{"id":456,"date":"2022-01-31T18:53:57","date_gmt":"2022-01-31T10:53:57","guid":{"rendered":"http:\/\/192.168.0.122:8088\/?p=456"},"modified":"2022-06-11T03:08:38","modified_gmt":"2022-06-10T19:08:38","slug":"ffplay%e6%ba%90%e7%a0%81%e5%88%86%e6%9e%90-streams_open","status":"publish","type":"post","link":"https:\/\/www.xianwaizhiyin.net\/?p=456","title":{"rendered":"FFplay\u6e90\u7801\u5206\u6790-streams_open"},"content":{"rendered":"\n<p>\u672c\u7cfb\u5217 \u4ee5 ffmpeg4.2 \u6e90\u7801\u4e3a\u51c6\uff0c\u4e0b\u8f7d\u5730\u5740\uff1a\u94fe\u63a5\uff1a<a href=\"https:\/\/pan.baidu.com\/s\/1VpUvpLhew-nuq4Dns80mOw\">\u767e\u5ea6\u7f51\u76d8<\/a> \u63d0\u53d6\u7801\uff1ag3k8<\/p>\n\n\n\n<p>FFplay \u6e90\u7801\u5206\u6790\u7cfb\u5217\u4ee5\u4e00\u6761\u7b80\u5355\u7684\u547d\u4ee4\u5f00\u59cb\uff0c<code class=\"prettyprint\" >ffplay -i a.mp4<\/code>\u3002a.mp4\u4e0b\u8f7d\u94fe\u63a5\uff1a<a href=\"https:\/\/pan.baidu.com\/s\/1RN1xRsQDGx65MGyB_T1IzA\">\u767e\u5ea6\u7f51\u76d8<\/a>\uff0c\u63d0\u53d6\u7801\uff1anl0s \u3002<\/p>\n\n\n\n<hr class=\"wp-block-separator has-css-opacity\"\/>\n\n\n\n<p>\u5982\u4e0b\u56fe\u6240\u793a\uff0c\u672c\u6587\u4e3b\u8981\u8bb2\u89e3 <strong>streams_open()<\/strong> \u51fd\u6570\u7684\u5185\u90e8\u903b\u8f91\u3002<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"635\" height=\"484\" src=\".\/wp-content\/uploads\/2022\/01\/ffplay-4-1.png\" alt=\"\" class=\"wp-image-459\"\/><\/figure>\n\n\n\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"825\" height=\"784\" src=\".\/wp-content\/uploads\/2022\/01\/ffplay-4-2.png\" alt=\"\" class=\"wp-image-457\"\/><\/figure>\n\n\n\n<p>\u5982\u4e0a\u56fe\u6240\u793a\uff0c<strong>streams_open()<\/strong> \u91cc\u9762\u6bd4\u8f83\u91cd\u8981\u7684\u51fd\u6570\u5c31\u662f \u521d\u59cb\u5316 frame_queue \u8ddf packet_queue\uff0c\u6211\u753b\u4e00\u4e2a\u6570\u636e\u7ed3\u6784\u56fe\u4f1a\u66f4\u5bb9\u6613\u7406\u89e3\u3002<\/p>\n\n\n\n<p>\u6570\u636e\u7ed3\u6784\u56fe\uff0c\u6211\u753b\u7740\u753b\u7740\uff0c\u4e0d\u5c0f\u5fc3\u753b\u51fa\u4e86\u6574\u4f53\u7684\u6570\u636e\u5173\u7cfb\u56fe\uff0c\u4e0d\u8fc7\u5927\u5bb6\u6682\u65f6\u53ea\u9700\u8981\u5173\u6ce8 Frame \u90a3\u5757\u5c31\u884c\u3002<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"2020\" height=\"1354\" src=\".\/wp-content\/uploads\/2022\/01\/ffplay-4-3.png\" alt=\"\" class=\"wp-image-458\"\/><\/figure>\n\n\n\n<p>\u5982\u4e0a\u56fe\u6240\u793a\uff0c\u6211\u5148\u7b80\u5355\u8bb2\u89e3\u4e00\u4e0b\u4e0a\u9762\u5168\u5c40\u7684\u6570\u636e\u5173\u7cfb\u56fe\u3002<\/p>\n\n\n\n<p>\u53ef\u4ee5\u770b\u5230 <strong>struct VideoState<\/strong> \u7edf\u9886\u4e86\u5168\u5c40\u3002\u6bcf\u4e00\u4e2a\u6570\u636e\u6d41\uff0c\u97f3\u9891\u6d41\uff0c\u89c6\u9891\u6d41\uff0c\u6570\u636e\u6d41\uff0c\u90fd\u6709\u5404\u81ea\u7684 <strong>struct FrameQueue<\/strong>\uff0c<strong>struct PacketQueue<\/strong>\uff0c<strong>struct Decoder<\/strong>\u3002<\/p>\n\n\n\n<ul class=\"wp-block-list\"><li><strong>struct FrameQueue<\/strong> : frame \u7f13\u5b58\u961f\u5217\uff0c\u7528\u4e8e\u7ed9SDL\u64ad\u653e\u3002<\/li><li><strong>struct PacketQueue<\/strong>: packet \u7f13\u5b58\u961f\u5217\uff0c\u7528\u6765\u89e3\u7801\u540e \u63d2\u5165 frame \u7f13\u5b58\u961f\u5217\u3002<\/li><li><strong>struct Decoder<\/strong> \uff1a\u89e3\u7801\u5668\u5c01\u88c5\u3002<\/li><\/ul>\n\n\n\n<p>\u6709\u4e00\u70b9\u9700\u8981\u6ce8\u610f\u7684\u662f <strong>FrameQueue<\/strong> \u662f\u4e00\u4e2a\u9759\u6001\u6570\u7ec4\uff0c<strong>PacketQueue<\/strong> \u662f\u4e00\u4e2a\u52a8\u6001\u94fe\u8868\u3002 <strong>FrameQueue<\/strong> \u76f8\u5bf9\u590d\u6742\u4e00\u70b9\uff0c\u540e\u9762\u4f1a\u8be6\u7ec6\u8bb2\u89e3\u3002<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<p>google_ads_content<\/p>\n\n\n\n<hr class=\"wp-block-separator has-css-opacity\"\/>\n\n\n\n<p>\u5148\u4ecb\u7ecd\u4e00\u4e0b <strong>struct Frame<\/strong> \u7ed3\u6784\u4f53\u91cc\u9762\u5404\u4e2a\u6210\u5458\u7684\u4f5c\u7528\u3002<\/p>\n\n\n\n<ul class=\"wp-block-list\"><li><strong>AVFrame *frame<\/strong>; \u5b58\u50a8\u89c6\u9891\u6216\u97f3\u9891\u7684 frame\u3002<\/li><li><strong>AVSubtitle sub<\/strong>; \u5b58\u50a8\u5b57\u5e55\u6570\u636e\uff0c\u4e0d\u7528\u5173\u6ce8\u3002<\/li><li><strong>int serial<\/strong>; Frame \u7684 serial \u53f7\uff0c\u4f5c\u7528\u662f \u62d6\u8fdb\u5ea6\u6761\uff0c\u6539\u53d8\u64ad\u653e\u4f4d\u7f6e\u540e\uff0c\u4e22\u5f03\u4e4b\u524d\u7f13\u5b58\u7684\u65e7Frame\u3002\u7b2c\u4e09\u7bc7\u6587\u7ae0\u8bf4\u8fc7\uff0c\u6539\u53d8\u64ad\u653e\u4f4d\u7f6e\uff0c\u5c31\u4f1a\u63d2\u5165\u4e00\u4e2a <strong>flush_pkt<\/strong> \u5230 <strong>PacketQueue<\/strong> \u961f\u5217\uff0c\u5bfc\u81f4 <strong>PacketQueue::serial + 1<\/strong> \uff0c\u4f46\u4e4b\u524d FrameQueue \u91cc\u91cc\u9762\u7f13\u5b58\u7684 Frame\u7684serial \u5e76\u6ca1\u6709+1\uff0c\u6240\u4ee5 \u65e7\u7684 Frame::serial \u4e0d\u7b49\u4e8e\u65b0\u7684 <strong>PacketQueue::serial<\/strong> \uff0c\u6240\u4ee5\u64ad\u653e\u4f4d\u7f6e\u6539\u53d8\u4e4b\u540e\uff0c\u7f13\u5b58\u91cc\u9762\u65e7\u7684Frame\u5c31\u4f1a\u4e22\u5f03\u4e0d\u8fdb\u884c\u64ad\u653e\u3002<\/li><li><strong>double pts<\/strong>; \u7531AVFrame\u7684pts\u8f6c\u6362\u5f97\u6765\uff0c\u64ad\u653e\u65f6\u95f4\uff0c\u5355\u4f4d\u662f \u79d2\u3002<\/li><li><strong>double duration<\/strong>; \u6301\u7eed\u65f6\u95f4\uff0c\u7531 frame_rate \u5e27\u7387\u8ba1\u7b97\u5f97\u5230\uff0c\u5355\u4f4d\u662f \u79d2\u3002<\/li><li><strong>int64_t pos<\/strong>; \u7b49\u4e8e AVFrame::pkt_pos\u3002<\/li><li><strong>int