Decode Wav files
WAV_Reader.cpp@2:18fdd269b401, 2017-03-01 (annotated)
- Committer:
- UHSLMarcus
- Date:
- Wed Mar 01 10:35:59 2017 +0000
- Revision:
- 2:18fdd269b401
- Parent:
- 1:c1046d91bff7
trying triple buffered aproach
Who changed what in which revision?
User | Revision | Line number | New contents of line |
---|---|---|---|
UHSLMarcus | 1:c1046d91bff7 | 1 | /* |
UHSLMarcus | 1:c1046d91bff7 | 2 | * WAV_Reader.cpp |
UHSLMarcus | 1:c1046d91bff7 | 3 | * |
UHSLMarcus | 1:c1046d91bff7 | 4 | * Created on: 23 Feb 2017 |
UHSLMarcus | 1:c1046d91bff7 | 5 | * Author: ML15AAF |
UHSLMarcus | 1:c1046d91bff7 | 6 | */ |
UHSLMarcus | 1:c1046d91bff7 | 7 | |
UHSLMarcus | 1:c1046d91bff7 | 8 | #include <WAV_Reader.h> |
UHSLMarcus | 1:c1046d91bff7 | 9 | |
UHSLMarcus | 1:c1046d91bff7 | 10 | WAV_Reader::Config::Config() { |
UHSLMarcus | 1:c1046d91bff7 | 11 | format_tag = 0; |
UHSLMarcus | 1:c1046d91bff7 | 12 | channels = 0; |
UHSLMarcus | 1:c1046d91bff7 | 13 | samples_per_sec = 0; |
UHSLMarcus | 1:c1046d91bff7 | 14 | avg_bytes_per_sec = 0; |
UHSLMarcus | 1:c1046d91bff7 | 15 | block_align = 0; |
UHSLMarcus | 1:c1046d91bff7 | 16 | bits_per_sample = 0; |
UHSLMarcus | 1:c1046d91bff7 | 17 | data_pos = 0; |
UHSLMarcus | 1:c1046d91bff7 | 18 | data_length = 0; |
UHSLMarcus | 1:c1046d91bff7 | 19 | file_size = 0; |
UHSLMarcus | 1:c1046d91bff7 | 20 | } |
UHSLMarcus | 1:c1046d91bff7 | 21 | |
UHSLMarcus | 1:c1046d91bff7 | 22 | WAV_Reader::WAV_Reader() : |
UHSLMarcus | 1:c1046d91bff7 | 23 | fpp(NULL), _current_pos(0), _loop(false) { |
UHSLMarcus | 1:c1046d91bff7 | 24 | |
UHSLMarcus | 1:c1046d91bff7 | 25 | } |
UHSLMarcus | 1:c1046d91bff7 | 26 | |
UHSLMarcus | 1:c1046d91bff7 | 27 | int WAV_Reader::open(FILE **filepp) { |
UHSLMarcus | 1:c1046d91bff7 | 28 | int success = 0; |
UHSLMarcus | 1:c1046d91bff7 | 29 | |
UHSLMarcus | 1:c1046d91bff7 | 30 | fpp = filepp; |
UHSLMarcus | 1:c1046d91bff7 | 31 | |
UHSLMarcus | 1:c1046d91bff7 | 32 | if (*filepp != NULL) { |
UHSLMarcus | 1:c1046d91bff7 | 33 | if (check_bytes(*fpp, "RIFF", 4)) { |
UHSLMarcus | 1:c1046d91bff7 | 34 | if (check_bytes(*fpp, "WAVE", 4, 8)) { |
UHSLMarcus | 1:c1046d91bff7 | 35 | config.file_size = read_num(*fpp, 4, 4); |
UHSLMarcus | 1:c1046d91bff7 | 36 | |
UHSLMarcus | 1:c1046d91bff7 | 37 | int chunk_pos = find_chunk(*fpp, "fmt ", config.file_size, 12); |
UHSLMarcus | 1:c1046d91bff7 | 38 | |
UHSLMarcus | 1:c1046d91bff7 | 39 | if (chunk_pos != -1) { |
