Vidio/README.md
2021-12-26 23:52:44 -08:00

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# Vidio
A simple Video I/O library written in Go. This library relies on [FFmpeg](https://www.ffmpeg.org/), and [FFProbe](https://www.ffmpeg.org/) which must be downloaded before usage.
## `Video`
The `Video` struct stores data about a video file you give it. The code below shows an example of sequentially reading the frames of the given video.
```go
video := NewVideo("input.mp4")
for video.NextFrame() {
// "frame" stores the video frame as a flattened RGB image.
frame := video.framebuffer // stored as: RGBRGBRGBRGB...
}
```
```go
type Video struct {
filename string
width int
height int
depth int
bitrate int
frames int
duration float64
fps float64
codec string
pix_fmt string
framebuffer []byte
pipe *io.ReadCloser
cmd *exec.Cmd
}
```
## `Camera`
The `Camera` can read from any cameras on the device running Vidio.
```go
type Camera struct {
name string
width int
height int
depth int
fps float64
codec string
framebuffer []byte
pipe *io.ReadCloser
cmd *exec.Cmd
}
```
```go
camera := NewCamera(0) // Get Webcam
defer camera.Close()
// Stream the webcam.
for camera.NextFrame() {
// "frame" stores the video frame as a flattened RGB image.
frame := camera.framebuffer // stored as: RGBRGBRGBRGB...
}
```
## `VideoWriter`
The `VideoWriter` is used to write frames to a video file. You first need to create a `Video` struct with all the desired properties of the new video you want to create such as width, height and framerate.
```go
type Options struct {
width int // Width of Output Frames
height int // Height of Output Frames
bitrate int // Bitrate
loop int // For GIFs only. -1=no loop, 0=loop forever, >0=loop n times
delay int // Delay for Final Frame of GIFs
macro int // macro size for determining how to resize frames for codecs
fps float64 // Frames per second
codec string // Codec for video
in_pix_fmt string // Pixel Format of incoming bytes
out_pix_fmt string // Pixel Format for video being written
}
```
```go
type VideoWriter struct {
filename string
width int
height int
bitrate int
loop int
delay int
macro int
fps float64
codec string
in_pix_fmt string
out_pix_fmt string
pipe *io.WriteCloser
cmd *exec.Cmd
}
```
```go
w, h, c := 1920, 1080, 3
options = Options{width: w, height: w, bitrate: 100000}
writer := NewVideoWriter("output.mp4", &options)
defer writer.Close() // Make sure to close writer.
frame = make([]byte, w*h*c) // Create Frame as RGB Image and modify.
writer.Write(frame) // Write Frame to video.
```
## Examples
Copy `input` to `output`.
```go
video := NewVideo(input)
options := Options{
width: video.width,
height: video.height,
fps: video.fps,
bitrate: video.bitrate
}
writer := NewVideoWriter(output, &options)
defer writer.Close()
for video.NextFrame() {
writer.Write(video.framebuffer)
}
```
# Acknowledgements
* Special thanks to [Zulko](http://zulko.github.io/) and his [blog post](http://zulko.github.io/blog/2013/09/27/read-and-write-video-frames-in-python-using-ffmpeg/) about using FFmpeg to process video.
* The [ImageIO-FFMPEG](https://github.com/imageio/imageio-ffmpeg/) project on GitHub.