File size: 5,107 Bytes
2785f78 | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 | import AVFoundation
import Foundation
import CoreMedia
class ContinuousSegmenter: NSObject, AVCaptureVideoDataOutputSampleBufferDelegate, AVCaptureAudioDataOutputSampleBufferDelegate {
// MARK: – Configuration
let segmentDuration: CMTime = .init(seconds: 2, preferredTimescale: 600)
let outputDir: URL
// MARK: – Capture
let session = AVCaptureSession()
let videoOutput = AVCaptureVideoDataOutput()
let audioOutput = AVCaptureAudioDataOutput()
// MARK: – Writer state
var currentWriter: AVAssetWriter?
var videoInput: AVAssetWriterInput?
var audioInput: AVAssetWriterInput?
var segmentStartTime: CMTime = .zero
var segmentIndex = 0
init(outputDir: URL) {
self.outputDir = outputDir
super.init()
setupSession()
// Prepare first writer starting at time zero
rollWriter(at: .zero)
}
private func setupSession() {
session.beginConfiguration()
session.sessionPreset = .high
// Screen input (main display)
let displayID = CGMainDisplayID()
guard let screenIn = AVCaptureScreenInput(displayID: displayID) else {
fatalError("❌ Unable to create screen input")
}
screenIn.minFrameDuration = CMTime(value: 1, timescale: 30)
screenIn.capturesCursor = true
session.addInput(screenIn)
// Audio input (system audio via BlackHole as default)
guard let audioDev = AVCaptureDevice.default(for: .audio),
let audioIn = try? AVCaptureDeviceInput(device: audioDev),
session.canAddInput(audioIn) else {
fatalError("❌ Unable to create audio input")
}
session.addInput(audioIn)
// Data outputs
let q = DispatchQueue(label: "segmentation.queue")
videoOutput.setSampleBufferDelegate(self, queue: q)
audioOutput.setSampleBufferDelegate(self, queue: q)
guard session.canAddOutput(videoOutput), session.canAddOutput(audioOutput) else {
fatalError("❌ Unable to add data outputs")
}
session.addOutput(videoOutput)
session.addOutput(audioOutput)
session.commitConfiguration()
}
private func rollWriter(at startTime: CMTime) {
// Finish previous writer asynchronously
if let oldWriter = currentWriter {
oldWriter.finishWriting {
print("✅ Finished segment \(self.segmentIndex - 1)")
}
}
// Set up new writer
do {
let filename = String(format: "segment_%03d.mov", segmentIndex)
let fileURL = outputDir.appendingPathComponent(filename)
try FileManager.default.createDirectory(at: outputDir, withIntermediateDirectories: true)
let writer = try AVAssetWriter(outputURL: fileURL, fileType: .mov)
// Video Input Configuration
let vSettings: [String: Any] = [
AVVideoCodecKey: AVVideoCodecType.h264,
AVVideoWidthKey: 1280,
AVVideoHeightKey: 720
]
let vInput = AVAssetWriterInput(mediaType: .video, outputSettings: vSettings)
vInput.expectsMediaDataInRealTime = true
writer.add(vInput)
// Audio Input Configuration
let aSettings: [String: Any] = [
AVFormatIDKey: kAudioFormatMPEG4AAC,
AVNumberOfChannelsKey: 2,
AVSampleRateKey: 48000,
AVEncoderBitRateKey: 128000
]
let aInput = AVAssetWriterInput(mediaType: .audio, outputSettings: aSettings)
aInput.expectsMediaDataInRealTime = true
writer.add(aInput)
// Assign new writer & inputs
currentWriter = writer
videoInput = vInput
audioInput = aInput
segmentStartTime = startTime
segmentIndex += 1
// Start writing session
writer.startWriting()
writer.startSession(atSourceTime: startTime)
print("▶️ Started segment \(segmentIndex - 1) at \(startTime.seconds) s")
} catch {
fatalError("❌ Could not start writer: \(error)")
}
}
func start() {
session.startRunning()
}
private func handle(_ sample: CMSampleBuffer, mediaType: AVMediaType) {
guard CMSampleBufferDataIsReady(sample), currentWriter != nil else { return }
let pts = CMSampleBufferGetPresentationTimeStamp(sample)
// Check for segment rollover
if CMTimeSubtract(pts, segmentStartTime) >= segmentDuration {
rollWriter(at: pts)
}
// Append to writer inputs
if mediaType == .video, let vInput = videoInput, vInput.isReadyForMoreMediaData {
vInput.append(sample)
}
if mediaType == .audio, let aInput = audioInput, aInput.isReadyForMoreMediaData {
aInput.append(sample)
}
}
// MARK: – Delegates
func captureOutput(_ output: AVCaptureOutput,
didOutput sampleBuffer: CMSampleBuffer,
from connection: AVCaptureConnection) {
if output === videoOutput {
handle(sampleBuffer, mediaType: .video)
} else if output === audioOutput {
handle(sampleBuffer, mediaType: .audio)
}
}
}
// === main ===
let cwd = URL(fileURLWithPath: FileManager.default.currentDirectoryPath)
let segmentsDir = cwd.appendingPathComponent("segments")
let segmenter = ContinuousSegmenter(outputDir: segmentsDir)
segmenter.start()
RunLoop.main.run()
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