1 /*
2  * Direct Stream Digital (DSD) decoder
3  * based on BSD licensed dsd2pcm by Sebastian Gesemann
4  * Copyright (c) 2009, 2011 Sebastian Gesemann. All rights reserved.
5  * Copyright (c) 2014 Peter Ross
6  *
7  * This file is part of FFmpeg.
8  *
9  * FFmpeg is free software; you can redistribute it and/or
10  * modify it under the terms of the GNU Lesser General Public
11  * License as published by the Free Software Foundation; either
12  * version 2.1 of the License, or (at your option) any later version.
13  *
14  * FFmpeg is distributed in the hope that it will be useful,
15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
17  * Lesser General Public License for more details.
18  *
19  * You should have received a copy of the GNU Lesser General Public
20  * License along with FFmpeg; if not, write to the Free Software
21  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
22  */
23 
24 #ifndef AVCODEC_DSD_H
25 #define AVCODEC_DSD_H
26 
27 #include <stddef.h>
28 #include <stdint.h>
29 
30 #define HTAPS   48               /** number of FIR constants */
31 #define FIFOSIZE 16              /** must be a power of two */
32 #define FIFOMASK (FIFOSIZE - 1)  /** bit mask for FIFO offsets */
33 
34 #if FIFOSIZE * 8 < HTAPS * 2
35 #error "FIFOSIZE too small"
36 #endif
37 
38 /**
39  * Per-channel buffer
40  */
41 typedef struct DSDContext {
42     uint8_t buf[FIFOSIZE];
43     unsigned pos;
44 } DSDContext;
45 
46 void ff_init_dsd_data(void);
47 
48 void ff_dsd2pcm_translate(DSDContext* s, size_t samples, int lsbf,
49                           const uint8_t *src, ptrdiff_t src_stride,
50                           float *dst, ptrdiff_t dst_stride);
51 #endif /* AVCODEC_DSD_H */
52