check_wav.c

   1 /*
   2  * Copyright (C) 2005-2012 Andre Noll <maan@systemlinux.org>
   3  *
   4  * Licensed under the GPL v2. For licencing details see COPYING.
   5  */
   6
   7 /** \file check_wav.c Detect and delete a wav header. */
   8
   9 #include <regex.h>
  10
  11 #include "para.h"
  12 #include "string.h"
  13 #include "list.h"
  14 #include "sched.h"
  15 #include "buffer_tree.h"
  16 #include "error.h"
  17 #include "check_wav.h"
  18
  19 /** Length of a standard wav header. */
  20 #define WAV_HEADER_LEN 44
  21
  22 enum check_wav_state {
  23         CWS_NEED_HEADER,
  24         CWS_HAVE_HEADER,
  25         CWS_NO_HEADER,
  26 };
  27
  28 struct check_wav_task {
  29         enum check_wav_state state;
  30         struct task task;
  31         struct btr_node *btrn;
  32         size_t min_iqs;
  33         /* Command line args. */
  34         struct wav_params params;
  35         /* Extracted from the wav header.*/
  36         unsigned channels;
  37         unsigned sample_format;
  38         unsigned sample_rate;
  39 };
  40
  41 static void check_wav_pre_select(struct sched *s, struct task *t)
  42 {
  43         struct check_wav_task *cwt = container_of(t, struct check_wav_task, task);
  44         int ret;
  45
  46         ret = btr_node_status(cwt->btrn, cwt->min_iqs, BTR_NT_INTERNAL);
  47         if (ret != 0)
  48                 sched_min_delay(s);
  49 }
  50
  51 static int check_wav_exec(struct btr_node *btrn, const char *cmd, char **result)
  52 {
  53         struct check_wav_task *cwt = btr_context(btrn);
  54         int val, header_val, given, arg;
  55
  56         header_val = cwt->channels;
  57         arg = cwt->params.channels_arg;
  58         given = cwt->params.channels_given;
  59         if (!strcmp(cmd, "channels"))
  60                 goto out;
  61
  62         header_val = cwt->sample_rate;
  63         arg = cwt->params.sample_rate_arg;
  64         given = cwt->params.sample_rate_given;
  65         if (!strcmp(cmd, "sample_rate"))
  66                 goto out;
  67
  68         header_val = cwt->sample_format;
  69         arg = cwt->params.sample_format_arg;
  70         given = cwt->params.sample_format_given;
  71         if (!strcmp(cmd, "sample_format"))
  72                 goto out;
  73
  74         return -ERRNO_TO_PARA_ERROR(ENOTSUP);
  75 out:
  76         if (given)
  77                 val = arg;
  78         else {
  79                 switch (cwt->state) {
  80                 case CWS_HAVE_HEADER:
  81                         val = header_val;
  82                         break;
  83                 case CWS_NO_HEADER:
  84                         /* Use default value */
  85                         val = arg;
  86                         break;
  87                 default:
  88                         return -E_BTR_NAVAIL;
  89                 }
  90         }
  91         *result = make_message("%d", val);
  92         return 1;
  93 }
  94
  95 static void check_wav_post_select(__a_unused struct sched *s, struct task *t)
  96 {
  97         struct check_wav_task *cwt = container_of(t, struct check_wav_task, task);
  98         struct btr_node *btrn = cwt->btrn;
  99         unsigned char *a;
 100         size_t sz;
 101         int ret;
 102         uint16_t bps; /* bits per sample */
 103         const char *sample_formats[] = {SAMPLE_FORMATS};
 104
 105         t->error = 0;
 106         ret = btr_node_status(btrn, cwt->min_iqs, BTR_NT_INTERNAL);
 107         if (ret <= 0)
 108                 goto out;
 109         if (cwt->state != CWS_NEED_HEADER)
 110                 goto pushdown;
 111         btr_merge(btrn, cwt->min_iqs);
 112         sz = btr_next_buffer(btrn, (char **)&a);
 113         if (sz < cwt->min_iqs) /* file size less than WAV_HEADER_SIZE */
 114                 goto pushdown;
 115         cwt->min_iqs = 0;
 116         /*
 117          * The default byte ordering assumed for WAVE data files is
 118          * little-endian. Files written using the big-endian byte ordering
 119          * scheme have the identifier RIFX instead of RIFF.
 120          */
 121         if (a[0] != 'R' || a[1] != 'I' || a[2] != 'F' ||
 122                         (a[3] != 'F' && a[3] != 'X')) {
 123                 PARA_NOTICE_LOG("wav header not found\n");
 124                 cwt->state = CWS_NO_HEADER;
 125                 sprintf(t->status, "check wav: no header");
 126                 goto out;
 127         }
 128         PARA_INFO_LOG("found wav header\n");
 129         cwt->state = CWS_HAVE_HEADER;
 130         sprintf(t->status, "check wav: have header");
 131         /* Only set those values which have not already been set. */
 132         cwt->channels = (unsigned)a[22];
 133         cwt->sample_rate = a[24] + (a[25] << 8) + (a[26] << 16) + (a[27] << 24);
 134         bps = a[34] + ((unsigned)a[35] << 8);
 135         if (bps != 8 && bps != 16) {
 136                 PARA_WARNING_LOG("%u bps not supported, assuming 16\n",
 137                         bps);
 138                 bps = 16;
 139         }
 140         /*
 141          * 8-bit samples are stored as unsigned bytes, ranging from 0
 142          * to 255.  16-bit samples are stored as 2's-complement signed
 143          * integers, ranging from -32768 to 32767.
 144          */
 145         if (bps == 8)
 146                 cwt->sample_format = SF_U8;
 147         else
 148                 cwt->sample_format = (a[3] == 'F')?
 149                         SF_S16_LE : SF_S16_BE;
 150         PARA_NOTICE_LOG("%dHz, %s, %s\n", cwt->sample_rate,
 151                 cwt->channels == 1? "mono" : "stereo",
 152                 sample_formats[cwt->sample_format]);
 153         btr_consume(btrn, WAV_HEADER_LEN);
 154 pushdown:
 155         btr_pushdown(btrn);
 156 out:
 157         t->error = ret;
 158         if (ret < 0)
 159                 btr_remove_node(&cwt->btrn);
 160 }
 161
 162 struct check_wav_task *check_wav_init(struct sched *s, struct btr_node *parent,
 163                 struct wav_params *params, struct btr_node **cwt_btrn)
 164 {
 165         struct check_wav_task *cwt = para_calloc(sizeof(*cwt));
 166
 167         cwt->state = CWS_NEED_HEADER;
 168         cwt->min_iqs = WAV_HEADER_LEN;
 169         cwt->params = *params;
 170         cwt->btrn = btr_new_node(&(struct btr_node_description)
 171                 EMBRACE(.name = "check_wav", .parent = parent,
 172                 .handler = check_wav_exec, .context = cwt));
 173         sprintf(cwt->task.status, "check_wav");
 174         cwt->task.pre_select = check_wav_pre_select;
 175         cwt->task.post_select = check_wav_post_select;
 176         if (cwt_btrn)
 177                 *cwt_btrn = cwt->btrn;
 178         register_task(s, &cwt->task);
 179         return cwt;
 180 }
 181
 182 void check_wav_shutdown(struct check_wav_task *cwt)
 183 {
 184         free(cwt);
 185 }