Module refactoring

submodules/MediaPlayer/Sources/FFMpegAudioFrameDecoder.swift

@@ -0,0 +1,65 @@
+import Foundation
+import CoreMedia
+import FFMpeg
+
+final class FFMpegAudioFrameDecoder: MediaTrackFrameDecoder {
+    private let codecContext: FFMpegAVCodecContext
+    private let swrContext: FFMpegSWResample
+    
+    private let audioFrame: FFMpegAVFrame
+    private var resetDecoderOnNextFrame = true
+    
+    init(codecContext: FFMpegAVCodecContext) {
+        self.codecContext = codecContext
+        self.audioFrame = FFMpegAVFrame()
+        
+        self.swrContext = FFMpegSWResample(sourceChannelCount: Int(codecContext.channels()), sourceSampleRate: Int(codecContext.sampleRate()), sourceSampleFormat: codecContext.sampleFormat(), destinationChannelCount: 2, destinationSampleRate: 44100, destinationSampleFormat: FFMPEG_AV_SAMPLE_FMT_S16)
+    }
+    
+    func decode(frame: MediaTrackDecodableFrame) -> MediaTrackFrame? {
+        let status = frame.packet.send(toDecoder: self.codecContext)
+        if status == 0 {
+            if self.codecContext.receive(into: self.audioFrame) {
+                return convertAudioFrame(self.audioFrame, pts: frame.pts, duration: frame.duration)
+            }
+        }
+        
+        return nil
+    }
+    
+    func takeRemainingFrame() -> MediaTrackFrame? {
+        return nil
+    }
+    
+    private func convertAudioFrame(_ frame: FFMpegAVFrame, pts: CMTime, duration: CMTime) -> MediaTrackFrame? {
+        guard let data = self.swrContext.resample(frame) else {
+            return nil
+        }
+        
+        var blockBuffer: CMBlockBuffer?
+        
+        let bytes = malloc(data.count)!
+        data.copyBytes(to: bytes.assumingMemoryBound(to: UInt8.self), count: data.count)
+        let status = CMBlockBufferCreateWithMemoryBlock(allocator: nil, memoryBlock: bytes, blockLength: data.count, blockAllocator: nil, customBlockSource: nil, offsetToData: 0, dataLength: data.count, flags: 0, blockBufferOut: &blockBuffer)
+        if status != noErr {
+            return nil
+        }
+        
+        var timingInfo = CMSampleTimingInfo(duration: duration, presentationTimeStamp: pts, decodeTimeStamp: pts)
+        var sampleBuffer: CMSampleBuffer?
+        var sampleSize = data.count
+        guard CMSampleBufferCreate(allocator: nil, dataBuffer: blockBuffer, dataReady: true, makeDataReadyCallback: nil, refcon: nil, formatDescription: nil, sampleCount: 1, sampleTimingEntryCount: 1, sampleTimingArray: &timingInfo, sampleSizeEntryCount: 1, sampleSizeArray: &sampleSize, sampleBufferOut: &sampleBuffer) == noErr else {
+            return nil
+        }
+        
+        let resetDecoder = self.resetDecoderOnNextFrame
+        self.resetDecoderOnNextFrame = false
+        
+        return MediaTrackFrame(type: .audio, sampleBuffer: sampleBuffer!, resetDecoder: resetDecoder, decoded: true)
+    }
+    
+    func reset() {
+        self.codecContext.flushBuffers()
+        self.resetDecoderOnNextFrame = true
+    }
+}