{"id":104,"date":"2019-03-28T11:10:24","date_gmt":"2019-03-28T03:10:24","guid":{"rendered":"http:\/\/feel.name\/?p=104"},"modified":"2019-03-28T11:10:24","modified_gmt":"2019-03-28T03:10:24","slug":"%e5%b8%b8%e7%94%a8%e8%af%ad%e9%9f%b3%e7%bc%96%e8%a7%a3%e7%a0%81%e4%bb%8b%e7%bb%8d","status":"publish","type":"post","link":"http:\/\/feel.name\/?p=104","title":{"rendered":"\u5e38\u7528\u8bed\u97f3\u7f16\u89e3\u7801\u4ecb\u7ecd"},"content":{"rendered":"\n

\u4e3b\u8981\u7684speech codec<\/strong> \u6709: G.711, G.723, G.726 , G.729, ILBC\uff0cQCELP, EVRC, AMR, SMV<\/p>\n\n\n\n

\u4e3b\u8981\u7684audiocodec<\/strong> \u6709: real audio, AAC,AC3, MP3, WMA, SBC\u7b49\uff0c\u5404\u79cd\u7f16\u89e3\u7801\u90fd\u6709\u5176\u5e94\u7528\u7684\u91cd\u70b9\u9886\u57df\u3002<\/p>\n\n\n\n

G.711<\/h2>\n\n\n\n

G.711\u5c31\u662f\u8bed\u97f3\u6a21\u62df\u4fe1\u53f7\u7684\u4e00\u79cd\u975e\u7ebf\u6027\u91cf\u5316\uff0c\u7ec6\u5206\u6709\u4e8c\u79cd:G.711 A-lawand\u548cG.711 u-law.<\/p>\n\n\n\n

\u4e0d\u540c\u7684\u56fd\u5bb6\u548c\u5730\u65b9\u90fd\u4f1a\u9009\u53d6\u4e00\u79cd\u4f5c\u4e3a\u81ea\u5df1\u7684\u6807\u51c6. <\/p>\n\n\n\n

G.711 bitrate \u662f64kbps. <\/p>\n\n\n\n

\u8be6\u7ec6\u7684\u8d44\u6599\u53ef\u4ee5\u5728ITU \u4e0a\u4e0b\u5230\u76f8\u5173\u7684spec\uff0c\u4e0b\u9762\u4e3b\u8981\u5217\u51fa\u4e00\u4e9b\u6027\u80fd\u53c2\u6570\uff1a
G.711\uff08PCM\u65b9\u5f0f\uff1aPCM\uff1d\u8109\u7801\u8c03\u5236 \uff1aPulse Code Modulation\uff09
\u2022 \u91c7\u6837\u7387\uff1a8kHz
\u2022 \u4fe1\u606f\u91cf\uff1a64kbps\uff0fchannel
\u2022 \u7406\u8bba\u5ef6\u8fdf\uff1a0.125msec
\u2022 \u54c1\u8d28\uff1aMOS\u503c4.10 <\/p>\n\n\n\n

G.723.1<\/strong><\/h2>\n\n\n\n

G.723.1\u662f\u4e00\u4e2a\u53cc\u901f\u7387\u7684\u8bed\u97f3\u7f16\u7801\u5668\uff0c\u662f ITU-T\u5efa\u8bae\u7684\u5e94\u7528\u4e8e\u4f4e\u901f\u7387\u591a\u5a92\u4f53\u670d\u52a1\u4e2d\u8bed\u97f3\u6216\u5176\u5b83\u97f3\u9891\u4fe1\u53f7\u7684\u538b\u7f29\u7b97\u6cd5\uff1b<\/p>\n\n\n\n

\u5176\u76ee\u6807\u5e94\u7528\u7cfb\u7edf\u5305\u62ecH.323\u3001H.324\u7b49\u591a\u5a92\u4f53\u901a\u4fe1\u7cfb\u7edf\uff0c\u76ee\u524d\u8be5\u7b97\u6cd5\u5df2\u6210\u4e3aIP\u7535\u8bdd\u7cfb\u7edf\u4e2d\u7684\u5fc5\u9009\u7b97\u6cd5\u4e4b\u4e00\uff1b<\/p>\n\n\n\n

\u7f16\u7801\u5668\u7684\u5e27\u957f\u4e3a30ms\uff0c\u8fd8\u67097.5ms\u7684\u524d\u77bb\uff0c\u7f16\u7801\u5668\u7684\u7b97\u6cd5\u65f6\u5ef6\u4e3a37.5ms\uff1b<\/p>\n\n\n\n

\u7f16\u7801\u5668\u9996\u5148\u5bf9\u8bed\u97f3\u4fe1\u53f7\u8fdb\u884c\u4f20\u7edf\u7535\u8bdd\u5e26\u5bbd\u7684\u6ee4\u6ce2\uff08\u57fa\u4e8eG.712\uff09\uff0c\u518d\u5bf9\u8bed\u97f3\u4fe1\u53f7\u7528\u4f20\u7edf8000-Hz\u901f\u7387\u8fdb\u884c\u62bd\u6837\uff08\u57fa\u4e8eG.711\uff09\uff0c\u5e76\u53d8\u6362\u621016 bit\u7ebf\u6027PCM\u7801\u4f5c\u4e3a\u8be5\u7f16\u7801\u5668\u7684\u8f93\u5165\uff1b\u5728\u89e3\u7801\u5668\u4e2d\u5bf9\u8f93\u51fa\u8fdb\u884c\u9006\u64cd\u4f5c\u6765\u91cd\u6784\u8bed\u97f3\u4fe1\u53f7\uff1b<\/p>\n\n\n\n

\u9ad8\u901f\u7387\u7f16\u7801\u5668\u4f7f\u7528\u591a\u8109\u51b2\u6700\u5927\u4f3c\u7136\u91cf\u5316\uff08MP-MLQ\uff09\uff0c\u4f4e\u901f\u7387\u7f16\u7801\u5668\u4f7f\u7528\u4ee3\u6570\u7801\u6fc0\u52b1\u7ebf\u6027\u9884\u6d4b\uff08ACELP\uff09\u65b9\u6cd5\uff0c\u7f16\u7801\u5668\u548c\u89e3\u7801\u5668\u90fd\u5fc5\u987b\u652f\u6301\u6b64\u4e24\u79cd\u901f\u7387\uff0c\u5e76\u80fd\u591f\u5728\u5e27\u95f4\u5bf9\u4e24\u79cd\u901f\u7387\u8fdb\u884c\u8f6c\u6362\uff1b<\/p>\n\n\n\n

\u6b64\u7cfb\u7edf\u540c\u6837\u80fd\u591f\u5bf9\u97f3\u4e50\u548c\u5176\u4ed6\u97f3\u9891\u4fe1\u53f7\u8fdb\u884c\u538b\u7f29\u548c\u89e3\u538b\u7f29\uff0c\u4f46\u5b83\u5bf9\u8bed\u97f3\u4fe1\u53f7\u6765\u8bf4\u662f\u6700\u4f18\u7684\uff1b\u91c7\u7528\u4e86\u6267\u884c\u4e0d\u8fde\u7eed\u4f20\u8f93\u7684\u9759\u97f3\u538b\u7f29\uff0c\u8fd9\u5c31\u610f\u5473\u7740\u5728\u9759\u97f3\u671f\u95f4\u7684\u6bd4\u7279\u6d41\u4e2d\u52a0\u5165\u4e86\u4eba\u4e3a\u7684\u566a\u58f0\u3002\u9664\u4e86\u9884\u7559\u5e26\u5bbd\u4e4b\u5916\uff0c\u8fd9\u79cd\u6280\u672f\u4f7f\u53d1\u4fe1\u673a\u7684\u8c03\u5236\u89e3\u8c03\u5668\u4fdd\u6301\u8fde\u7eed\u5de5\u4f5c\uff0c\u5e76\u4e14\u907f\u514d\u4e86\u8f7d\u6ce2\u4fe1\u53f7\u7684\u65f6\u901a\u65f6\u65ad\u3002<\/p>\n\n\n\n

G.726<\/strong><\/h2>\n\n\n\n

   G.726\u6709\u56db\u79cd\u7801\u7387\uff1a40, 32, 24, 16 kbit\/s Adaptive Differential Pulse CodeModulation(ADPCM-\u81ea\u9002\u5e94\u5dee\u5206PCM)\uff0c\u6700\u4e3a\u5e38\u7528\u7684\u65b9\u5f0f\u662f 32 kbit\/s\uff0c\u4f46\u7531\u4e8e\u5176\u53ea\u662f G.711\u901f\u7387\u7684\u4e00\u534a\uff0c\u6240\u4ee5\u53ef\u5c06\u7f51\u7edc\u7684\u53ef\u5229\u7528\u7a7a\u95f4\u589e\u52a0\u4e86\u4e00\u500d\u3002<\/p>\n\n\n\n

