/*
* Squeezelite - lightweight headless squeezebox emulator
*
* (c) Adrian Smith 2012, 2013, triode1@btinternet.com
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
*/
// DSP over PCM (DOP) specific functions
#include "squeezelite.h"
#if DSD
extern struct buffer *outputbuf;
extern struct outputstate output;
#define LOCK_O mutex_lock(outputbuf->mutex)
#define UNLOCK_O mutex_unlock(outputbuf->mutex)
// check for 32 dop marker frames to see if this is dop in flac
// dop is always encoded in 24 bit samples with marker 0x0005xxxx or 0x00FAxxxx
bool is_flac_dop(u32_t *lptr, u32_t *rptr, frames_t frames) {
int matched = 0;
u32_t next = 0;
while (frames--) {
if (((*lptr & 0x00FF0000) == 0x00050000 && (*rptr & 0x00FF0000) == 0x00050000) ||
((*lptr & 0x00FF0000) == 0x00FA0000 && (*rptr & 0x00FF0000) == 0x00FA0000)) {
if (*lptr >> 24 == next) {
matched++;
next = ( 0x05 + 0xFA ) - next;
} else {
next = *lptr >> 24;
matched = 1;
}
} else {
return false;
}
if (matched == 32) {
return true;
}
++lptr; ++rptr;
}
return false;
}
// update the dop marker and potentially invert polarity for frames in the output buffer
// performaned on all output including silence to maintain marker phase consitency
void update_dop(u32_t *ptr, frames_t frames, bool invert) {
static u32_t marker = 0x05;
if (!invert) {
while (frames--) {
u32_t scaled_marker = marker << 24;
*ptr = (*ptr & 0x00FFFFFF) | scaled_marker;
++ptr;
*ptr = (*ptr & 0x00FFFFFF) | scaled_marker;
++ptr;
marker = ( 0x05 + 0xFA ) - marker;
}
} else {
while (frames--) {
u32_t scaled_marker = marker << 24;
*ptr = ((~(*ptr)) & 0x00FFFFFF) | scaled_marker;
++ptr;
*ptr = ((~(*ptr)) & 0x00FFFFFF) | scaled_marker;
++ptr;
marker = ( 0x05 + 0xFA ) - marker;
}
}
}
// fill silence buffer with 10101100 which represents dop silence
// leave marker zero it will be updated at output, leave lsb zero
void dop_silence_frames(u32_t *ptr, frames_t frames) {
while (frames--) {
*ptr++ = 0x00ACAC00;
*ptr++ = 0x00ACAC00;
}
}
void dop_init(bool enable, unsigned delay) {
LOCK_O;
output.has_dop = enable;
output.dop_delay = delay;
UNLOCK_O;
}
#endif // DSD