| | 71 | void Sound::checkSpeechFileEndianness() { |
| | 72 | // Some mac versions (not all of them) use big endian waw, although |
| | 73 | // the waw header doesn't indicate it. |
| | 74 | // Use heuristic to determine endianness of speech. |
| | 75 | // The heuristic consist in computing the sum of the absolute difference for |
| | 76 | // every two consecutive samples. This is done both with a big endian and a |
| | 77 | // little endian assumption. The one with the smallest sum should be the |
| | 78 | // correct one (the sound wave is supposed to be relatively smooth). |
| | 79 | // It needs at least 1000 samples to get stable result (the code below is |
| | 80 | // using the first 2000 samples of the waw sound. |
| | 81 | |
| | 82 | // Init speach file if not already done. |
| | 83 | if (!_currentCowFile) { |
| | 84 | // Open one of the speech file. It uses SwordEngine::_systemVars.currentCD |
| | 85 | // to decide which file to open, therefore if it is currently set to zero |
| | 86 | // we have to set it to either 1 or 2 (I decided to set it to 1 as this is |
| | 87 | // more likely to be the first file that will be needed). |
| | 88 | bool no_current_cd = false; |
| | 89 | if (SwordEngine::_systemVars.currentCD == 0) { |
| | 90 | SwordEngine::_systemVars.currentCD = 1; |
| | 91 | no_current_cd = true; |
| | 92 | } |
| | 93 | initCowSystem(); |
| | 94 | if (no_current_cd) { |
| | 95 | // In case it fails with CD1 retyr with CD2 |
| | 96 | if (!_currentCowFile) { |
| | 97 | SwordEngine::_systemVars.currentCD = 2; |
| | 98 | initCowSystem(); |
| | 99 | } |
| | 100 | // Reset curentCD flag |
| | 101 | SwordEngine::_systemVars.currentCD = 0; |
| | 102 | } |
| | 103 | } |
| | 104 | |
| | 105 | // Testing for endianness makes sense only if using the nom compressed files. |
| | 106 | if (_cowHeader == NULL || (_cowMode != CowWave && _cowMode != CowDemo)) |
| | 107 | return; |
| | 108 | |
| | 109 | // I picked the sample to use randomly (I just made sure it is long enough so that there is |
| | 110 | // a fair change of the heuristic to have a stable result and work for every languages). |
| | 111 | int roomNo = _currentCowFile == 1 ? 1 : 129; |
| | 112 | int localNo = _currentCowFile == 1 ? 2 : 933; |
| | 113 | // Get the speech data and apply the heuristic |
| | 114 | uint32 locIndex = _cowHeader[roomNo] >> 2; |
| | 115 | uint32 sampleSize = _cowHeader[locIndex + (localNo * 2)]; |
| | 116 | uint32 index = _cowHeader[locIndex + (localNo * 2) - 1]; |
| | 117 | if (sampleSize) { |
| | 118 | uint32 size; |
| | 119 | double be_diff_sum = 0., le_diff_sum = 0.; |
| | 120 | _bigEndianSpeech = false; |
| | 121 | int16 *data = uncompressSpeech(index + _cowHeaderSize, sampleSize, &size); |
| | 122 | // Compute average of differecen between two consecutive samples for both BE and LE |
| | 123 | if (data) { |
| | 124 | if (size > 4000) |
| | 125 | size = 2000; |
| | 126 | else |
| | 127 | size /= 2; |
| | 128 | int16 prev_be_value = (int16)SWAP_BYTES_16(*((uint16*)(data))); |
| | 129 | for (uint32 i = 1 ; i < size ; ++i) { |
| | 130 | le_diff_sum += fabs(data[i] - data[i-1]); |
| | 131 | int16 be_value = (int16)SWAP_BYTES_16(*((uint16*)(data + i))); |
| | 132 | be_diff_sum += fabs(be_value - prev_be_value); |
| | 133 | prev_be_value = be_value; |
| | 134 | } |
| | 135 | delete [] data; |
| | 136 | } |
| | 137 | // Set the big endian flag |
| | 138 | _bigEndianSpeech = (be_diff_sum < le_diff_sum); |
| | 139 | if (_bigEndianSpeech) |
| | 140 | debug(6, "Mac version: using big endian speech file"); |
| | 141 | else |
| | 142 | debug(6, "Mac version: using little endian speech file"); |
| | 143 | debug(8, "Speech endianness heuristic: average = %f for BE and %f for LE, computed on %d samples)", be_diff_sum / (size - 1), le_diff_sum / (size - 1), size); |
| | 144 | } |
| | 145 | } |
| | 146 | |
| | 147 | |
