我在.wav(声音(文件中使用adpcm时遇到一些问题。在这个问题的开头,我应该说,我没有读过所有关于ADPCM的东西,只是想快速实现并努力。。。(只是培训代码(我从MicroChip的pdf guid adpcm中实现了它。(最好说是复制/粘贴和编辑,创建类(
测试代码:
const std::vector<int8_t> data = {
64, 67, 71, 75, 79, 83, 87, 91, 94, 98, 101, 104, 107, 110, 112,
115, 117, 119, 121, 123, 124, 125, 126, 126, 127, 127, 127, 126, 126, 125,
124, 123, 121, 119, 117, 115, 112, 110, 107, 104, 101, 98, 94, 91, 87,
83, 79, 75, 71, 67, 64, 60, 56, 52, 48, 44, 40, 36, 33, 29,
26, 23, 20, 17, 15, 12, 10, 8, 6, 4, 3, 2, 1, 1, 0,
0, 0, 1, 1, 2, 3, 4, 6, 8, 10, 12, 15, 17, 20, 23,
26, 29, 33, 36, 40, 44, 48, 52, 56, 60, 64};
void function() {
std::vector<uint8_t> en;
std::vector<uint8_t> de;
{ // encode
wave::ADPCM adpcm;
// 32768
for (size_t i{0}; i < data.size() - 3; i += 4) {
int16_t first{static_cast<int16_t>(
~((static_cast<uint16_t>(data[i]) & 0xff) |
((static_cast<uint16_t>(data[i + 1]) << 8) & 0xff00)) +
1)};
int16_t second{static_cast<int16_t>(
~((static_cast<uint16_t>(data[i + 2]) & 0xff) |
((static_cast<uint16_t>(data[i + 3]) << 8) & 0xff00)) +
1)};
en.push_back(static_cast<uint8_t>((adpcm.ADPCMEncoder(first) & 0x0f) |
(adpcm.ADPCMEncoder(second) << 4)));
}
}
{ // decode
wave::ADPCM adpcm;
for (auto val : en) {
int16_t result = ~adpcm.ADPCMDecoder(val & 0xf) + 1;
int8_t temp0 = ((result)&0xff);
int8_t temp1 = ((result)&0xff00) >> 8;
de.push_back(temp0);
de.push_back(temp1);
result = ~adpcm.ADPCMDecoder(val >> 4) + 1;
temp0 = ((result)&0xff);
temp1 = (result & 0xff00) >> 8;
de.push_back(temp0);
de.push_back(temp1);
}
}
int i{0};
for (auto val : de) {
qDebug() << "real:" << data[i] << "decoded: " << val;
i++;
}
}
我确信我的类和编码/解码是正确的,解码后我应该做些什么来显示正确的数字(但我不知道哪一个选角失败(。
为什么我确定?因为当我在QDebug中看到我的输出时,每隔一个样本(解码后(都是正确的(错误很少,在大数据中错误会比现在小(,但其他样本都是失败的
我的输出:
real: 26 decoded: 6
real: 29 decoded: 32
real: 33 decoded: 5
real: 36 decoded: 48
real: 40 decoded: 6
real: 44 decoded: 32
real: 48 decoded: 5
real: 52 decoded: 48
real: 56 decoded: 4
real: 60 decoded: 64
数据在设备中为8位
好的,我找到了我的答案
当你在任何数字上有错误时,你的错误都在低位!所以我的预测是在两个数字上,然后这个数字在低位,有很多错误!