FFmpeg 7 channel layout source refactoring

Author: kartik-venugopal

FFmpegPlayer.xcodeproj/project.xcworkspace/xcuserdata/kven.xcuserdatad/UserInterfaceState.xcuserstate

@@ -125,21 +125,25 @@ struct FFmpegChannelLayoutsMapper {
     /// - returns: A corresponding AVFoundation channel layout, if there exists a mapping for the given
     ///            ffmpeg channel layout. Nil otherwise.
     ///
-    static func mapLayout(ffmpegLayout: Int) -> AVAudioChannelLayout? {
+    static func mapLayout(ffmpegLayout: AVChannelLayout) -> AVAudioChannelLayout? {
 
-        if let layoutTag = layoutsMap[ffmpegLayout] {
+        if let layoutTag = layoutsMap[Int(ffmpegLayout.u.mask)] {
             return AVAudioChannelLayout(layoutTag: layoutTag)
         }
 
         return nil
     }
 
-    static func readableString(for channelLayout: Int64, channelCount: Int32) -> String {
+    static func readableString(for channelLayout: AVChannelLayout, channelCount: Int32) -> String {
 
         let layoutStringPointer = UnsafeMutablePointer<Int8>.allocate(capacity: 100)
         defer {layoutStringPointer.deallocate()}
 
-        av_get_channel_layout_string(layoutStringPointer, 100, channelCount, UInt64(channelLayout))
+        withUnsafePointer(to: channelLayout) {ptr -> Void in
+            av_channel_layout_describe(ptr, layoutStringPointer, 100)
+        }
+        
+//        av_get_channel_layout_string(layoutStringPointer, 100, channelCount, UInt64(channelLayout))
         return String(cString: layoutStringPointer).replacingOccurrences(of: "(", with: " (").capitalized
     }
 }

Sources/FFmpeg/Utils/FFmpegChannelLayoutsMapper.swift

@@ -74,7 +74,10 @@ class FFmpegDecoder {
 
     let resampleCtx: FFmpegAVAEResamplingContext?
 
-    private(set) lazy var audioFormat: FFmpegAudioFormat = FFmpegAudioFormat(sampleRate: codec.sampleRate, channelCount: codec.channelCount, channelLayout: codec.channelLayout, sampleFormat: codec.sampleFormat)
+    private(set) lazy var audioFormat: FFmpegAudioFormat = FFmpegAudioFormat(sampleRate: codec.sampleRate, 
+                                                                             channelCount: codec.channelCount,
+                                                                             channelLayout: codec.channelLayout,
+                                                                             sampleFormat: codec.sampleFormat)
 
     private(set) lazy var channelCount: Int = Int(audioFormat.channelCount)
 

Sources/FFmpeg/Utils/FFmpegDecoder.swift

@@ -125,7 +125,7 @@ class AudioFileContext {
         self.sampleRate = sampleRateDouble
         self.frameCount = Int64(sampleRateDouble * theFormatContext.duration)
 
-        let channelLayout: AVAudioChannelLayout = FFmpegChannelLayoutsMapper.mapLayout(ffmpegLayout: Int(codec.channelLayout)) ?? .stereo
+        let channelLayout: AVAudioChannelLayout = FFmpegChannelLayoutsMapper.mapLayout(ffmpegLayout: codec.channelLayout) ?? .stereo
 
         self.audioFormat = AVAudioFormat(standardFormatWithSampleRate: sampleRateDouble, channelLayout: channelLayout)
 

Sources/FFmpeg/Wrappers/AudioFileContext.swift

@@ -52,7 +52,7 @@ class FFmpegAudioCodec: FFmpegCodec {
     ///
     /// Describes the number and physical / spatial arrangement of the channels. (e.g. "5.1 surround" or "stereo")
     ///
-    var channelLayout: Int64 = 0
+    var channelLayout: AVChannelLayout = .init()
 
     ///
     /// Instantiates an AudioCodec object, given a pointer to its parameters.
@@ -63,12 +63,13 @@ class FFmpegAudioCodec: FFmpegCodec {
 
         try super.init(fromParameters: paramsPointer)
 
-        self.sampleFormat = FFmpegSampleFormat(encapsulating: context.sample_fmt)
-        self.channelCount = params.channels
-        
         // Correct channel layout if necessary.
         // NOTE - This is necessary for some files like WAV files that don't specify a channel layout.
-        self.channelLayout = context.channel_layout != 0 ? Int64(context.channel_layout) : av_get_default_channel_layout(context.channels)
+//        self.channelLayout = context.channel_layout != 0 ? Int64(context.channel_layout) : av_get_default_channel_layout(context.channels)
+        self.channelLayout = context.ch_layout
+        
+        self.sampleFormat = FFmpegSampleFormat(encapsulating: context.sample_fmt)
+        self.channelCount = params.ch_layout.nb_channels
 
         // Use multithreading to speed up decoding.
         self.contextPointer.pointee.thread_count = Self.threadCount
@@ -83,7 +84,8 @@ class FFmpegAudioCodec: FFmpegCodec {
         // Some streams may contain the wrong header information. So, recompute these
         // values after opening the codec.
 
