1280×720@30.0 (5)</td> </tr> <tr> <td height="36">3.2</td> <td align="right">216,000</td> <td align="right">5,120</td> <td align="right">20,000</td> <td align="right">25,000</td> <td align="right">60,000</td> <td align="right">80,000</td> <td width="218">1,280×720@60.0 (5)<br />1,280×1,024@42.2 (4)</td> </tr> <tr> <td height="54">4</td> <td align="right">245,760</td> <td align="right">8,192</td> <td align="right">20,000</td> <td align="right">25,000</td> <td align="right">60,000</td> <td align="right">80,000</td> <td width="218">1,280×720@68.3 (9)<br />1,920×1,080@30.1 (4)<br />2,048×1,024@30.0 (4)</td> </tr> <tr> <td height="54">4.1</td> <td align="right">245,760</td> <td align="right">8,192</td> <td align="right">50,000</td> <td align="right">62,500</td> <td align="right">150,000</td> <td align="right">200,000</td> <td width="218">1,280×720@68.3 (9)<br />1,920×1,080@30.1 (4)<br />2,048×1,024@30.0 (4)</td> </tr> <tr> <td height="36">4.2</td> <td align="right">522,240</td> <td align="right">8,704</td> <td align="right">50,000</td> <td align="right">62,500</td> <td align="right">150,000</td> <td align="right">200,000</td> <td width="218">1,920×1,080@64.0 (4)<br />2,048×1,080@60.0 (4)</td> </tr> <tr> <td height="90">5</td> <td align="right">589,824</td> <td align="right">22,080</td> <td align="right">135,000</td> <td align="right">168,750</td> <td align="right">405,000</td> <td align="right">540,000</td> <td width="218">1,920×1,080@72.3 (13)<br />2,048×1,024@72.0 (13)<br />2,048×1,080@67.8 (12)<br />2,560×1,920@30.7 (5)<br />3,680×1,536@26.7 (5)</td> </tr> <tr> <td height="54">5.1</td> <td align="right">983,040</td> <td align="right">36,864</td> <td align="right">240,000</td> <td align="right">300,000</td> <td align="right">720,000</td> <td align="right">960,000</td> <td width="218">1,920×1,080@120.5 (16)<br />4,096×2,048@30.0 (5)<br />4,096×2,304@26.7 (5)</td> </tr> </tbody> </table> <h3>Appendix B: MaxDpbMbs Table</h3> <table border="1" cellspacing="1" cellpadding="1" ID="Table1"><colgroup> <col width="59" /> <col width="96" /></colgroup> <tbody> <tr> <td width="59" height="18">Level</td> <td width="96">MaxDpbMbs</td> </tr> <tr> <td height="18">1</td> <td align="right">396</td> </tr> <tr> <td height="18">1b</td> <td align="right">396</td> </tr> <tr> <td height="18">1.1</td> <td align="right">900</td> </tr> <tr> <td height="18">1.2</td> <td align="right">2,376</td> </tr> <tr> <td height="18">1.3</td> <td align="right">2,376</td> </tr> <tr> <td height="18">2</td> <td align="right">2,376</td> </tr> <tr> <td height="18">2.1</td> <td align="right">4,752</td> </tr> <tr> <td height="18">2.2</td> <td align="right">8,100</td> </tr> <tr> <td height="18">3</td> <td align="right">8,100</td> </tr> <tr> <td height="18">3.1</td> <td align="right">18,000</td> </tr> <tr> <td height="18">3.2</td> <td align="right">20,480</td> </tr> <tr> <td height="18">4</td> <td align="right">32,768</td> </tr> <tr> <td height="18">4.1</td> <td align="right">32,768</td> </tr> <tr> <td height="18">4.2</td> <td align="right">34,816</td> </tr> <tr> <td height="18">5</td> <td align="right">110,400</td> </tr> <tr> <td height="18">5.1</td> <td align="right">184,320</td> </tr> </tbody> </table> </body> </html> 