G.726\u5177\u4f53\u89c4\u5b9a\u4e86\u4e00\u4e2a 64 kbpsA-law \u6216 \u00b5-law PCM \u4fe1\u53f7\u662f\u5982\u4f55\u88ab\u8f6c\u5316\u4e3a40, 32, 24\u621616 kbps \u7684ADPCM \u901a\u9053\u7684\u3002\u5728\u8fd9\u4e9b\u901a\u9053\u4e2d\uff0c24\u548c16 kbps \u7684\u901a\u9053\u88ab\u7528\u4e8e\u6570\u5b57\u7535\u8def\u500d\u589e\u8bbe\u5907(DCME)\u4e2d\u7684\u8bed\u97f3\u4f20\u8f93\uff0c\u800c40 kbps \u901a\u9053\u5219\u88ab\u7528\u4e8e DCME \u4e2d\u7684\u6570\u636e\u89e3\u8c03\u4fe1\u53f7\uff08\u5c24\u5176\u662f4800 kbps \u6216\u66f4\u9ad8\u7684\u8c03\u5236\u89e3\u8c03\u5668\uff09\u3002<\/p>\n\n\n\n

G.726 encoder \u8f93\u5165\u4e00\u822c\u90fd\u662fG.711 encoder\u7684\u8f93\u51fa\uff1a64kbps A-law oru-law.\u5176\u7b97\u6cd5\u5b9e\u8d28\u5c31\u662f\u4e00\u4e2aADPCM\uff0c \u81ea\u9002\u5e94\u91cf\u5316\u7b97\u6cd5\u3002<\/p>\n\n\n\n

G.729<\/strong><\/h2>\n\n\n\n

  G.729\u8bed\u97f3\u538b\u7f29\u7f16\u8bd1\u7801\u7b97\u6cd5
\u91c7\u7528\u7b97\u6cd5\u662f\u5171\u8f6d\u7ed3\u6784\u7684\u4ee3\u6570\u7801\u6fc0\u52b1\u7ebf\u6027\u9884\u6d4b(CSACELP)\uff0c\u662f\u57fa\u4e8eCELP\u7f16\u7801\u6a21\u578b\u7684\u7b97\u6cd5\uff1b\u80fd\u591f\u5b9e\u73b0\u5f88\u9ad8\u7684\u8bed\u97f3\u8d28\u91cf\uff08\u957f\u8bdd\u97f3\u8d28\uff09\u548c\u5f88\u4f4e\u7684\u7b97\u6cd5\u5ef6\u4e16\uff1b\u7b97\u6cd5\u5e27\u957f\u4e3a10ms\uff0c\u7f16\u7801\u5668\u542b5ms\u524d\u77bb\uff0c\u7b97\u6cd5\u65f6\u5ef615ms\uff1b\u5176\u91cd\u5efa\u8bed\u97f3\u8d28\u91cf\u5728\u5927\u591a\u6570\u5de5\u4f5c\u73af\u5883\u4e0b\u7b49\u540c\u4e8e32kb\/s\u7684ADPCM\uff08G.726\uff09\uff0cMOS\u5206\u5927\u4e8e4.0\uff1b\u7f16\u7801\u65f6\u8f93\u516516bitPCM\u8bed\u97f3\u4fe1\u53f7\uff0c\u8f93\u51fa2\u8fdb\u5236\u6bd4\u7279\u6d41\uff1b\u8bd1\u7801\u65f6\u8f93\u5165\u4e3a2\u8fdb\u5236\u6bd4\u7279\u6d41\uff0c\u8f93\u51fa16bitPCM\u8bed\u97f3\u4fe1\u53f7\uff1b\u5728\u8bed\u97f3\u4fe1\u53f78KHz\u53d6\u6837\u7684\u57fa\u7840\u4e0a\uff0c16bit\u7ebf\u6027PCM\u540e\u8fdb\u884c\u7f16\u7801\uff0c\u538b\u7f29\u540e\u6570\u636e\u901f\u7387\u4e3a8Kbps\uff1b\u5177\u6709\u76f8\u5f53\u4e8e16\uff1a1\u7684\u538b\u7f29\u7387\u3002
G.729\u7cfb\u5217\u5728\u5f53\u524d\u7684VOIP\u5f97\u5230\u5e7f\u6cdb\u7684\u5e94\u7528\uff0c\u4e14\u76f8\u5173\u5206\u652f\u8f83\u591a\uff0c\u53ef\u4ee5\u76f4\u63a5\u4eceITU\u7f51\u4e0a\u5f97\u5230source code \u548c\u76f8\u5173\u6587\u6863\u3002
G.729\uff08CS-ACELP\u65b9\u5f0f\uff1aConjugateStructure Algebraic Code Excited Linear Prediction\uff09
\u2022 \u91c7\u6837\u7387\uff1a8kHz
\u2022 \u4fe1\u606f\u91cf\uff1a8kbps\uff0fchannel
\u2022 \u5e27\u957f\uff1a10msec
\u2022 \u7406\u8bba\u5ef6\u8fdf\uff1a15msec
\u2022 \u54c1\u8d28\uff1aMOS\u503c3.9<\/p>\n\n\n\n

