| 1 | /* license:BSD-3-Clause |
| 2 | * copyright-holders:Aaron Giles |
| 3 | *************************************************************************** |
| 4 | |
| 5 | flac.c |
| 6 | |
| 7 | FLAC compression wrappers |
| 8 | |
| 9 | ***************************************************************************/ |
| 10 | |
| 11 | #include <string.h> |
| 12 | |
| 13 | #include <libchdr/flac.h> |
| 14 | #define DR_FLAC_IMPLEMENTATION |
| 15 | #define DR_FLAC_NO_STDIO |
| 16 | #include <dr_libs/dr_flac.h> |
| 17 | |
| 18 | /*************************************************************************** |
| 19 | * FLAC DECODER |
| 20 | *************************************************************************** |
| 21 | */ |
| 22 | |
| 23 | static size_t flac_decoder_read_callback(void *userdata, void *buffer, size_t bytes); |
| 24 | static drflac_bool32 flac_decoder_seek_callback(void *userdata, int offset, drflac_seek_origin origin); |
| 25 | static void flac_decoder_metadata_callback(void *userdata, drflac_metadata *metadata); |
| 26 | static void flac_decoder_write_callback(void *userdata, void *buffer, size_t bytes); |
| 27 | |
| 28 | |
| 29 | /* getters (valid after reset) */ |
| 30 | static uint32_t sample_rate(flac_decoder *decoder) { return decoder->sample_rate; } |
| 31 | static uint8_t channels(flac_decoder *decoder) { return decoder->channels; } |
| 32 | static uint8_t bits_per_sample(flac_decoder *decoder) { return decoder->bits_per_sample; } |
| 33 | |
| 34 | /*------------------------------------------------- |
| 35 | * flac_decoder - constructor |
| 36 | *------------------------------------------------- |
| 37 | */ |
| 38 | |
| 39 | int flac_decoder_init(flac_decoder *decoder) |
| 40 | { |
| 41 | decoder->decoder = NULL; |
| 42 | decoder->sample_rate = 0; |
| 43 | decoder->channels = 0; |
| 44 | decoder->bits_per_sample = 0; |
| 45 | decoder->compressed_offset = 0; |
| 46 | decoder->compressed_start = NULL; |
| 47 | decoder->compressed_length = 0; |
| 48 | decoder->compressed2_start = NULL; |
| 49 | decoder->compressed2_length = 0; |
| 50 | decoder->uncompressed_offset = 0; |
| 51 | decoder->uncompressed_length = 0; |
| 52 | decoder->uncompressed_swap = 0; |
| 53 | return 0; |
| 54 | } |
| 55 | |
| 56 | /*------------------------------------------------- |
| 57 | * flac_decoder - destructor |
| 58 | *------------------------------------------------- |
| 59 | */ |
| 60 | |
| 61 | void flac_decoder_free(flac_decoder* decoder) |
| 62 | { |
| 63 | if ((decoder != NULL) && (decoder->decoder != NULL)) { |
| 64 | drflac_close(decoder->decoder); |
| 65 | decoder->decoder = NULL; |
| 66 | } |
| 67 | } |
| 68 | |
| 69 | /*------------------------------------------------- |
| 70 | * reset - reset state with the original |
| 71 | * parameters |
| 72 | *------------------------------------------------- |
| 73 | */ |
| 74 | |
| 75 | static int flac_decoder_internal_reset(flac_decoder* decoder) |
| 76 | { |
| 77 | decoder->compressed_offset = 0; |
| 78 | flac_decoder_free(decoder); |
| 79 | decoder->decoder = drflac_open_with_metadata( |
| 80 | flac_decoder_read_callback, flac_decoder_seek_callback, |
| 81 | flac_decoder_metadata_callback, decoder, NULL); |
| 82 | return (decoder->decoder != NULL); |
| 83 | } |
| 84 | |
| 85 | /*------------------------------------------------- |