width<\/strong>; \u7b49\u4e8e AVFrame::width<\/li><li><strong>int height<\/strong>; \u7b49\u4e8e AVFrame::height<\/li><li><strong>int format<\/strong>; \u7b49\u4e8e AVFrame::format<\/li><li><strong>AVRational sar<\/strong>; \u7b49\u4e8e AVFrame::sample_aspect_ratio\u3002 sar \u8fd9\u4e2a\u53d8\u91cf\u9700\u8981\u4ed4\u7ec6\u8bb2\u89e3\u4e00\u4e0b\uff0c\u6211\u521a\u5f00\u59cb\u4e5f\u88ab\u8fd9\u4e2asar\u641e\u61f5\u3002\u6211\u4e4b\u524d\u4ee5\u4e3a sar \u7b49\u4e8e width\/height \u3002\u540e\u6765\u53d1\u73b0\u4e0d\u662f\u3002\u5176\u5b9esar \u662f\u4ee5\u524d\u7684\u663e\u793a\u8bbe\u5907\u8bbe\u8ba1\u7684\u5386\u53f2\u9057\u7559\u95ee\u9898\uff0c\u4e0d\u7528\u8fc7\u591a\u5173\u6ce8\uff0c\u53ea\u9700\u8981\u77e5\u9053\uff0c\u663e\u793a\u7684\u65f6\u5019\u7528 sar \u8fd9\u4e2a\u6bd4\u4f8b\u62c9\u4f38width \u8ddfheight \u4f5c\u4e3a\u663e\u793a\u7a97\u53e3\uff0c\u56fe\u50cf\u64ad\u653e\u5c31\u4e0d\u4f1a\u626d\u66f2\u4e86\u3002\u63a8\u8350\u9605\u8bfb\uff0c<a href=\"https:\/\/blog.csdn.net\/zhizhuodewo6\/article\/details\/105247557\">ffmpeg\u89e3\u6790\u51fa\u7684\u89c6\u9891\u53c2\u6570PAR\uff0cDAR\uff0cSAR\u7684\u610f\u4e49<\/a> \u8ddf <a href=\"https:\/\/www.animemusicvideos.org\/guides\/avtech3\/theory-videoaspectratios.html\">theory-videoaspectratios<\/a><\/li><li><strong>int uploaded<\/strong>; uploaded\u53ea\u5bf9\u89c6\u9891\u5e27\u6709\u6548\uff0c\u97f3\u9891\u5e27\u6ca1\u7528\u3002\u5f53\u524dAVFrame\u7684\u6570\u636e\u662f\u5426\u5df2\u7ecf\u6e32\u67d3\u5230 <strong>VideoState::vid_texture<\/strong> \uff0cvid_texture \u662f\u4e00\u4e2a SDL_Texture \u7ed3\u6784\u3002\u89c6\u9891\u5e27\u4e3a\u4ec0\u4e48\u8981\u5b9a\u4e49\u8fd9\u4e48\u4e00\u4e2a\u53d8\u91cfuploaded\u5462\uff1f\u662f\u56e0\u4e3a\u97f3\u89c6\u9891\u540c\u6b65\u6709\u65f6\u5019\u9700\u8981\u91cd\u590d\u64ad\u653e\u4e0a\u4e00\u5e27\u89c6\u9891\uff0c\u4e0a\u4e00\u5e27\u5982\u679c\u5df2\u7ecf\u62f7\u8d1d\u8fc7\u7ed9 SDL_Texture \u4e86\uff0cuploaded \u5c31\u4f1a\u7f6e\u4e3a 1\uff0c\u5c31\u53ef\u4ee5\u76f4\u63a5\u628a <strong>VideoState::vid_texture<\/strong> \u4e22\u7ed9 SDL \u7684render\u6e32\u67d3\u5c31\u884c\uff0c\u8282\u7701\u5f00\u9500\u3002<\/li><li><strong>int flip_v<\/strong>; \u8c8c\u4f3c\u662f\u63a7\u5236\u64ad\u653e\u7ffb\u8f6c\u7684\uff0cAVFrame::linesize \u5982\u679c\u662f\u8d1f\u6570\uff0cflip_v \u5c31\u662f 1\u3002\u4e0d\u7528\u7279\u522b\u5173\u6ce8\u3002<\/li><\/ul>\n\n\n\n<hr class=\"wp-block-separator has-css-opacity\"\/>\n\n\n\n<p>\u63a5\u7740\u4ecb\u7ecd\u4e00\u4e0b <strong>struct FrameQueue<\/strong> \u7ed3\u6784\u4f53\u91cc\u9762\u5404\u4e2a\u6210\u5458\u7684\u4f5c\u7528\u3002<\/p>\n\n\n\n<ul class=\"wp-block-list\"><li><strong>Frame queue[FRAME_QUEUE_SIZE]<\/strong> ; Frame \u9759\u6001\u6570\u7ec4\uff0c\u7528\u6765\u5b58\u50a8\u591a\u4e2aFrame\uff0c\u5f62\u6210\u961f\u5217\uff0cFRAME_QUEUE_SIZE\u7b49\u4e8e16\u3002<\/li><li><strong>int rindex<\/strong>; \u8bfb\u7d22\u5f15\uff0c\u5f53\u524d\u8bfb\u53d6\u5230\u90a3\u4e2aFrame\uff0c\u901a\u8fc7 <strong>queue[rindex]<\/strong> \u53ef\u4ee5\u53d6\u51fa Frame\u3002\uff08\u5b9e\u9645\u4e0a\u8fd8\u6709\u4e00\u4e2a <strong>rindex_shown<\/strong>\uff0c\u8fd9\u4e2a\u53d8\u91cf\u540e\u7eed\u8bb2\u89e3\uff09<\/li><li><strong>int windex<\/strong>; \u5199\u7d22\u5f15\uff0c\u901a\u8fc7 <strong>queue[windex]<\/strong> \u5224\u65ad\u89e3\u7801\u51fa\u6765\u7684AVFrame \u5e94\u8be5\u5199\u5230\u54ea\u91cc\u3002<\/li><li><strong>int size<\/strong>; \u5f53\u524d\u961f\u5217\u5df2\u7ecf\u7f13\u5b58\u4e86\u591a\u5c11\u4e2a Frame\u3002<\/li><li><strong>int max_size<\/strong>; \u961f\u5217\u6700\u591a\u53ef\u7f13\u5b58\u591a\u5c11 Frame\uff0cmax_size \u53ef\u4ee5 \u5c0f\u4e8e FRAME_QUEUE_SIZE\u3002<\/li><li><strong>int keep_last;<\/strong> \u64ad\u653e\u4e4b\u540e\u662f\u5426\u4fdd\u5b58\u4e0a\u4e00\u5e27\u5728\u961f\u5217\u91cc\u9762\u4e0d\u9500\u6bc1<\/li><li><strong>int rindex_shown<\/strong>; \u9700\u8981\u91cd\u70b9\u8bb2\u89e3<\/li><li><strong>SDL_mutex *mutex<\/strong>; \u9501\uff0c\u961f\u5217\u4fee\u6539\u7684\u65f6\u5019\u9700\u8981\u52a0\u9501\u3002<\/li><li><strong>SDL_cond *cond<\/strong>; \u6761\u4ef6\u53d8\u91cf\uff0c\u7528\u4e8e\u89e3\u7801\u7ebf\u7a0b\u8ddf\u64ad\u653e\u7ebf\u7a0b\u901a\u4fe1\u3002\u4f8b\u5982\u5982\u679c FrameQueue \u6570\u636e\u6ee1\u4e86\uff0c\u6ca1\u6cd5\u518d\u5199\u5c31\u4f1a\u52a0\u9501\uff0c\u7136\u540ewait cond\u7b49\u5f85\u8fd9\u4e2a\u6761\u4ef6\u53d8\u91cf\u88ab\u5524\u9192\u3002\u90a3\u8fd9\u4e2a\u6761\u4ef6\u53d8\u91cf\u4ec0\u4e48\u65f6\u5019\u4f1a\u88ab\u5524\u9192\u5462\uff1f\u64ad\u653e\u7684\u65f6\u5019\u9700\u8981\u53d6 FrameQueue \u7684\u6570\u636e\u51fa\u6765\u64ad\u653e\uff0c\u64ad\u653e\u5b8c\u540e\u9500\u6bc1\u4e00\u5e27\u6570\u636e\uff0c\u8fd9\u65f6\u5019 FrameQueue \u6570\u636e\u5c31\u4e0d\u6ee1\u4e86\uff0c\u5c31\u4f1a signal cond\uff0c\u901a\u77e5\u89e3\u7801\u7ebf\u7a0b\u7ee7\u7eed\u89e3\u7801\uff0c\u7ee7\u7eed\u5199 FrameQueue \u3002\u76f8\u53cd\uff0c\u5982\u679c FrameQueue \u6570\u636e\u7a7a\u4e86\uff0c\u64ad\u653e\u7ebf\u7a0b\u4e5f\u4f1a\u52a0\u9501\uff0c\u7136\u540ewait cond\u7b49\u5f85\u8fd9\u4e2a\u6761\u4ef6\u53d8\u91cf\u88ab\u5524\uff0c\u89e3\u7801\u7ebf\u7a0b\u6709\u6570\u636e\u5199\u5165 FrameQueue \u4e86\uff0c\u5c31\u4f1a\u901a\u8fc7 cond \u5524\u9192\u64ad\u653e\u7ebf\u7a0b\u7ee7\u7eed\u64ad\u653e\u3002<\/li><li><strong>PacketQueue *pktq<\/strong>; \u5bf9\u5e94\u7684 Packet \u961f\u5217\uff0cframe \u90fd\u662f\u4ece packet \u89e3\u7801\u51fa\u6765\u7684\u3002<\/li><\/ul>\n\n\n\n<p><strong>FrameQueue<\/strong> \u91cc\u9762\u7684 <strong>keep_last<\/strong> \u8ddf <strong>rindex_shown<\/strong> \u8fd9\u4e24\u4e2a\u53d8\u91cf\u6bd4\u8f83\u96be\u61c2\uff0c\u6211\u4ed4\u7ec6\u8bb2\u89e3\u4e00\u4e0b\u3002keep_last \u5176\u5b9e\u662f\u4e00\u4e2a\u4e34\u65f6\u53d8\u91cf\uff0c\u4ed6\u7684\u4f5c\u7528\u662f\u63a7\u5236 <strong>rindex_shown<\/strong> \u53d8\u6210 1\u3002<strong>rindex_shown<\/strong> \u8fd9\u4e2a\u53d8\u91cf\u540d\u6211\u4e2a\u4eba\u8ba4\u4e3a\u8d77\u7684\u4e0d\u592a\u597d\uff0c\u6211\u4e00\u773c\u770b\u8fd9\u4e2a\u53d8\u91cf\u6ca1\u6cd5\u770b\u51fa\u4ed6\u662f\u505a\u4ec0\u4e48\u7684\u3002\u6216\u8005\u8bf4\u8fd9\u4e2a\u903b\u8f91\u672c\u8eab\u5c31\u590d\u6742\uff0c\u8ddf\u53d8\u91cf\u547d\u540d\u65e0\u5173\u3002<\/p>\n\n\n\n<p>keep_last \u662f\u5982\u4f55\u63a7\u5236 rindex_shown \u53d8\u6210 1 \u7684\u5462\uff0c\u8bf7\u770b\u4e0b\u9762\u4ee3\u7801\u3002<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code class=\"prettyprint\" >static void frame_queue_next(FrameQueue *f)\n{\n    if (f-&gt;keep_last &amp;&amp; !f-&gt;rindex_shown) {\n        f-&gt;rindex_shown = 1; \/\/\u6ce8\u610f\u8fd9\u884c\u4ee3\u7801\u3002\n        return;\n    }\n    frame_queue_unref_item(&amp;f-&gt;queue&#091;f-&gt;rindex]);\n    if (++f-&gt;rindex == f-&gt;max_size)  \/\/\u6ce8\u610f\u8fd9\u884c\u4ee3\u7801\u3002\n        f-&gt;rindex = 0;\n    SDL_LockMutex(f-&gt;mutex);\n    f-&gt;size--;\n    SDL_CondSignal(f-&gt;cond);\n    SDL_UnlockMutex(f-&gt;mutex);\n}<\/code><\/pre>\n\n\n\n<p>\u53ef\u4ee5\u770b\u5230 <strong>f-&gt;keep_last &amp;&amp; !f-&gt;rindex_shown<\/strong> \u4f1a\u5bfc\u81f4 rindex_show \u7f6e\u4e3a 1\uff0c\u7136\u540e\u5c31return \u4e86\uff0c\u6ca1\u6709\u6267\u884c\u540e\u9762\u7684 <strong>frame_queue_unref_item()<\/strong>\uff0c <strong>++f-&gt;rindex<\/strong> \u4e5f\u6ca1\u6709\u6267\u884c\uff0c\u4e5f\u5c31\u662f\u8bf4 <strong>rindex<\/strong> \u8bfb\u7d22\u5f15\u6ca1\u6709\u504f\u79fb\u3002<\/p>\n\n\n\n<p>\u5230\u8fd9\u91cc\uff0c\u8bfb\u8005\u53ef\u80fd\u4f1a\u6709\u7591\u60d1\uff0c\u5982\u679c <strong>rindex<\/strong> \u8bfb\u7d22\u5f15\u6ca1\u6709\u504f\u79fb\uff0c\u4e0b\u6b21\u7528 <strong>queue[rindex]<\/strong> \u7684\u65b9\u5f0f\u8bfb\u4e0b\u4e00\u5e27\u4e0d\u5c31\u8bfb\u4e0d\u5230\u4e86\u5417\uff1f<\/p>\n\n\n\n<p>\u5bf9\uff0c<strong>queue[rindex]<\/strong> \u786e\u5b9e\u8bfb\u4e0d\u5230\u4e0b\u4e00\u5e27\uff0c\u6240\u4ee5ffplay \u8bfb\u53d6\u961f\u5217\u5e27\u7528\u7684\u662f <strong>queue[ rindex + rindex_shown ]<\/strong>\u3002<\/p>\n\n\n\n<p>\u5206\u6790\u5230\u8fd9\u91cc\uff0c\u53ef\u80fd\u8bfb\u8005\u5230\u8fd9\u91cc\u8fd8\u662f\u4e0d\u592a\u7406\u89e3\uff0c\u6211\u4e3e\u4e2a\u4f8b\u5b50\u3002<\/p>\n\n\n\n<p>\u5047\u5982\u73b0\u5728\u64ad\u653e\u7ebf\u7a0b\u4ece FrameQueue \u91cc\u9762\u53d6\u7b2c\u4e00\u5e27\u51fa\u6765\u64ad\u653e\uff0c\u56e0\u4e3a\u662f\u7b2c\u4e00\u5e27\uff0c\u6240\u4ee5 