45 lines
1.0 KiB
Dart
45 lines
1.0 KiB
Dart
import 'dart:typed_data';
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class G711Decoder {
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// G.711 µ-law解码
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Uint8List decodeG711uLaw(Uint8List data) {
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List<int> decodedData = [];
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for (int i = 0; i < data.length; i++) {
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int sample = _decodeG711uLawSample(data[i]);
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decodedData.add(sample);
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}
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return Uint8List.fromList(decodedData);
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}
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// G.711 µ-law样本解码
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int _decodeG711uLawSample(int uLawByte) {
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const int bias = 0x84;
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const int mask = 0x7F;
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uLawByte = ~uLawByte;
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int sign = uLawByte & 0x80;
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int exponent = (uLawByte & 0x70) >> 4;
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int mantissa = uLawByte & 0x0F;
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int sample = ((bias << exponent) + mantissa) * (sign == 0 ? 1 : -1);
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return sample & mask; // 防止溢出
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}
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}
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void main() {
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G711Decoder g711Decoder = G711Decoder();
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// 假设 g711Data 是G.711 µ-law编码的数据
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Uint8List g711Data =
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Uint8List.fromList([/* your G.711 µ-law encoded data */]);
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// 解码
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List<int> decodedData = g711Decoder.decodeG711uLaw(g711Data);
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// 处理解码后的数据，例如播放音频
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print(decodedData);
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}
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