Is it possible to split an audio file into individual samples in Flutter? Does anyone know a suitable way?
Yes, you can use this simple plugin to import, cut and then export new audio files
https://pub.dev/packages/audiocutter
and then u can use this code:
import 'package:audiocutter/audiocutter.dart';
var start = 15.0;
var end = 25.5;
// Set The Path to You Your File To Import
var path = 'path/to/audio/file.mp3';
// Get path to cut file and do whatever you want with it.
var outputFilePath = await AudioCutter.cutAudio(path, start, end);
Related
I'm trying to convert a file to a list of image file. Ideally with an option to extract a frame every X milliseconds.
Do you know if it possible to do so with flutter using ffmpeg?
Been trying with export_video_frame plugin but it is very slow and not stable.
Try the below snippet:
String command = "-i ${videoFilePath} -r $imagesCount -f image2 ${outputPath}image-%3d.png"
FFmpegKit.execute(command).then((session) async {
final returnCode = await session.getReturnCode();
if (ReturnCode.isSuccess(returnCode)) {
print("Success!!!!");
} else {
print("Failed!!!!");
}
}
);
Replace videoFilePath with the input file path and outputPath with the directory path where you want to save the images. Also, the imagesCount with how many images you want per frame.
I need to extract some random images from gallery without the picker option. Please be clear that I don't want to open picker for this, just extract images if user tapped the button.
You could use dart:io to get the files in a directory and display one of the image files in the directory.
import 'dart:io' as io;
var files = io.Directory("/storage/emulated/0/DCIM/Camera").listSync();
final _random = new math.Random();
var idx= _random.nextInt(files.length) ;
var file = files[idx];
//TODO display the file.
In a flutter app, I'm trying to read a large csv file one line at a time by opening a stream on it. The issue is that when i try to listen to the stream the execution just skips over that code block and the program ends.
The file I'm opening is located in my assets folder and I've confirmed programmatically that it does exist before opening the stream. Changing the file the stream is opened on doesn't help, the same problem persists. I've also tried to change the way i listen to the stream, following different methods provided by Darts official documentation (that code is commented out) but the outcome is again the same. The assets have been declared in the pubspec.yaml. When i change the code to read the file as a String the program works perfectly but I want to use a stream because the file is so massive that creating a String object for it would take a large amount of time and memory.
void trainDigitsStream() async{
List<List<List>> filters = createRandomFilter(4, 4, 1, -1, 1);
List flattened= new List<double>();
File file = new File("assets/digit_train_data.csv");
if(file.existsSync())print("EXISTS!");
Stream<List<int>> stream = file.openRead();
Stream lines = utf8.decoder.bind(stream).transform(LineSplitter());
/*
try{
await for (var line in lines){
print(line);
}
print("file ended");
}catch(e){
print(e);
}
*/
lines.listen((data){//code exits here, execution never reaches next line
String line = data.toString();
List<List> instance = new List<List<int>>();
List x = new List<int>();
int i = 0;
line.split(',').forEach((d){
x.add(int.parse(d));
i++;
if(i == 28){
instance.add(x);
x = new List<int>();
i = 0;
}
});
List<List<List>> kernels = new List<List<List<double>>>();
List<List> pools = new List<List>();
filters.forEach((f){kernels.add(convo.applyFilter(instance, f, 0));});
kernels.forEach((k){pools.add(pool.maxPool(k, 2));});
pools.forEach((p){flattened.addAll(p);});
});
}
It's hard without further information, It would be better if you can post more information.
So I guess the problem should be , please check the following two steps.
1. Register the assets folder in pubspec.yaml
flutter:
assets:
- assets/digit_train_data.csv
2. You need to use rootBundle to access this csv file, reference document https://flutter.dev/docs/development/ui/assets-and-images
import 'dart:async' show Future;
import 'package:flutter/services.dart' show rootBundle;
Future<String> loadAsset() async {
return await rootBundle.loadString('assets/digit_train_data.csv');
}
similar question here Flutter - Read text file from assets
I would like to do image annotation for my Ionic Application. So the flow of the app would be using the camera plugin to take a picture and use FabricJs to draw on the image then save the file.
I hit the roadblock when I am trying to save or overwrite the file. Apparently the source "http://localhost:8080/file/data/user/0/***/files/1547183479807.png" file does not update.
The flow of the app
1) Take picture with #ionic-native/camera
2) Copy the file to a local directory
3) Use this.win.Ionic.WebView.convertFileSrc to convert the file name to "http://localhost:8080/file/data/user/0/***/files/1547183479807.png"
4) Push to another page to access the canvas
5) Use the link to setBackground to my canvas (FabricJs)
6) Draw on the image (Manually)
7) Save the file via overwriting the existing file but nothing works from here on.
I tried to
- overwrite with writeFile & writeExisitingFile, did not work.
- removeFile and writeFile and did not work.
