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• aarch64: Factorize code for CPU feature detection on Apple platforms

  12 March 2024, by Martin Storsjö

  aarch64: Factorize code for CPU feature detection on Apple platforms
  Signed-off-by: Martin Storsjö <martin@martin.st>
  

  • [DH] libavutil/aarch64/cpu.c

• Read ID3 tags generated using Apple's id3taggenerator

  9 October 2024, by Damiaan Dufaux

  Hi I am creating an HLS stream with ID3 tags using Apple's HTTP Live Streaming (HLS) Tools, FFmpeg and NodeJS. When I try to read out the stream using an AVPlayer and AVPlayerItemMetadataOutput on macOS I'm not able to read out the ID3 tags. When I use the same code to read out a sample stream containing ID3 tags I do see them popping up. What am I doing wrong?

  


  Reproduction:

  


  Streaming

  


  I generate an infinite HLS stream from a 5 minute long mpeg ts file using this command:

  


  ffmpeg -stream_loop -1 -re -i 5m.ts -c:v copy -c:a copy -f mpegts -strict -2 - | mediastreamsegmenter -b http://DamiaanTheoPro14.local:8081/ -f /tmp/hlsId3/video -D -m -M 50000 -log /tmp/hlsId3/log.txt


  


  I serve that HLS stream using nodejs builtin http-server

  


  ID3 tag generation

  


  Then I emit some ID3 tags using the following commands:

  


  id3taggenerator -title foo -artist bar -a localhost:50000
id3taggenerator -text "foo bar" -d "sample text" -r -a localhost:50000


  


  Reading

  


  Now to read out the tags I use this little SwiftUI app:

  


  import SwiftUI
import AVKit

let bipbopUrl = URL(string: "https://devstreaming-cdn.apple.com/videos/streaming/examples/bipbop_16x9/bipbop_16x9_variant.m3u8")!
let localUrl = URL(string: "http://damiaantheopro14.local:8081/prog_index.m3u8")!
let local = AVPlayerItem(url: localUrl)
let bipbop = AVPlayerItem(url: bipbopUrl)

struct ContentView: View {
    let player = AVPlayer()
    let observer = Id3Observer()
    var lastTag: AVMetadataGroup?
    
    var body: some View {
        VStack {
            HStack {
                Button("BipBop") {
                    player.replaceCurrentItem(with: bipbop)
                    bipbop.add(observer.metadataOutput)
                }
                Button("Local") {
                    player.replaceCurrentItem(with: local)
                    local.add(observer.metadataOutput)
                }
                Button("🅧") {
                    player.replaceCurrentItem(with: nil)
                }
            }
            VideoPlayer(player: player)
        }
        .padding()
    }
}

class Id3Observer: NSObject, AVPlayerItemMetadataOutputPushDelegate {
    let metadataOutput = AVPlayerItemMetadataOutput()
    
    override init() {
        super.init()
        metadataOutput.setDelegate(self, queue: .global())
    }
    
    func metadataOutput(_ output: AVPlayerItemMetadataOutput, didOutputTimedMetadataGroups groups: [AVTimedMetadataGroup], from: AVPlayerItemTrack?) {
        print("metadataOutput", groups.count)
        print("\t", groups.map { group in
            group.items.map { item in
                "\(item.dataType) \(item.keySpace!) \(item.key!) \(item.time.seconds) \(item.duration.seconds.rounded())"
            }.joined(separator: "/n/t")
        }.joined(separator: "\n\t"))
    }
}


  


• Combining two video from ffmpeg

  27 January 2024, by Astha

  I want to combine two mp4 videos to form a single mp4 video using ffmpeg.

  



  what i tried so far is

  



  ffmpeg -i input1.mp4 -i input2.mp4 output.mp4


  



  But, every time i get the video with video codec of first input and not the other. How can i combine them? Any idea on this will be highly appreciated.