UHSLMarcus | 1:c1046d91bff7 | 40 | config.format_tag = read_num(*fpp, 2, chunk_pos + 8); |
UHSLMarcus | 1:c1046d91bff7 | 41 | config.channels = read_num(*fpp, 2, chunk_pos + 10); |
UHSLMarcus | 1:c1046d91bff7 | 42 | config.samples_per_sec = read_num(*fpp, 4, chunk_pos + 12); |
UHSLMarcus | 1:c1046d91bff7 | 43 | config.avg_bytes_per_sec = read_num(*fpp, 4, chunk_pos + 16); |
UHSLMarcus | 1:c1046d91bff7 | 44 | config.block_align = read_num(*fpp, 2, chunk_pos + 20); |
UHSLMarcus | 1:c1046d91bff7 | 45 | config.bits_per_sample = read_num(*fpp, 2, chunk_pos + 22); |
UHSLMarcus | 1:c1046d91bff7 | 46 | } else success = WAV_READER_FO_NO_FMT; |
UHSLMarcus | 1:c1046d91bff7 | 47 | |
UHSLMarcus | 1:c1046d91bff7 | 48 | chunk_pos = find_chunk(*fpp, "data", config.file_size, 12); |
UHSLMarcus | 1:c1046d91bff7 | 49 | |
UHSLMarcus | 1:c1046d91bff7 | 50 | if (chunk_pos != -1) { |
UHSLMarcus | 1:c1046d91bff7 | 51 | config.data_length = read_num(*fpp, 4, chunk_pos + 4); |
UHSLMarcus | 1:c1046d91bff7 | 52 | config.data_pos = chunk_pos + 8; |
UHSLMarcus | 1:c1046d91bff7 | 53 | reset(); |
UHSLMarcus | 1:c1046d91bff7 | 54 | |
UHSLMarcus | 1:c1046d91bff7 | 55 | } else success = success + WAV_READER_FO_NO_DATA; |
UHSLMarcus | 1:c1046d91bff7 | 56 | |
UHSLMarcus | 1:c1046d91bff7 | 57 | if (success == 0) success = config.data_length; |
UHSLMarcus | 1:c1046d91bff7 | 58 | |
UHSLMarcus | 1:c1046d91bff7 | 59 | } else success = WAV_READER_FO_NOT_WAV; |
UHSLMarcus | 1:c1046d91bff7 | 60 | } else success = WAV_READER_FO_NOT_RIFF; |
UHSLMarcus | 1:c1046d91bff7 | 61 | } else success = WAV_READER_FO_NULL_PTR; |
UHSLMarcus | 1:c1046d91bff7 | 62 | |
UHSLMarcus | 1:c1046d91bff7 | 63 | |
UHSLMarcus | 1:c1046d91bff7 | 64 | |
UHSLMarcus | 1:c1046d91bff7 | 65 | return success; |
UHSLMarcus | 1:c1046d91bff7 | 66 | } |
UHSLMarcus | 1:c1046d91bff7 | 67 | |
UHSLMarcus | 2:18fdd269b401 | 68 | int WAV_Reader::read(int buff[], int size, int len) { |
UHSLMarcus | 1:c1046d91bff7 | 69 | int data_left = config.data_length - _current_pos; |
UHSLMarcus | 2:18fdd269b401 | 70 | int to_read = len*size; |
UHSLMarcus | 1:c1046d91bff7 | 71 | |
UHSLMarcus | 1:c1046d91bff7 | 72 | if (to_read > data_left) { |
UHSLMarcus | 1:c1046d91bff7 | 73 | if (data_left == 0 && _loop) { |
UHSLMarcus | 1:c1046d91bff7 | 74 | reset(); |
UHSLMarcus | 1:c1046d91bff7 | 75 | } else { |
UHSLMarcus | 1:c1046d91bff7 | 76 | to_read = data_left; |
UHSLMarcus | 1:c1046d91bff7 | 77 | } |
UHSLMarcus | 1:c1046d91bff7 | 78 | } |
