It directly determines file size of the video along with the quality.
Bitrate tells the encoder about how many bits should each second of video have. Contrary to popular belief, resolution does not affect file size. Typically people use 360p (that’s a shorthand naming made popular by HD televison, meaning picture has height of 360 with width corresponding to wanted aspect ratio), 480p, 720p and 1080p resolutions, as those correspond to common screen sizes, which avoids excessive blurriness. If you choose a low resolution, the video will be small and it will be blurry when users will put it full-screen. Resolution gives “sharpness” to the overall image. Step 2: Choose resolution, bitrate and profile Now you’ll have to decide on two things - the resolution, bitrate and profile you want those videos in. If you already know what “bitrates, profiles etc.” are and just want the command lines skip to step 4 or sample command lines. As I don’t use any machines with OS X you’ll have to check for yourself. OS X users: MacPorts should be able to compile and install FFmpeg with libvpx and libx264. Windows users: Zeranoe has great static builds of FFmpeg for Windows with libx264 and libvpx included. Don’t forget libx264 for H.264 and libvpx for VP8/WEBM if you want that support.
I strongly suggest you use a stable FFmpeg build (that’s 0.9 at the moment) instead of git master. Ubuntu users: UbuntuForums has a great guide for compiling newest FFMpeg build. Step 1: Get a new build of FFmpeg Most distribution builds are very old, buggy and have numerous issues. So here’s my guide for encoding web videos using recent FFMpeg versions for Flash and HTML5. 출처 : H.264 Web Video Encoding Tutorial With FFmpeg Web is full of articles about encoding videos with FFmpeg, however most of them are obsolete and use old non-working FFmpeg parameters.
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