// license:BSD-3-Clause
// copyright-holders:Aaron Giles
/***************************************************************************
flac.c
FLAC compression wrappers
***************************************************************************/
#include <assert.h>
#include <string.h>
#include "flac.h"
//**************************************************************************
// FLAC DECODER
//**************************************************************************
static FLAC__StreamDecoderReadStatus flac_decoder_read_callback_static(const FLAC__StreamDecoder *decoder, FLAC__byte buffer[], size_t *bytes, void *client_data);
FLAC__StreamDecoderReadStatus flac_decoder_read_callback(void* client_data, FLAC__byte buffer[], size_t *bytes);
static void flac_decoder_metadata_callback_static(const FLAC__StreamDecoder *decoder, const FLAC__StreamMetadata *metadata, void *client_data);
static FLAC__StreamDecoderTellStatus flac_decoder_tell_callback_static(const FLAC__StreamDecoder *decoder, FLAC__uint64 *absolute_byte_offset, void *client_data);
static FLAC__StreamDecoderWriteStatus flac_decoder_write_callback_static(const FLAC__StreamDecoder *decoder, const FLAC__Frame *frame, const FLAC__int32 * const buffer[], void *client_data);
FLAC__StreamDecoderWriteStatus flac_decoder_write_callback(void* client_data, const FLAC__Frame *frame, const FLAC__int32 * const buffer[]);
static void flac_decoder_error_callback_static(const FLAC__StreamDecoder *decoder, FLAC__StreamDecoderErrorStatus status, void *client_data);
// 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; }
static uint32_t total_samples(flac_decoder *decoder) { return FLAC__stream_decoder_get_total_samples(decoder->decoder); }
static FLAC__StreamDecoderState state(flac_decoder *decoder) { return FLAC__stream_decoder_get_state(decoder->decoder); }
static const char *state_string(flac_decoder *decoder) { return FLAC__stream_decoder_get_resolved_state_string(decoder->decoder); }
//-------------------------------------------------
// flac_decoder - constructor
//-------------------------------------------------
void flac_decoder_init(flac_decoder *decoder)
{
decoder->decoder = FLAC__stream_decoder_new();
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;
}
//-------------------------------------------------
// flac_decoder - destructor
//-------------------------------------------------
void flac_decoder_free(flac_decoder* decoder)
{
if ((decoder != NULL) && (decoder->decoder != NULL))
FLAC__stream_decoder_delete(decoder->decoder);
}
//-------------------------------------------------
// reset - reset state with the original
// parameters
//-------------------------------------------------
static int flac_decoder_internal_reset(flac_decoder* decoder)
{
decoder->compressed_offset = 0;
if (FLAC__stream_decoder_init_stream(decoder->decoder,
&flac_decoder_read_callback_static,
NULL,
&flac_decoder_tell_callback_static,
NULL,
NULL,
&flac_decoder_write_callback_static,
&flac_decoder_metadata_callback_static,
&flac_decoder_error_callback_static, decoder) != FLAC__STREAM_DECODER_INIT_STATUS_OK)
return 0;
return FLAC__stream_decoder_process_until_end_of_metadata(decoder->decoder);
}
//-------------------------------------------------
// 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 >> 8;
decoder->custom_header[0x09] = decoder->custom_header[0x0b] = block_size & 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 FLAC__byte *)(decoder->custom_header);
decoder->compressed_length = sizeof(decoder->custom_header);
decoder->compressed2_start = (const FLAC__byte *)(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;
// loop until we get everything we want
while (decoder->uncompressed_offset < decoder->uncompressed_length)
if (!FLAC__stream_decoder_process_single(decoder->decoder))
return 0;
return 1;
}
/*
//-------------------------------------------------
// decode - decode to an multiple independent
// data streams
//-------------------------------------------------
bool flac_decoder::decode(int16_t **samples, uint32_t num_samples, bool swap_endian)
{
// make sure we don't have too many channels
int chans = channels();
if (chans > ARRAY_LENGTH(m_uncompressed_start))
return false;
// configure the uncompressed buffer
memset(m_uncompressed_start, 0, sizeof(m_uncompressed_start));
for (int curchan = 0; curchan < chans; curchan++)
m_uncompressed_start[curchan] = samples[curchan];
m_uncompressed_offset = 0;
m_uncompressed_length = num_samples;
m_uncompressed_swap = swap_endian;
// loop until we get everything we want
while (m_uncompressed_offset < m_uncompressed_length)
if (!FLAC__stream_decoder_process_single(m_decoder))
return false;
return true;
}
*/
//-------------------------------------------------
// finish - finish up the decode
//-------------------------------------------------
uint32_t flac_decoder_finish(flac_decoder* decoder)
{
// get the final decoding position and move forward
FLAC__uint64 position = 0;