iLBC(internet lowbitrate codec)<\/strong><\/h2>\n\n\n\n

         \u662f\u5168\u7403\u8457\u540d\u8bed\u97f3\u5f15\u64ce\u63d0\u4f9b\u5546Global IP Sound\u5f00\u53d1\uff0c\u5b83\u662f\u4f4e\u6bd4\u7279\u7387\u7684\u7f16\u7801\u89e3\u7801\u5668\uff0c\u63d0\u4f9b\u5728\u4e22\u5305\u65f6\u5177\u6709\u7684\u5f3a\u5927\u7684\u5065\u58ee\u6027\u3002iLBC \u63d0\u4f9b\u7684\u8bed\u97f3\u97f3\u8d28\u7b49\u540c\u4e8e\u6216\u8d85\u8fc7 G.729 \u548c G.723.1\uff0c\u5e76\u6bd4\u5176\u5b83\u4f4e\u6bd4\u7279\u7387\u7684\u7f16\u7801\u89e3\u7801\u5668\u66f4\u80fd\u963b\u6b62\u4e22\u5305\u3002iLBC \u4ee513.3 kb\/s (\u6bcf\u5e2730\u6beb\u79d2)\u548c15.2 kb\/s (\u6bcf\u5e2720\u6beb\u79d2)\u901f\u5ea6\u8fd0\u884c\uff0c\u5f88\u9002\u5408\u62e8\u53f7\u8fde\u63a5\u3002
         iLBC\u7684\u4e3b\u8981\u4f18\u52bf\u5728\u4e8e\u5bf9\u4e22\u5305\u7684\u5904\u7406\u80fd\u529b\u3002iLBC\u72ec\u7acb\u5904\u7406\u6bcf\u4e00\u4e2a\u8bed\u97f3\u5305\uff0c\u662f\u4e00\u79cd\u7406\u60f3\u7684\u5305\u4ea4\u6362\u7f51\u7edc\u8bed\u97f3\u7f16\u89e3\u7801\u3002\u5728\u6b63\u5e38\u60c5\u51b5\u4e0b\uff0ciLBC\u4f1a\u8bb0\u5f55\u4e0b\u5f53\u524d\u6570\u636e\u7684\u76f8\u5173\u53c2\u6570\u548c\u6fc0\u52b1\u4fe1\u53f7\uff0c\u4ee5\u4fbf\u5728\u4e4b\u540e\u7684\u6570\u636e\u4e22\u5931\u7684\u60c5\u51b5\u4e0b\u8fdb\u884c\u5904\u7406\uff1b\u5728\u5f53\u524d\u6570\u636e\u63a5\u6536\u6b63\u5e38\u800c\u4e4b\u524d\u6570\u636e\u5305\u4e22\u5931\u7684\u60c5\u51b5\u4e0b\uff0ciLBC\u4f1a\u5bf9\u5f53\u524d\u89e3\u7801\u51fa\u7684\u8bed\u97f3\u548c\u4e4b\u524d\u6a21\u62df\u751f\u6210\u7684\u8bed\u97f3\u8fdb\u884c\u5e73\u6ed1\u5904\u7406\uff0c\u4ee5\u6d88\u9664\u4e0d\u8fde\u8d2f\u7684\u611f\u89c9\uff1b\u5728\u5f53\u524d\u6570\u636e\u5305\u4e22\u5931\u7684\u60c5\u51b5\u4e0b\uff0ciLBC\u4f1a\u5bf9\u4e4b\u524d\u8bb0\u5f55\u4e0b\u6765\u7684\u6fc0\u52b1\u4fe1\u53f7\u4f5c\u76f8\u5173\u5904\u7406\u5e76\u4e0e\u968f\u673a\u4fe1\u53f7\u8fdb\u884c\u6df7\u5408\uff0c\u4ee5\u5f97\u5230\u6a21\u62df\u7684\u6fc0\u52b1\u4fe1\u53f7\uff0c\u4ece\u800c\u5f97\u5230\u66ff\u4ee3\u4e22\u5931\u8bed\u97f3\u7684\u6a21\u62df\u8bed\u97f3\u3002\u603b\u7684\u6765\u8bf4\uff0c\u548c\u6807\u51c6\u7684\u4f4e\u4f4d\u901f\u7387\u7f16\u89e3\u7801\u76f8\u6bd4\uff0ciLBC\u4f7f\u7528\u66f4\u591a\u81ea\u7136\u3001\u6e05\u6670\u7684\u5143\u7d20\uff0c\u7cbe\u786e\u7684\u6a21\u4eff\u51fa\u539f\u59cb\u8bed\u97f3\u4fe1\u53f7\uff0c\u88ab\u8a89\u4e3a\u66f4\u9002\u5408\u5305\u4ea4\u6362\u7f51\u7edc\u4f7f\u7528\u7684\u53ef\u83b7\u5f97\u9ad8\u8bed\u97f3\u8d28\u91cf\u7684\u7f16\u89e3\u7801\u3002
\u6b64\u5916\uff0c\u5927\u90e8\u5206\u6807\u51c6\u7684\u4f4e\u4f4d\u901f\u7387\u7f16\u89e3\u7801\uff0c\u5982G.723.1\u548cG.729\uff0c\u4ec5\u5bf9300Hz\u2014\u20143400Hz\u7684\u9891\u7387\u8303\u56f4\u8fdb\u884c\u7f16\u7801\u3002\u5728\u8fd9\u4e2a\u9891\u7387\u8303\u56f4\u91cc\uff0c\u7528G.711\u7f16\u89e3\u7801\u6240\u8fbe\u5230\u7684\u8bed\u97f3\u8d28\u91cf\uff0c\u5c31\u662f\u4f20\u7edfPSTN\u7f51\u7edc\u8fdb\u884c\u8bed\u97f3\u901a\u8bdd\u7684\u6548\u679c\u3002
iLBC\u5145\u5206\u5229\u7528\u4e860\u2014\u20144000Hz\u7684\u9891\u7387\u5e26\u5bbd\u8fdb\u884c\u7f16\u7801\uff0c\u62e5\u6709\u8d85\u6e05\u6670\u7684\u8bed\u97f3\u8d28\u91cf\uff0c\u8fd9\u5927\u5927\u8d85\u51fa\u4f20\u7edf300Hz\u2014\u20143400Hz\u7684\u9891\u7387\u8303\u56f4\u3002
\u5e7f\u53d7\u6b22\u8fce\u7684Skype\u7f51\u7edc\u7535\u8bdd\u7684\u6838\u5fc3\u6280\u672f\u4e4b\u4e00\u5c31\u662fiLBC\u8bed\u97f3\u7f16\u89e3\u7801\u6280\u672f\uff0cGlobal IP Sound\u79f0\u8be5\u7f16\u7801\u5668\u8bed\u97f3\u54c1\u8d28\u4f18\u4e8ePSTN\uff0c\u800c\u4e14\u80fd\u5fcd\u53d7\u9ad8\u8fbe30%\u7684\u5c01\u5305\u635f\u5931\u3002
\u603b\u7684\u6765\u8bf4\uff0c\u5728\u76f8\u540c\u7684\u5305\u4ea4\u6362\u901a\u4fe1\u6761\u4ef6\u4e0b\uff0ciLBC\u7684\u8bed\u97f3\u8d28\u91cf\u6548\u679c\u6bd4G.729\u3001G.723.1\u4ee5\u53caG.711\u66f4\u597d\uff0c\u58f0\u97f3\u66f4\u52a0\u5706\u6da6\u9971\u6ee1\uff0c\u4e14\u4e22\u5305\u7387\u8d8a\u9ad8\uff0ciLBC\u5728\u8bed\u97f3\u8d28\u91cf\u4e0a\u7684\u4f18\u52bf\u5c31\u8d8a\u660e\u663e\uff01
\u76ee\u524d\uff0c\u5728\u56fd\u9645\u5e02\u573a\u4e0a\u5df2\u7ecf\u6709\u5f88\u591aVoIP\u7684\u8bbe\u5907\u548c\u5e94\u7528\u5382\u5546\u628aiLBC\u96c6\u6210\u5230\u4ed6\u4eec\u7684\u4ea7\u54c1\u4e2d\u3002\u5982\uff1aSkype, Nortel\u7b49\u3002\u5728\u56fd\u5185\u5e02\u573a\u4e0a\uff0c\u76ee\u524d\u5c1a\u65e0VoIP\u5382\u5bb6\u6b63\u5f0f\u63a8\u51fa\u652f\u6301\u201ciLBC\u201d\u7684\u7f51\u5173\u8bbe\u5907\uff0c\u8fc5\u65f6\u516c\u53f8 \u7387\u5148\u63a8\u51fa\u652f\u6301\u201ciLBC\u201d\u7684\u4e2d\u7ee7\u7f51\u5173\u548cIAD\u8bbe\u5907\u3002<\/p>\n\n\n\n

\u5982\u4f55\u8ba1\u7b97\u4e00\u8def\u8bdd\u97f3\u6d88\u8017\u7684\u5e26\u5bbd<\/p>\n\n\n\n

\u5728voice\u8fd9\u65b9\u9762\uff0c\u662f\u5982\u4f55\u8ba1\u7b97\u4f7f\u7528\u67d0\u79cdcodec\u6240\u6d88\u8017\u7684\u5e26\u5bbd\u5462\uff1f\u5728\u9ed8\u8ba4\u60c5\u51b5\u4e0b\uff0c\u628a\u6a21\u62df\u8bdd\u97f3\u8f6c\u6362\u4e3a\u6570\u5b57\u8bdd\u97f3\u540e\uff0c\u630920ms\u4e00\u6bb520ms\u4e00\u6bb5\u5207\u5f00\uff0c\u7528rtp\u5c01\u88c5\u8d77\u6765\uff0c\u7136\u540e\u5305\u4e0audp header\uff0cip header\uff0c\u6700\u540e\u662flayer 2\u7684\u5305\u5934\uff0c\u7136\u540e\u53d1\u51fa\u53bb\u3002
\u5047\u8bbe\u54b1\u4eec\u7528g.729\u7f16\u7801\uff0c\u5e76\u5728ethernet\u4e0a\u4f20\u8f93\u3002\u4e00\u8d77\u6765\u7b97\u7b97\u4e00\u8def\u8bdd\u97f3\u9700\u8981\u591a\u5927\u5e26\u5bbd\u5427\u3002
g.729\u6bcf\u8def\u8bdd\u97f3\u662f8kbit\/s\uff0c\u90a3\u4e48\u5f00\u59cb\u8f6c\u6362\uff1a
8000bps \/ 8 = 1000 bytes\/s\uff0c\u5f97\u5230g.729\u6bcf\u79d2\u9700\u8981\u5e26\u5bbd1000 bytes
\u90a3\u4e48\u9ed8\u8ba4\u90fd\u662f\u628a20ms\u7684\u8bdd\u97f3\u5c01\u6210\u4e00\u4e2apacket\uff0c\u4e5f\u5c31\u53ef\u4ee5\u7b97\u51fa1\u79d2\u5185\u53d1\u9001\u591a\u5c11\u4e2apacket\uff1a
1s \/ 20ms = 50\u4e2a
\u4e5f\u5c31\u662f\u8bf4g.729\u6bcf20ms\u9700\u8981\u7684\u5e26\u5bbd\u4e3a\uff1a1000bytes\/s \/ 50 =20bytes\/s
\u4e4b\u540e\u4ee5\u592a\u7f51\u5e27\u59346-byte\uff0cip\u5305\u593420-byte\uff0cudp\u5305\u59348-byte\uff0crtp\u5305\u593412-byte\uff0c\u8fd9\u6837\uff0c\u518d\u52a0\u4e0ag.729\u7684payload\u4e3a20bytes\uff0c\u4e5f\u5c31\u662f\u8bf4\u6bcf20ms\u5c31\u8981\u4ea7\u751f\u4e00\u4e2a6 + 20 + 8 + 12 +20 = 66-byte\u957f\u5ea6\u7684\u5e27\uff0c\u90a3\u4e48\u4e00\u79d2\u5c31\u8981\u53d1\u900150\u4e2a66-byte\uff0c\u7b49\u4e8e3300-byte\uff0c\u8f6c\u6210kbit\/s\uff1a 3300byte\/s * 8\/1000 = 26.4kbit\/s
\u6700\u7ec8\u5f97\u51fag.729\u4e00\u8def\u8bdd\u97f3\u5360\u7528\u5e26\u5bbd\uff08\u5305\u62eclayer2 header\uff09\u4e3a26.4kbps<\/p>\n\n\n\n

