![]() See this for more information.Ĭhoosing a bitrate gives you even more choice, since you can pick anything above 0. If you just want a number to start experimenting, try 23. huge files) and 51 means the worst possible quality. For the h264 encoders, you can use the constant quality, and in that case you will be prompted for the level you want (called CRF, constant rate factor), where 0 means the best quality (that is, lossless encoding, a.k.a. ![]() The encoder we will be using for vp8 doesn’t handle this option well, at least for short clips, so I’d suggest always choosing a bitrate in that case. A video’s bitrate is actually an average, since harder-to-encode scenes (lots of movement, etc) will use more bits and easier scenes will use less.Įncoders will also give you the option of choosing a quality level, so that the encoder will choose the bitrate for you, while trying to maintain that level of quality. As you can probably tell, the higher the bitrate, the bigger the video and the higher the quality. The unit normally used is kilobits per second (1 kilobit = 1024 bits = 128 bytes). Like the framerate, the bitrate refers to the amount of bits (that is, the size of the video) per second of video. If you just want a value to start experimenting, try 18 fps for 24 fps sources and 22 fps for 30 fps sources, this will give you approximately 3/4 of the original speed. If you want slow motion, choose a smaller value. If you want it to play at regular speed, just leave it the same as your source. But to complicate things a bit, for technical reasons, these will not be exactly 24 and 30, but actually 24,000/1,001 and 30,000/1,001, which is why they will sometimes be referred to as 23.976 and 29.97 fps.īelow, there will be a time when you’ll have to opportunity to choose the framerate of your clip. One of these images is called a frame, and the framerate is the amount of frames that are displayed during one second.įor most videos, the frame rate will be either 24 or 30 fps (frames per second). FramerateĪ video works by showing you a series of images in very short succession, creating the illusion of movement (which is also how TVs and computer monitors work). I’ll also assume your final clip will not contain any audio. I’d personally recommend using webm whenever possible simply by the fact that it is open and free from patents and legal restrictions, but there are many factors involved in the decision and you should use whichever one is best for you.ĭuring this tutorial, I’ll assume your source video (the one you’re extracting a clip from) is either an AVI or MP4, containing H264 video. The second, by Chrome, Firefox and Opera. The first of these can be played out of the box, among the biggest browsers, by Chrome and Safari. VP8 video and Vorbis audio muxed into a WebM file.H264 video and AAC audio muxed into an MP4 file and.For html5 video (the one which can be played by browsers without a plugin, like flash), at this point in time, we’ll be interested only in two combinations: Video files consist of one or more video and audio tracks, muxed together using a muxer, or container format. Really quick introduction to digital video Formats How to create gif-like loopable video clips JIndex
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