diff options
Diffstat (limited to 'deps/libchdr/src/libchdr_flac.c')
| -rw-r--r-- | deps/libchdr/src/libchdr_flac.c | 302 |
1 files changed, 302 insertions, 0 deletions
diff --git a/deps/libchdr/src/libchdr_flac.c b/deps/libchdr/src/libchdr_flac.c new file mode 100644 index 0000000..54d374f --- /dev/null +++ b/deps/libchdr/src/libchdr_flac.c @@ -0,0 +1,302 @@ +/* license:BSD-3-Clause + * copyright-holders:Aaron Giles +*************************************************************************** + + flac.c + + FLAC compression wrappers + +***************************************************************************/ + +#include <assert.h> +#include <string.h> + +#include <libchdr/flac.h> +#define DR_FLAC_IMPLEMENTATION +#include <dr_libs/dr_flac.h> + +/*************************************************************************** + * FLAC DECODER + *************************************************************************** + */ + +static size_t flac_decoder_read_callback(void *userdata, void *buffer, size_t bytes); +static drflac_bool32 flac_decoder_seek_callback(void *userdata, int offset, drflac_seek_origin origin); +static void flac_decoder_metadata_callback(void *userdata, drflac_metadata *metadata); +static void flac_decoder_write_callback(void *userdata, void *buffer, size_t len); + + +/* getters (valid after reset) */ +static uint32_t sample_rate(flac_decoder *decoder) { return decoder->sample_rate; } +static uint8_t channels(flac_decoder *decoder) { return decoder->channels; } +static uint8_t bits_per_sample(flac_decoder *decoder) { return decoder->bits_per_sample; } + +/*------------------------------------------------- + * flac_decoder - constructor + *------------------------------------------------- + */ + +int flac_decoder_init(flac_decoder *decoder) +{ + decoder->decoder = NULL; + decoder->sample_rate = 0; + decoder->channels = 0; + decoder->bits_per_sample = 0; + decoder->compressed_offset = 0; + decoder->compressed_start = NULL; + decoder->compressed_length = 0; + decoder->compressed2_start = NULL; + decoder->compressed2_length = 0; + decoder->uncompressed_offset = 0; + decoder->uncompressed_length = 0; + decoder->uncompressed_swap = 0; + return 0; +} + +/*------------------------------------------------- + * flac_decoder - destructor + *------------------------------------------------- + */ + +void flac_decoder_free(flac_decoder* decoder) +{ + if ((decoder != NULL) && (decoder->decoder != NULL)) + drflac_close(decoder->decoder); + decoder->decoder = NULL; +} + +/*------------------------------------------------- + * reset - reset state with the original + * parameters + *------------------------------------------------- + */ + +static int flac_decoder_internal_reset(flac_decoder* decoder) +{ + decoder->compressed_offset = 0; + flac_decoder_free(decoder); + decoder->decoder = drflac_open_with_metadata( + flac_decoder_read_callback, flac_decoder_seek_callback, + flac_decoder_metadata_callback, decoder, NULL); + return (decoder->decoder != NULL); +} + +/*------------------------------------------------- + * reset - reset state with new memory parameters + * and a custom-generated header + *------------------------------------------------- + */ + +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) +{ + /* modify the template header with our parameters */ + static const uint8_t s_header_template[0x2a] = + { + 0x66, 0x4C, 0x61, 0x43, /* +00: 'fLaC' stream header */ + 0x80, /* +04: metadata block type 0 (STREAMINFO), */ + /* flagged as last block */ + 0x00, 0x00, 0x22, /* +05: metadata block length = 0x22 */ + 0x00, 0x00, /* +08: minimum block size */ + 0x00, 0x00, /* +0A: maximum block size */ + 0x00, 0x00, 0x00, /* +0C: minimum frame size (0 == unknown) */ + 0x00, 0x00, 0x00, /* +0F: maximum frame size (0 == unknown) */ + 0x0A, 0xC4, 0x42, 0xF0, 0x00, 0x00, 0x00, 0x00, /* +12: sample rate (0x0ac44 == 44100), */ + /* numchannels (2), sample bits (16), */ + /* samples in stream (0 == unknown) */ + 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, /* +1A: MD5 signature (0 == none) */ + 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 /* +2A: start of stream data */ + }; + memcpy(decoder->custom_header, s_header_template, sizeof(s_header_template)); + decoder->custom_header[0x08] = decoder->custom_header[0x0a] = (block_size*num_channels) >> 8; + decoder->custom_header[0x09] = decoder->custom_header[0x0b] = (block_size*num_channels) & 0xff; + decoder->custom_header[0x12] = sample_rate >> 12; + decoder->custom_header[0x13] = sample_rate >> 4; + decoder->custom_header[0x14] = (sample_rate << 4) | ((num_channels - 1) << 1); + + /* configure the header ahead of the provided buffer */ + decoder->compressed_start = (const uint8_t *)(decoder->custom_header); + decoder->compressed_length = sizeof(decoder->custom_header); + decoder->compressed2_start = (const uint8_t *)(buffer); + decoder->compressed2_length = length; + return flac_decoder_internal_reset(decoder); +} + +/*------------------------------------------------- + * decode_interleaved - decode to an interleaved + * sound stream + *------------------------------------------------- + */ + +int flac_decoder_decode_interleaved(flac_decoder* decoder, int16_t *samples, uint32_t num_samples, int swap_endian) +{ + /* configure the uncompressed buffer */ + memset(decoder->uncompressed_start, 0, sizeof(decoder->uncompressed_start)); + decoder->uncompressed_start[0] = samples; + decoder->uncompressed_offset = 0; + decoder->uncompressed_length = num_samples; + decoder->uncompressed_swap = swap_endian; + +#define BUFFER 2352 /* bytes per CD audio sector */ + int16_t buffer[BUFFER]; + uint32_t buf_samples = BUFFER / channels(decoder); + /* loop until we get everything we want */ + while (decoder->uncompressed_offset < decoder->uncompressed_length) { + uint32_t frames = (num_samples < buf_samples ? num_samples : buf_samples); + if (!drflac_read_pcm_frames_s16(decoder->decoder, frames, buffer)) + return 0; + flac_decoder_write_callback(decoder, buffer, frames*sizeof(*buffer)*channels(decoder)); + num_samples -= frames; + } + return 1; +} + +/*------------------------------------------------- + * finish - finish up the decode + *------------------------------------------------- + */ + +uint32_t flac_decoder_finish(flac_decoder* decoder) +{ + /* get the final decoding position and move forward */ + drflac *flac = decoder->decoder; + uint64_t position = decoder->compressed_offset; + + /* ugh... there's no function to obtain bytes used in drflac :-/ */ + position -= DRFLAC_CACHE_L2_LINES_REMAINING(&flac->bs) * sizeof(drflac_cache_t); + position -= DRFLAC_CACHE_L1_BITS_REMAINING(&flac->bs) / 8; + position -= flac->bs.unalignedByteCount; + + /* adjust position if we provided the header */ + if (position == 0) + return 0; + if (decoder->compressed_start == (const uint8_t *)(decoder->custom_header)) + position -= decoder->compressed_length; + + flac_decoder_free(decoder); + return position; +} + +/*------------------------------------------------- + * read_callback - handle reads from the input + * stream + *------------------------------------------------- + */ + +#define MIN(x, y) ((x) < (y) ? (x) : (y)) + +static size_t flac_decoder_read_callback(void *userdata, void *buffer, size_t bytes) +{ + flac_decoder* decoder = (flac_decoder*)userdata; + uint8_t *dst = buffer; + + /* copy from primary buffer first */ + uint32_t outputpos = 0; + if (outputpos < bytes && decoder->compressed_offset < decoder->compressed_length) + { + uint32_t bytes_to_copy = MIN(bytes - outputpos, decoder->compressed_length - decoder->compressed_offset); + memcpy(&dst[outputpos], decoder->compressed_start + decoder->compressed_offset, bytes_to_copy); + outputpos += bytes_to_copy; + decoder->compressed_offset += bytes_to_copy; + } + + /* once we're out of that, copy from the secondary buffer */ + if (outputpos < bytes && decoder->compressed_offset < decoder->compressed_length + decoder->compressed2_length) + { + uint32_t bytes_to_copy = MIN(bytes - outputpos, decoder->compressed2_length - (decoder->compressed_offset - decoder->compressed_length)); + memcpy(&dst[outputpos], decoder->compressed2_start + decoder->compressed_offset - decoder->compressed_length, bytes_to_copy); + outputpos += bytes_to_copy; + decoder->compressed_offset += bytes_to_copy; + } + + return outputpos; +} + +/*------------------------------------------------- + * metadata_callback - handle STREAMINFO metadata + *------------------------------------------------- + */ + +static void flac_decoder_metadata_callback(void *userdata, drflac_metadata *metadata) +{ + flac_decoder *decoder = userdata; + + /* ignore all but STREAMINFO metadata */ + if (metadata->type != DRFLAC_METADATA_BLOCK_TYPE_STREAMINFO) + return; + + /* parse out the data we care about */ + decoder->sample_rate = metadata->data.streaminfo.sampleRate; + decoder->bits_per_sample = metadata->data.streaminfo.bitsPerSample; + decoder->channels = metadata->data.streaminfo.channels; +} + +/*------------------------------------------------- + * write_callback - handle writes to the output + * stream + *------------------------------------------------- + */ + +static void flac_decoder_write_callback(void *userdata, void *buffer, size_t bytes) +{ + int sampnum, chan; + int shift, blocksize; + flac_decoder * decoder = (flac_decoder *)userdata; + int16_t *sampbuf = (int16_t *)buffer; + int sampch = channels(decoder); + uint32_t offset = decoder->uncompressed_offset; + uint16_t usample; + + /* interleaved case */ + shift = decoder->uncompressed_swap ? 8 : 0; + blocksize = bytes / (sampch * sizeof(sampbuf[0])); + if (decoder->uncompressed_start[1] == NULL) + { + int16_t *dest = decoder->uncompressed_start[0] + offset * sampch; + for (sampnum = 0; sampnum < blocksize && offset < decoder->uncompressed_length; sampnum++, offset++) + for (chan = 0; chan < sampch; chan++) { + usample = (uint16_t)*sampbuf++; + *dest++ = (int16_t)((usample << shift) | (usample >> shift)); + } + } + + /* non-interleaved case */ + else + { + for (sampnum = 0; sampnum < blocksize && offset < decoder->uncompressed_length; sampnum++, offset++) + for (chan = 0; chan < sampch; chan++) { + usample = (uint16_t)*sampbuf++; + if (decoder->uncompressed_start[chan] != NULL) + decoder->uncompressed_start[chan][offset] = (int16_t) ((usample << shift) | (usample >> shift)); + } + } + decoder->uncompressed_offset = offset; +} + + +/*------------------------------------------------- + * seek_callback - handle seeks on the output + * stream + *------------------------------------------------- + */ + +static drflac_bool32 flac_decoder_seek_callback(void *userdata, int offset, drflac_seek_origin origin) +{ + flac_decoder * decoder = (flac_decoder *)userdata; + uint32_t length = decoder->compressed_length + decoder->compressed2_length; + + if (origin == drflac_seek_origin_start) { + uint32_t pos = offset; + if (pos <= length) { + decoder->compressed_offset = pos; + return 1; + } + } else if (origin == drflac_seek_origin_current) { + uint32_t pos = decoder->compressed_offset + offset; + if (pos <= length) { + decoder->compressed_offset = pos; + return 1; + } + } + return 0; +} + |