\u8bed\u97f3\u7f16\u7801\u7684\u5e26\u5bbd\u8ba1\u7b97<\/p>\n\n\n\n

VOIP Bandwidth consumption naturally dependson the codecused.  
VOIP\u6d88\u8017\u7684\u5e26\u5bbd\u4e00\u822c\u53d6\u51b3\u4e8e\u6240\u4f7f\u7528\u7684\u8bed\u97f3\u7f16\u7801.
When calculating bandwidth, one can’t assume that everychannel is used all thetime. Normal conversation includes a lot of silence,which often means nopackets are sent at all.So even if one voice call sets uptwo 64 Kbit RTPstreams over UDP over IP over Ethernet (which adds overhead),the full bandwidthis not used at all times.  
\u8ba1\u7b97\u5e26\u5bbd\u65f6,\u4e0d\u80fd\u5047\u8bbe\u6bcf\u4e00\u4e2a\u901a\u9053\u90fd\u5904\u4e8e\u4f7f\u7528\u72b6\u6001.\u6b63\u5e38\u7684\u901a\u8bdd\u8fc7\u7a0b\u5305\u62ec\u4e00\u7cfb\u5217\u7684\u9759\u97f3,\u4e5f\u5c31\u610f\u5473\u7740\u5e76\u4e0d\u662f\u4e00\u76f4\u90fd\u6709\u5305\u5728\u4f20\u9001.\u6240\u4ee5\u4e00\u4e2a\u8bed\u97f3\u547c\u53eb\u5efa\u7acb\u4e24\u4e2a\u7ecf\u8fc7UDP,IP\u548c\u4ee5\u592a\u7f51\u768464Kbit\u7684RTP\u6d41(\u603b\u5f00\u9500),\u5168\u90e8\u5e26\u5bbd\u5e76\u672b\u4e00\u76f4\u88ab\u4f7f\u7528.
A codec that sends a 64kb stream results in a much largerIP network stream. Themain cause of the extra bandwidth usage is IP and UDPheaders. VoIP sends smallpackets and so, many times, the headers are actuallymuch larger than the datapart of the packet.  
\u4e00\u4e2a\u4f20\u900164kb\u6d41\u7684\u8bed\u97f3\u7f16\u7801\u5f88\u5927\u7a0b\u5ea6\u4e0a\u90fd\u662fIP\u7f51\u7edc\u6d41\u7684\u7ed3\u679c.\u989d\u5916\u7684\u5e26\u5bbd\u4f7f\u7528\u4e3b\u8981\u662fIP\u6216UDP\u5934\u7684\u589e\u52a0.VOIP\u53ea\u4f20\u9001\u5c11\u91cf\u7684\u5305,\u5f88\u591a\u65f6\u5019,\u5b9e\u9645\u4e0a\u662f\u5305\u5934\u8fdc\u8fdc\u5927\u4e8e\u5305\u6570\u636e.
Codec       BR          NEB
G.711      64 Kbps      87.2Kbps
G.729       8 Kbps       31.2 Kbps
G.723.1    6.4 Kbps       21.9Kbps
G.723.1    5.3 Kbps       20.8Kbps
G.726      32 Kbps      55.2 Kbps
G.726      24 Kbps      47.2 Kbps
G.728      16 Kbps      31.5 Kbps
iLBC        15 Kbps      27.7 Kbps  
BR = Bit rate
NEB = Nominal Ethernet Bandwidth (one direction)
\u6839\u636e\u6211\u7684\u4f7f\u7528\u7ecf\u9a8c\uff0c8K\u7684G.729\u52a0\u4e0aIP\u5c01\u88c5\u540e\u8fbe\u523032K,\u4e3a\u4e86\u9632\u5c01\u6740\uff0c\u8fd8\u6709\u7684\u7528\u6237\u4f7f\u7528IP Sec\u8bbe\u5907\u5c06\u8bed\u97f3\u505a\u6210VPN\uff0c\u8fd9\u6837G.729\u52a0\u4e0aIP\u5c01\u88c5\uff0c\u518d\u52a0\u4e0aVPN\u4f1a\u8fbe\u523060\u591aK\u3002
\u6ce8:\u5934\u4e09\u6bb5\u4e2d\u6587\u662f\u6211\u81ea\u5df1\u8bd1\u8fc7\u6765\u7684,\u6240\u4ee5\u8bfb\u8d77\u6765\u5e76\u4e0d\u600e\u4e48\u51c6\u786e,\u800c\u4e14\u4f1a\u611f\u89c9\u522b\u626d,\u5475\u5475.\u591a\u591a\u5305\u6db5\u4e86.\u6709\u5174\u8da3\u7684\u670b\u53cb\u53ef\u4ee5\u518d\u8bd1\u4e00\u6b21.\u4ee5\u4f9b\u501f\u9274.
\u96c6\u7fa4\u901a\u8f6f\u4ea4\u6362\u7535\u8bdd-\u6240\u9700\u5e26\u5bbd\u8bf4\u660e
VoIP\u6240\u9700\u8981\u7684\u5e26\u5bbd\uff0c\u901a\u5e38\u53d6\u51b3\u4e8e\u5b83\u6240\u4f7f\u7528\u7684codec\u7f16\u7801\u65b9\u6cd5\u3002\u5728\u8ba1\u7b97\u5e26\u5bbd\u65f6\uff0c\u4e0d\u80fd\u5047\u5b9a\u6bcf\u4e2a\u901a\u9053\u603b\u662f\u5728\u4f7f\u7528\u4e4b\u4e2d\u3002\u901a\u5e38\u7684\u4f1a\u8bdd\u8fc7\u7a0b\u4e2d\u5305\u62ec\u5927\u91cf\u7684\u9759\u9ed8\u65f6\u6bb5\uff0c\u5c31\u662f\u4e0d\u53d1\u9001\u4efb\u4f55\u6570\u636e\u5305\u3002
\u4e00\u4e2a\u4f1a\u8bdd\u5efa\u7acb\u4e86\u4e24\u4e2a64kbps\u7684RTP\u6d41\uff0c\u5728UDP\/IP\/Ethernet\u4e0a,\u5e76\u975e\u5728\u6240\u6709\u7684\u65f6\u95f4\u90fd\u4f7f\u7528\u5168\u90e8\u7684\u5e26\u5bbd\u3002
\u4e00\u79cd\u7f16\u7801\u65b9\u6cd5\u53d1\u900164kbps\u7684\u6570\u636e\u6d41\uff0c\u4f1a\u5bfc\u81f4\u5927\u5f97\u591a\u7684IP\u7f51\u7684\u6570\u636e\u6d41\uff0c\u5f15\u8d77\u989d\u5916\u5e26\u5bbd\u7684\u4e3b\u8981\u539f\u56e0\u662fIP\u548cUDP\u7684\u62a5\u6587\u5934.\u5f53VoIP\u53d1\u9001\u5c0f\u7684\u6570\u636e\u5305\u65f6\uff0c\u5728\u5927\u591a\u6570\u65f6\u5019\uff0c\u62a5\u6587\u5934\u5b9e\u9645\u4e0a\u8981\u6bd4\u5305\u4e2d\u7684\u6570\u636e\u5927\u5f97\u591a\u3002
\u4e0b\u9762\u7684\u8868\u5217\u51fa\u4e86\u5404\u79cd\u7f16\u7801\u65b9\u6cd5\uff0c\u6240\u9700\u8981\u7684\u5e26\u5bbd\uff1a<\/p>\n\n\n\n
\u7f16\u7801\u65b9\u6cd5<\/td>\u7f16\u7801\u6240\u9700\u5e26\u5bbd<\/td>\u5b9e\u9645\u6240\u9700\u8981\u7684\u7f51\u7edc\u5e26\u5bbd<\/td><\/tr>
G.711<\/td>64 Kbps<\/td>87.2 Kbps<\/td><\/tr>
G.729<\/td>8 Kbps<\/td>31.2 Kbps<\/td><\/tr>
G.723.1<\/td>6.4 Kbps<\/td>21.9 Kbps<\/td><\/tr>
G.723.1<\/td>5.3 Kbps<\/td>20.8 Kbps<\/td><\/tr>
G.726<\/td>32 Kbps<\/td>55.2 Kbps<\/td><\/tr>
G.726<\/td>24 Kbps<\/td>47.2 Kbps<\/td><\/tr>
G.728<\/td>16 Kbps<\/td>31.5 Kbps<\/td><\/tr><\/tbody><\/table>\n\n\n\n

\u7f16\u7801\u6240\u9700\u5e26\u5bbd\uff0c\u662f\u6307\u7406\u8bba\u4e0a\u6240\u9700\u8981\u7684\u5e26\u5bbd\u3002\u4f46\u5728\u5b9e\u9645\u7684\u4f20\u8f93\u8fc7\u7a0b\u4e2d\uff0c\u8fd8\u8981\u4ed8\u51fa\u5176\u4ed6\u7684\u6d88\u8017\uff0c\u5982\u62a5\u6587\u5934\u3002\u771f\u6b63\u9700\u8981\u7684\u5e26\u5bbd\u662f\u5b9e\u9645\u6240\u9700\u8981\u7684\u7f51\u7edc\u5e26\u5bbd\uff0c\u8fd9\u662f\u5927\u81f4\u7684\u6570\u503c\uff0c\u800c\u4e0d\u662f\u4e25\u683c\u7684\u7cbe\u786e\u503c\u3002\u5b9e\u9645\u6240\u9700\u8981\u7684\u7f51\u7edc\u5e26\u5bbd\u901a\u5e38\u662f\u4ee5\u592a\u7f51\u6240\u9700\u8981\u7684\u5e26\u5bbd\uff0c\u6216\u8005\u662fppp\u8fde\u63a5\u6240\u8981\u7684\u5e26\u5bbd\u3002
QQ\u4f7f\u7528\u7684\u7f16\u7801\u6280\u672fGIPS\uff0c\u5b9e\u9645\u4f7f\u7528\u8d77\u6765\u611f\u89c9\u58f0\u97f3\u6bd4\u8f83\u6e05\u6670\uff0c\u76f8\u5bf9\u4e8eSIP\u7684\u7f16\u7801\u5c31\u663e\u5f97\u58f0\u97f3\u6709\u4e9b\u4e0d\u597d\uff0c\u8bf7\u95ee\uff0cGIPS\u7406\u8bba\u5360\u7528\u7684\u5e26\u5bbd\u6709\u591a\u5927\uff1f\u80fd\u4e0d\u80fd\u5728SIP\u52a0\u5165GIPS\u7f16\u7801\u65b9\u5f0f\uff1f
GIPS\u516c\u53f8\u7528\u7684\u8bed\u97f3\u7f16\u7801\u6280\u672f\u662f iLBC\u7f16\u7801\u3002GIPS\u6280\u672f\u53ef\u6839\u636e\u5e26\u5bbd\u72b6\u51b5\u81ea\u52a8\u8c03\u8282\u7f16\u7801\u7801\u7387\uff0c\u63d0\u4f9b\u4f4e\u7801\u7387\u9ad8\u8d28\u91cf\u7684\u97f3\u9891\u3002<\/p>\n\n\n\n

