Merge commit 'meins/next'
[paraslash.git] / wav_filter.c
1 /*
2 * Copyright (C) 2005-2008 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 "para.h"
10
11 #include "list.h"
12 #include "sched.h"
13 #include "filter.h"
14 #include "string.h"
15 #include "portable_io.h"
16
17 /** size of the output buffer */
18 #define WAV_OUTBUF_SIZE 81920
19 /** a wav header is always 44 bytes */
20 #define WAV_HEADER_LEN 44
21 /** always write 16 bit header */
22 #define BITS 16
23
24 static void make_wav_header(unsigned int channels, unsigned int samplerate,
25 struct filter_node *fn)
26 {
27
28 char *headbuf = fn->buf;
29 unsigned int size = 0x7fffffff;
30 int bytespersec = channels * samplerate * BITS / 8;
31 int align = channels * BITS / 8;
32
33 assert(channels);
34 PARA_DEBUG_LOG("writing wave header: %d channels, %d KHz\n", channels, samplerate);
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);
41 write_u16(headbuf + 20, 1); /* format */
42 write_u16(headbuf + 22, channels);
43 write_u32(headbuf + 24, samplerate);
44 write_u32(headbuf + 28, bytespersec);
45 write_u16(headbuf + 32, align);
46 write_u16(headbuf + 34, BITS);
47 memcpy(headbuf + 36, "data", 4);
48 write_u32(headbuf + 40, size - 44);
49 }
50
51 static ssize_t wav_convert(char *inbuf, size_t len, struct filter_node *fn)
52 {
53 size_t copy;
54 int *bof = fn->private_data;
55
56 if (*bof) {
57 if (!len)
58 return 0;
59 make_wav_header(fn->fc->channels, fn->fc->samplerate, fn);
60 fn->loaded = WAV_HEADER_LEN;
61 *bof = 0;
62 // return 0;
63 }
64 copy = PARA_MIN(len, fn->bufsize - fn->loaded);
65 memmove(fn->buf + fn->loaded, inbuf, copy);
66 fn->loaded += copy;
67 // PARA_DEBUG_LOG("len = %d, copy = %d\n", len, copy);
68 return copy;
69 }
70
71 static void wav_close(struct filter_node *fn)
72 {
73 free(fn->buf);
74 fn->buf = NULL;
75 free(fn->private_data);
76 fn->private_data = NULL;
77 }
78
79 static void wav_open(struct filter_node *fn)
80 {
81 int *bof;
82
83 fn->bufsize = WAV_OUTBUF_SIZE;
84 fn->buf = para_malloc(fn->bufsize);
85 fn->private_data = para_malloc(sizeof(int));
86 bof = fn->private_data;
87 fn->loaded = 0;
88 *bof = 1;
89 PARA_INFO_LOG("wav filter node: %p, output buffer: %p, loaded: %zd\n",
90 fn, fn->buf, fn->loaded);
91 }
92
93 /**
94 * the init function of the wav filter
95 *
96 * \param f struct to initialize
97 */
98 void wav_filter_init(struct filter *f)
99 {
100 f->convert = wav_convert;
101 f->close = wav_close;
102 f->open = wav_open;
103 }