wav.c

   1 /*
   2  * Copyright (C) 2005-2006 Andre Noll <maan@systemlinux.org>
   3  *
   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.
   8  *
   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.
  13  *
  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.
  17  */
  18
  19 /** \file wav.c a filter that inserts a wave header */
  20
  21 #include "gcc-compat.h"
  22 #include "para.h"
  23
  24 #include "list.h"
  25 #include "filter.h"
  26 #include "string.h"
  27
  28 #define WAV_OUTBUF_SIZE 81920
  29 #define WAV_HEADER_LEN 44
  30 #define BITS 16
  31
  32 /* derived from oggdec.c of the vorbis-tools-1.0.1 package */
  33 #define WRITE_U32(buf, x) (buf)[0] = (unsigned char)((x) & 0xff);\
  34         (buf)[1] = (unsigned char)(((x) >> 8) & 0xff);\
  35         (buf)[2] = (unsigned char)(((x) >> 16) & 0xff);\
  36         (buf)[3] = (unsigned char)(((x) >> 24) & 0xff);
  37 #define WRITE_U16(buf, x) (buf)[0] = (unsigned char)((x) & 0xff);
  38
  39 static void make_wav_header(int channels, int samplerate, struct filter_node *fn)
  40 {
  41
  42         char *headbuf = fn->buf;
  43         unsigned int size = 0x7fffffff;
  44         int bytespersec = channels * samplerate * BITS / 8;
  45         int align = channels * BITS / 8;
  46
  47         PARA_DEBUG_LOG("writing wave header: %d channels, %d KHz\n", channels, samplerate);
  48         memset(headbuf, 0, WAV_HEADER_LEN);
  49         memcpy(headbuf, "RIFF", 4);
  50         WRITE_U32(headbuf + 4, size - 8);
  51         memcpy(headbuf + 8, "WAVE", 4);
  52         memcpy(headbuf + 12, "fmt ", 4);
  53         WRITE_U32(headbuf + 16, 16);
  54         WRITE_U16(headbuf + 20, 1);     /* format */
  55         WRITE_U16(headbuf + 22, channels);
  56         WRITE_U32(headbuf + 24, samplerate);
  57         WRITE_U32(headbuf + 28, bytespersec);
  58         WRITE_U16(headbuf + 32, align);
  59         WRITE_U16(headbuf + 34, BITS);
  60         memcpy(headbuf + 36, "data", 4);
  61         WRITE_U32(headbuf + 40, size - 44);
  62 }
  63
  64 static ssize_t wav_convert(char *inbuf, size_t len, struct filter_node *fn)
  65 {
  66         size_t copy;
  67         int *bof = fn->private_data;
  68
  69         if (*bof) {
  70                 make_wav_header(fn->fci->channels, fn->fci->samplerate, fn);
  71                 fn->loaded = WAV_HEADER_LEN;
  72                 *bof = 0;
  73 //              return 0;
  74         }
  75         copy = MIN(len, fn->bufsize - fn->loaded);
  76         memmove(fn->buf + fn->loaded, inbuf, copy);
  77         fn->loaded += copy;
  78 //      PARA_DEBUG_LOG("len = %d, copy = %d\n", len, copy);
  79         return copy;
  80 }
  81
  82 static void wav_close(struct filter_node *fn)
  83 {
  84         free(fn->buf);
  85         fn->buf = NULL;
  86         free(fn->private_data);
  87         fn->private_data = NULL;
  88 }
  89
  90 static void wav_open(struct filter_node *fn)
  91 {
  92         int *bof;
  93
  94         fn->bufsize = WAV_OUTBUF_SIZE;
  95         fn->buf = para_malloc(fn->bufsize);
  96         fn->private_data = para_malloc(sizeof(int));
  97         bof = fn->private_data;
  98         *bof = 1;
  99         PARA_DEBUG_LOG("wav filter node: %p, output buffer: %p, loaded: %d\n",
 100                 fn, fn->buf, fn->loaded);
 101 }
 102
 103 void wav_init(struct filter *f)
 104 {
 105         f->convert = wav_convert;
 106         f->close = wav_close;
 107         f->open = wav_open;
 108 }