GIPS\u7684\u6838\u5fc3\u6280\u672f\uff08\u7f51\u7edc\u81ea\u9002\u5e94\u7b97\u6cd5\uff0c\u4e22\u5305\u8865\u507f\u7b97\u6cd5\u548c\u56de\u58f0\u6d88\u9664\u7b97\u6cd5\uff09\u53ef\u5f88\u597d\u5730\u89e3\u51b3\u8bed\u97f3\u5ef6\u8fdf\u4e0e\u56de\u58f0\u95ee\u9898\uff0c\u5e26\u6765\u5b8c\u7f8e\u97f3\u8d28\uff0c\u63d0\u4f9b\u6bd4\u7535\u8bdd\u8fd8\u6e05\u6670\u7684\u8bed\u97f3\u901a\u8bdd\u6548\u679c\u3002<\/p>\n\n\n\n

iLBC\u82e5\u91c730ms\u4e00\u5e27\uff0c\u5219\u7406\u8bba\u5e26\u5bbd\u9700\u898113.33 kbps\u3002\u82e520ms \u4e00\u5e27\uff0c\u5219\u7406\u8bba\u5e26\u5bbd\u9700\u898115.2kbps \u3002
iLBC\u7684\u8bed\u97f3\u8d28\u91cf\u8981\u6bd4 G.729A\u597d\u4e9b\uff0c\u4f46\u662f\u80fd\u591f\u5bb9\u5fcd\u4e22\u5931\u66f4\u591a\u7684\u5305\uff1b\u4e5f\u5c31\u662f\u5728\u4e22\u5305\u540e\uff0ciLBC\u6062\u590d\u80fd\u529b\u66f4\u5f3a\u3002
iLBC\u8ba1\u7b97\u590d\u6742\u5ea6\u4e0eG.729A\u5dee\u4e0d\u591a\u3002\u90fd\u662f\u8ba1\u7b97\u5ea6\u6bd4\u8f83\u590d\u6742\u7684\u7b97\u6cd5\u3002
SIP\u7ec8\u7aef\u4e2d\uff0c\u4e5f\u6709\u4f7f\u7528 iLBC\u7f16\u7801\u7684\u3002skype \u3001QQ\u5728\u8bed\u97f3\u7f16\u7801\u4e0a\u5e76\u6ca1\u6709\u4ec0\u4e48\u4f18\u52bf\u3002\u7531\u4e8e\u5b83\u4eec\u662f\u79c1\u6709\u534f\u8bae\uff0c\u76ee\u524d\u5728\u7a7f\u900f\u79c1\u7f51\uff08NAT\uff09\u548c\u9632\u706b\u5899\u4e0a\uff0c\u66f4\u597d\u505a\u4e9b\uff0c\u6240\u4ee5\u5a92\u4f53\u6d41\u7684\u8def\u5f84\uff0c\u53ef\u80fd\u6bd4SIP\u6807\u51c6\uff08\u76ee\u524d\uff09\u597d\u505a\u4e9b\u800c\u5df2\u3002\u7a7f\u900f\u6613\uff0c\u8def\u5f84\u9009\u5f97\u8fd1\u4e9b\uff0c\u97f3\u8d28\u5c31\u663e\u5f97\u597d\u4e9b\u3002
G711\u5728\u5927\u7ea6\u6709 100Kbps \u5e26\u5bbd\u65f6\uff0c\u6709\u5f88\u597d\u7684\u8bed\u97f3\u8d28\u91cf\u3002
G.726 \u5728\u5927\u7ea6\u6709 50Kbps \u5e26\u5bbd\u65f6\uff0c\u6709\u597d\u7684\u8bed\u97f3\u8d28\u91cf\u3002
G.729 \u5728\u5927\u7ea6\u6709 30Kbps \u5e26\u5bbd\u65f6\uff0c\u6709\u597d\u7684\u8bed\u97f3\u8d28\u91cf\u3002

GIPS\u516c\u53f8\u7528\u7684\u8bed\u97f3\u7f16\u7801\u6280\u672f\u662f\u5e26\u5bbd\u53ef\u53d8\u7684\u7801\u7387\uff0c\u4e5f\u5c31\u662f\u6839\u636e\u7f51\u7edc \u5b9e\u9645\u7684\u5e26\u5bbd\u72b6\u6001\uff0c\u8c03\u6574\u8bed\u97f3\u7f16\u7801\u7684\u538b\u7f29\u6bd4\u7387\u3002 \u4e5f\u5c31\u662f\u5e26\u5bbd\u8d8a\u5c11\uff0c\u8bed\u97f3\u538b\u7f29\u5f97\u8d8a\u5389\u5bb3\uff0c\u5931\u771f\u635f\u5931\u8d8a\u591a\uff1b\u5e26\u5bbd\u8d8a\u597d\uff0c\u5c31\u538b\u7f29\u4e0d\u5389\u5bb3\uff0c\u5931\u771f\u635f\u5931\u5c11\u3002
\u6ce8\u610f\u8bed\u97f3\u7f16\u7801\u7528\u7684\u538b\u7f29\uff0c\u90fd\u662f\u6709\u635f\u538b\u7f29\uff0c\u4e5f\u5c31\u538b\u7f29\u540e\u8bed\u97f3\u4f1a\u4e9b\u5931\u771f\u3002
\u4ec0\u4e48\u662fiLBC\uff1f
iLBC\u662f\u4e00\u79cd\u4e13\u4e3a\u5305\u4ea4\u6362\u7f51\u7edc\u901a\u4fe1\u8bbe\u8ba1\u7684\u7f16\u89e3\u7801\uff0c\u4f18\u4e8e\u76ee\u524d\u6d41\u884c\u7684G.729\u3001G.723.1\uff0c\u5bf9\u4e22\u5305\u8fdb\u884c\u4e86\u7279\u6709\u5904\u7406\uff0c\u65e2\u4f7f\u5728\u4e22\u5305\u7387 \u76f8\u5f53\u9ad8\u7684\u7f51\u7edc\u73af\u5883\u4e0b\uff0c\u4ecd\u53ef\u83b7\u5f97\u975e\u5e38\u6e05\u6670\u7684\u8bed\u97f3\u6548\u679c\u3002
iLBC\u6240\u5360\u7528\u5e26\u5bbd\uff1f
   30ms ptime\u7684iLBC\u6240\u5360\u7528\u7684\u603b\u901a\u4fe1\u5e26\u5bbd\u6bd4\u901a\u5e38\u91c7\u7528\u7684ptime 20ms\u7684G.729\u7684\u5e26\u5bbd\u8fd8\u8981\u5c0f\uff0c\u4ee5\u4e0b\u662fiLBC\u4e0e\u4f20\u7edf\u7f16\u89e3\u7801\u5360\u7528\u5e26\u5bbd\u5217\u8868\uff1a
iLBC\u2014\u2014\u8bed\u97f3\u8d28\u91cf\u7684\u98de\u8dc3
\u8bed\u97f3\u8d28\u91cf\u4e00\u76f4\u662fVoIP\u5e94\u7528\u7684\u4e3b\u8981\u96be\u70b9\uff0c\u5982\u4f55\u4fdd\u8bc1\u548c\u63d0\u9ad8IP\u7f51\u7edc\u4f20\u8f93\u8bed\u97f3\u7684\u901a\u8bdd\u6548\u679c\uff0c\u662fVoIP\u5e94\u7528\u8feb\u5207\u9700\u8981\u89e3\u51b3\u7684\u95ee\u9898\u3002\u201ciLBC\u201d\u7f16\u89e3\u7801\u7684\u51fa\u73b0\uff0c\u89e3\u51b3\u4e86\u5728\u5305\u4ea4\u6362\u7684IP\u7f51\u7edc\u4e2d\uff0c\u4f20\u8f93\u8bed\u97f3\u6240\u9047\u5230\u7684\u7f51\u7edc\u4e22\u5305\u4e25\u91cd\u5f71\u54cd\u901a\u8bdd\u8d28\u91cf\u7b49\u5b9e\u9645\u95ee\u9898\uff0c\u5b9e\u73b0\u4e86\u201c\u8bed\u97f3\u8d28\u91cf\u7684\u98de\u8dc3\u201d\u3002
\u4e0b\u56fe\u4e3a\u5728\u4e0d\u540c\u7684\u7f51\u7edc\u4e22\u5305\u73af\u5883\u4e0b\uff0c\u4f7f\u7528iLBC\u4e0eG.729A\u3001G.723.1\u7f16\u89e3\u7801\u7684\u8bed\u97f3\u8d28\u91cf\u6bd4\u8f83\u3002
\u56fe1. iLBC\u4e0e G.729A\u3001G.723.1\u7684\u6bd4\u8f83(Dynastat, Inc)
\u65e0\u8bba\u5728\u9ad8\u4e22\u5305\u7387\u6761\u4ef6\u4e0b\u8fd8\u662f\u5728\u6ca1\u6709\u4e22\u5305\u7684\u6761\u4ef6\u4e0b\uff0ciLBC\u7684\u8bed\u97f3\u8d28\u91cf\u90fd\u4f18\u4e8e\u76ee\u524d\u6d41\u884c\u7684G.723.1, G.729A\u7b49\u6807\u51c6\u7f16\u89e3\u7801\uff1b\u800c\u4e14\u4e22\u5305\u7387\u8d8a\u5927\uff0c\u4f7f\u7528iLBC\u7684\u8bed\u97f3\u8d28\u91cf\u4f18\u52bf\u8d8a\u660e\u663e\u3002\u901a\u5e38\u60c5\u51b5\u4e0b\uff0c\u4e3a\u4e86\u8861\u91cfIP\u7f51\u7edc\u8bed\u97f3\u8d28\u91cf\uff0c\u5c06\u22655\uff05\u4e22\u5305\u7387\u7684\u7f51\u7edc\u60c5\u51b5\u5b9a\u4e49\u4e3aVoIP\u7684\u6781\u9650\u7f51\u7edc\u6761\u4ef6\u3002\u7ecf\u8fc7\u8bed\u97f3\u8d28\u91cf\u6d4b\u8bd5\uff0c\u5373\u4f7f\u57285\uff05\u4e22\u5305\u7387\u7684\u60c5\u51b5\u4e0b\uff0ciLBC\u4ecd\u7136\u80fd\u591f\u63d0\u4f9b\u76f8\u5f53\u4e8eGSM\u624b\u673a\u7684\u8bed\u97f3\u8d28\u91cf\u3002<\/p>\n\n\n\n