-        self.channelLayout = context.channel_layout != 0 ? Int64(context.channel_layout) : av_get_default_channel_layout(context.channels)
+//        self.channelLayout = context.channel_layout != 0 ? Int64(context.channel_layout) : av_get_default_channel_layout(context.channels)
+        self.channelLayout = context.ch_layout
         self.sampleFormat = FFmpegSampleFormat(encapsulating: context.sample_fmt)
     }
 

Sources/FFmpeg/Wrappers/FFmpegAudioCodec.swift

@@ -23,7 +23,7 @@ struct FFmpegAudioFormat {
     let channelCount: Int32
 
     /// An ffmpeg identifier for the physical / spatial layout of channels. eg. "5.1 surround" or "stereo".
-    let channelLayout: Int64
+    let channelLayout: AVChannelLayout
 
     /// PCM sample format
     let sampleFormat: FFmpegSampleFormat

Sources/FFmpeg/Wrappers/FFmpegAudioFormat.swift

@@ -82,9 +82,9 @@ class FFmpegAudioStream: FFmpegStreamProtocol {
 
     var sampleRate: Int32 {codecParams.sample_rate}
 
-    var channelCount: Int32 {codecParams.channels}
+    var channelCount: Int32 {codecParams.ch_layout.nb_channels}
 
-    var channelLayout: UInt64 {codecParams.channel_layout}
+    var channelLayout: UInt64 {codecParams.ch_layout.u.mask}
 
     ///
     /// All metadata key / value pairs available for this stream.

Sources/FFmpeg/Wrappers/FFmpegAudioStream.swift

@@ -18,7 +18,7 @@ class FFmpegCodec {
     ///
     /// A pointer to the encapsulated AVCodec object.
     ///
-    var pointer: UnsafeMutablePointer<AVCodec>!
+    var pointer: UnsafePointer<AVCodec>!
 
     ///
     /// The encapsulated AVCodec object.

Sources/FFmpeg/Wrappers/FFmpegCodec.swift

@@ -30,12 +30,12 @@ class FFmpegFrame {
     ///
     /// Describes the number and physical / spatial arrangement of the channels. (e.g. "5.1 surround" or "stereo")
     ///
-    var channelLayout: UInt64 {avFrame.channel_layout}
+    var channelLayout: AVChannelLayout {avFrame.ch_layout}
 
     ///
     /// Number of channels of audio data.
     ///
-    var channelCount: Int32 {avFrame.channels}
+    var channelCount: Int32 {avFrame.ch_layout.nb_channels}
 
     lazy var intChannelCount: Int = Int(channelCount)
 

Sources/FFmpeg/Wrappers/FFmpegFrame.swift

@@ -51,25 +51,31 @@ class FFmpegResamplingContext {
     ///
     /// The channel layout of the input samples.
     ///
-    var inputChannelLayout: Int64? {
+    var inputChannelLayout: AVChannelLayout? {
 
         didSet {
 
             if let channelLayout = inputChannelLayout {
-                av_opt_set_channel_layout(rawPointer, "in_channel_layout", channelLayout, 0)
+                
+                withUnsafePointer(to: channelLayout) {ptr -> Void in
+                    av_opt_set_chlayout(rawPointer, "in_channel_layout", ptr, 0)
+                }
             }
         }
     }
 
     ///
     /// The (desired) channel layout of the output samples.
     ///
-    var outputChannelLayout: Int64? {
+    var outputChannelLayout: AVChannelLayout? {
 
         didSet {
 
             if let channelLayout = outputChannelLayout {
-                av_opt_set_channel_layout(rawPointer, "out_channel_layout", channelLayout, 0)
+                
+                withUnsafePointer(to: channelLayout) {ptr -> Void in
+                    av_opt_set_chlayout(rawPointer, "out_channel_layout", ptr, 0)
+                }
             }
         }
     }
@@ -183,7 +189,7 @@ class FFmpegAVAEResamplingContext: FFmpegResamplingContext {
     ///
     private static let standardSampleFormat: AVSampleFormat = AV_SAMPLE_FMT_FLTP
 
-    init?(channelLayout: Int64, sampleRate: Int64, inputSampleFormat: AVSampleFormat) {
+    init?(channelLayout: AVChannelLayout, sampleRate: Int64, inputSampleFormat: AVSampleFormat) {
 
         super.init()