Merge branch 't/doc'
[paraslash.git] / wav_filter.c
1 /*
2 * Copyright (C) 2005-2013 Andre Noll <maan@systemlinux.org>
3 *
4 * Licensed under the GPL v2. For licencing details see COPYING.
5 */
6
7 /** \file wav_filter.c A filter that inserts a wave header. */
8
9 #include <regex.h>
10
11 #include "para.h"
12 #include "error.h"
13 #include "list.h"
14 #include "sched.h"
15 #include "ggo.h"
16 #include "buffer_tree.h"
17 #include "filter.h"
18 #include "string.h"
19 #include "portable_io.h"
20
21 /** A wav header is always 44 bytes. */
22 #define WAV_HEADER_LEN 44
23 /** Always write 16 bit header. */
24 #define BITS 16
25
26 static void make_wav_header(unsigned int channels, unsigned int sample_rate,
27 char *headbuf)
28 {
29
30 unsigned int size = 0x7fffffff;
31 int bytespersec = channels * sample_rate * BITS / 8;
32 int align = channels * BITS / 8;
33
34 PARA_DEBUG_LOG("writing wave header: %d channels, %d KHz\n", channels, sample_rate);
35 memset(headbuf, 0, WAV_HEADER_LEN);
36 memcpy(headbuf, "RIFF", 4);
37 write_u32(headbuf + 4, size - 8);
38 memcpy(headbuf + 8, "WAVE", 4);
39 memcpy(headbuf + 12, "fmt ", 4);
40 write_u32(headbuf + 16, 16); /* 16 + extra format bytes (zero) */
41 write_u16(headbuf + 20, 1); /* format (1 == PCM/uncompressed) */
42 write_u16(headbuf + 22, channels);
43 write_u32(headbuf + 24, sample_rate);
44 write_u32(headbuf + 28, bytespersec);
45 write_u16(headbuf + 32, align); /* number of bytes per sample slice */
46 write_u16(headbuf + 34, BITS); /* significant bits per sample */
47 memcpy(headbuf + 36, "data", 4); /* chunk ID */
48 write_u32(headbuf + 40, size - 44); /* chunk size */
49 }
50
51 static void wav_close(struct filter_node *fn)
52 {
53 free(fn->private_data);
54 fn->private_data = NULL;
55 }
56
57 static void wav_open(struct filter_node *fn)
58 {
59 int *bof;
60
61 fn->private_data = para_malloc(sizeof(int));
62 bof = fn->private_data;
63 *bof = 1;
64 }
65
66 static void wav_pre_select(struct sched *s, struct task *t)
67 {
68 struct filter_node *fn = container_of(t, struct filter_node, task);
69 size_t iqs = btr_get_input_queue_size(fn->btrn);
70
71 t->error = 0;
72 if (iqs == 0)
73 return;
74 sched_min_delay(s);
75 }
76
77 static int wav_post_select(__a_unused struct sched *s, struct task *t)
78 {
79 struct filter_node *fn = container_of(t, struct filter_node, task);
80 struct btr_node *btrn = fn->btrn;
81 size_t iqs = btr_get_input_queue_size(btrn);
82 int ret;
83 char *header, *buf;
84 int32_t rate, ch;
85
86 if (iqs == 0) {
87 ret = -E_WAV_EOF;
88 if (btr_no_parent(btrn))
89 goto err;
90 return 0;
91 }
92 ret = btr_exec_up(btrn, "sample_rate", &buf);
93 if (ret < 0) {
94 ret = -E_WAV_BAD_FC;
95 goto err;
96 }
97 ret = para_atoi32(buf, &rate);
98 free(buf);
99 if (ret < 0)
100 goto err;
101 ret = btr_exec_up(btrn, "channels", &buf);
102 if (ret < 0) {
103 ret = -E_WAV_BAD_FC;
104 goto err;
105 }
106 ret = para_atoi32(buf, &ch);
107 free(buf);
108 if (ret < 0)
109 goto err;
110 header = para_malloc(WAV_HEADER_LEN);
111 make_wav_header(ch, rate, header);
112 btr_add_output(header, WAV_HEADER_LEN, btrn);
113 ret = -E_WAV_SUCCESS;
114 err:
115 if (ret == -E_WAV_SUCCESS)
116 btr_splice_out_node(btrn);
117 else {
118 btr_remove_node(&fn->btrn);
119 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
120 }
121 return ret;
122 }
123
124 /**
125 * The init function of the wav filter.
126 *
127 * \param f Structure to initialize.
128 */
129 void wav_filter_init(struct filter *f)
130 {
131 f->close = wav_close;
132 f->open = wav_open;
133 f->pre_select = wav_pre_select;
134 f->post_select = wav_post_select;
135 }