UHSLMarcus | 1:c1046d91bff7 | 79 | |
UHSLMarcus | 2:18fdd269b401 | 80 | char* bytes = new char[to_read]; |
UHSLMarcus | 2:18fdd269b401 | 81 | size_t read_bytes = fread(bytes, 1, to_read, *fpp); |
UHSLMarcus | 2:18fdd269b401 | 82 | read_bytes -= read_bytes % size; |
UHSLMarcus | 2:18fdd269b401 | 83 | int count = 0; |
UHSLMarcus | 2:18fdd269b401 | 84 | for (int i = 0; i < read_bytes; i += size){ |
UHSLMarcus | 2:18fdd269b401 | 85 | buff[count++] = get_num(bytes+i, size); |
UHSLMarcus | 2:18fdd269b401 | 86 | } |
UHSLMarcus | 2:18fdd269b401 | 87 | delete[] bytes; |
UHSLMarcus | 2:18fdd269b401 | 88 | move_read_position(read_bytes, _current_pos); |
UHSLMarcus | 1:c1046d91bff7 | 89 | |
UHSLMarcus | 2:18fdd269b401 | 90 | to_read = len*size - read_bytes; |
UHSLMarcus | 1:c1046d91bff7 | 91 | if (to_read > 0 && _loop) { |
UHSLMarcus | 2:18fdd269b401 | 92 | read_bytes += read(buff + read_bytes/size, size, to_read); |
UHSLMarcus | 1:c1046d91bff7 | 93 | } |
UHSLMarcus | 1:c1046d91bff7 | 94 | |
UHSLMarcus | 2:18fdd269b401 | 95 | return read_bytes; |
UHSLMarcus | 1:c1046d91bff7 | 96 | } |
UHSLMarcus | 1:c1046d91bff7 | 97 | |
UHSLMarcus | 1:c1046d91bff7 | 98 | void WAV_Reader::reset() { |
UHSLMarcus | 1:c1046d91bff7 | 99 | seek(0, 0); |
UHSLMarcus | 1:c1046d91bff7 | 100 | } |
UHSLMarcus | 1:c1046d91bff7 | 101 | |
UHSLMarcus | 1:c1046d91bff7 | 102 | bool WAV_Reader::loop() { |
UHSLMarcus | 1:c1046d91bff7 | 103 | return _loop; |
UHSLMarcus | 1:c1046d91bff7 | 104 | } |
UHSLMarcus | 1:c1046d91bff7 | 105 | |
UHSLMarcus | 1:c1046d91bff7 | 106 | void WAV_Reader::loop(bool enable) { |
UHSLMarcus | 1:c1046d91bff7 | 107 | _loop = enable; |
UHSLMarcus | 1:c1046d91bff7 | 108 | } |
UHSLMarcus | 1:c1046d91bff7 | 109 | |
UHSLMarcus | 1:c1046d91bff7 | 110 | void WAV_Reader::seek(int num, int start) { |
UHSLMarcus | 1:c1046d91bff7 | 111 | if (start < 0) start = _current_pos; |
UHSLMarcus | 1:c1046d91bff7 | 112 | move_read_position(num, start); |
UHSLMarcus | 1:c1046d91bff7 | 113 | fseek(*fpp, _current_pos + config.data_pos, SEEK_SET); |
UHSLMarcus | 1:c1046d91bff7 | 114 | } |
UHSLMarcus | 1:c1046d91bff7 | 115 | |
UHSLMarcus | 1:c1046d91bff7 | 116 | uint16_t WAV_Reader::channels() { |
UHSLMarcus | 1:c1046d91bff7 | 117 | return config.channels; |
UHSLMarcus | 1:c1046d91bff7 | 118 | } |
UHSLMarcus | 1:c1046d91bff7 | 119 | |
UHSLMarcus | 1:c1046d91bff7 | 120 | uint32_t WAV_Reader::samples_per_sec() { |
UHSLMarcus | 1:c1046d91bff7 | 121 | return config.samples_per_sec; |
