2 * Copyright (C) 2005 Andre Noll <maan@tuebingen.mpg.de>
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 "buffer_tree.h"
19 #include "portable_io.h"
21 /** A wav header is always 44 bytes. */
22 #define WAV_HEADER_LEN 44
23 /** Always write 16 bit header. */
26 static void make_wav_header(unsigned int channels, unsigned int sample_rate,
30 unsigned int size = 0x7fffffff;
31 int bytespersec = channels * sample_rate * BITS / 8;
32 int align = channels * BITS / 8;
34 PARA_DEBUG_LOG("writing wave header: %u channels, %u 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 */
51 static void wav_close(struct filter_node *fn)
53 free(fn->private_data);
54 fn->private_data = NULL;
57 static void wav_open(struct filter_node *fn)
61 fn->private_data = para_malloc(sizeof(int));
62 bof = fn->private_data;
66 static void wav_pre_select(struct sched *s, void *context)
68 struct filter_node *fn = context;
69 size_t iqs = btr_get_input_queue_size(fn->btrn);
76 static int wav_post_select(__a_unused struct sched *s, void *context)
78 struct filter_node *fn = context;
79 struct btr_node *btrn = fn->btrn;
80 size_t iqs = btr_get_input_queue_size(btrn);
87 if (btr_no_parent(btrn))
91 ret = btr_exec_up(btrn, "sample_rate", &buf);
96 ret = para_atoi32(buf, &rate);
100 ret = btr_exec_up(btrn, "channels", &buf);
105 ret = para_atoi32(buf, &ch);
109 header = para_malloc(WAV_HEADER_LEN);
110 make_wav_header(ch, rate, header);
111 btr_add_output(header, WAV_HEADER_LEN, btrn);
112 ret = -E_WAV_SUCCESS;
114 if (ret == -E_WAV_SUCCESS)
115 btr_splice_out_node(&fn->btrn);
117 btr_remove_node(&fn->btrn);
118 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
124 * The init function of the wav filter.
126 * \param f Structure to initialize.
128 void wav_filter_init(struct filter *f)
130 f->close = wav_close;
132 f->pre_select = wav_pre_select;
133 f->post_select = wav_post_select;