{"id":79,"date":"2017-08-23T15:51:10","date_gmt":"2017-08-23T20:51:10","guid":{"rendered":"http:\/\/ciraldo.stream\/uwm-vfx2\/?page_id=79"},"modified":"2017-10-24T17:46:42","modified_gmt":"2017-10-24T22:46:42","slug":"image-sequences","status":"publish","type":"page","link":"https:\/\/ciraldo.stream\/uwm-vfx2\/topics\/image-sequences\/","title":{"rendered":"Image Sequences"},"content":{"rendered":"

Image Sequences<\/h1>\n

 <\/p>\n

Sometimes it’s helpful to render a composition as a folder full of still image files<\/strong> as opposed to e.g., a Quicktime file. This is called an image sequence.<\/strong><\/p>\n

\"Example
Example of an image sequence<\/figcaption><\/figure>\n

In the illustration above, a comp called Hello<\/strong> has been rendered as an image sequence<\/strong>. Each frame is output as a separate .jpg file, each numbered chronologically from 00000 to 00029 (30 files total). Audio is stored elsewhere; image sequences<\/strong> are silent.<\/p>\n

(Rendering longer comps<\/strong> can potentially create a folder with thousands and thousands of image files. Lower-powered computers can become sluggish <\/strong>when trying to deal with folders with so many files. At a certain point you may need to break up <\/strong>such a render into multiple renders into separate folders.<\/strong>)<\/p>\n

Uses for image sequences<\/h2>\n

While it’s usually simpler to render Quicktime files, in some cases images sequences<\/strong> can be very helpful.<\/p>\n

    \n
  1. \n
    ENABLES Re-Rendering Sections Of Existing Renders<\/h5>\n

    This is not possible with Quicktimes — you have to re-render the whole file. With images sequences, you can delete the files that represent the section to re-render, and then tell AE to only render the missing frames.
    \n

    \"Deleting
    Deleting Sections Of An Image Sequence<\/figcaption><\/figure>\n<\/li>\n
  2. \n
    Resilient To AE Render Crashes<\/h5>\n

    If AE crashes during the render of a Quicktime file, the work up until that point will be lost, and the render must start over. With images sequences, AE can pick up where it left off.<\/li>\n

  3. \n
    Support For FANCY Bit Depths & COLOR MANAGEMENT<\/h5>\n

    Projects that deal with 32-bit color depth, linear color, and\/or that use a non-vanilla color profile, will probably not be able to render out all that detail and info to any Quicktime or AVI formats. An ima<\/li>\n

  4. \n
    Archival Of Important Video<\/h5>\n

    Files on disks can get corrupted over time. When a Quicktime file gets corrupted, the whole file is usually lost. With an image sequence, only the corrupted frames are lost.<\/li>\n

  5. \n
    Multi-Machine Rendering<\/h5>\n

    Share a folder on the network and then render an image sequence to that folder from multiple computers each running AE. Each computer simply renders the next “missing” frame.<\/li>\n<\/ol>\n

    [More detailed info on the pros and cons of image sequences may be found on this page<\/a>.]<\/p>\n

    Rendering an image sequence<\/h2>\n

    In AE, you can choose to render as an image sequence from the Render Queue<\/strong> panel. Click on the blue word Lossless<\/strong>\u00a0next to the Output Module chooser.<\/p>\n

    \"\"<\/p>\n

    The Output Module settings<\/strong> window will open, and in the Format section<\/strong> you can choose from various output formats, among which are several Image<\/strong>\u00a0Sequence<\/strong> formats.<\/p>\n

    PNG<\/strong>\u00a0Sequence<\/strong> is a nice basic choice, since it is\u00a0lossless, compressed,\u00a0<\/strong>allows for including alpha<\/strong> (transparency) info in the render, and if needed can do Trillions of Colors<\/strong> (for 16-bits per pixel projects.)<\/p>\n

