wav_filter.c

   1 /* Copyright (C) 2005 Andre Noll <maan@tuebingen.mpg.de>, see file COPYING. */
   2
   3 /** \file wav_filter.c A filter that inserts a wave header. */
   4
   5 #include <regex.h>
   6
   7 #include "para.h"
   8 #include "error.h"
   9 #include "list.h"
  10 #include "sched.h"
  11 #include "buffer_tree.h"
  12 #include "filter.h"
  13 #include "string.h"
  14 #include "portable_io.h"
  15
  16 /** A wav header is always 44 bytes. */
  17 #define WAV_HEADER_LEN 44
  18 /** Always write 16 bit header. */
  19 #define BITS 16
  20
  21 static void make_wav_header(unsigned int channels, unsigned int sample_rate,
  22                 char *headbuf)
  23 {
  24
  25         unsigned int size = 0x7fffffff;
  26         int bytespersec = channels * sample_rate * BITS / 8;
  27         int align = channels * BITS / 8;
  28
  29         PARA_DEBUG_LOG("writing wave header: %u channels, %u KHz\n", channels, sample_rate);
  30         memset(headbuf, 0, WAV_HEADER_LEN);
  31         memcpy(headbuf, "RIFF", 4);
  32         write_u32(headbuf + 4, size - 8);
  33         memcpy(headbuf + 8, "WAVE", 4);
  34         memcpy(headbuf + 12, "fmt ", 4);
  35         write_u32(headbuf + 16, 16); /* 16 + extra format bytes (zero) */
  36         write_u16(headbuf + 20, 1);     /* format (1 == PCM/uncompressed) */
  37         write_u16(headbuf + 22, channels);
  38         write_u32(headbuf + 24, sample_rate);
  39         write_u32(headbuf + 28, bytespersec);
  40         write_u16(headbuf + 32, align); /* number of bytes per sample slice */
  41         write_u16(headbuf + 34, BITS); /* significant bits per sample */
  42         memcpy(headbuf + 36, "data", 4); /* chunk ID */
  43         write_u32(headbuf + 40, size - 44); /* chunk size */
  44 }
  45
  46 static void wav_close(struct filter_node *fn)
  47 {
  48         free(fn->private_data);
  49         fn->private_data = NULL;
  50 }
  51
  52 static void wav_open(struct filter_node *fn)
  53 {
  54         int *bof;
  55
  56         fn->private_data = para_malloc(sizeof(int));
  57         bof = fn->private_data;
  58         *bof = 1;
  59 }
  60
  61 static void wav_pre_select(struct sched *s, void *context)
  62 {
  63         struct filter_node *fn = context;
  64         size_t iqs = btr_get_input_queue_size(fn->btrn);
  65
  66         if (iqs == 0)
  67                 return;
  68         sched_min_delay(s);
  69 }
  70
  71 static int wav_post_select(__a_unused struct sched *s, void *context)
  72 {
  73         struct filter_node *fn = context;
  74         struct btr_node *btrn = fn->btrn;
  75         size_t iqs = btr_get_input_queue_size(btrn);
  76         int ret;
  77         char *header, *buf;
  78         int32_t rate, ch;
  79
  80         if (iqs == 0) {
  81                 ret = -E_WAV_EOF;
  82                 if (btr_no_parent(btrn))
  83                         goto err;
  84                 return 0;
  85         }
  86         ret = btr_exec_up(btrn, "sample_rate", &buf);
  87         if (ret < 0) {
  88                 ret = -E_WAV_BAD_FC;
  89                 goto err;
  90         }
  91         ret = para_atoi32(buf, &rate);
  92         free(buf);
  93         if (ret < 0)
  94                 goto err;
  95         ret = btr_exec_up(btrn, "channels", &buf);
  96         if (ret < 0) {
  97                 ret = -E_WAV_BAD_FC;
  98                 goto err;
  99         }
 100         ret = para_atoi32(buf, &ch);
 101         free(buf);
 102         if (ret < 0)
 103                 goto err;
 104         header = para_malloc(WAV_HEADER_LEN);
 105         make_wav_header(ch, rate, header);
 106         btr_add_output(header, WAV_HEADER_LEN, btrn);
 107         ret = -E_WAV_SUCCESS;
 108 err:
 109         if (ret == -E_WAV_SUCCESS)
 110                 btr_splice_out_node(&fn->btrn);
 111         else {
 112                 btr_remove_node(&fn->btrn);
 113                 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
 114         }
 115         return ret;
 116 }
 117
 118 const struct filter lsg_filter_cmd_com_wav_user_data = {
 119         .close = wav_close,
 120         .open = wav_open,
 121         .pre_select = wav_pre_select,
 122         .post_select = wav_post_select,
 123 };