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Reading AVI, Quicktime, etc "Movies"
Movie files, such as AVIs, Quicktimes, REDcode R3D, MP4s, MTS, and M2Ts, etc) can be convenient due to their simplicity (a single file copied directly from the camera) and small size. However, these formats have limitations that can make them of limited use in post-production:
1. There is a vast profusion of compression and file formats, and
2. Inter-frame compression makes it time-consuming to access any specific frame.
SynthEyes uses the operating system, ie Windows, Linux, or macOS, to read most movie files. SynthEyes does not contain the complex code to read movie files "on its own," with the exception of ARRIRAW-only MXF, Blackmagic RAW, and RED files, which are built in. It is the purpose of the operating system to provide this kind of shared capability to all the applications, so that each one does not have to do so, which would be impossible. SynthEyes for Linux can only read ARRIRAW-only MXF, Blackmagic RAW, and RED movies.
Important Windows 10 Tip! Microsoft has (re)moved support for HEVC/H.265 files to an optional Windows Store download (free or $0.99). These files are typically produced by the latest cameras (especially 360VR) and drones, with a .mp4 file extension — though .mp4 may contain several different codecs, not just H.265. If you are unable to open HEVC/H.265 files, please see HEVC/H.265 on Windows 10.
WARNING: SynthEyes reads movies by frame, retrieving each image they contain. Other applications such as After Effects, read movies by time. Due to the nature of how cameras work and the use of unsynchronized clock rates, time-based readers have a nasty habit of duplicating frames in the middle of movies, and skipping frames at the end. Using SynthEyes to convert movies to sequences (or precisely-timed ProRes movies) can avoid these differences and preserve the original images.
WARNING : you may encounter substantial delays the first time you open a "movie" file using Quicktime on the Mac or Windows Media Foundation on Windows, as the file must be indexed to locate the time stamp of each frame. This index is written with a ".atimes", ".btimes", or ".times" extension so that subsequent opens occur rapidly. (If you turn off the Write frame index files preference, no times file is written, and each re-opening will take as long as the first.)
WARNING : SynthEyes can itself read only MXF files that contain ARRIRAW data. MXF files are “containers” that may have data from a wide variety of different codecs. MXFs containing data other than ARRIRAW are passed to the operating system, which may or may not be able to read them.
Much like still cameras can produce "RAW" images that require special software to read them and produce standard PNGs or JPEGs, some cameras produce specialized image formats that must be converted to standard formats for further use. (See the section on reading RED files.)
The operating system software loaded on your particular machine plays a large part in determining what movies can be read. If you have a particular hardware device that produces movie files, such as a camera or disk recorder, be sure to install the software that came with that device, so that its files can be read. Or, you may have to look online for the appropriate codec for footage supplied by a customer. Older legacy codecs are being dropped by the operating system vendors.
Highly compressed files produced by cameras are not well-suited for post- production, as reading a single frame often requires decompressing many others first. SynthEyes often reads frames out of order, either at your request or during multi- threaded processing, so reading inter-frame compressed files can take a very long time, especially if there are few keyframes. A file with few keyframes can make scrubbing painfully slow . If a movie file format is used, compression formats such as ARRIRAW, Blackmagic RAW, or Apple ProRes™ are better for, or specifically intended for, post- production.
BIGGER WARNING : We highly advise against using programs such as Quicktime Player to "trim" compressed files with inter-frame compression such as h.26x codecs. This can produce files that contain frames that should not be shown, and different programs will interpret the file differently, ie showing or not showing some or all of the "hidden" frames. This will cause a world of trouble. Always write a clean recompressed version for interchange among programs, even if you will use the trimmed version for final assembly.
In addition to programs supplied by camera vendors, programs such as After Effects and Final Cut specialize in "importing" footage from cameras and decompressing the camera-specific acquisition formats to more useful post-production- ready image sequences.
The use of movie files must be carefully considered. For further information on using them and configuring readers, see the section Advanced Details: Reading "Movie" Files . Also, SynthEyes's Disk Caching feature can make working with movie files (and IFLs) more efficient.
Due to these inherent limitations, much primary post-production work is done with image sequences instead of movie files or specialized movie file formats.
©2024 Boris FX, Inc. — UNOFFICIAL — Converted from original PDF.