love creating videos? read these tips from the 90's
Wondering why there's a 90s' digital camera on the post? It's because this is a post from the 90s. And why a still camera for a blog post on video? To fondly remember that not the same camera was used for photo and video as they do today. These tricks are here for adding that something special to the videos you’ve created. These tips are from late nineties - be warned, what you read might sound a little uncommon, but that’s okay. These theories were good back then - these are good today as well. Yes, there have been improvements in storage and graphics technologies in the past 20 years but the theory remains the same. This article lets you understand the humble beginnings of digital video.
Avoid Dropped Frames
If the system is slow, it may not write some frames to the disk and dropped frames will occur. The result is a null frame that takes up virtually no space and simply mimics the last frame. More dropped frames result in a jerkier video and are more apparent at low frame rates. Dropped frames usually come in bursts, thus the video will have large jerks instead of slight jitters. If you are compressing the video in real-time, dropped frames occur when the data rate is the highest-when the most action occurs, which is the worst time for a jerky video.
To avoid dropped frames, you can try decreasing the frame rate or the video resolution. Also, optimise the hard disk and close all open applications while capturing. If you still don’t get a smooth video, turn off preview while capturing if possible. You can also try reducing any real-time effects the capture software may be applying to the video. If you have a good processor but a slow hard disk, increase the compression quality so that smaller chunks of data are written to the disk.
Many codecs compress video with keyframes. One frame (the keyframe) stores the entire image with the colour information of every pixel. For subsequent frames (delta frames), only the differences between those and the preceding frame are stored. To get to a frame, the decompressor will first get information about the keyframe, then all subsequent frames to build the final image. More keyframes mean larger files, but lesser seek time. Also, frames further away from the keyframe are more susceptible to low quality, since each time only an approximate difference is stored. Thus, you should keep the keyframe interval to as low as possible.
If your hardware allows it, plan beforehand whether you want to record sound along with the video itself or from an external source. An external source usually means much better quality, but can also prove to be sluggish and is a hassle. Since one audio file is created for every video, you have to keep track of double the number of files in post-production. Also, synchronising audio and video involves more time and has to be done perfectly. However, if you capture video and audio simultaneously and the system is slow, it may be susceptible to dropping frames as it has to process the video and the audio at the same time.
Use Faster Partitions
Files stored at the start of a disk are faster to access. Make sure that the video is captured to a partition which is at the start of the disk and which is not already too full. Note that the position of the actual data matters, not the size or position of the partition. For a disk split in half, data at the end of the first partition (when the drive is nearly full) will be read at the same speed as data at the start of the second.
If you are applying multiple effects to the video, arrange them in the best possible order if the software allows you to do so. Doing so can cut the conversion process by half or even more. For example, if you apply a filter to smoothen out the video and another one to resize it, place the resize filter first-the smoothening filter will have to work on a smaller image and also, you would want the smoothening to work on the resized image for best quality.
For DivX, the final movie size should be in multiples of 16 pixels. Sometimes it can be in multiples of 8 and, very rarely, 32. When capturing video, pick a frame size close to the final output.
In Windows environment, AVI files with CD-quality audio (176 Kbps) are quite a waste of space, especially for home videos. Traditionally, 8-bit audio at 44 KHz is good enough. Also, compress the audio with a codec. This will reduce the size of the audio to between half and a quarter of its original size with very little loss in quality. MP3 is the best codec to encode audio. However, on slow machines it can cause synchronisation problems in the video.
Nix Intros and Trailers
Use computer-generated graphics sparingly with video. Video compressors are adapted to natural images and do not perform optimally on saturated colours and sharp edges. Depending on the codec, title screens and overlay items can adversely affect video quality, especially at low bitrates. If you must include them, make openings and trailers independent - don’t use transitions to blend them with the video and have them start and end on keyframe boundaries. Align the position and size of overlay items to square pixel boundaries and make them opaque. Transparent regions on the logo will be translated as a complex tile by the codec and will take up a lot of space. If the logo is opaque, the codec will ignore it between keyframes, saving a lot of overheads.
Today 1080p HD is king, marked by its predominance in nearly every screen - from ubiquitous but small phone screens to giant living-room panels! And 4K is on the horizon. For more on digital video technology, read our 2007 post about Super Hi-Vision with 22.2 surround sound.