UHSLMarcus | 1:c1046d91bff7 | 122 | } |
UHSLMarcus | 1:c1046d91bff7 | 123 | |
UHSLMarcus | 2:18fdd269b401 | 124 | uint32_t WAV_Reader::bytes_per_sec() { |
UHSLMarcus | 2:18fdd269b401 | 125 | return config.avg_bytes_per_sec; |
UHSLMarcus | 2:18fdd269b401 | 126 | } |
UHSLMarcus | 2:18fdd269b401 | 127 | |
UHSLMarcus | 1:c1046d91bff7 | 128 | uint16_t WAV_Reader::block_align() { |
UHSLMarcus | 1:c1046d91bff7 | 129 | return config.block_align; |
UHSLMarcus | 1:c1046d91bff7 | 130 | } |
UHSLMarcus | 1:c1046d91bff7 | 131 | |
UHSLMarcus | 1:c1046d91bff7 | 132 | uint16_t WAV_Reader::bits_per_sample() { |
UHSLMarcus | 1:c1046d91bff7 | 133 | return config.bits_per_sample; |
UHSLMarcus | 1:c1046d91bff7 | 134 | } |
UHSLMarcus | 1:c1046d91bff7 | 135 | |
UHSLMarcus | 2:18fdd269b401 | 136 | uint32_t WAV_Reader::data_length() { |
UHSLMarcus | 2:18fdd269b401 | 137 | return config.data_length; |
UHSLMarcus | 2:18fdd269b401 | 138 | } |
UHSLMarcus | 2:18fdd269b401 | 139 | |
UHSLMarcus | 1:c1046d91bff7 | 140 | /** Private **/ |
UHSLMarcus | 1:c1046d91bff7 | 141 | |
UHSLMarcus | 1:c1046d91bff7 | 142 | int WAV_Reader::read_bytes(FILE *fp, char* out, int len_to_read, int start_off) { |
UHSLMarcus | 1:c1046d91bff7 | 143 | fseek(fp, start_off, SEEK_SET); |
UHSLMarcus | 1:c1046d91bff7 | 144 | |
UHSLMarcus | 1:c1046d91bff7 | 145 | for (int i = 0; i < len_to_read; i++) { |
UHSLMarcus | 1:c1046d91bff7 | 146 | out[i] = fgetc(fp); |
UHSLMarcus | 1:c1046d91bff7 | 147 | } |
UHSLMarcus | 1:c1046d91bff7 | 148 | |
UHSLMarcus | 1:c1046d91bff7 | 149 | return len_to_read; |
UHSLMarcus | 1:c1046d91bff7 | 150 | |
UHSLMarcus | 1:c1046d91bff7 | 151 | } |
UHSLMarcus | 1:c1046d91bff7 | 152 | |
UHSLMarcus | 1:c1046d91bff7 | 153 | bool WAV_Reader::check_bytes(FILE *fp, char* check, int len, int start) { |
UHSLMarcus | 1:c1046d91bff7 | 154 | bool success = false; |
UHSLMarcus | 1:c1046d91bff7 | 155 | char extracted[len + 1]; |
UHSLMarcus | 1:c1046d91bff7 | 156 | |
UHSLMarcus | 1:c1046d91bff7 | 157 | read_bytes(fp, extracted, len, start); |
UHSLMarcus | 1:c1046d91bff7 | 158 | extracted[len] = 0; |
UHSLMarcus | 1:c1046d91bff7 | 159 | |
UHSLMarcus | 1:c1046d91bff7 | 160 | success = strcmp(extracted, check) == 0; |
UHSLMarcus | 1:c1046d91bff7 | 161 | |
UHSLMarcus | 1:c1046d91bff7 | 162 | return success; |
UHSLMarcus | 1:c1046d91bff7 | 163 | } |
UHSLMarcus | 1:c1046d91bff7 | 164 | |
UHSLMarcus | 1:c1046d91bff7 | 165 | uint32_t WAV_Reader::read_num(FILE *fp, int len, int start) { |
