Recherche avancée

Sur d’autres sites (6699)

• FFmpeg drawtext filter error : "Cannot find a valid font for the family Sans"

  7 septembre 2024, par fatdrogen

  I'm trying to add text overlay to a video using FFmpeg's drawtext filter in my iOS app, but I'm encountering the following error :

  


  error : Cannot load default config file

  


  ERROR : Cannot find a valid font for the family Sans

  


  ERROR : Error initializing filter 'drawtext'

  


  ERROR : with args 'text=write some thing :'

  


  Here's the relevant part of my FFmpeg command :

  


  Copydrawtext=text='write some thing '

  


  Questions :

  


  What's causing this error, and how can I resolve it ?
Is there a way to specify a font that's guaranteed to be available on iOS devices ?
Are there any alternative approaches to adding text overlay in FFmpeg that might avoid this issue ?

  


  Environment :

  


  Platform : iOS
FFmpeg : Using MobileFFmpeg library
Swift

  


  Any help or guidance would be greatly appreciated !

  


  func makeGIFData(asset: AVAsset,  startTime: Double, endTime: Double, rotation: Double, overlayText: String) async throws -> Data {
    let fileName = "\(ProcessInfo.processInfo.globallyUniqueString)_input.mp4"
    let fileURL = URL(fileURLWithPath: NSTemporaryDirectory()).appendingPathComponent(fileName)
    
    // Export the asset to a temporary file
    guard let exporter = try? await AVAssetExportSession(asset: asset, presetName: AVAssetExportPresetHighestQuality) else {
        throw NSError(domain: "GIFConversionError", code: -1, userInfo: [NSLocalizedDescriptionKey: "Failed to create AVAssetExportSession"])
    }
    
    exporter.outputURL = fileURL
    exporter.outputFileType = .mp4
    exporter.timeRange = CMTimeRange(start: CMTime(seconds: startTime, preferredTimescale: 600), end: CMTime(seconds: endTime, preferredTimescale: 600))
    
    do {
        try await exporter.export()
    } catch {
        throw NSError(domain: "GIFConversionError", code: -2, userInfo: [NSLocalizedDescriptionKey: "Failed to export video: \(error.localizedDescription)"])
    }
    
    let outfileName = "\(ProcessInfo.processInfo.globallyUniqueString)_outfile.gif"
    let outfileURL = URL(fileURLWithPath: NSTemporaryDirectory()).appendingPathComponent(outfileName)
    
    // Get video dimensions
    guard let track = try? await asset.loadTracks(withMediaType: .video).first,
          let videoSize = try? await track.load(.naturalSize) else {
        throw NSError(domain: "GIFConversionError", code: -4, userInfo: [NSLocalizedDescriptionKey: "Failed to get video dimensions"])
    }
    
    // Prepare FFmpeg command
    var command = "-i \(fileURL.path) -vf "
    
    
    // Add text overlay
    let escapedText = overlayText.replacingOccurrences(of: ":", with: "\\:").replacingOccurrences(of: "'", with: "\\'")
    let fontColor = textColor.toHexString()
    
    // Use a more universally available font, or provide multiple options
    filters += ",drawtext=text='write some thing ':"
    
    // Add palette generation and application
    filters += ",split[s0][s1];[s0]palettegen[p];[s1][p]paletteuse"
    
    // Add filters to command
    command += "\"\(filters)\""
    
    // Finalize command
    command += " -loop 0 \(outfileURL.path)"
    
    print("FFmpeg command: \(command)")
    
    let startTime = CFAbsoluteTimeGetCurrent()
    
    let result = MobileFFmpeg.execute(command)
    
    if result != RETURN_CODE_SUCCESS {
        throw NSError(domain: "GIFConversionError", code: Int(result), userInfo: [NSLocalizedDescriptionKey: "FFmpeg conversion failed"])
    }
    
    let timeElapsed = CFAbsoluteTimeGetCurrent() - startTime
    print("Time elapsed: \(timeElapsed) s.")
    
    // Read the generated GIF file
    guard let gifData = try? Data(contentsOf: outfileURL) else {
        throw NSError(domain: "GIFConversionError", code: -3, userInfo: [NSLocalizedDescriptionKey: "Failed to read generated GIF file"])
    }
    
    print("Animated GIF data created successfully. Size: \(gifData.count) bytes")
    
    // Clean up temporary files
    try? FileManager.default.removeItem(at: fileURL)
    try? FileManager.default.removeItem(at: outfileURL)
    
    return gifData
}
'''


  


• How to merge video file with audio file and maintain creation time ?

  19 janvier 2021, par madprogramer

  I was finicking around with youtube-dl and ended up downloading a video that youtube-dl wasn't able to merge the generated audio and video. After some investigation, I found that there was an issue in my ffmpeg config.

  


  Normally, if you actually run youtube-dl a second time after fixing ffmpeg, it will automatically merge the files for you. But as fate would have it, the online video has since been deleted so youtube-dl freaks out.

  


  Fortunately ffmpeg itself can also merge audio and video files, but loses a very nice feature youtube-dl's implementation has, keeping the creation time of the files (i.e. creation rather than download or publication time).

  


  Is there any way to merge an audio and video file and keep the creation/last modified date ?

  


• dshow : allow selecting devices by an alternative name (workaround for devices with...

  23 janvier 2015, par rogerdpack

  dshow : allow selecting devices by an alternative name (workaround for devices with symbols in them), allow specifying capture pins by name and alternative (unique) name
  Signed-off-by : rogerdpack <rogerpack2005@gmail.com>
  

  • [DH] doc/indevs.texi
  • [DH] libavdevice/dshow.c