1 /* Copyright (C) 2005 Andre Noll <maan@tuebingen.mpg.de>, see file COPYING. */
3 /** \file wav_filter.c A filter that inserts a wave header. */
11 #include "buffer_tree.h"
14 #include "portable_io.h"
16 /** A wav header is always 44 bytes. */
17 #define WAV_HEADER_LEN 44
18 /** Always write 16 bit header. */
21 static void make_wav_header(unsigned int channels
, unsigned int sample_rate
,
25 unsigned int size
= 0x7fffffff;
26 int bytespersec
= channels
* sample_rate
* BITS
/ 8;
27 int align
= channels
* BITS
/ 8;
29 PARA_DEBUG_LOG("writing wave header: %u channels, %u KHz\n", channels
, sample_rate
);
30 memset(headbuf
, 0, WAV_HEADER_LEN
);
31 memcpy(headbuf
, "RIFF", 4);
32 write_u32(headbuf
+ 4, size
- 8);
33 memcpy(headbuf
+ 8, "WAVE", 4);
34 memcpy(headbuf
+ 12, "fmt ", 4);
35 write_u32(headbuf
+ 16, 16); /* 16 + extra format bytes (zero) */
36 write_u16(headbuf
+ 20, 1); /* format (1 == PCM/uncompressed) */
37 write_u16(headbuf
+ 22, channels
);
38 write_u32(headbuf
+ 24, sample_rate
);
39 write_u32(headbuf
+ 28, bytespersec
);
40 write_u16(headbuf
+ 32, align
); /* number of bytes per sample slice */
41 write_u16(headbuf
+ 34, BITS
); /* significant bits per sample */
42 memcpy(headbuf
+ 36, "data", 4); /* chunk ID */
43 write_u32(headbuf
+ 40, size
- 44); /* chunk size */
46 static void wav_close(struct filter_node
*fn
)
48 free(fn
->private_data
);
49 fn
->private_data
= NULL
;
52 static void wav_open(struct filter_node
*fn
)
56 fn
->private_data
= para_malloc(sizeof(int));
57 bof
= fn
->private_data
;
61 static void wav_pre_select(struct sched
*s
, void *context
)
63 struct filter_node
*fn
= context
;
64 size_t iqs
= btr_get_input_queue_size(fn
->btrn
);
71 static int wav_post_select(__a_unused
struct sched
*s
, void *context
)
73 struct filter_node
*fn
= context
;
74 struct btr_node
*btrn
= fn
->btrn
;
75 size_t iqs
= btr_get_input_queue_size(btrn
);
82 if (btr_no_parent(btrn
))
86 ret
= btr_exec_up(btrn
, "sample_rate", &buf
);
91 ret
= para_atoi32(buf
, &rate
);
95 ret
= btr_exec_up(btrn
, "channels", &buf
);
100 ret
= para_atoi32(buf
, &ch
);
104 header
= para_malloc(WAV_HEADER_LEN
);
105 make_wav_header(ch
, rate
, header
);
106 btr_add_output(header
, WAV_HEADER_LEN
, btrn
);
107 ret
= -E_WAV_SUCCESS
;
109 if (ret
== -E_WAV_SUCCESS
)
110 btr_splice_out_node(&fn
->btrn
);
112 btr_remove_node(&fn
->btrn
);
113 PARA_ERROR_LOG("%s\n", para_strerror(-ret
));
118 const struct filter lsg_filter_cmd_com_wav_user_data
= {
121 .pre_select
= wav_pre_select
,
122 .post_select
= wav_post_select
,