- tried converting to ArrayBuffer rather than Blob and did not work
- tried creating another new file, did not work too (it seems like after I push to a new page, all the file functions does not affect the files)
- tried using native cordova but did not work too.
- delete that same files twice, (first time I did not get an error but the second time I got an error saying "File Does not exist" but when I view the source, the file is also there and appearing in my thumbnail on my App.
private copyFileToLocalDir(namePath, currentName, newFileName,id,index) {
this.file.copyFile(namePath, currentName, this.file.dataDirectory, newFileName).then(success => {
const keys = id.split('-');
let filename = this.file.dataDirectory + newFileName;
this.fp = this.win.Ionic.WebView.convertFileSrc(filename) ;
this.navCtrl.push(AnnotationsPage, {
filepath: this.fp,
filename: newFileName
});
this.presentToast("Image Successfully Added",'middle');
}, error => {
this.presentToast('Error while storing file.','middle');
});
}
Annotation.ts
savePicture() {
let image = this.canvas.toDataURL({
format: 'png'
});
this.saveBase64(image);
}
public saveBase64(base64:string):Promise<string>{
return new Promise((resolve, reject)=>{
var realData = base64.split(",")[1]
let blob=this.b64toBlob(realData,"image/png")
this.file.writeFile(this.file.dataDirectory,this.filename,blob,{replace:true})
// this.file.writeExistingFile(this.file.dataDirectory,this.filename, blob)
.then((val)=>{
console.log('Write Info',val)
let fp = this.win.Ionic.WebView.convertFileSrc(this.file.dataDirectory+this.filename) ;
})
.catch((err)=>{
console.log('error writing blob')
console.log(err);
// reject(err)
})
})
}
b64toBlob(b64Data, contentType) {
contentType = contentType || '';
var sliceSize = 512;
var byteCharacters = atob(b64Data);
var byteArrays = [];
for (var offset = 0; offset < byteCharacters.length; offset += sliceSize) {
var slice = byteCharacters.slice(offset, offset + sliceSize);
var byteNumbers = new Array(slice.length);
for (var i = 0; i < slice.length; i++) {
byteNumbers[i] = slice.charCodeAt(i);
}
var byteArray = new Uint8Array(byteNumbers);
byteArrays.push(byteArray);
}
I check the base64 file, it is working fine (Throw the data to an online converter and it display the picture.
After the function "copyFileToLocalDir", it seems like I am unable to modify the files store in the local directory.
Thanks in advance. Feel free to ask me more question. 7 hours and no result.
Update on the testing, I am doing.
Did File.readAsDataUrl and as expected the file file:///data/user/0/*/files/1547231914843.png updated from the old image to the new edited. (Tested the base64 on some online converter) but it still does not reflect on the source http://localhost:8080/file/data/user/0/***/files/1547231914843.png
Thanks to all those who read through.
After tons of testing, I found out that Ionic Webview's files, will not be updated unless you recall them again (Kind of like a cache and apparently there is no way to reset or flush the cache).
So in my case, I would need to remove the image from the webview and call it out again then it will go back to retrieve again or create another file with another file name and display it.
I'm trying to use the share() method, including an image, but I'm having trouble supplying the proper path to the image. Where should I put the image file, and what is the path (putting in the default package and trying "jar:///myimage.png" didn't work), and why is this not documented clearly?
image can be stored in storage which is following path for window
C:\Users\userName.cn1
and the image can be read by using following codes
InputStream is = Storage.getInstance().createInputStream("tizbn.JPG");
EncodedImage i = EncodedImage.create(is, is.available());
Loading image from default folder
Image i =EncodedImage.create("/tizbn.png");
Loading image From Theme
EncodedImage current = (EncodedImage) fetchResourceFile().getImage("tizbn.png");
The share API works with https://www.codenameone.com/javadoc/com/codename1/io/FileSystemStorage.html[FileSystemStorage] and not with https://www.codenameone.com/javadoc/com/codename1/io/Storage.html[Storage].
You need to save the file into a file system path which is always an absolute path, we recommend using the app home to store files. There is a sample in the developer guide section on the ShareButton covering this:
Form hi = new Form("ShareButton");
ShareButton sb = new ShareButton();
sb.setText("Share Screenshot");
hi.add(sb);
Image screenshot = Image.createImage(hi.getWidth(), hi.getHeight());
hi.revalidate();
hi.setVisible(true);
hi.paintComponent(screenshot.getGraphics(), true);
String imageFile = FileSystemStorage.getInstance().getAppHomePath() + "screenshot.png";
try(OutputStream os = FileSystemStorage.getInstance().openOutputStream(imageFile)) {
ImageIO.getImageIO().save(screenshot, os, ImageIO.FORMAT_PNG, 1);
} catch(IOException err) {
Log.e(err);
}
sb.setImageToShare(imageFile, "image/png");