| 86 | * reset - reset state with new memory parameters |
| 87 | * and a custom-generated header |
| 88 | *------------------------------------------------- |
| 89 | */ |
| 90 | |
| 91 | int flac_decoder_reset(flac_decoder* decoder, uint32_t sample_rate, uint8_t num_channels, uint32_t block_size, const void *buffer, uint32_t length) |
| 92 | { |
| 93 | /* modify the template header with our parameters */ |
| 94 | static const uint8_t s_header_template[0x2a] = |
| 95 | { |
| 96 | 0x66, 0x4C, 0x61, 0x43, /* +00: 'fLaC' stream header */ |
| 97 | 0x80, /* +04: metadata block type 0 (STREAMINFO), */ |
| 98 | /* flagged as last block */ |
| 99 | 0x00, 0x00, 0x22, /* +05: metadata block length = 0x22 */ |
| 100 | 0x00, 0x00, /* +08: minimum block size */ |
| 101 | 0x00, 0x00, /* +0A: maximum block size */ |
| 102 | 0x00, 0x00, 0x00, /* +0C: minimum frame size (0 == unknown) */ |
| 103 | 0x00, 0x00, 0x00, /* +0F: maximum frame size (0 == unknown) */ |
| 104 | 0x0A, 0xC4, 0x42, 0xF0, 0x00, 0x00, 0x00, 0x00, /* +12: sample rate (0x0ac44 == 44100), */ |
| 105 | /* numchannels (2), sample bits (16), */ |
| 106 | /* samples in stream (0 == unknown) */ |
| 107 | 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, /* +1A: MD5 signature (0 == none) */ |
| 108 | 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 /* +2A: start of stream data */ |
| 109 | }; |
| 110 | memcpy(decoder->custom_header, s_header_template, sizeof(s_header_template)); |
| 111 | decoder->custom_header[0x08] = decoder->custom_header[0x0a] = (block_size*num_channels) >> 8; |
| 112 | decoder->custom_header[0x09] = decoder->custom_header[0x0b] = (block_size*num_channels) & 0xff; |
| 113 | decoder->custom_header[0x12] = sample_rate >> 12; |
| 114 | decoder->custom_header[0x13] = sample_rate >> 4; |
| 115 | decoder->custom_header[0x14] = (sample_rate << 4) | ((num_channels - 1) << 1); |
| 116 | |
| 117 | /* configure the header ahead of the provided buffer */ |
| 118 | decoder->compressed_start = (const uint8_t *)(decoder->custom_header); |
| 119 | decoder->compressed_length = sizeof(decoder->custom_header); |
| 120 | decoder->compressed2_start = (const uint8_t *)(buffer); |
| 121 | decoder->compressed2_length = length; |
| 122 | return flac_decoder_internal_reset(decoder); |
| 123 | } |
| 124 | |
| 125 | /*------------------------------------------------- |
| 126 | * decode_interleaved - decode to an interleaved |
| 127 | * sound stream |
| 128 | *------------------------------------------------- |
| 129 | */ |
| 130 | |
| 131 | int flac_decoder_decode_interleaved(flac_decoder* decoder, int16_t *samples, uint32_t num_samples, int swap_endian) |
| 132 | { |
| 133 | /* configure the uncompressed buffer */ |
| 134 | memset(decoder->uncompressed_start, 0, sizeof(decoder->uncompressed_start)); |
| 135 | decoder->uncompressed_start[0] = samples; |
| 136 | decoder->uncompressed_offset = 0; |
| 137 | decoder->uncompressed_length = num_samples; |
| 138 | decoder->uncompressed_swap = swap_endian; |
| 139 | |
| 140 | #define BUFFER 2352 /* bytes per CD audio sector */ |
| 141 | int16_t buffer[BUFFER]; |
| 142 | uint32_t buf_samples = BUFFER / channels(decoder); |
| 143 | /* loop until we get everything we want */ |
| 144 | while (decoder->uncompressed_offset < decoder->uncompressed_length) { |