 Internet\u8bdd\u97f3\u5206\u7ec4\u4f20\u8f93\u6280\u672f<\/p>\n\n\n\n

\u5728IP\u7f51\u4e2d\u4f20\u8f93\u5c42\u6709\u4e24\u4e2a\u5e76\u5217\u7684\u534f\u8bae\uff1aTCP\u548cUDP\u3002<\/p>\n\n\n\n

TCP\u662f\u9762\u5411\u8fde\u63a5\u7684\uff0c\u5b83\u63d0\u4f9b\u9ad8\u53ef\u9760\u6027\u670d\u52a1\uff1bUCP\u662f\u65e0\u8fde\u63a5\u7684\uff0c\u5b83\u63d0\u4f9b\u9ad8\u6548\u7387\u7684\u670d\u52a1\u3002<\/p>\n\n\n\n

\u9ad8\u53ef\u9760\u6027\u7684TCP\u7528\u4e8e\u4e00\u6b21\u4f20\u8f93\u8981\u4ea4\u6362\u5927\u91cf\u62a5\u6587\u7684\u60c5\u51b5\uff0c\u9ad8\u6548\u7387\u7684UDP\u7528\u4e8e\u4e00\u6b21\u4ea4\u6362\u5c11\u91cf\u7684\u62a5\u6587\u6216\u5b9e\u65f6\u6027\u8981\u6c42\u8f83\u9ad8\u7684\u4fe1\u606f\u3002<\/p>\n\n\n\n

\u5b9e\u65f6\u4f20\u8f93\u534f\u8baeRTP\u63d0\u4f9b\u5177\u6709\u5b9e\u65f6\u7279\u5f81\u7684\u3001\u7aef\u5230\u7aef\u7684\u6570\u636e\u4f20\u8f93\u4e1a\u52a1\uff0c\u53ef\u4ee5\u7528\u6765\u4f20\u9001\u58f0\u97f3\u548c\u6d3b\u52a8\u56fe\u50cf\u6570\u636e\uff0c\u5728\u8fd9\u9879\u6570\u636e\u4f20\u8f93\u4e1a\u52a1\u4e2d\u5305\u542b\u4e86\u88c5\u8f7d\u6570\u636e\u7684\u6807\u8bc6\u7b26\u3001\u5e8f\u5217\u53f7\u3001\u65f6\u6233\u4ee5\u53ca\u4f20\u9001\u76d1\u89c6\u3002\u901a\u5e38RTP\u7684\u534f\u8bae\u6570\u636e\u5355\u5143\u662f\u7528UDP\u5206\u7ec4\u6765\u627f\u8f7d\u7684\u3002\u800c\u4e14\u4e3a\u4e86\u5c3d\u91cf\u51cf\u5c11\u65f6\u5ef6\uff0c\u8bdd\u97f3\u51c0\u8377\u901a\u5e38\u90fd\u5f88\u77ed\u3002\u56fe3\u8868\u793a\u4e00\u4e2aIP\u8bdd\u97f3\u5206\u7ec4\u7684\u7ed3\u6784\uff0c\u56fe\u4e2d IP\uff0cUDP\u548cRTP\u7684\u63a7\u5236\u5934\u90fd\u6309\u6700\u5c0f\u957f\u5ea6\u8ba1\u7b97\u3002 \u8fd9\u79cdIP\u8bdd\u97f3\u5206\u7ec4\u7684\u5f00\u9500\u5f88\u5927\uff0c\u7ea6\u4e3a66\uff05\uff5e80\uff05\u3002\u4e8e\u662f\u6709\u4eba\u63d0\u51fa\u4e86\u7ec4\u5408RTP\u5206\u7ec4\u7684\u6982\u5ff5<\/p>\n\n\n\n

 \u91c7\u7528\u8fd9\u79cd\u7ec4\u5408\u590d\u7528\u65b9\u6cd5\u7684\u786e\u53ef\u4ee5\u5927\u5927\u63d0\u9ad8\u4f20\u8f93\u6548\u7387\uff0c\u4f46\u662f\u76ee\u524d\u5c1a\u65e0\u6807\u51c6\u3002<\/p>\n\n\n\n

\u5982\u679c\u652f\u6301RTP\u7684\u7f51\u7edc\u80fd\u63d0\u4f9b\u7ec4\u64ad\u529f\u80fd\uff0c\u5219\u5b83\u4e5f\u53ef\u7528\u7ec4\u64ad\u65b9\u5f0f\u5c06\u6570\u636e\u9001\u7ed9\u591a\u4e2a\u76ee\u7684\u7528\u6237\u3002<\/p>\n\n\n\n

RTP \u672c\u8eab\u6ca1\u6709\u63d0\u4f9b\u4efb\u4f55\u786e\u4fdd\u53ca\u65f6\u4f20\u9001\u7684\u673a\u5236\uff0c\u4e5f\u6ca1\u6709\u63d0\u4f9b\u4efb\u4f55\u4f20\u8f93\u8d28\u91cf\u4fdd\u8bc1\u7684\u673a\u5236\uff0c\u56e0\u800c\u4e1a\u52a1\u8d28\u91cf\u5b8c\u5168\u7531\u4e0b\u5c42\u7f51\u7edc\u7684\u8d28\u91cf\u6765\u51b3\u5b9a\u3002\u540c\u65f6\uff0cRTP\u4e0d\u4fdd\u8bc1\u6570\u636e\u5305\u6309\u5e8f\u53f7\u4f20\u9001\uff0c\u5373\u4f7f\u4e0b\u5c42\u7f51\u7edc\u63d0\u4f9b\u53ef\u9760\u6027\u4f20\u9001\uff0c\u4e5f\u4e0d\u80fd\u4fdd\u8bc1\u6570\u636e\u5305\u7684\u987a\u5e8f\u5230\u8fbe\u3002\u5305\u542b\u5728RTP\u4e2d\u7684\u5e8f\u5217\u53f7\u5c31\u662f\u4f9b\u63a5\u6536\u65b9\u91cd\u65b0\u5bf9\u6570\u636e\u5305\u6392\u5e8f\u4e4b\u7528\u3002<\/p>\n\n\n\n

\u4e0eRTP\u76f8\u914d\u5957\u7684\u53e6\u4e00\u4e2a\u534f\u8bae\u662fRTCP\u534f\u8bae\u3002RTCP\u662fRTP\u7684\u63a7\u5236\u534f\u8bae\uff0c\u5b83\u7528\u4e8e\u76d1\u89c6\u4e1a\u52a1\u8d28\u91cf\u5e76\u4e0e\u6b63\u5728\u8fdb\u884c\u7684\u4f1a\u8bdd\u8005\u4f20\u9001\u4fe1\u606f\u3002<\/p>\n\n\n\n

