Editing MP3/Wav Files in a Flutter App (Dart) - dart

Is it possible in a Flutter App to "concatenate" sound files without calling Swift/Java code to handle it for me? (Partially because I don't know Swift, and partially because I haven't figured out ffmpeg yet) The microphone provides either mp3 or wav files, and either works fine for me.
I'm attempting to make a Recording app that has more functionality than the ones I've previously found. Specifically, I want it to be able to pause the recording for an indefinite amount of time, and start again WITHOUT creating two files for the user to save -- it should combine them and save it later as a single file.

You can take a look about this
medcorder_audio
and for splitting
audiocutter

Related

libffmpeg: writing an RTSP stream to an output file

I'm working with libffmpeg in an iOS app. My goal is to connect to an RTSP source and write the media out to a file that can later be used with the iOS media player. Ideally I'd like to do this without transcoding the incoming data. I also want to be able to later re-encode the media with AVAssetExportSession if the user chooses to do so.
Because I want to create a file that is compatible with iOS, I'm limited (I believe) to mpeg, mp4 or quicktime (mov) formats.
Whenever I try to use one of these formats, I see the following warnings during my call to avformat_write_header:
[mov # 0x16401c00] Codec for stream 0 does not use global headers but container format requires global headers
[mov # 0x16401c00] Codec for stream 1 does not use global headers but container format requires global headers
My understanding is that the header wants to know the ultimate file size, which I do not know (the RTSP server is live streaming a camera, and the user stops the recording whenever they want). I guess that makes sense, but I know that others have successfully done this using the ffmpeg command line, so I'm confused as to what else I need to do here.
If I ignore the warning, I can still proceed with writing the file. If I choose mpeg or mp4 formats, my app crashes when I call av_write_trailer. If I use mov, I can successfully close the file, and the file does play back, but usually fails when I try to hand it to the AVAssetExportSession.
I would appreciate any insight into this. Thanks.
Frank
I found what appears to be a solution -- at least, it eliminates the warning. I had to set the CODEC_FLAG_GLOBAL_HEADER on both the audio and video codecs, before calling avcodec_open2.

How to first download audio files from URLs and then play all - iOS

I have got multiple audio files on server.
I want to download all audio files first, and then when all are downloaded, i need to play them one after another.
What will be the best approach to achieve this?
Thanks!

How to copy audio stream using FFMpeg API ( not a command line tool )

I'm developing some Video Editing Apps on Android.
the objective of the app is "Editing Videos on Android".
and...
I'm just completed making video file using some images.
but.. I can't attach audio into the video.
my method is same as follows.
1.VideoStream, audio stream creation using AVFormatContext
2.Movie encoding in video stream was successful
3.Encode codec open in audio stream was successful
4.Set sample format to AV_SAMPLE_FMT_FLTP
5.Sample rate and channel was set same as source audio
6.Choose appropriate Decoder and read packet
7.Convert packets using swr_converter, setting same as sample format
8.Encode converted data
9.memory deallocation
10.END!
Problem is here:
Video of finally created video file was normally played. but the Audio wasn't.
It heared like weird. It have many noises and plays slowly.
I've googled with many keywords but they only say about "FFmpeg command line usage".
I wanna make with FFMpeg API. not a Command line tool.
Please help.
Your question is vague without some kind of code to go along with it, as trust me there are a lot of things that can go wrong when using ffmpeg's libraries directly (and on Windows there is no debuging). Unfortunately ffmpeg's libraries are not well documented so it is generally best to read the source code for ffmpeg in order to use its libraries. Find the equivalent command line options to perform what you want and track that through ffmpeg's source to see the library calls.

How to embed images and sounds in an iPhone app?

I am having a real hard time understanding how to embed many images and sounds in an iPhone app. When I say embed, I mean I want the images and sounds to be downloaded with the app, and some of those images will appear when the app is run. Other images are just saved in the app's disk space, so that when a user presses a button, the image or sound will be accessed and displayed or played.
I have read tutorials on using 'core data' and such, but that only seems like a way to create objects that can be used to reference such data items, or for storing small files as binary data. Can someone please tell me how in xcode I can specify a directory of images and .mp3s to be loaded onto a phone with my app, and how I can then call those media with code?
Some example code for the following would completely solve my problem:
An app is loaded onto a phone, and it contains 3 buttons. If the user presses button #1, a sound is heard. Button #2 plays a different sound, and button #3 changes a UIImageView to a different picture. (this isn't a homework assignment or something, but if I could code this example, I could do everything I need to in my app and understand the process)
Thanks!
I mean I want the images and sounds to be downloaded with the app
Simply add the images and sounds to your project. Make sure you specify (in the Add Files to Project dialog) that they are to copied into the project and that they are to be part of the target. The result will be that the images and sounds will be built into your app (in what is called its bundle, in particular the main bundle - see the NSBundle docs). You can then fetch them out, as needed, in code. For example, to fetch an image, use imageNamed:. To refer to a sound, refer to the file as a resource within the main bundle.
Other images are just saved in the app's disk space
That is a completely different matter. You will have to get the images from somewhere while the app runs. There is no way to have the user download the app and the image end up in the app's disk space: the app must populate its disk space, in real time, as the app runs. At the time the user downloads the app, the associated disk space, outside the app bundle itself, will be empty.
For images, see the responses to this question.
Sound is similar to images, but is loaded differently, this tutorial show how to load and play sounds.
For files that are saved after the app is installed, you will need to download and save those files in your code. For starters, see Apple's guide to the iOS file system

Downloading and saving files with AIR for iOs

For a project we need to download and save pdf files on an IPAD device for offline use through an AIR for iOs application.
After a lot of searching I haven't found much information on this subject. My question is, can it be done, and if so, can you provide us with some pointers to lead us in the right direction.
Thanks for your time!
Sure, first you check if you can access the web - can use a class like air.net.URLMonitor, if you can you can set up a URLStream instance.
You get data while its downloading the file using the progress event, write that out to a File instance using the FileStream class.
To display the PDF file you can use a StageWebView or HTMLLoader.

Resources