    \"\"<\/p>\n

    Click OK,<\/strong> then back in the Render Queue panel you’ll see that the\u00a0Output To<\/strong>\u00a0option now looks like this:<\/p>\n

    \"\"<\/p>\n

    Which means that when rendering, AE will create a folder called Comp To Render\u00a0<\/strong>and begin putting\u00a0.png<\/strong> files into that folder with names like:<\/p>\n

    Comp To Render_00001.png,\u00a0
    \n Comp To Render_00002.png,\u00a0
    \n Comp To Render_00003.png,\u00a0
    \n <\/strong>…and so on.<\/p>\n

    These names are based on the composition’s name,\u00a0but you can click on the blue text to change the output filenames if you like.<\/p>\n

    Importing an image sequence<\/h2>\n

    To import an image sequence into After Effects or Premiere, select the very first image of the sequence<\/strong> and make sure the\u00a0PNG Sequence<\/strong> option is checked like below:<\/p>\n

    \"\"<\/p>\n

    No inherent frame rate,
    \n so use “Interpret Footage”<\/h2>\n

    Image sequences do not have an inherent frame rate,<\/strong> unlike Quicktime files, say.\u00a0 In other words, if you handed me a Quicktime file, I could tell you its frame rate.\u00a0 But, if you handed me a folder full of .JPGs,<\/strong> I wouldn’t have a clue what the original frame rate was.<\/p>\n

    So, when importing<\/strong> an image sequence into AE or Premiere, you must specify\/verify the frame rate<\/strong> or the app will use some default guess, such as 30fps etc. (Some programs allow you to specify a default frame rate<\/strong> when importing.)<\/p>\n

    In AE and Premiere, you can change the frame rate of an image sequence via the Interpret Footage command.\u00a0<\/strong>In AE you would select File > Interpret Footage > Main…<\/strong> in order to make adjustments.<\/p>\n

    \"\"<\/p>\n

    Use the Interpret Footage settings window to set the frame rate appropriately. It should match the original source material’s frame rate, natch.<\/strong><\/p>\n

    “Skip Existing Files”<\/h2>\n

    Image sequence benefits such as recovering from failed renders, being able to re-render sub-sections of a composition, or multi-machine rendering won’t work until you enable Skip Existing Files<\/strong> in the Render Queue. Open the Render Queue and click on the blue text saying “Best Settings”<\/strong>\u00a0(next to Render Settings) as in the image below.<\/p>\n

    \"\"<\/p>\n

    This will open the Render Settings window where you should enable the Skip Existing Files checkbox:<\/strong><\/p>\n

    \"\"<\/p>\n

    Now, when you re-render an image sequence into the same folder as an existing render, it will automatically skip any existing files.<\/p>\n

    A\u00a0crashed render will pick up where it left off,<\/strong>\u00a0you can manually delete frames you want to re-render,<\/strong>\u00a0and multiple computers can cooperatively render<\/strong> to the same network folder.<\/p>\n

    In the Render Queue, use “Duplicate with Filename”<\/h2>\n

    To take advantage of the Skip Existing Files setting, you have to make sure to render to the same folder and filename(s).<\/strong>\u00a0 Otherwise, you’ll probably accidentally create an entirely new folder of image files.<\/strong>\u00a0Nasty.<\/p>\n

    In the Render Queue, select the name of the comp and do\u00a0Edit >\u00a0Duplicate with File Name\u00a0<\/strong>to duplicate a render task and preserve the output folder and filename(s).<\/strong> It’s also accessible via a right mouse click.<\/strong><\/p>\n

    \"\"<\/p>\n

    Smooth playback in Premiere<\/h2>\n

    When working with imported image sequences in Premiere, you may want to make sure that the image sequence clips get pre-rendered to Premiere Preview files<\/strong> so that they play back smoothly.<\/p>\n

    Multi-Machine Rendering (aka Render Farming)<\/h2>\n

    This can help speed up a long render by getting multiple computers to all render the same comp at once. The general idea looks something like this:<\/p>\n