FFMPEG SCALE TO 480P HOW TO
FFMPEG SCALE TO 480P 480P

Let’s go further and find a solution to the problem 2 mentioned above: how to skip resize if the input resolution is lower than the target ? ffmpeg -i input.mp4 -vf 'scale=min(640,iw):trunc(ow/a/2)*2' output.mp4 The expression trunc(ow/a/2)*2 as vertical resolution means: use as output height the output width (ow = in this case 640) divided for input aspect ratio and approximated to the nearest multiple of 2 (I’m sure most of you are practiced with this kind of calculation). To enforce a “divisible by x” rule, you can simply use the emebedded expression evaluation engine: ffmpeg -i input.mp4 -vf 'scale=640:trunc(ow/a/2)*2' output.mp4 Unfortunately, depending by input resolution, this may end with a odd value or an even value witch is not divisable by 2 as requested by H.264. With -1 in the vertical resolution you delegate to FFmpeg the calculation of the right value to keep the same aspect ratio of input (default) or obtain the aspect radio specified with -aspect switch (if present). The following command line scales the input to the desired resolution the same way as -s: ffmpeg -i input.mp4 -vf 'scale=640:360' output.mp4īut scale provides you also with a way to specifing only the vertical or horizontal resolution and calculate the other to keep the same aspect ratio of the input: ffmpeg -i input.mp4 -vf 'scale=640:-1' output.mp4 Far more control is provided by the filter “scale”. In FFmpeg you can use the -s switch to set the resolution of the output but this is a not flexible solution. Take a look at previous articles for such informations. Note that to simplify command lines I’ll omit the parameters dedicated to H.264 and AAc encoding. So, using the same “recipe” style of the previous articles of this series, I’ll try to solve some common problems with specific command line samples focused on filtering. For very complex workflows an external controller is still necessary but filters come handy when you need to do the job straight and simple.įFmpeg filtering is a wide topic because there are hundreds of filters and thousands of combinations. Grabbing shots only on scene changes may be far more efficient.įFmpeg can satisfy these kinds of complex analysis, handling and filtering tasks even without an external logic using the embedded filtering engine ( -vf ). everybody needs thumbnails generation, but it’s difficult to find a shot really representative of the video content. You need to be able to specify a sequence of filtering and/or manipulation tasks.Ĥ.

Like, for istance, deinterlacing, watermarking and denoising. sometime video needs to be filtered, scaled and filtered again. Again you’d need some external logic to read the metadata of the input and setup a dedicated encoding profile.ģ. now let’s suppose you want also to encode video at the target resolution only if the input has an equal or higher resolution and keep the original otherwise. In this case you need to analyze the input file and decide what profile to apply depending by input aspect ratio.Ģ. you have input files of several resolutions and aspect ratios and you have to encode them to two target output formats (one for 16:9 and one for 4:3). Not only, the elaborations that you need to do in a video project may go beyond a simple transcoding and involve a deeper capacity of analysis, handling and “filtering” of video files.ġ. Transcoding is not a “static” matter, it is dynamic because you may have in input a very wide range of content’s types and you may have to set encoding parameters accordingly (This is particularly true for user generated contents). PART IV – FFmpeg for streaming (revised 0)

FFMPEG SCALE TO 480P 480P

with a 320GB HDD, the prev mentioned netbook, some retro game roms and some 480p video files makes an excellent mobile entertainment center.PART II – Parameters and recipes (revised 0) I have batocera installed on it and i need 480p video to play on it. I have an old 32bit Intel Atom Acer netbook, its not much good for anything. ffmpeg -i YOURVID.mkv -vf scale=-1:480 -vcodec mpeg4 -qscale 3 /path/to/new/output.mp4 it did, indeed, work great for me on my freebsd machine with ffpmeg installed.

then all files will be in that one directory. easiest thing to do though is be in the dir with the original 720p/1080p video and just use the filename.mkv then output it to that same dir by just using an and not a path.

maybe you werent in the dir with the vid files? or something? you should replace YOURVID.mkv with your file OR /path/to/your/file.mkv as well as replace /path/to/output.mkv with the file name or a file path to the converted output 480p file.

Ffmpeg scale to 480p