\u56e0\u6b64\uff0c\u6211\u4eec\u53ef\u4ee5\u6839\u636e\u8fd9\u4e2a\u56fe\uff13\u8ba1\u7b97\u51fa\u6bcf\u8defG.729\u7f16\u7801\u7684\u5e26\u5bbd\u5360\u7528\u91cf\uff1a<\/p>\n\n\n\n

\u5e26\u5bbd\u5360\u7528\uff1d\u4f20\u8f93\u7684\u603b\u5b57\u8282\u6570 \/ \u4f20\u8f93\u7684\u603b\u65f6\u95f4<\/p>\n\n\n\n

\u5e26\u5bbd\uff1d(20byte\uff08IP\u5934\uff09+8byte\uff08UDP\u5934\uff09+12byte\uff08RTP\u5934\uff09+20byte(\u6570\u636e))\/\uff12\uff10ms=60byte\/20ms<\/p>\n\n\n\n

\u4ee5\u4e0a\u8ba1\u7b97\u516c\u5f0f\u542b\u4e49\u4e3a\uff1a\u6bcf20ms\uff0c\u9700\u8981\u4f20\u8f93\u7684\u5b57\u8282\u6570\u5305\u62ec20\u4e2a\u5b57\u8282\u7684IP\u5305\u5934\uff0c8\u4e2a\u5b57\u8282\u7684UDP\u5305\u5934\uff0c12\u5404\u5b57\u8282\u7684RTP\u5305\u5934\uff0c20\u5b57\u8282\u7684\u8bed\u97f3\u6570\u636e\u517160\u5b57\u8282\uff0c\u7ed3\u679c\u4e3a\uff1a3 byte\/ms=3000byte\/s=24000bit\/s\uff1d24kbit\/s\u3002<\/p>\n\n\n\n

\u56e0\u6b64\uff0c\u7406\u8bba\u4e0aG.729\u4e2d\u6bcf\u4e2a\u6570\u636e\u5305\u5305\u542b\u4e24\u5e27\u8bed\u97f3\u7684\u7f16\u7801\u65b9\u5f0f\uff0c\u5360\u7528\u5e26\u5bbd24kbit\/s\uff0c\u800c\u53c8\u6709\u5c01\u88c5\u6548\u7387\u7684\u4f30\u7b97\u516c\u5f0f\u4e3a\uff1a<\/p>\n\n\n\n

\u5c01\u88c5\u6548\u7387=[\uff08\u538b\u7f29\u540e\u7684\u8bed\u97f3\u5305\u00d7 n \u00d7 \u5e27\u957f\/ 8\uff09] \/ [\uff08\u538b\u7f29\u540e\u7684\u8bed\u97f3\u5305\u00d7n\u00d7 \u5e27\u957f\/ 8 \uff09\uff0b40] \u3002<\/p>\n\n\n\n

n\u8868\u793a\u6253\u8fdbn\u4e2a\u8bed\u97f3\u5305\u3002<\/p>\n\n\n\n

\u4ee5G.729\u4fe1\u6e90\u7f16\u7801\u4e3a\u4f8b\uff0c\u5982\u4e00\u4e2aRTP\u5305\u6253\u8fdb\u4e00\u4e2a\u8bed\u97f3\u5305\uff0c\u5219\u5b9e\u9645\u4f20\u9001\u7801\u6d41\u4e3a40kbit\/s\uff0c\u65f6\u5ef6\u7ea6\u4e3a 10 ms\uff1b<\/p>\n\n\n\n

\u5982\u6253\u4e24\u4e2a\u8bed\u97f3\u5305\uff0c\u5219\u5b9e\u9645\u4f20\u9001\u7801\u6d41\u4e3a24kbit\/s\uff0c\u65f6\u5ef6\u7ea6\u4e3a 20ms\uff1b<\/p>\n\n\n\n

\u5982\u6253\u56db\u4e2a\u8bed\u97f3\u5305\uff0c\u5b9e\u9645\u4f20\u9001\u7801\u6d41\u4e3a16kbit\/s\uff0c\u65f6\u5ef6\u4e3a40ms\u3002<\/p>\n\n\n\n

\u4e3a\u4fdd\u8bc1\u7f16\u7801\u6253\u5305\u7684\u65f6\u5ef6\uff0c\u82e5\u5c06\u7f3a\u7701\u8bed\u97f3\u5305\u7684\u6570\u91cf\u5b9a\u4e3a\u4e24\u4e2a\uff0c\u5b9e\u9645\u4f20\u9001\u7801\u6d41\u5373\u4e3a24kbit\/s\uff0c\u800c\u4e0d\u662f8kbit\/s\u3002<\/p>\n\n\n\n

\u56e0\u6b64\u5bf9\u4e8e\u8bed\u97f3\u4e1a\u52a1\u8fd9\u7c7b\u5b9e\u65f6\u6027\u8981\u6c42\u975e\u5e38\u9ad8\u7684\u4e1a\u52a1\uff0c\u8981\u4fdd\u8bc1\u8bed\u97f3\u7684\u8d28\u91cf\uff0c\u6839\u636eITU-T\u6807\u51c6\u8bed\u97f3\u7684\u5168\u7a0b\u5f80\u8fd4\u65f6\u5ef6\u5e94\u5f53\u63a7\u5236\u5728450ms\u4e3a\u5b9c\uff0c\u7f16\u7801\u6253\u5305\u540e\u5f62\u6210\u7684\u5355\u4f4d\u7801\u6d41\u901a\u5e38\u662f\u572820kbit\/s\u3002 <\/p>\n\n\n\n

\u7531\u4ee5\u4e0a\u8bba\u8ff0\u6211\u4eec\u77e5\u9053\uff0c\u6bcf\u8defG.729\u7f16\u7801\u7684IP\u8bed\u97f3\u5360\u7528\u7ea620Kbit\/s\u7684\u5e26\u5bbd\uff0c\u5b9e\u9645\u5360\u7528\u7684\u603b\u5e26\u5bbd\u6570\uff1d\u8bed\u97f3\u603b\u8def\u6570*20Kbit\/s\u3002<\/p>\n\n\n\n

\u8bed\u97f3\u7f16\u89e3\u7801\u65b9\u5f0f\u53ca\u5176\u6240\u5360\u7528\u7684\u5e26\u5bbd\u7684\u5173\u7cfb 
\u8bed\u97f3\u7f16\u7801\u7684\u5e26\u5bbd\u548c\u5b9e\u9645\u6240\u5360\u7528\u7684\u5e26\u5bbd\u662f\u4e0d\u540c\u7684\uff0c\u8bed\u97f3\u7f16\u7801\u7684\u5e26\u5bbd\u662f\u5b9e\u9645\u8bed\u97f3\u5305\u7684\u5e26\u5bbd\uff0c\u800c\u8bed\u97f3\u5305\u5728IP\u7f51\u7edc\u4e0a\u4f20\u8f93\u65f6\uff0c\u8fd8\u9700\u8981\u589e\u52a0\u5404\u79cd\u5305\u5934\uff0c\u5982RTP\u5305\u5934\u3001UDP\u5305\u5934\u3001IP\u5305\u5934\u3002\u7531\u4e8e\u8bed\u97f3\u5305\u672c\u8eab\u5f88\u5c0f\uff0c\u6240\u4ee5\u76f8\u5bf9\u800c\u8a00\u8fd9\u4e9b\u989d\u5916\u7684\u5e26\u5bbd\u662f\u5f88\u53ef\u89c2\u7684\u3002\u5728\u4e0b\u8868\u4e2d\u5217\u51fa\u4e86\u5404\u79cd\u7f16\u7801\u65b9\u5f0f\u4e0b\u7684\u6253\u5305\u65f6\u957f\u4ee5\u53ca\u6240\u5bf9\u5e94\u7684\u5b9e\u9645\u5e26\u5bbd\u3002

\u5b9e\u9645\u5e26\u5bbd\u4e0e\u8bed\u97f3\u7f16\u7801\u548c\u6253\u5305\u65f6\u957f\u7684\u5173\u7cfb\uff1a
\u8bed\u97f3\u7f16\u89e3\u7801        \u6253\u5305\u65f6\u957f     \u8bed\u97f3\u6570\u636e\u5e26\u5bbd    \u5b9e\u9645\u6240\u5360\u5e26\u5bbd
G.723.1(5.3K)       30ms        5.3K            5.3*(20+40)\/20=   16.2K 
G.723.1(5.3K)       60ms        5.3K            5.3*(40+40)\/40=   10.6K
G.723.1(6.3K)       30ms        6.3K            6.3*(24+40)\/24=   16.8K
G.723.1(6.3K)       60ms        6.3K            6.3*(48+40)\/48=   11.6K
G.729               20ms        8K              8*(20+40)\/20=   24K  
G.729               60ms        8K              8*(60+40)\/60=   13.3K
\u7531\u4e0a\u8868\u53ef\u4ee5\u5f88\u660e\u663e\u7684\u770b\u51fa\uff0c\u6253\u5305\u65f6\u95f4\u8d8a\u957f\uff0c\u6240\u5360\u7528\u7684\u5b9e\u9645\u5e26\u5bbd\u8d8a\u5c0f\uff0c\u4f46\u65f6\u5ef6\u8d8a\u5927\u3002