rindex_shown \u6b64\u65f6\u662f 0\uff0crindex \u4e5f\u662f 0\u3002<strong>queue[ rindex + rindex_shown ]<\/strong><\/p>\n\n\n\n<p>\u8fd9\u6837\u786e\u5b9e\u53d6\u51fa\u6765\u7684\u662f 0 \u7d22\u5f15\u7684Frame\u3002\u64ad\u653e\u5b8c\u4e4b\u540e\uff0c\u5c31\u4f1a\u8c03 <strong>frame_queue_next()<\/strong> \u51fd\u6570\uff0c\u56e0\u4e3a\u662f\u7b2c\u4e00\u6b21\u8c03 frame_queue_next()\uff0c\u6240\u4ee5\u5c31\u8dd1\u8fdb\u53bb <strong>if (f-&gt;keep_last &amp;&amp; !f-&gt;rindex_shown)<\/strong> \u8fd9\u4e2a\u6761\u4ef6\uff0c\u7136\u540e<strong>return<\/strong>\uff0c\u7b2c\u4e00\u5e27\u7684frame\u6570\u636e\u6ca1\u6709\u9500\u6bc1\uff0c <strong>rindex<\/strong> \u8bfb\u7d22\u5f15\u4e5f\u6ca1\u6709\u504f\u79fb\uff0c\u4f46\u662f\uff0c\u4f46\u662f rindex_shown \u53d8\u6210 1\u4e86\uff0c<strong>queue[ rindex + rindex_shown ]<\/strong> \u5c31\u80fd\u6b63\u786e\u8bfb\u5230 \u7b2c\u4e8c\u5e27\u4e86\u3002<\/p>\n\n\n\n<p>\u5176\u5b9e\u6e90\u4ee3\u7801\u8bfb\u53d6\u64ad\u653e\u5e27 \u771f\u6b63\u7684\u7528\u6cd5 \u662f <strong>queue[ (rindex + rindex_shown) % f-&gt;max_size]<\/strong> \uff0c\u91cc\u9762\u8fd8\u6709 <strong>% f-&gt;max_size<\/strong> \u64cd\u4f5c\uff0c\u8fd9\u662f\u4e2a\u56de\u73af\u5904\u7406\u3002\u4f8b\u5982\u5982\u679c rindex \u5df2\u7ecf\u9012\u589e\u6210 16 \uff0cmax_size \u662f16\uff0c\u90a3 16%16 \uff0c\u53d6\u4f59\u6570\u3002\u5c31\u662f0\uff0crindex\u518d+1\uff0c17%16\uff0c\u4f59\u6570\u5c31\u662f1\u3002<\/p>\n\n\n\n<p>\u8fd9\u4e2a\u5c31\u662f <strong>keep_last<\/strong> \u8ddf <strong>rindex_shown<\/strong> \u7684\u4f5c\u7528\uff0c\u4fdd\u5b58\u64ad\u653e\u7684\u4e0a\u4e00\u5e27\u5728\u961f\u5217\u91cc\u9762\u3002\u90a3\u4fdd\u5b58\u5728\u961f\u5217\u91cc\u9762\u6709\u4ec0\u4e48\u7528\u5462\uff1f\u7528\u89c6\u9891\u6d41\u4e3e\u4f8b\uff0c\u5f53SDL\u7a97\u53e3\u53d8\u5c0f\u7684\u65f6\u5019\uff0cffplay \u53ef\u4ee5\u53d6\u4e0a\u4e00\u5e27frame\uff0c\u91cd\u65b0\u6e32\u67d3 texture \u6765\u9002\u5e94\u7f29\u5c0f\u540e\u7684\u7a97\u53e3\u5927\u5c0f\u3002<\/p>\n\n\n\n<p>\u8fd8\u6709\u4e00\u4e2a\u6ce8\u610f\u7684\u5730\u65b9\u662f\uff0c\u5b57\u5e55\u6d41\u6ca1\u6709\u7528\u5230 keep_last \u8ddf rindex_shown\uff0c\u97f3\u9891\u6d41\u597d\u50cf\u4e5f\u662f\u6ca1\u7528\u5230 keep_last \u8ddf rindex_shown\uff0c\u867d\u7136\u97f3\u9891\u6d41\u521d\u59cb\u5316\u961f\u5217\u7684\u65f6\u5019\u628a keep_last \u8bbe\u7f6e\u4e3a1\uff0c\u6211\u4e2a\u4eba\u611f\u89c9\u597d\u50cf\u53ea\u6709\u89c6\u9891\u6d41\u7528\u5230 keep_last \u8ddf rindex_shown\u3002<\/p>\n\n\n\n<p>\u4e0b\u9762\u662f\u521d\u59cb\u5316 Frame \u961f\u5217\u4ee3\u7801\uff0c\u6ce8\u610f\u770b\u6700\u540e\u4e00\u4e2a\u53c2\u6570 keep_last \u662f1 \u8fd8\u662f 0.