static int parse_dmix_coeffs(struct xll_chset *chs)
{
struct xll_decoder *xll = chs->decoder;
int m, n;
if (chs->primary_chset) {
m = dmix_primary_nch[chs->dmix_type];
n = chs->nchannels;
} else {
m = chs->dmix_m;
n = chs->nchannels + 2; // Two extra columns for scales
}
// Reallocate downmix coefficients matrix
if (ta_zalloc_fast(xll->chset, &chs->dmix_coeff, m * n, sizeof(int)) < 0)
return -DCADEC_ENOMEM;
if (chs->primary_chset) {
chs->dmix_scale = NULL;
chs->dmix_scale_inv = NULL;
} else {
chs->dmix_scale = chs->dmix_coeff + m * chs->nchannels;
chs->dmix_scale_inv = chs->dmix_coeff + m * (chs->nchannels + 1);
}
int *coeff_ptr = chs->dmix_coeff;
for (int i = 0; i < m; i++) {
int scale_inv = 0;
// Downmix scale
// Only for non-primary channel sets
if (!chs->primary_chset) {
int code = bits_get(&xll->bits, 9);
int sign = (code >> 8) - 1; code &= 0xff;
if (code > 0) {
unsigned int index = code - 1;
enforce(index >= 40 && index < dca_countof(dmix_table), "Invalid downmix scale index");
int scale = dmix_table[index];
scale_inv = dmix_table_inv[index - 40];
chs->dmix_scale[i] = (scale ^ sign) - sign;
chs->dmix_scale_inv[i] = (scale_inv ^ sign) - sign;
} else {
chs->dmix_scale[i] = 0;
chs->dmix_scale_inv[i] = 0;
}
}
// Downmix coefficients
for (int j = 0; j < chs->nchannels; j++) {
int code = bits_get(&xll->bits, 9);
int sign = (code >> 8) - 1; code &= 0xff;
if (code > 0) {
unsigned int index = code - 1;
enforce(index < dca_countof(dmix_table), "Invalid downmix coefficient index");
int coeff = dmix_table[index];
if (!chs->primary_chset)
// Multiply by |InvDmixScale| to get |UndoDmixScale|
coeff = mul16(scale_inv, coeff);
// Convert sign
*coeff_ptr++ = (coeff ^ sign) - sign;
} else {
*coeff_ptr++ = 0;
}
}
}
int exss_parse(struct exss_parser *exss, uint8_t *data, int size)
{
int i, j, ret;
bits_init(&exss->bits, data, size);
// Extension substream sync word
bits_skip(&exss->bits, 32);
// User defined bits
bits_skip(&exss->bits, 8);
// Extension substream index
exss->exss_index = bits_get(&exss->bits, 2);
// Flag indicating short or long header size
bool wide_hdr = bits_get1(&exss->bits);
// Extension substream header length
int header_size = bits_get(&exss->bits, 8 + 4 * wide_hdr) + 1;
// Check CRC
if ((ret = bits_check_crc(&exss->bits, 32 + 8, header_size * 8)) < 0) {
exss_err("Invalid EXSS header checksum");
return ret;
}
exss->exss_size_nbits = 16 + 4 * wide_hdr;
// Number of bytes of extension substream
exss->exss_size = bits_get(&exss->bits, exss->exss_size_nbits) + 1;
if (exss->exss_size > size) {
exss_err("Packet too short for EXSS frame");
return -DCADEC_EBADDATA;
}
// Per stream static fields presence flag
exss->static_fields_present = bits_get1(&exss->bits);
if (exss->static_fields_present) {
// Reference clock code
bits_skip(&exss->bits, 2);
// Extension substream frame duration
bits_skip(&exss->bits, 3);
// Timecode presence flag
if (bits_get1(&exss->bits)) {
// Timecode data
bits_skip(&exss->bits, 32);
bits_skip(&exss->bits, 4);
}
// Number of defined audio presentations
exss->npresents = bits_get(&exss->bits, 3) + 1;
// Number of audio assets in extension substream
exss->nassets = bits_get(&exss->bits, 3) + 1;
// Reject unsupported features for now
if (exss->npresents > 1 || exss->nassets > 1) {
exss_err_once("Multiple audio presentations "
"and/or assets are not supported");
return -DCADEC_ENOSUP;
}
// Active extension substream mask for audio presentation
int active_exss_mask[8];
for (i = 0; i < exss->npresents; i++)
active_exss_mask[i] = bits_get(&exss->bits, exss->exss_index + 1);
// Active audio asset mask
for (i = 0; i < exss->npresents; i++)
for (j = 0; j <= exss->exss_index; j++)
if (active_exss_mask[i] & (1 << j))
bits_skip(&exss->bits, 8);
// Mixing metadata enable flag
exss->mix_metadata_enabled = bits_get1(&exss->bits);
if (exss->mix_metadata_enabled) {
