| 76 | } |
| 77 | |
| 78 | WaveData parseWav(IODevicePtr device) { |
| 79 | const size_t sigLength = 4; |
| 80 | unique_ptr<char[]> riffSig(new char[sigLength + 1]()); // RIFF\0 |
| 81 | unique_ptr<char[]> waveSig(new char[sigLength + 1]()); // WAVE\0 |
| 82 | unique_ptr<char[]> fmtSig(new char[sigLength + 1]()); // fmt \0 |
| 83 | unique_ptr<char[]> dataSig(new char[sigLength + 1]()); // data\0 |
| 84 | |
| 85 | // RIFF Chunk Descriptor |
| 86 | device->seek(0); |
| 87 | device->readFull(riffSig.get(), sigLength); |
| 88 | |
| 89 | uint32_t fileSize = readLEType<uint32_t>(device); |
| 90 | fileSize += sigLength + sizeof(fileSize); |
| 91 | if (fileSize != device->size()) |
| 92 | throw AudioException(strf("Wav file is wrong size, reports {} is actually {}", fileSize, device->size())); |
| 93 | |
| 94 | device->readFull(waveSig.get(), sigLength); |
| 95 | |
| 96 | if ((strcmp(riffSig.get(), "RIFF") != 0) || (strcmp(waveSig.get(), "WAVE") != 0)) { // bytes are not magic |
| 97 | auto p = [](char a) { return isprint(a) ? a : '?'; }; |
| 98 | throw AudioException(strf("Wav file has wrong magic bytes, got `{:c}{:c}{:c}{:c}' and `{:c}{:c}{:c}{:c}' but expected `RIFF' and `WAVE'", |
| 99 | p(riffSig[0]), p(riffSig[1]), p(riffSig[2]), p(riffSig[3]), p(waveSig[0]), p(waveSig[1]), p(waveSig[2]), p(waveSig[3]))); |
| 100 | } |
| 101 | |
| 102 | // fmt subchunk |
| 103 | |
| 104 | device->readFull(fmtSig.get(), sigLength); |
| 105 | if (strcmp(fmtSig.get(), "fmt ") != 0) { // friendship is magic |
| 106 | auto p = [](char a) { return isprint(a) ? a : '?'; }; |
| 107 | throw AudioException(strf("Wav file fmt subchunk has wrong magic bytes, got `{:c}{:c}{:c}{:c}' but expected `fmt '", |
| 108 | p(fmtSig[0]), |
| 109 | p(fmtSig[1]), |
| 110 | p(fmtSig[2]), |
| 111 | p(fmtSig[3]))); |
| 112 | } |
| 113 | |
| 114 | uint32_t fmtSubchunkSize = readLEType<uint32_t>(device); |
| 115 | fmtSubchunkSize += sigLength; |
| 116 | if (fmtSubchunkSize < 20) |
| 117 | throw AudioException(strf("fmt subchunk is sized wrong, expected 20 got {}. Is this wav file not PCM?", fmtSubchunkSize)); |
| 118 | |
| 119 | uint16_t audioFormat = readLEType<uint16_t>(device); |
| 120 | if (audioFormat != 1) |
| 121 | throw AudioException("audioFormat data indicates that wav file is something other than PCM format. Unsupported."); |
| 122 | |
| 123 | uint16_t wavChannels = readLEType<uint16_t>(device); |
| 124 | uint32_t wavSampleRate = readLEType<uint32_t>(device); |
| 125 | uint32_t wavByteRate = readLEType<uint32_t>(device); |
| 126 | uint16_t wavBlockAlign = readLEType<uint16_t>(device); |
| 127 | uint16_t wavBitsPerSample = readLEType<uint16_t>(device); |
| 128 | |
| 129 | if (wavBitsPerSample != 16) |
| 130 | throw AudioException("Only 16-bit PCM wavs are supported."); |
| 131 | if (wavByteRate * 8 != wavSampleRate * wavChannels * wavBitsPerSample) |
| 132 | throw AudioException("Sanity check failed, ByteRate is wrong"); |
| 133 | if (wavBlockAlign * 8 != wavChannels * wavBitsPerSample) |
| 134 | throw AudioException("Sanity check failed, BlockAlign is wrong"); |
| 135 | |