1 /* Copyright (C) 2005 Andre Noll <maan@tuebingen.mpg.de>, see file COPYING. */
3 /** \file compress_filter.c Paraslash's dynamic audio range compressor. */
6 * Uses ideas of AudioCompress, (C) 2002-2004 M. Hari Nezumi <magenta@trikuare.cx>
12 #include "filter_cmd.lsg.h"
16 #include "buffer_tree.h"
21 #define U32_OPTVAL(_opt, _lpr) (FILTER_CMD_OPT_UINT32_VAL(COMPRESS, _opt, _lpr))
23 /** Data specific to the compress filter. */
24 struct private_compress_data
{
25 /** The current multiplier. */
26 unsigned current_gain
;
27 /** Maximal admissible gain. */
29 /** Number of samples already seen. */
31 /** Absolute value of the maximal sample in the current block. */
35 static void compress_close(struct filter_node
*fn
)
37 free(fn
->private_data
);
40 static int compress_post_select(__a_unused
struct sched
*s
, void *context
)
42 struct filter_node
*fn
= context
;
43 struct private_compress_data
*pcd
= fn
->private_data
;
44 struct btr_node
*btrn
= fn
->btrn
;
45 bool inplace
= btr_inplace_ok(btrn
);
50 uint32_t inertia
= U32_OPTVAL(INERTIA
, fn
->lpr
);
51 unsigned mask
= (1U << U32_OPTVAL(BLOCKSIZE
, fn
->lpr
)) - 1U;
54 ret
= btr_node_status(btrn
, fn
->min_iqs
, BTR_NT_INTERNAL
);
59 btr_merge(btrn
, fn
->min_iqs
);
60 length
= btr_next_buffer(btrn
, &inbuf
) & ~(size_t)1;
61 if (length
== 0) { /* eof and 1 byte available */
62 ret
= -E_COMPRESS_EOF
;
65 ip
= (int16_t *)inbuf
;
69 op
= para_malloc(length
);
70 for (i
= 0; i
< length
/ 2; i
++) {
71 /* be careful in that heat, my dear */
79 sample
*= pcd
->current_gain
;
80 sample
>>= inertia
+ 1;
81 if (sample
> 32767) { /* clip */
82 PARA_WARNING_LOG("clip: %d\n", sample
);
84 pcd
->current_gain
= (3 * pcd
->current_gain
+
87 } else if (sample
> pcd
->peak
)
89 sample
>>= U32_OPTVAL(DAMP
, fn
->lpr
);
90 op
[i
] = neg
? -sample
: sample
;
91 if (++pcd
->num_samples
& mask
)
93 // PARA_DEBUG_LOG("gain: %u, peak: %u\n", pcd->current_gain,
96 if (pcd
->peak
< U32_OPTVAL(TARGET_LEVEL
, fn
->lpr
)) {
97 if (pcd
->current_gain
< pcd
->max_gain
)
100 pcd
->current_gain
= PARA_MAX(pcd
->current_gain
- 2,
105 btr_pushdown_one(btrn
);
107 btr_consume(btrn
, length
);
108 btr_add_output((char *)op
, length
, btrn
);
113 btr_remove_node(&fn
->btrn
);
117 static void compress_open(struct filter_node
*fn
)
119 struct private_compress_data
*pcd
= para_calloc(sizeof(*pcd
));
120 uint32_t inertia
= U32_OPTVAL(INERTIA
, fn
->lpr
);
121 uint32_t aggressiveness
= U32_OPTVAL(AGGRESSIVENESS
, fn
->lpr
);
123 fn
->private_data
= pcd
;
124 fn
->min_iqs
= 2; /* 16 bit audio */
125 pcd
->current_gain
= 1U << inertia
;
126 pcd
->max_gain
= (1U << inertia
) * (1.0 + 3.0 * aggressiveness
/ 10.0);
129 static void *compress_setup(const struct lls_parse_result
*lpr
)
133 val
= U32_OPTVAL(BLOCKSIZE
, lpr
);
134 if (val
== 0 || val
> 31) {
135 PARA_EMERG_LOG("blocksize (%u) out of range\n", val
);
138 val
= U32_OPTVAL(AGGRESSIVENESS
, lpr
);
140 PARA_EMERG_LOG("aggressiveness (%u) out of range\n", val
);
143 val
= U32_OPTVAL(INERTIA
, lpr
);
144 if (val
== 0 || val
> 14) {
145 PARA_EMERG_LOG("inertia (%u) out of range\n", val
);
148 val
= U32_OPTVAL(TARGET_LEVEL
, lpr
);
150 PARA_EMERG_LOG("target-level (%u) out of range\n", val
);
153 val
= U32_OPTVAL(DAMP
, lpr
);
155 PARA_EMERG_LOG("damp (%u) out of range\n", val
);
158 return NULL
; /* no need for a config structure */
161 const struct filter lsg_filter_cmd_com_compress_user_data
= {
162 .setup
= compress_setup
,
163 .open
= compress_open
,
164 .close
= compress_close
,
165 .pre_select
= generic_filter_pre_select
,
166 .post_select
= compress_post_select
,