2 * Copyright (C) 2005-2007 Andre Noll <maan@systemlinux.org>
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; either version 2 of the License, or
7 * (at your option) any later version.
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111, USA.
19 /** \file wav.c a filter that inserts a wave header */
28 /** size of the output buffer */
29 #define WAV_OUTBUF_SIZE 81920
30 /** a wav header is always 44 bytes */
31 #define WAV_HEADER_LEN 44
32 /** always write 16 bit header */
36 * write a 32 bit unsigned value to a buffer
38 * \param buf the buffer to write to
39 * \param x the value to write
41 #define WRITE_U32(buf, x) (buf)[0] = (unsigned char)((x) & 0xff);\
42 (buf)[1] = (unsigned char)(((x) >> 8) & 0xff);\
43 (buf)[2] = (unsigned char)(((x) >> 16) & 0xff);\
44 (buf)[3] = (unsigned char)(((x) >> 24) & 0xff);
47 * write a 16 bit unsigned value to a buffer
49 * \param buf the buffer to write to
50 * \param x the value to write
52 #define WRITE_U16(buf, x) (buf)[0] = (unsigned char)((x) & 0xff);
54 static void make_wav_header(unsigned int channels, unsigned int samplerate,
55 struct filter_node *fn)
58 char *headbuf = fn->buf;
59 unsigned int size = 0x7fffffff;
60 int bytespersec = channels * samplerate * BITS / 8;
61 int align = channels * BITS / 8;
63 PARA_DEBUG_LOG("writing wave header: %d channels, %d KHz\n", channels, samplerate);
64 memset(headbuf, 0, WAV_HEADER_LEN);
65 memcpy(headbuf, "RIFF", 4);
66 WRITE_U32(headbuf + 4, size - 8);
67 memcpy(headbuf + 8, "WAVE", 4);
68 memcpy(headbuf + 12, "fmt ", 4);
69 WRITE_U32(headbuf + 16, 16);
70 WRITE_U16(headbuf + 20, 1); /* format */
71 WRITE_U16(headbuf + 22, channels);
72 WRITE_U32(headbuf + 24, samplerate);
73 WRITE_U32(headbuf + 28, bytespersec);
74 WRITE_U16(headbuf + 32, align);
75 WRITE_U16(headbuf + 34, BITS);
76 memcpy(headbuf + 36, "data", 4);
77 WRITE_U32(headbuf + 40, size - 44);
80 static ssize_t wav_convert(char *inbuf, size_t len, struct filter_node *fn)
83 int *bof = fn->private_data;
86 make_wav_header(fn->fc->channels, fn->fc->samplerate, fn);
87 fn->loaded = WAV_HEADER_LEN;
91 copy = PARA_MIN(len, fn->bufsize - fn->loaded);
92 memmove(fn->buf + fn->loaded, inbuf, copy);
94 // PARA_DEBUG_LOG("len = %d, copy = %d\n", len, copy);
98 static void wav_close(struct filter_node *fn)
102 free(fn->private_data);
103 fn->private_data = NULL;
106 static void wav_open(struct filter_node *fn)
110 fn->bufsize = WAV_OUTBUF_SIZE;
111 fn->buf = para_malloc(fn->bufsize);
112 fn->private_data = para_malloc(sizeof(int));
113 bof = fn->private_data;
115 PARA_INFO_LOG("wav filter node: %p, output buffer: %p, loaded: %zd\n",
116 fn, fn->buf, fn->loaded);
120 * the init function of the wav filter
122 * \param f struct to initialize
124 void wav_init(struct filter *f)
126 f->convert = wav_convert;
127 f->close = wav_close;