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. */
17 #include "portable_io.h"
19 /** size of the output buffer */
20 #define WAV_OUTBUF_SIZE 81920
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 samplerate,
27 struct filter_node *fn)
30 char *headbuf = fn->buf;
31 unsigned int size = 0x7fffffff;
32 int bytespersec = channels * samplerate * BITS / 8;
33 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 if (!fn->fc->channels || !fn->fc->samplerate) {
61 PARA_ERROR_LOG("%s\n", para_strerror(E_WAV_BAD_FC));
64 make_wav_header(fn->fc->channels, fn->fc->samplerate, fn);
65 fn->loaded = WAV_HEADER_LEN;
69 copy = PARA_MIN(len, fn->bufsize - fn->loaded);
70 memmove(fn->buf + fn->loaded, inbuf, copy);
72 // PARA_DEBUG_LOG("len = %d, copy = %d\n", len, copy);
76 static void wav_close(struct filter_node *fn)
80 free(fn->private_data);
81 fn->private_data = NULL;
84 static void wav_open(struct filter_node *fn)
88 fn->bufsize = WAV_OUTBUF_SIZE;
89 fn->buf = para_malloc(fn->bufsize);
90 fn->private_data = para_malloc(sizeof(int));
91 bof = fn->private_data;
94 PARA_INFO_LOG("wav filter node: %p, output buffer: %p, loaded: %zd\n",
95 fn, fn->buf, fn->loaded);
99 * the init function of the wav filter
101 * \param f struct to initialize
103 void wav_filter_init(struct filter *f)
105 f->convert = wav_convert;
106 f->close = wav_close;