| 145 | uint32_t frames = (num_samples < buf_samples ? num_samples : buf_samples); |
| 146 | if (!drflac_read_pcm_frames_s16(decoder->decoder, frames, buffer)) |
| 147 | return 0; |
| 148 | flac_decoder_write_callback(decoder, buffer, frames*sizeof(*buffer)*channels(decoder)); |
| 149 | num_samples -= frames; |
| 150 | } |
| 151 | return 1; |
| 152 | } |
| 153 | |
| 154 | /*------------------------------------------------- |
| 155 | * finish - finish up the decode |
| 156 | *------------------------------------------------- |
| 157 | */ |
| 158 | |
| 159 | uint32_t flac_decoder_finish(flac_decoder* decoder) |
| 160 | { |
| 161 | /* get the final decoding position and move forward */ |
| 162 | drflac *flac = decoder->decoder; |
| 163 | uint64_t position = decoder->compressed_offset; |
| 164 | |
| 165 | /* ugh... there's no function to obtain bytes used in drflac :-/ */ |
| 166 | position -= DRFLAC_CACHE_L2_LINES_REMAINING(&flac->bs) * sizeof(drflac_cache_t); |
| 167 | position -= DRFLAC_CACHE_L1_BITS_REMAINING(&flac->bs) / 8; |
| 168 | position -= flac->bs.unalignedByteCount; |
| 169 | |
| 170 | /* adjust position if we provided the header */ |
| 171 | if (position == 0) |
| 172 | return 0; |
| 173 | if (decoder->compressed_start == (const uint8_t *)(decoder->custom_header)) |
| 174 | position -= decoder->compressed_length; |
| 175 | |
| 176 | flac_decoder_free(decoder); |
| 177 | return position; |
| 178 | } |
| 179 | |
| 180 | /*------------------------------------------------- |
| 181 | * read_callback - handle reads from the input |
| 182 | * stream |
| 183 | *------------------------------------------------- |
| 184 | */ |
| 185 | |
| 186 | #define MIN(x, y) ((x) < (y) ? (x) : (y)) |
| 187 | |
| 188 | static size_t flac_decoder_read_callback(void *userdata, void *buffer, size_t bytes) |
| 189 | { |
| 190 | flac_decoder* decoder = (flac_decoder*)userdata; |
| 191 | uint8_t *dst = buffer; |
| 192 | |
| 193 | /* copy from primary buffer first */ |
| 194 | uint32_t outputpos = 0; |
| 195 | if (outputpos < bytes && decoder->compressed_offset < decoder->compressed_length) |
| 196 | { |
| 197 | uint32_t bytes_to_copy = MIN(bytes - outputpos, decoder->compressed_length - decoder->compressed_offset); |
| 198 | memcpy(&dst[outputpos], decoder->compressed_start + decoder->compressed_offset, bytes_to_copy); |
| 199 | outputpos += bytes_to_copy; |
| 200 | decoder->compressed_offset += bytes_to_copy; |
| 201 | } |
| 202 | |
| 203 | /* once we're out of that, copy from the secondary buffer */ |
| 204 | if (outputpos < bytes && decoder->compressed_offset < decoder->compressed_length + decoder->compressed2_length) |
| 205 | { |
| 206 | uint32_t bytes_to_copy = MIN(bytes - outputpos, decoder->compressed2_length - (decoder->compressed_offset - decoder->compressed_length)); |
| 207 | memcpy(&dst[outputpos], decoder->compressed2_start + decoder->compressed_offset - decoder->compressed_length, bytes_to_copy); |
| 208 | outputpos += bytes_to_copy; |
| 209 | decoder->compressed_offset += bytes_to_copy; |
| 210 | } |
| 211 | |
| 212 | return outputpos; |
| 213 | } |
| 214 | |
| 215 | /*------------------------------------------------- |
| 216 | * metadata_callback - handle STREAMINFO metadata |
| 217 | *------------------------------------------------- |
| 218 | */ |
| 219 | |
