ss select the starting time in the source file y automatic overwrite of the output file croptop, -cropleft, -cropright, -cropbottom crop input video frame on each side t N encode only N seconds of video (you can use also the hh:mm:ss.ddd format)
sameq ffmpeg tries to keep the visual quality of the input aspect set the aspect ratio i.e: 4:3 or 16:9 You can also use fractional values like 30000/1001 instead of 29.97 vcodec choose video codec or use “copy” to bypass video encoding acodec choose audio codec or use “copy” to bypass audio encoding f set video format (for the input if before of -i, for output otherwise) codecs print the list of supported codecs (E=encode,D=decode) Let’s start with a selection of the most important, not codec related, parameters: -formats print the list of supported file formats Sometimes it is instead necessary to specify some important parameters to avoid errors or to optimize the encoding. Very often, FFmpeg infers the parameters from the context, for example the input or output format from the file extention and it also applies default values to unspecified parameters. I’ll focus on the possiblity to use RTMP as input and/or output in the fourth part of this series, while in the following examples I’ll use only the local file option.įFmpeg supports litterally hundreds of parameters and options. Input_file and output_file can be defined not only as file system objects but a number of protocols are supported: file, http, pipe, rtp/rtsp, raw udp, rtmp. This is the base structure of an FFmpeg invocation:įfmpeg -i input_file output_file Remember that there are several libraries that can be included or excluded in the build and so if you need something special or a fine control onthe capabilities of your build, the longest path is the best.
#Ffmpeg download speed code#
The shortest path if you don’t want to built from source code is to visit Zeranoe’s FFmpeg builds.
#Ffmpeg download speed how to#
But first of all, how to find a build of FFmpeg to start managing your video? Other formats are marginal, even Google’s VP8 which is still in a too early phase of adoption.įFmpeg is vast subject, so I’ll focus on what I think to be the most important options and a useful selection of command lines. So why target different formats ? A streaming professional has primarily to master H.264. H.264 is supported by Flash (99% of computers + mobile), iOS, Android, BlackBerry, low-end mobile devices, STBs and Connected TVs. FFmpeg supports hundreds of AV formats and codecs as input and output (for a complete list type ffmpeg -formats and ffmpeg -codecs) but you know that nowadays the most important output format is without doubt H.264. This post is dedicated to the most important parameters and ends with an example of transcoding to H.264.
#Ffmpeg download speed update#
(because of the success of this series I have decided to revise the content of the articles, update the syntax of command lines to recent api changes and extend the series with a fifth part, good reading!)Īfter the short introduction of the previous article, now it’s time to see FFmpeg in action. PART IV – FFmpeg for streaming (revised 0) PART II – Parameters and recipes (revised 0)
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