242cb4bb0d1529ae3d8756083e04be04bf16d008
2 * Copyright (C) 2005-2008 Andre Noll <maan@systemlinux.org>
4 * Licensed under the GPL v2. For licencing details see COPYING.
7 /** \file wav_filter.c A filter that inserts a wave header. */
16 /** size of the output buffer */
17 #define WAV_OUTBUF_SIZE 81920
18 /** a wav header is always 44 bytes */
19 #define WAV_HEADER_LEN 44
20 /** always write 16 bit header */
24 * write a 32 bit unsigned value to a buffer
26 * \param buf the buffer to write to
27 * \param x the value to write
29 #define WRITE_U32(buf, x) (buf)[0] = (unsigned char)((x) & 0xff);\
30 (buf)[1] = (unsigned char)(((x) >> 8) & 0xff);\
31 (buf)[2] = (unsigned char)(((x) >> 16) & 0xff);\
32 (buf)[3] = (unsigned char)(((x) >> 24) & 0xff);
35 * write a 16 bit unsigned value to a buffer
37 * \param buf the buffer to write to
38 * \param x the value to write
40 #define WRITE_U16(buf, x) (buf)[0] = (unsigned char)((x) & 0xff);
42 static void make_wav_header(unsigned int channels
, unsigned int samplerate
,
43 struct filter_node
*fn
)
46 char *headbuf
= fn
->buf
;
47 unsigned int size
= 0x7fffffff;
48 int bytespersec
= channels
* samplerate
* BITS
/ 8;
49 int align
= channels
* BITS
/ 8;
52 PARA_DEBUG_LOG("writing wave header: %d channels, %d KHz\n", channels
, samplerate
);
53 memset(headbuf
, 0, WAV_HEADER_LEN
);
54 memcpy(headbuf
, "RIFF", 4);
55 WRITE_U32(headbuf
+ 4, size
- 8);
56 memcpy(headbuf
+ 8, "WAVE", 4);
57 memcpy(headbuf
+ 12, "fmt ", 4);
58 WRITE_U32(headbuf
+ 16, 16);
59 WRITE_U16(headbuf
+ 20, 1); /* format */
60 WRITE_U16(headbuf
+ 22, channels
);
61 WRITE_U32(headbuf
+ 24, samplerate
);
62 WRITE_U32(headbuf
+ 28, bytespersec
);
63 WRITE_U16(headbuf
+ 32, align
);
64 WRITE_U16(headbuf
+ 34, BITS
);
65 memcpy(headbuf
+ 36, "data", 4);
66 WRITE_U32(headbuf
+ 40, size
- 44);
69 static ssize_t
wav_convert(char *inbuf
, size_t len
, struct filter_node
*fn
)
72 int *bof
= fn
->private_data
;
77 make_wav_header(fn
->fc
->channels
, fn
->fc
->samplerate
, fn
);
78 fn
->loaded
= WAV_HEADER_LEN
;
82 copy
= PARA_MIN(len
, fn
->bufsize
- fn
->loaded
);
83 memmove(fn
->buf
+ fn
->loaded
, inbuf
, copy
);
85 // PARA_DEBUG_LOG("len = %d, copy = %d\n", len, copy);
89 static void wav_close(struct filter_node
*fn
)
93 free(fn
->private_data
);
94 fn
->private_data
= NULL
;
97 static void wav_open(struct filter_node
*fn
)
101 fn
->bufsize
= WAV_OUTBUF_SIZE
;
102 fn
->buf
= para_malloc(fn
->bufsize
);
103 fn
->private_data
= para_malloc(sizeof(int));
104 bof
= fn
->private_data
;
107 PARA_INFO_LOG("wav filter node: %p, output buffer: %p, loaded: %zd\n",
108 fn
, fn
->buf
, fn
->loaded
);
112 * the init function of the wav filter
114 * \param f struct to initialize
116 void wav_filter_init(struct filter
*f
)
118 f
->convert
= wav_convert
;
119 f
->close
= wav_close
;