wav_filter.c

   1 /*
   2  * Copyright (C) 2005-2009 Andre Noll <maan@systemlinux.org>
   3  *
   4  * Licensed under the GPL v2. For licencing details see COPYING.
   5  */
   6
   7 /** \file wav_filter.c A filter that inserts a wave header. */
   8
   9 #include <regex.h>
  10 #include <stdbool.h>
  11
  12 #include "para.h"
  13 #include "error.h"
  14 #include "list.h"
  15 #include "sched.h"
  16 #include "ggo.h"
  17 #include "buffer_tree.h"
  18 #include "filter.h"
  19 #include "string.h"
  20 #include "portable_io.h"
  21
  22 /** size of the output buffer */
  23 #define WAV_OUTBUF_SIZE 81920
  24 /** a wav header is always 44 bytes */
  25 #define WAV_HEADER_LEN 44
  26 /** always write 16 bit header */
  27 #define BITS 16
  28
  29 static void make_wav_header(unsigned int channels, unsigned int samplerate,
  30                 struct filter_node *fn)
  31 {
  32
  33         char *headbuf = fn->buf;
  34         unsigned int size = 0x7fffffff;
  35         int bytespersec = channels * samplerate * BITS / 8;
  36         int align = channels * BITS / 8;
  37
  38         PARA_DEBUG_LOG("writing wave header: %d channels, %d KHz\n", channels, samplerate);
  39         memset(headbuf, 0, WAV_HEADER_LEN);
  40         memcpy(headbuf, "RIFF", 4);
  41         write_u32(headbuf + 4, size - 8);
  42         memcpy(headbuf + 8, "WAVE", 4);
  43         memcpy(headbuf + 12, "fmt ", 4);
  44         write_u32(headbuf + 16, 16); /* 16 + extra format bytes (zero) */
  45         write_u16(headbuf + 20, 1);     /* format (1 == PCM/uncompressed) */
  46         write_u16(headbuf + 22, channels);
  47         write_u32(headbuf + 24, samplerate);
  48         write_u32(headbuf + 28, bytespersec);
  49         write_u16(headbuf + 32, align); /* number of bytes per sample slice */
  50         write_u16(headbuf + 34, BITS); /* significant bits per sample */
  51         memcpy(headbuf + 36, "data", 4); /* chunk ID */
  52         write_u32(headbuf + 40, size - 44); /* chunk size */
  53 }
  54
  55 static ssize_t wav_convert(char *inbuf, size_t len, struct filter_node *fn)
  56 {
  57         size_t copy;
  58         int *bof = fn->private_data;
  59
  60         if (*bof) {
  61                 if (!len)
  62                         return 0;
  63                 if (!fn->fc->channels || !fn->fc->samplerate) {
  64                         PARA_ERROR_LOG("%s\n", para_strerror(E_WAV_BAD_FC));
  65                         return -E_WAV_BAD_FC;
  66                 }
  67                 make_wav_header(fn->fc->channels, fn->fc->samplerate, fn);
  68                 fn->loaded = WAV_HEADER_LEN;
  69                 *bof = 0;
  70 //              return 0;
  71         }
  72         copy = PARA_MIN(len, fn->bufsize - fn->loaded);
  73         memmove(fn->buf + fn->loaded, inbuf, copy);
  74         fn->loaded += copy;
  75 //      PARA_DEBUG_LOG("len = %d, copy = %d\n", len, copy);
  76         return copy;
  77 }
  78
  79 static void wav_close(struct filter_node *fn)
  80 {
  81         free(fn->buf);
  82         fn->buf = NULL;
  83         free(fn->private_data);
  84         fn->private_data = NULL;
  85 }
  86
  87 static void wav_open(struct filter_node *fn)
  88 {
  89         int *bof;
  90
  91         fn->bufsize = WAV_OUTBUF_SIZE;
  92         fn->buf = para_malloc(fn->bufsize);
  93         fn->private_data = para_malloc(sizeof(int));
  94         bof = fn->private_data;
  95         fn->loaded = 0;
  96         *bof = 1;
  97         PARA_INFO_LOG("wav filter node: %p, output buffer: %p, loaded: %zd\n",
  98                 fn, fn->buf, fn->loaded);
  99 }
 100
 101 /**
 102  * the init function of the wav filter
 103  *
 104  * \param f struct to initialize
 105  */
 106 void wav_filter_init(struct filter *f)
 107 {
 108         f->convert = wav_convert;
 109         f->close = wav_close;
 110         f->open = wav_open;
 111 }