{"id":3461,"date":"2013-06-21T17:42:53","date_gmt":"2013-06-21T14:42:53","guid":{"rendered":"http:\/\/mummila.net\/nuudelisoppa\/?p=3461"},"modified":"2013-06-21T17:46:28","modified_gmt":"2013-06-21T14:46:28","slug":"transcoding-note-better-crop-without-avidemux","status":"publish","type":"post","link":"https:\/\/mummila.net\/nuudelisoppa\/2013\/06\/21\/transcoding-note-better-crop-without-avidemux\/","title":{"rendered":"Transcoding note: better crop without Avidemux"},"content":{"rendered":"<p>I came up with a better way to crop the videos: as before, figure out the best deinterlacer (say, yadif) with Avidemux, but then just look up the timecode (say, 123 seconds) for a good reference frame and go straight to avconv:<\/p>\n<pre><code>avconv -ss 123 -y -i input.mpeg -vsync 1 -r 1 -t 1 -vf yadif=0:0 -an frame%d.png<\/code><\/pre>\n<p>(Note that putting seek time with <code>-ss<\/code> prior to the input <code>-i<\/code> makes seeking faster but less precise.)<\/p>\n<p>Now open the frame in Gthumb (or whatever is the snappiest photo resizing and cropping tool at the time), and go through the <a href=\"http:\/\/mummila.net\/nuudelisoppa\/2013\/06\/16\/video-transcoding-notes\/#croppingnote\">resize and cropping procedure I described earlier<\/a>. Turns out Avidemux 2.5.4 is pretty clumsy at this: for example, it forbids resizing to odd numbers while avconv allows it, so getting the numbers in a visual tool that also allows odd numbers makes better results.<\/p>\n<p>Back in the day, multiples of 16 in pixel dimensions were all but required for codecs&#8217; compression not to crash and burn, but from my tests it would seem multiples of 4 or even 2 are fine for VP8.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>I came up with a better way to crop the videos: as before, figure out the best deinterlacer (say, yadif) with Avidemux, but then just look up the timecode (say, 123 seconds) for a good reference frame and go straight to avconv: avconv -ss 123 -y -i input.mpeg -vsync 1 -r 1 -t 1 -vf [&hellip;]<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-3461","post","type-post","status-publish","format-standard","hentry","category-uncategorized"],"_links":{"self":[{"href":"https:\/\/mummila.net\/nuudelisoppa\/wp-json\/wp\/v2\/posts\/3461","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/mummila.net\/nuudelisoppa\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/mummila.net\/nuudelisoppa\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/mummila.net\/nuudelisoppa\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/mummila.net\/nuudelisoppa\/wp-json\/wp\/v2\/comments?post=3461"}],"version-history":[{"count":3,"href":"https:\/\/mummila.net\/nuudelisoppa\/wp-json\/wp\/v2\/posts\/3461\/revisions"}],"predecessor-version":[{"id":3465,"href":"https:\/\/mummila.net\/nuudelisoppa\/wp-json\/wp\/v2\/posts\/3461\/revisions\/3465"}],"wp:attachment":[{"href":"https:\/\/mummila.net\/nuudelisoppa\/wp-json\/wp\/v2\/media?parent=3461"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/mummila.net\/nuudelisoppa\/wp-json\/wp\/v2\/categories?post=3461"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/mummila.net\/nuudelisoppa\/wp-json\/wp\/v2\/tags?post=3461"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}