{"id":1054,"date":"2016-04-23T16:22:13","date_gmt":"2016-04-23T16:22:13","guid":{"rendered":"http:\/\/endcrawl.com\/blog\/?p=1054"},"modified":"2022-05-25T18:07:06","modified_gmt":"2022-05-25T18:07:06","slug":"why-are-my-end-titles-jittering","status":"publish","type":"post","link":"http:\/\/endcrawl.com\/blog\/why-are-my-end-titles-jittering\/","title":{"rendered":"Why Are My End Titles Jittering?"},"content":{"rendered":"

Making\u00a0end titles can be the bane of your existence. For starters, there are the endless revisions:<\/p>\n

\"Endcrawl<\/a><\/p>\n

“We swear, we’re only going to render our ‘Final’ once!”<\/p>\n<\/div>\n

But those\u00a0troublesome motion artifacts are even worse. They go by many\u00a0nicknames:\u00a0jitter, judder, flicker, flutter, shimmer, stutter, ringing, pulsing, strobing. Taming them can seem like a dark art. Luckily, it’s not.<\/p>\n

It comes down to two things. We call them jitter<\/strong> and stutter<\/strong>.<\/p>\n

1. Jitter<\/h2>\n

What does it look like?<\/h3>\n

Glad you asked:<\/p>\n

\"This<\/p>\n

Subpixel motion -> temporal aliasing -> jitter<\/p>\n<\/div>\n

What causes it?<\/h3>\n

Jitter is\u00a0caused by sub-pixel motion<\/em>. This means that the number of pixels your credits travel\u00a0each frame is not a round integer like 3.00, but a decimal like 3.18752.<\/p>\n

Sub-pixel motion\u00a0is accomplished by subtly shifting the pattern of grey (actually, semi-transparent) pixels at the edges of each glyph. Changing\u00a0those\u00a0grey pixels frame-to-frame\u00a0results in temporal aliasing<\/em>. That’s what makes your end titles\u00a0jitter.<\/p>\n

That\u00a0shifting pattern usually has a phase\u2014it repeats itself every n<\/em> number of frames. This yields the typical\u00a0\u201cpulsing\u201d or \u201cstrobing\u201d effect.<\/p>\n

How did it sneak into my workflow?<\/h3>\n

Sub-pixel motion generally comes from two places:<\/p>\n

    \n
  1. Your title designer simply keyframed<\/strong> an in- and out-point instead of specifying a scroll speed. This method, while common, virtually\u00a0guarantees that you’ll land on a non-integer\u00a0scroll speed.<\/li>\n
  2. You received a clean render, but it was re-sized in post<\/strong>. 95% of our reports of \u201comg, jitter\u201d come down to this.<\/li>\n<\/ol>\n

    Resizing happens when\u00a0your\u00a0DI workflow is based off a\u00a0non-standard raster. For example, we\u2019ve previously written about 2048×1152 being a bad idea<\/a>. And here’s why:\u00a0if your\u00a0end titles were originally moving at 3 pixels per frame, the\u00a0\u201c1152p\u201d workflow is guaranteeing a\u00a0scroll speed of 2.8125 pixels per frame<\/strong>\u00a0in all of your masters. Which, as a reminder, is going to look like this:<\/p>\n

    \"This<\/p>\n

    Did we mention how we feel about “1152p”?<\/p>\n<\/div>\n

    Even if your post team swears up and down that\u00a0that your titles are not being resized, be cautious: HD monitors and 2k D-Cinema projectors still have a maximum vertical resolution of 1080 lines. So\u00a0if you’re not resizing\u00a0in\u00a0the timeline itself, it’s still possible that your titles are being scaled in the\u00a0signal path to the\u00a0display. The results are the same.<\/p>\n

    We\u2019ve even seen theaters that run everything through a scaler in the projection booth. This is bad kung fu.<\/p>\n

    How To Fix It<\/h3>\n
      \n
    1. First, only scroll at safe integer speeds.<\/strong><\/li>\n
    2. Second,\u00a0don’t\u00a0re-size<\/strong> your end titles. Make separate renders for separate\u00a0deliverables\u00a0instead of relying on\u00a0a single \u201cmaster\u201d end titles render.<\/li>\n
    3. Third, avoid non-standard rasters<\/strong> in your DI workflow. But\u00a0if that ship has sailed, you can still request that your post team insert a smooth, DCI-compliant, square-pixel render into your DCP authoring timelines. They won\u2019t love you (or me) for saying this.\u00a0But it will make your movie look better.<\/li>\n<\/ol>\n

      2. Stutter<\/h2>\n

      What does it look like?<\/h3>\n

      The scroll feels\u00a0herky-jerky. Stepping through the video frame-by-frame, everything looks fine. But at\u00a0real time\u00a0playback it seems to be bouncing along\u00a0instead of flowing smoothly.<\/p>\n

      What causes it?<\/h3>\n

      Several factors are things are conspiring against us\u00a0here:<\/p>\n