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