UHSLMarcus | 1:c1046d91bff7 | 166 | char extracted[len]; |
UHSLMarcus | 1:c1046d91bff7 | 167 | read_bytes(fp, extracted, len, start); |
UHSLMarcus | 1:c1046d91bff7 | 168 | |
UHSLMarcus | 1:c1046d91bff7 | 169 | return get_num(extracted, len); |
UHSLMarcus | 1:c1046d91bff7 | 170 | } |
UHSLMarcus | 1:c1046d91bff7 | 171 | |
UHSLMarcus | 1:c1046d91bff7 | 172 | uint32_t WAV_Reader::get_num(char input[], int byte_count) { |
UHSLMarcus | 1:c1046d91bff7 | 173 | |
UHSLMarcus | 1:c1046d91bff7 | 174 | uint32_t output = 0; |
UHSLMarcus | 1:c1046d91bff7 | 175 | for (int i = 0; i < byte_count; i++) { |
UHSLMarcus | 2:18fdd269b401 | 176 | // numbers are stored least significant byte. So reverse and add to find the number |
UHSLMarcus | 1:c1046d91bff7 | 177 | output += input[i] << (i * 8); |
UHSLMarcus | 1:c1046d91bff7 | 178 | } |
UHSLMarcus | 1:c1046d91bff7 | 179 | |
UHSLMarcus | 1:c1046d91bff7 | 180 | return output; |
UHSLMarcus | 1:c1046d91bff7 | 181 | |
UHSLMarcus | 1:c1046d91bff7 | 182 | } |
UHSLMarcus | 1:c1046d91bff7 | 183 | |
UHSLMarcus | 1:c1046d91bff7 | 184 | int WAV_Reader::find_chunk(FILE *fp, char* check, int max_len, int start) { |
UHSLMarcus | 1:c1046d91bff7 | 185 | int result = -1; |
UHSLMarcus | 2:18fdd269b401 | 186 | |
UHSLMarcus | 1:c1046d91bff7 | 187 | int pos = start; |
UHSLMarcus | 1:c1046d91bff7 | 188 | |
UHSLMarcus | 1:c1046d91bff7 | 189 | while ((pos + 8) < max_len && result == -1) { |
UHSLMarcus | 1:c1046d91bff7 | 190 | if (check_bytes(fp, check, 4, pos)) result = pos; |
UHSLMarcus | 1:c1046d91bff7 | 191 | else pos += read_num(fp, 4, pos + 4) + 8; |
UHSLMarcus | 1:c1046d91bff7 | 192 | } |
UHSLMarcus | 1:c1046d91bff7 | 193 | |
UHSLMarcus | 1:c1046d91bff7 | 194 | return result; |
UHSLMarcus | 1:c1046d91bff7 | 195 | |
UHSLMarcus | 1:c1046d91bff7 | 196 | } |
UHSLMarcus | 1:c1046d91bff7 | 197 | |
UHSLMarcus | 1:c1046d91bff7 | 198 | int WAV_Reader::move_read_position(int count, int start) { |
UHSLMarcus | 1:c1046d91bff7 | 199 | _current_pos = start + count; |
UHSLMarcus | 1:c1046d91bff7 | 200 | if (_current_pos > config.data_length) { |
UHSLMarcus | 1:c1046d91bff7 | 201 | if (loop()) _current_pos %= config.data_length; |
UHSLMarcus | 1:c1046d91bff7 | 202 | else _current_pos = config.data_length; |
UHSLMarcus | 1:c1046d91bff7 | 203 | } |
UHSLMarcus | 1:c1046d91bff7 | 204 | |
UHSLMarcus | 1:c1046d91bff7 | 205 | return _current_pos; |
UHSLMarcus | 1:c1046d91bff7 | 206 | } |