// Mixing metadata adjustment level
bits_skip(&exss->bits, 2);
// Number of bits for mixer output speaker activity mask
int spkr_mask_nbits = (bits_get(&exss->bits, 2) + 1) << 2;
// Number of mixing configurations
exss->nmixoutconfigs = bits_get(&exss->bits, 2) + 1;
// Speaker layout mask for mixer output channels
for (i = 0; i < exss->nmixoutconfigs; i++)
exss->nmixoutchs[i] = count_chs_for_mask(bits_get(&exss->bits, spkr_mask_nbits));
}
} else {
exss->npresents = 1;
exss->nassets = 1;
}
// Reallocate assets
if (ta_zalloc_fast(exss, &exss->assets, exss->nassets, sizeof(struct exss_asset)) < 0)
return -DCADEC_ENOMEM;
// Size of encoded asset data in bytes
int offset = header_size;
for (i = 0; i < exss->nassets; i++) {
exss->assets[i].asset_offset = offset;
exss->assets[i].asset_size = bits_get(&exss->bits, exss->exss_size_nbits) + 1;
offset += exss->assets[i].asset_size;
if (offset > exss->exss_size) {
exss_err("Asset out of bounds");
return -DCADEC_EBADDATA;
}
}
// Audio asset descriptor
for (i = 0; i < exss->nassets; i++) {
exss->assets[i].parser = exss;
if ((ret = parse_descriptor(&exss->assets[i])) < 0)
return ret;
if ((ret = set_exss_offsets(&exss->assets[i])) < 0) {
exss_err("Invalid extension size in asset descriptor");
return ret;
}
}
// Backward compatible core present
// Backward compatible core substream index
// Backward compatible core asset index
// Reserved
// Byte align
// CRC16 of extension substream header
if ((ret = bits_seek(&exss->bits, header_size * 8)) < 0)
exss_err("Read past end of EXSS header");
return ret;
}
static int parse_dmix_coeffs(struct xll_chset *chs)
{
struct xll_decoder *xll = chs->decoder;
int m, n;
if (chs->primary_chset) {
m = dmix_primary_nch[chs->dmix_type];
n = chs->nchannels;
} else {
m = chs->dmix_m;
n = chs->nchannels + 2; // Two extra columns for scales
}
// Reallocate downmix coefficients buffer
if (ta_zalloc_fast(xll->chset, &chs->dmix_coeff, m * n * 2, sizeof(int)) < 0)
return -DCADEC_ENOMEM;
// Setup buffer pointers for current and previous frame
bool valid = (chs->dmix_coeffs_signature == XLL_DMIX_SIGNATURE(chs));
chs->dmix_coeff_cur = chs->dmix_coeff + m * n * chs->dmix_coeffs_parity;
chs->dmix_coeff_pre = chs->dmix_coeff + m * n * (chs->dmix_coeffs_parity ^ valid);
if (chs->primary_chset) {
chs->dmix_scale_cur = chs->dmix_scale_pre = NULL;
chs->dmix_scale_inv_cur = chs->dmix_scale_inv_pre = NULL;
} else {
chs->dmix_scale_cur = chs->dmix_coeff_cur + m * chs->nchannels;
chs->dmix_scale_pre = chs->dmix_coeff_pre + m * chs->nchannels;
chs->dmix_scale_inv_cur = chs->dmix_coeff_cur + m * (chs->nchannels + 1);
chs->dmix_scale_inv_pre = chs->dmix_coeff_pre + m * (chs->nchannels + 1);
}
int *coeff_ptr = chs->dmix_coeff_cur;
for (int i = 0; i < m; i++) {
int scale_inv = 0;
// Downmix scale
// Only for non-primary channel sets
if (!chs->primary_chset) {
int code = bits_get(&xll->bits, 9);
int sign = (code >> 8) - 1; code &= 0xff;
if (code > 0) {
unsigned int index = code - 1;
if (index < 40 || index >= dca_countof(dmix_table)) {
xll_err("Invalid downmix scale index");
return -DCADEC_EBADDATA;
}
int scale = dmix_table[index];
scale_inv = dmix_table_inv[index - 40];
chs->dmix_scale_cur[i] = (scale ^ sign) - sign;
chs->dmix_scale_inv_cur[i] = (scale_inv ^ sign) - sign;
} else {
chs->dmix_scale_cur[i] = 0;
chs->dmix_scale_inv_cur[i] = 0;
}
}
// Downmix coefficients
for (int j = 0; j < chs->nchannels; j++) {
int code = bits_get(&xll->bits, 9);
int sign = (code >> 8) - 1; code &= 0xff;
if (code > 0) {
unsigned int index = code - 1;
if (index >= dca_countof(dmix_table)) {
xll_err("Invalid downmix coefficient index");
return -DCADEC_EBADDATA;
}
int coeff = dmix_table[index];
if (!chs->primary_chset)
// Multiply by |InvDmixScale| to get |UndoDmixScale|
coeff = mul16(scale_inv, coeff);
// Convert sign
*coeff_ptr++ = (coeff ^ sign) - sign;
} else {
*coeff_ptr++ = 0;
}
}
}
