{"id":1154,"date":"2016-10-19T09:06:26","date_gmt":"2016-10-19T13:06:26","guid":{"rendered":"http:\/\/blog.uvm.edu\/ctl-projects\/?p=1154"},"modified":"2016-10-19T09:06:26","modified_gmt":"2016-10-19T13:06:26","slug":"ffmpeg-tweaks-for-ss-uvmtoob-bug-in-server-settings","status":"publish","type":"post","link":"https:\/\/blog.uvm.edu\/waw\/2016\/10\/19\/ffmpeg-tweaks-for-ss-uvmtoob-bug-in-server-settings\/","title":{"rendered":"ffmpeg tweaks for SS UVMToob ; Bug in server settings"},"content":{"rendered":"<p>MPEG-DASH streams in FF and Chrome \u00a0were failing with a No Suitable Media Files error. I thought that maybe this was a lingering key frame interval issue.<\/p>\n<p>&nbsp;<\/p>\n<p>While researching I delved\u00a0ever deeper into ffmpeg and libx264 alchemy. I learned enough to convinve myself that Constant Bit Rare (CBR) files were the root cause of the fuzzy &#8220;high definition&#8221; transcodes I was getting from visually pristine yet low bit-rate input files. So I switched to Constant Rate Factor (CRF) compression, but maintaining the same max bitrates of 600, 1000, and 3000K.<\/p>\n<p>&nbsp;<\/p>\n<p>Old<\/p>\n<p>-vcodec libx264 -vf &#8220;scale=min(480,iw):trunc(ow\/a\/2)*2&#8221; -vb 600k -r 30 -force_key_frames &#8216;expr:gte(t,n_forced*2)&#8217; -pix_fmt yuv420p -c:a aac -b:a 128k -ar 44100 -f mp4<\/p>\n<p>New<\/p>\n<p>-acodec aac -b:a 128k -ac 2 -ar 44100 \u00a0-af &#8220;aresample=first_pts=0&#8221; -pix_fmt yuv420p -vsync -1 -sn -vcodec libx264 -r 30 -vf &#8220;scale=min(480,iw):trunc(ow\/a\/2)*2&#8221; -threads 0 -maxrate 600k -bufsize 600k -preset faster \u00a0-tune film \u00a0-x264opts keyint=60:min-keyint=60:no-scenecut -map_metadata -1 -f mp4 -y<\/p>\n<p>Also, there were some conflicting options set for captions, causing videos with captions to fail when attempting DASH streaming. Fixed. Now 99% HTML5\/DASH<\/p>\n","protected":false},"excerpt":{"rendered":"<p>MPEG-DASH streams in FF and Chrome \u00a0were failing with a No Suitable Media Files error. I thought that maybe this was a lingering key frame interval issue. &nbsp; While researching I delved\u00a0ever deeper into ffmpeg and libx264 alchemy. I learned &hellip; <a href=\"https:\/\/blog.uvm.edu\/waw\/2016\/10\/19\/ffmpeg-tweaks-for-ss-uvmtoob-bug-in-server-settings\/\">Continue reading <span class=\"meta-nav\">&rarr;<\/span><\/a><\/p>\n","protected":false},"author":7,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[41826],"tags":[42758,59912,243430],"class_list":["post-1154","post","type-post","status-publish","format-standard","hentry","category-wes","tag-boffins","tag-media-manager","tag-streaming-media"],"_links":{"self":[{"href":"https:\/\/blog.uvm.edu\/waw\/wp-json\/wp\/v2\/posts\/1154","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/blog.uvm.edu\/waw\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/blog.uvm.edu\/waw\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/blog.uvm.edu\/waw\/wp-json\/wp\/v2\/users\/7"}],"replies":[{"embeddable":true,"href":"https:\/\/blog.uvm.edu\/waw\/wp-json\/wp\/v2\/comments?post=1154"}],"version-history":[{"count":0,"href":"https:\/\/blog.uvm.edu\/waw\/wp-json\/wp\/v2\/posts\/1154\/revisions"}],"wp:attachment":[{"href":"https:\/\/blog.uvm.edu\/waw\/wp-json\/wp\/v2\/media?parent=1154"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blog.uvm.edu\/waw\/wp-json\/wp\/v2\/categories?post=1154"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blog.uvm.edu\/waw\/wp-json\/wp\/v2\/tags?post=1154"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}