\u8bf4\u660e
1\u3001RTP\u5305\u5934\uff1a12bytes   UDP\u5305\u5934\uff1a8bytes    IP\u5305\u5934\uff1a20bytes\u3002
2\u3001\u8868\u4e2d\u7684\u5e26\u5bbd\u8ba1\u7b97\u4e2d\u6ca1\u6709\u5305\u542b\u7269\u7406\u5e27\u5934\uff0c\u9700\u6839\u636e\u5177\u4f53\u7f51\u7edc\u800c\u5b9a\u3002
3\u3001\u8868\u4e2d\u7684\u5e26\u5bbd\u8ba1\u7b97\u4e2d\uff0c\u6ca1\u6709\u8003\u8651\u9759\u97f3\u68c0\u6d4b\u3002\u9759\u97f3\u68c0\u6d4b\u7684\u6548\u7387\u630960\uff05\u8ba1\u7b97\u3002<\/p>\n\n\n\n

\u97f3\u9891\uff1a<\/p>\n\n\n\n
\u540d\u79f0<\/td>     \u91c7\u6837\u7387<\/td>\u91c7\u6837\u7cbe\u5ea6<\/td>\u5360\u7528\u5e26\u5bbd(kbps)<\/td><\/tr>
G.723.1<\/td>8k<\/td>16bit<\/td>5.3 ~ 6.3kbps<\/td><\/tr>
ILBC<\/td>8k<\/td>16bit<\/td>13.33 ~ 15.2kbps<\/td><\/tr>
CCITT A-LAW<\/td>8k<\/td>16bit<\/td>64 ~ 128kbps<\/td><\/tr><\/tbody><\/table>\n\n\n\n


\u89c6\u9891\uff1a<\/strong><\/p>\n\n\n\n
\u56fe\u50cf\u5206\u8fa8\u7387 \u2014\u2014 \u5e27\u6570<\/td>\u5360\u7528\u5e26\u5bbd(kbps)<\/td><\/tr>
160 \u00d7 120 \u2014\u2014 5 ~ 30fps<\/td>20 ~ 100kbps<\/td><\/tr>
176 \u00d7 144 \u2014\u2014 5 ~ 25fps<\/td>20 ~ 110kbps<\/td><\/tr>
320 \u00d7 240 \u2014\u2014 5 ~ 30fps<\/td>40 ~ 200kbps<\/td><\/tr>
352 \u00d7 288 \u2014\u2014 5 ~ 25fps<\/td>40 ~ 220kbps<\/td><\/tr>
640 \u00d7 480 \u2014\u2014 5 ~ 30fps<\/td>120 ~ 1000kbps<\/td><\/tr>
720 \u00d7 576 \u2014\u2014 5 ~ 25fps<\/td>120 ~ 1500kbps<\/td><\/tr><\/tbody><\/table>\n\n\n\n

\u56fd\u9645\u7535\u4fe1\u8054\u76df G \u7cfb\u5217\u5178\u578b\u8bed\u97f3\u538b\u7f29\u6807\u51c6\u7684\u53c2\u6570\u6bd4\u8f83<\/p>\n\n\n\n
\u7b97\u6cd5<\/td>\u7c7b\u578b<\/td>\u7801\u7387 (kbit\/s)<\/td>\u7b97\u6cd5\u5ef6\u65f6 (ms)<\/td><\/tr>
G.711<\/td>A-Law \/ \u03bc -Law<\/td>64<\/td>0<\/td><\/tr>
G.722<\/td>SB-ADPCM<\/td>64\/56\/48<\/td>0<\/td><\/tr>
G.723.1<\/td>MP-MLQ\/ACELP<\/td>6.3\/5.3<\/td>37.5<\/td><\/tr>
G.726<\/td>ADPCM<\/td>16\/24\/32\/40<\/td>0<\/td><\/tr>
G.727<\/td>Embedded ADPCM<\/td>16\/24\/32\/40<\/td>0<\/td><\/tr>
G.728<\/td>LD-CELP<\/td>16<\/td>< 2<\/td><\/tr>
G.729<\/td>CS-ACELP<\/td>8<\/td>15<\/td><\/tr><\/tbody><\/table>\n\n\n\n


PCM\u76848K\u91c7\u6837\u7387\u7684\u7531\u6765\uff1aNyquist(\u90a3\u594e\u65af\u7279)\u5b9a\u7406\u8ba4\u4e3a\u5982\u679c\u4ee5\u6700\u9ad8\u9891\u73872\u500d\u7684\u901f\u7387\u91c7\u6837\uff0c\u5c31\u53ef\u4ee5\u5c06\u4fe1\u53f7\u5b8c\u6574\u5730\u6062\u590d\u5230\u6a21\u62df\u5f62\u5f0f\u2014\u2014\u5927\u591a\u6570\u58f0\u97f3\u90fd\u4f4e\u4e8e4KHz\uff1b
A-law\u4e0eu-law\uff0c\u90fd\u4f7f\u7528\u538b\u7f29\u7b97\u6cd5\u57288\u4f4d\u4e2d\u5f97\u523012-13\u4f4d\u7684PCM\u8d28\u91cf\uff0c\u67d0\u4e9b\u60c5\u51b5\u4e0bu-law\u7684\u58f0\u97f3\u8d28\u91cf\u7a0d\u597d\u4e8eA-law\uff1b\u5982\u679c\u9700\u8981u-law\u5230a-law\u7684\u8f6c\u6362\uff0c\u5219\u7531u-law\u56fd\u5bb6\u8d1f\u8d23\uff1b
\u7f16\u7801\u5668\u5206\u7c7b\uff1a\u6ce2\u5f62\u7f16\u7801\u5668\u2014\u2014PCM\u3001ADPCM\uff0c\u5229\u7528\u6ce2\u5f62\u5197\u4f59\u7279\u6027\u7f16\u7801\u7684\u538b\u7f29\u6280\u672f\uff1b\u6e90\u7f16\u7801\u5668\u2014\u2014\u5229\u7528\u58f0\u97f3\u4ea7\u751f\u7684\u6e90\u7279\u6027\uff0c\u53ea\u53d1\u9001\u539f\u59cb\u8bed\u97f3\u7684\u7b80\u5316\u7279\u5f81\u4fe1\u606f\uff0c\u5305\u62ecLPC\uff08linear predictivecoding\uff09\uff0cCELP\uff08code excitedlinear prediction compression\uff09\uff0cMP-MLQ\uff08multipulse,multilevel quantization\uff09\u7b49
G.7xx\u7cfb\u5217\u4e0ePCM\u7b49\u7684\u5173\u7cfb\uff0c\u524d\u8005\u662f\u6807\u51c6\uff0c\u540e\u8005\u662f\u7b97\u6cd5\uff1b
\u8861\u91cf\u7f16\u7801\u4f18\u52a3\u7684\u6807\u51c6\uff1abit\u7387\uff0c\u65f6\u5ef6\uff0c\u590d\u6742\u5ea6\uff0c\u8d28\u91cf\uff1b
\u8bed\u97f3\u8d28\u91cf\u7684\u8bc4\u6d4b\uff1a\u4e3b\u89c2\u8bc4\u6d4bMOS\uff08mean opinion score\uff0c\u5e73\u5747\u610f\u89c1\u5f97\u5206\uff09\uff0c\u7531\u4eba\u6839\u636e\u4e3b\u89c2\u611f\u53d7\u7ed9\u51fa\uff1b\u5ba2\u89c2\u8bc4\u6d4bPSQM\uff08Perceptual SpeechQuality Measurement\uff0c\u77e5\u89c9\u8bed\u97f3\u8d28\u91cf\u6d4b\u91cf\uff09\uff0c\u7531\u8ba1\u7b97\u673a\u6839\u636e\u67d0\u4e9b\u5ba2\u89c2\u6570\u636e\u7ed9\u51fa\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"

\u4e3b\u8981\u7684speech codec \u6709: G.711, G.723, G.726 , G.72…<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[6],"tags":[],"class_list":["post-104","post","type-post","status-publish","format-standard","hentry","category-cxbc"],"_links":{"self":[{"href":"http:\/\/feel.name\/index.php?rest_route=\/wp\/v2\/posts\/104","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/feel.name\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/feel.name\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/feel.name\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/feel.name\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=104"}],"version-history":[{"count":1,"href":"http:\/\/feel.name\/index.php?rest_route=\/wp\/v2\/posts\/104\/revisions"}],"predecessor-version":[{"id":105,"href":"http:\/\/feel.name\/index.php?rest_route=\/wp\/v2\/posts\/104\/revisions\/105"}],"wp:attachment":[{"href":"http:\/\/feel.name\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=104"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/feel.name\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=104"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/feel.name\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=104"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}