b7329c48bce647b113638a5609b39de698ef81fd
2 * Copyright (C) 2005-2009 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 #include "portable_io.h"
18 /** size of the output buffer */
19 #define WAV_OUTBUF_SIZE 81920
20 /** a wav header is always 44 bytes */
21 #define WAV_HEADER_LEN 44
22 /** always write 16 bit header */
25 static void make_wav_header(unsigned int channels
, unsigned int samplerate
,
26 struct filter_node
*fn
)
29 char *headbuf
= fn
->buf
;
30 unsigned int size
= 0x7fffffff;
31 int bytespersec
= channels
* samplerate
* BITS
/ 8;
32 int align
= channels
* BITS
/ 8;
35 PARA_DEBUG_LOG("writing wave header: %d channels, %d KHz\n", channels
, samplerate
);
36 memset(headbuf
, 0, WAV_HEADER_LEN
);
37 memcpy(headbuf
, "RIFF", 4);
38 write_u32(headbuf
+ 4, size
- 8);
39 memcpy(headbuf
+ 8, "WAVE", 4);
40 memcpy(headbuf
+ 12, "fmt ", 4);
41 write_u32(headbuf
+ 16, 16); /* 16 + extra format bytes (zero) */
42 write_u16(headbuf
+ 20, 1); /* format (1 == PCM/uncompressed) */
43 write_u16(headbuf
+ 22, channels
);
44 write_u32(headbuf
+ 24, samplerate
);
45 write_u32(headbuf
+ 28, bytespersec
);
46 write_u16(headbuf
+ 32, align
); /* number of bytes per sample slice */
47 write_u16(headbuf
+ 34, BITS
); /* significant bits per sample */
48 memcpy(headbuf
+ 36, "data", 4); /* chunk ID */
49 write_u32(headbuf
+ 40, size
- 44); /* chunk size */
52 static ssize_t
wav_convert(char *inbuf
, size_t len
, struct filter_node
*fn
)
55 int *bof
= fn
->private_data
;
60 make_wav_header(fn
->fc
->channels
, fn
->fc
->samplerate
, fn
);
61 fn
->loaded
= WAV_HEADER_LEN
;
65 copy
= PARA_MIN(len
, fn
->bufsize
- fn
->loaded
);
66 memmove(fn
->buf
+ fn
->loaded
, inbuf
, copy
);
68 // PARA_DEBUG_LOG("len = %d, copy = %d\n", len, copy);
72 static void wav_close(struct filter_node
*fn
)
76 free(fn
->private_data
);
77 fn
->private_data
= NULL
;
80 static void wav_open(struct filter_node
*fn
)
84 fn
->bufsize
= WAV_OUTBUF_SIZE
;
85 fn
->buf
= para_malloc(fn
->bufsize
);
86 fn
->private_data
= para_malloc(sizeof(int));
87 bof
= fn
->private_data
;
90 PARA_INFO_LOG("wav filter node: %p, output buffer: %p, loaded: %zd\n",
91 fn
, fn
->buf
, fn
->loaded
);
95 * the init function of the wav filter
97 * \param f struct to initialize
99 void wav_filter_init(struct filter
*f
)
101 f
->convert
= wav_convert
;
102 f
->close
= wav_close
;