<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code class=\"prettyprint\" >if (frame_queue_init(&amp;is-&gt;pictq, &amp;is-&gt;videoq, VIDEO_PICTURE_QUEUE_SIZE, 1) &lt; 0)\n        goto fail;\nif (frame_queue_init(&amp;is-&gt;subpq, &amp;is-&gt;subtitleq, SUBPICTURE_QUEUE_SIZE, 0) &lt; 0)\n        goto fail;\nif (frame_queue_init(&amp;is-&gt;sampq, &amp;is-&gt;audioq, SAMPLE_QUEUE_SIZE, 1) &lt; 0)\n        goto fail;<\/code><\/pre>\n\n\n\n<hr class=\"wp-block-separator has-css-opacity\"\/>\n\n\n\n<p>\u597d\u4e86\uff0c\u5206\u6790\u5230\u8fd9\u91cc\uff0c\u4e00\u90e8\u5206\u7684\u6570\u636e\u7ed3\u6784\u5df2\u7ecf\u5206\u6790\u5b8c\u6bd5\uff0c\u6587\u7ae0\u5f00\u5934\u7684 <strong>frame_queue_init()<\/strong> \u81ea\u884c\u770b\u4ee3\u7801\u5373\u53ef\u7406\u89e3\uff0c\u5c31\u662f\u4e00\u4e9b\u53d8\u91cf\u8d4b\u503c\u3002<\/p>\n\n\n\n<p>\u7136\u540e <strong>stream_open() <\/strong>\u540e\u9762\u7684 <strong>init_clock()<\/strong> \u521d\u59cb\u5316\u65f6\u949f\uff0c\u672c\u6587\u6682\u65f6\u4e0d\u8be6\u7ec6\u5206\u6790\u65f6\u949f\uff0c\u5148\u7b80\u5355\u4ecb\u7ecd\u65f6\u949f\u7684\u4f5c\u7528\uff0cclock \u662f\u7528\u6765\u63a7\u5236\u97f3\u89c6\u9891\u540c\u6b65\u7684\uff0c\u5982\u679c\u53ea\u64ad\u653e\u89c6\u9891\uff0c\u5b9e\u9645\u4e0aclock\u8fd9\u4e2a\u7ed3\u6784\u4f53\u662f\u6ca1\u7528\u7684\uff0c\u53ea\u64ad\u653e\u97f3\u9891\u4e5f\u662f\u3002\u89c6\u9891\u5c31\u6309\u7167\u5e27\u7387\u64ad\u653e\uff0c\u97f3\u9891\u5c31\u6309\u7167\u91c7\u6837\u7387\u64ad\u653e\u5c31\u884c\u3002\u4f46\u5982\u679c\u97f3\u89c6\u9891\u540c\u65f6\u64ad\u653e\uff0c\u65f6\u95f4\u957f\u4e86\u4f1a\u4ea7\u751f\u4e0d\u540c\u6b65\uff0c\u81f3\u4e8e\u4e3a\u4ec0\u4e48\u4f1a\u4e0d\u540c\u6b65\uff0c\u81ea\u884c\u767e\u5ea6\uff0c\u7b54\u6848\u592a\u591a\u4e86\uff0c\u6211\u4e0d\u7c98\u8d34\u4e86\u3002<\/p>\n\n\n\n<p>\u5728 <strong>stream_open(<\/strong>) \u51fd\u6570\u7684\u6700\u540e \u8c03\u7528\u4e86SDL_CreateThread \u521b\u5efa\u4e00\u4e2a\u65b0\u7684\u7ebf\u7a0b\uff0cread_thread\uff0c\u8fd9\u662f\u7b2c\u4e8c\u4e2a\u7ebf\u7a0b\u3002<\/p>\n\n\n\n<pre class=\"wp-block-preformatted\">is-&gt;read_tid &nbsp; &nbsp; = SDL_CreateThread(read_thread, \"read_thread\", is);<\/pre>\n\n\n\n<p>read_thread() \u51fd\u6570\u4e0b\u7bc7\u6587\u7ae0\u518d\u7ee7\u7eed\u5206\u6790\u3002<\/p>\n\n\n\n<hr class=\"wp-block-separator has-css-opacity\"\/>\n\n\n\n<p>ffplay \u6e90\u7801\u5206\u6790\uff0c<strong>stream_open(<\/strong>) \u5206\u6790\u5b8c\u6bd5\u3002<\/p>\n\n\n\n<p>\u00a9\u7248\u6743\u6240\u5c5e\uff1a\u77e5\u8bc6\u661f\u7403\uff1a\u5f26\u5916\u4e4b\u97f3\uff0cQQ\uff1a2338195090\u3002<\/p>\n\n\n\n<p>\u7531\u4e8e\u7b14\u8005\u7684\u6c34\u5e73\u6709\u9650\uff0c \u52a0\u4e4b\u7f16\u5199\u7684\u540c\u65f6\u8fd8\u8981\u53c2\u4e0e\u5f00\u53d1\u5de5\u4f5c\uff0c\u6587\u4e2d\u96be\u514d\u4f1a\u51fa\u73b0\u4e00\u4e9b\u9519\u8bef\u6216\u8005\u4e0d\u51c6\u786e\u7684\u5730\u65b9\uff0c\u6073\u8bf7\u8bfb\u8005\u6279\u8bc4\u6307\u6b63\u3002\u5982\u679c\u8bfb\u8005\u6709\u4efb\u4f55\u5b9d\u8d35\u610f\u89c1\uff0c\u53ef\u4ee5\u52a0\u6211\u5fae\u4fe1 Loken1\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u672c\u7cfb\u5217 \u4ee5 ffmpeg4.2 \u6e90\u7801\u4e3a\u51c6\uff0c\u4e0b\u8f7d\u5730\u5740\uff1a\u94fe\u63a5\uff1a\u767e\u5ea6\u7f51\u76d8 \u63d0\u53d6\u7801\uff1ag3k8 FFplay \u6e90\u7801\u5206\u6790\u7cfb [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[10,1],"tags":[],"class_list":["post-456","post","type-post","status-publish","format-standard","hentry","category-ffplay","category-uncategorized"],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v18.2 - https:\/\/yoast.com\/wordpress\/plugins\/seo\/ -->\n<title>FFplay\u6e90\u7801\u5206\u6790-streams_open - \u5f26\u5916\u4e4b\u97f3<\/title>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/www.xianwaizhiyin.net\/?p=456\" \/>\n<meta property=\"og:locale\" content=\"zh_CN\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"FFplay\u6e90\u7801\u5206\u6790-streams_open - \u5f26\u5916\u4e4b\u97f3\" \/>\n<meta property=\"og:description\" content=\"\u672c\u7cfb\u5217 \u4ee5 ffmpeg4.2 \u6e90\u7801\u4e3a\u51c6\uff0c\u4e0b\u8f7d\u5730\u5740\uff1a\u94fe\u63a5\uff1a\u767e\u5ea6\u7f51\u76d8 \u63d0\u53d6\u7801\uff1ag3k8 FFplay \u6e90\u7801\u5206\u6790\u7cfb [&hellip;]\" \/>\n<meta property=\"og:url\" content=\"https:\/\/www.xianwaizhiyin.net\/?p=456\" \/>\n<meta property=\"og:site_name\" content=\"\u5f26\u5916\u4e4b\u97f3\" \/>\n<meta property=\"article:published_time\" content=\"2022-01-31T10:53:57+00:00\" \/>\n<meta property=\"article:modified_time\" content=\"2022-06-10T19:08:38+00:00\" \/>\n<meta property=\"og:image\" content=\"http:\/\/.\/wp-content\/uploads\/2022\/01\/ffplay-4-1.png\" \/>\n<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n<meta name=\"twitter:label1\" content=\"\u4f5c\u8005\" \/>\n\t<meta name=\"twitter:data1\" content=\"loken\" \/>\n\t<meta name=\"twitter:label2\" content=\"\u9884\u8ba1\u9605\u8bfb\u65f6\u95f4\" \/>\n\t<meta name=\"twitter:data2\" content=\"3 \u5206\" \/>\n<script type=\"application\/ld+json\" class=\"yoast-schema-graph\">{\"@context\":\"https:\/\/schema.org\",\"@graph\":[{\"@type\":\"WebSite\",\"@id\":\"https:\/\/www.xianwaizhiyin.net\/#website\",\"url\":\"https:\/\/www.xianwaizhiyin.net\/\",\"name\":\"\u5f26\u5916\u4e4b\u97f3\",\"description\":\"FFmpeg\u3001WebRTC\uff0cSRS \u97f3\u89c6\u9891\u3001\u6d41\u5a92\u4f53\u6280\u672f\",\"potentialAction\":[{\"@type\":\"SearchAction\",\"target\":{\"@type\":\"EntryPoint\",\"urlTemplate\":\"https:\/\/www.xianwaizhiyin.net\/?s={search_term_string}\"},\"query-input\":\"required 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