| 220 | static void flac_decoder_metadata_callback(void *userdata, drflac_metadata *metadata) |
| 221 | { |
| 222 | flac_decoder *decoder = userdata; |
| 223 | |
| 224 | /* ignore all but STREAMINFO metadata */ |
| 225 | if (metadata->type != DRFLAC_METADATA_BLOCK_TYPE_STREAMINFO) |
| 226 | return; |
| 227 | |
| 228 | /* parse out the data we care about */ |
| 229 | decoder->sample_rate = metadata->data.streaminfo.sampleRate; |
| 230 | decoder->bits_per_sample = metadata->data.streaminfo.bitsPerSample; |
| 231 | decoder->channels = metadata->data.streaminfo.channels; |
| 232 | } |
| 233 | |
| 234 | /*------------------------------------------------- |
| 235 | * write_callback - handle writes to the output |
| 236 | * stream |
| 237 | *------------------------------------------------- |
| 238 | */ |
| 239 | |
| 240 | static void flac_decoder_write_callback(void *userdata, void *buffer, size_t bytes) |
| 241 | { |
| 242 | int sampnum, chan; |
| 243 | int shift, blocksize; |
| 244 | flac_decoder * decoder = (flac_decoder *)userdata; |
| 245 | int16_t *sampbuf = (int16_t *)buffer; |
| 246 | int sampch = channels(decoder); |
| 247 | uint32_t offset = decoder->uncompressed_offset; |
| 248 | uint16_t usample; |
| 249 | |
| 250 | /* interleaved case */ |
| 251 | shift = decoder->uncompressed_swap ? 8 : 0; |
| 252 | blocksize = bytes / (sampch * sizeof(sampbuf[0])); |
| 253 | if (decoder->uncompressed_start[1] == NULL) |
| 254 | { |
| 255 | int16_t *dest = decoder->uncompressed_start[0] + offset * sampch; |
| 256 | for (sampnum = 0; sampnum < blocksize && offset < decoder->uncompressed_length; sampnum++, offset++) |
| 257 | for (chan = 0; chan < sampch; chan++) { |
| 258 | usample = (uint16_t)*sampbuf++; |
| 259 | *dest++ = (int16_t)((usample << shift) | (usample >> shift)); |
| 260 | } |
| 261 | } |
| 262 | |
| 263 | /* non-interleaved case */ |
| 264 | else |
| 265 | { |
| 266 | for (sampnum = 0; sampnum < blocksize && offset < decoder->uncompressed_length; sampnum++, offset++) |
| 267 | for (chan = 0; chan < sampch; chan++) { |
| 268 | usample = (uint16_t)*sampbuf++; |
| 269 | if (decoder->uncompressed_start[chan] != NULL) |
| 270 | decoder->uncompressed_start[chan][offset] = (int16_t) ((usample << shift) | (usample >> shift)); |
| 271 | } |
| 272 | } |
| 273 | decoder->uncompressed_offset = offset; |
| 274 | } |
| 275 | |
| 276 | |
| 277 | /*------------------------------------------------- |
| 278 | * seek_callback - handle seeks on the output |
| 279 | * stream |
| 280 | *------------------------------------------------- |
| 281 | */ |
| 282 | |
| 283 | static drflac_bool32 flac_decoder_seek_callback(void *userdata, int offset, drflac_seek_origin origin) |
| 284 | { |
| 285 | flac_decoder * decoder = (flac_decoder *)userdata; |
| 286 | uint32_t length = decoder->compressed_length + decoder->compressed2_length; |
| 287 | |
| 288 | if (origin == drflac_seek_origin_start) { |
| 289 | uint32_t pos = offset; |
| 290 | if (pos <= length) { |
| 291 | decoder->compressed_offset = pos; |
| 292 | return 1; |
| 293 | } |
| 294 | } else if (origin == drflac_seek_origin_current) { |
| 295 | uint32_t pos = decoder->compressed_offset + offset; |
| 296 | if (pos <= length) { |
| 297 | decoder->compressed_offset = pos; |
| 298 | return 1; |
| 299 | } |
| 300 | } |
| 301 | return 0; |
| 302 | } |
| 303 | |