FLAC__stream_decoder_get_decode_position(decoder->decoder, &position);
FLAC__stream_decoder_finish(decoder->decoder);
// adjust position if we provided the header
if (position == 0)
return 0;
if (decoder->compressed_start == (const FLAC__byte *)(decoder->custom_header))
position -= decoder->compressed_length;
return position;
}
//-------------------------------------------------
// read_callback - handle reads from the input
// stream
//-------------------------------------------------
#define MIN(x, y) ((x) < (y) ? (x) : (y))
FLAC__StreamDecoderReadStatus flac_decoder_read_callback_static(const FLAC__StreamDecoder *decoder, FLAC__byte buffer[], size_t *bytes, void *client_data)
{
return flac_decoder_read_callback(client_data, buffer, bytes);
}
FLAC__StreamDecoderReadStatus flac_decoder_read_callback(void* client_data, FLAC__byte buffer[], size_t *bytes)
{
flac_decoder* decoder = (flac_decoder*)client_data;
uint32_t expected = *bytes;
// 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(&buffer[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(&buffer[outputpos], decoder->compressed2_start + decoder->compressed_offset - decoder->compressed_length, bytes_to_copy);
outputpos += bytes_to_copy;
decoder->compressed_offset += bytes_to_copy;
}
*bytes = outputpos;
// return based on whether we ran out of data
return (*bytes < expected) ? FLAC__STREAM_DECODER_READ_STATUS_END_OF_STREAM : FLAC__STREAM_DECODER_READ_STATUS_CONTINUE;
}
//-------------------------------------------------
// metadata_callback - handle STREAMINFO metadata
//-------------------------------------------------
void flac_decoder_metadata_callback_static(const FLAC__StreamDecoder *decoder, const FLAC__StreamMetadata *metadata, void *client_data)
{
flac_decoder *fldecoder;
// ignore all but STREAMINFO metadata
if (metadata->type != FLAC__METADATA_TYPE_STREAMINFO)
return;
// parse out the data we care about
fldecoder = (flac_decoder *)(client_data);
fldecoder->sample_rate = metadata->data.stream_info.sample_rate;
fldecoder->bits_per_sample = metadata->data.stream_info.bits_per_sample;
fldecoder->channels = metadata->data.stream_info.channels;
}
//-------------------------------------------------
// tell_callback - handle requests to find out
// where in the input stream we are
//-------------------------------------------------
FLAC__StreamDecoderTellStatus flac_decoder_tell_callback_static(const FLAC__StreamDecoder *decoder, FLAC__uint64 *absolute_byte_offset, void *client_data)
{
*absolute_byte_offset = ((flac_decoder *)client_data)->compressed_offset;
return FLAC__STREAM_DECODER_TELL_STATUS_OK;
}
//-------------------------------------------------
// write_callback - handle writes to the output
// stream
//-------------------------------------------------
FLAC__StreamDecoderWriteStatus flac_decoder_write_callback_static(const FLAC__StreamDecoder *decoder, const FLAC__Frame *frame, const FLAC__int32 * const buffer[], void *client_data)
{
return flac_decoder_write_callback(client_data, frame, buffer);
}
FLAC__StreamDecoderWriteStatus flac_decoder_write_callback(void *client_data, const FLAC__Frame *frame, const FLAC__int32 * const buffer[])
{
int shift, blocksize;
flac_decoder * decoder = (flac_decoder *)client_data;
assert(frame->header.channels == channels(decoder));
// interleaved case
shift = decoder->uncompressed_swap ? 8 : 0;
blocksize = frame->header.blocksize;
if (decoder->uncompressed_start[1] == NULL)
{
int sampnum, chan;
int16_t *dest = decoder->uncompressed_start[0] + decoder->uncompressed_offset * frame->header.channels;
for (sampnum = 0; sampnum < blocksize && decoder->uncompressed_offset < decoder->uncompressed_length; sampnum++, decoder->uncompressed_offset++)
for (chan = 0; chan < frame->header.channels; chan++)
*dest++ = (int16_t)((((uint16_t)buffer[chan][sampnum]) << shift) | (((uint16_t)buffer[chan][sampnum]) >> shift));
}
// non-interleaved case
else
{
int sampnum, chan;
for (sampnum = 0; sampnum < blocksize && decoder->uncompressed_offset < decoder->uncompressed_length; sampnum++, decoder->uncompressed_offset++)
for (chan = 0; chan < frame->header.channels; chan++)
if (decoder->uncompressed_start[chan] != NULL)
decoder->uncompressed_start[chan][decoder->uncompressed_offset] = (int16_t) ( (((uint16_t)(buffer[chan][sampnum])) << shift) | ( ((uint16_t)(buffer[chan][sampnum])) >> shift) );
}
return FLAC__STREAM_DECODER_WRITE_STATUS_CONTINUE;
}
/**
* @fn void flac_decoder::error_callback_static(const FLAC__StreamDecoder *decoder, FLAC__StreamDecoderErrorStatus status, void *client_data)
*
* @brief -------------------------------------------------
* error_callback - handle errors (ignore them)
* -------------------------------------------------.
*
* @param decoder The decoder.
* @param status The status.
* @param [in,out] client_data If non-null, information describing the client.
*/
void flac_decoder_error_callback_static(const FLAC__StreamDecoder *decoder, FLAC__StreamDecoderErrorStatus status, void *client_data)
{
}