- #Ffmpeg crop filter variables how to
- #Ffmpeg crop filter variables mac os
- #Ffmpeg crop filter variables code
- #Ffmpeg crop filter variables mac
(uint8_t const * const *)pFrameCropped->data, // Pointers to the planes of the source slice Sws_scale(sws_ctx, // the scaling context previously created with sws_getContext() pict.linesize = number of bytes per line Sws_ctx = sws_getContext(CODEC_WIDTH, // src widthĪv_picture_crop((AVPicture*)pFrameCropped,
#Ffmpeg crop filter variables code
This is a part of my code : AVFrame *pFrame = NULL īmp = SDL_CreateYUVOverlay(CODEC_WIDTH, // width But when i reading the code, i don't find a way to finish it. Before posting here, i read here that the function wasn't finish yet. I get a "yellow" overlay on the cropped video and my application crashes after fews seconds. In the FFMPEG API, we can use the function av_picture_crop ( here). I have a HD video 1280*720 (i only worked with mp4) and i want to select a VGA-screen anywhere in the HD video (I mean cropping a VGA screen in a HD video), recuperate the data and display it on screen.
#Ffmpeg crop filter variables how to
We get it with the previously defined helper getVideoInfo.I learned how to use FFMPEG API with dranger's tutorial, and I implemented a video reader using the library SDL to display the video. Let’s create a helper function that gets the duration for us: export const getVideoInfo = (inputPath: string) => `])Īs was the case with the previous function, we must first know the length of the video in order to calculate when to extract each frame.
ffprobe is a tool that lets us get the metadata of a video, among other things. In order to get the duration of the video, we can use ffprobe, which comes with FFmpeg. For this, of course, we must first get the video duration.
In order for the fragment to be a meaningful and representative sample of the video content, it is best if we get it from a point somewhere around 25–75 percent of the total length of the video. The video fragment preview is pretty straightforward to create all we have to do is slice the video at the right moment. I will be using Childish Gambino’s “ This is America” video for testing purposes. Now that we know what tools to use for video manipulation from within Node.js runtime, let’s create the previews in the formats mentioned above. env file: FFMPEG_PATH="D:/ffmpeg/bin/ffmpeg.exe"īoth paths have to be set if they are not already available in our $PATH. ) or by our providing the paths to the executables through the environment variables. The fluent-ffmpeg library depends on the ffmpeg executable being either on our $PATH (so it is callable from the CLI like: ffmpeg.
#Ffmpeg crop filter variables mac
The installation process is pretty straightforward if you are on Mac or Linux machine. Also, in our examples, there won’t be anything too fancy going on. It also implements many useful features, such as tracking the progress of a command and error handling.Īlthough the commands can get pretty complicated quickly, there’s very good documentation available for the tool. The library, available on npm, generates the FFmpeg commands for us and executes them. under a wide variety of build environments, machine architectures, and configurations.īoasting such an impressive resume, FFmpeg is the perfect choice for video manipulation done from inside of the program, able to run in many different environments.įFmpeg is accessible through CLI, but the framework can be easily controlled through the node-fluent-ffmpeg library.
#Ffmpeg crop filter variables mac os
It is also highly portable: FFmpeg compiles, runs, and passes our testing infrastructure FATE across Linux, Mac OS X, Microsoft Windows, the BSDs, Solaris, etc.
No matter if they were designed by some standards committee, the community or a corporation. It supports the most obscure ancient formats up to the cutting edge. In the documentation, we read:įFmpeg is the leading multimedia framework, able to decode, encode, transcode, mux, demux, stream, filter and play pretty much anything that humans and machines have created. Manipulating a video with Node.js itself would be extremely hard, so instead we are going to use the most popular video manipulation tool: FFmpeg. We are going to take a closer look at how to implement both of these approaches. Another popular way of creating a preview is to take a few frames from a video and make a slideshow. YouTube, for instance, plays a 3- to 4-second excerpt from a video whenever users hover over its thumbnail. Generating video previews with Node.js and FFmpegĮvery website that deals with video streaming in any way has a way of showing a short preview of a video without actually playing it. Maciej Cieślar Follow A JavaScript developer and a blogger at.
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