-/*
- * Copyright (C) 2005-2013 Andre Noll <maan@systemlinux.org>
- *
- * Licensed under the GPL v2. For licencing details see COPYING.
- */
+/* Copyright (C) 2005 Andre Noll <maan@tuebingen.mpg.de>, see file COPYING. */
/** \file check_wav.c Detect and delete a wav header. */
#include "buffer_tree.h"
#include "error.h"
#include "check_wav.h"
+#include "portable_io.h"
/** Length of a standard wav header. */
#define WAV_HEADER_LEN 44
+/** The possible states of a check_wav instance. */
enum check_wav_state {
+ /** Initial state, less than \p WAV_HEADER_LEN bytes available. */
CWS_NEED_HEADER,
+ /** Wav hader was detected. */
CWS_HAVE_HEADER,
+ /** First part of the stream did not look like a wav header. */
CWS_NO_HEADER,
};
unsigned sample_rate;
};
-void check_wav_pre_select(struct sched *s, struct check_wav_context *cwc)
+/**
+ * Request a minimal timeout if not idle.
+ *
+ * \param s The scheduler instance.
+ * \param cwc The buffer tree node is derived from this.
+ *
+ * If no data is available and the buffer tree node is not in error state, the
+ * function does nothing.
+ */
+void check_wav_pre_monitor(struct sched *s, struct check_wav_context *cwc)
{
int ret = btr_node_status(cwc->btrn, cwc->min_iqs, BTR_NT_INTERNAL);
if (ret != 0)
sched_min_delay(s);
}
-static int check_wav_exec(struct btr_node *btrn, const char *cmd, char **result)
+static int check_wav_exec(const struct btr_node *btrn, const char *cmd, char **result)
{
struct check_wav_context *cwc = btr_context(btrn);
int val, header_val, given, arg;
return 1;
}
-int check_wav_post_select(struct check_wav_context *cwc)
+/**
+ * Filter out the wav header, pushdown everything else.
+ *
+ * \param cwc The context of this instance.
+ *
+ * This function looks at the first \p WAV_HEADER_SIZE bytes of the input queue
+ * of the btrn of \a cwc. If they look like a wav header, the function extracts
+ * the information of interest and swallows this part of the stream. Otherwise
+ * it is pushed down to all children. In either case the rest of the input is
+ * pushed down as well.
+ *
+ * Once the first part has been processed this way, the state of the instance
+ * changes from \p CWS_NEED_HEADER to \p CWS_HAVE_HEADER or \p CWS_NO_HEADER.
+ *
+ * \return Standard.
+ */
+int check_wav_post_monitor(struct check_wav_context *cwc)
{
struct btr_node *btrn = cwc->btrn;
unsigned char *a;
size_t sz;
int ret;
- uint16_t bps; /* bits per sample */
+ uint16_t format_code, bps; /* bits per sample */
const char *sample_formats[] = {SAMPLE_FORMATS};
if (!btrn)
PARA_INFO_LOG("found wav header\n");
cwc->state = CWS_HAVE_HEADER;
/* Only set those values which have not already been set. */
- cwc->channels = (unsigned)a[22];
- cwc->sample_rate = a[24] + (a[25] << 8) + (a[26] << 16) + (a[27] << 24);
- bps = a[34] + ((unsigned)a[35] << 8);
- if (bps != 8 && bps != 16) {
+ cwc->channels = a[22];
+ format_code = read_u16(a + 20);
+ if (format_code != 1 && format_code != 3) {
+ cwc->state = CWS_NO_HEADER;
+ goto out;
+ }
+ cwc->sample_rate = read_u32(a + 24);
+ bps = read_u16(a + 34);
+ if (bps != 8 && bps != 16 && bps != 32) {
PARA_WARNING_LOG("%u bps not supported, assuming 16\n",
bps);
bps = 16;
}
+ if ((bps < 32 && format_code != 1) || (bps == 32 && format_code != 3)) {
+ PARA_WARNING_LOG("invalid bps/format_code (%u/%u)\n",
+ bps, format_code);
+ cwc->state = CWS_NO_HEADER;
+ goto out;
+ }
/*
* 8-bit samples are stored as unsigned bytes, ranging from 0
* to 255. 16-bit samples are stored as 2's-complement signed
*/
if (bps == 8)
cwc->sample_format = SF_U8;
- else
+ else if (bps == 16)
cwc->sample_format = (a[3] == 'F')?
SF_S16_LE : SF_S16_BE;
- PARA_NOTICE_LOG("%dHz, %s, %s\n", cwc->sample_rate,
+ else /* 32 bit */
+ cwc->sample_format = (a[3] == 'F')?
+ SF_FLOAT_LE : SF_FLOAT_BE;
+ PARA_NOTICE_LOG("%uHz, %s, %s\n", cwc->sample_rate,
cwc->channels == 1? "mono" : "stereo",
sample_formats[cwc->sample_format]);
btr_consume(btrn, WAV_HEADER_LEN);
return ret;
}
+/**
+ * Allocate and set up a new check_wav instance.
+ *
+ * \param parent This buffer tree node will be the parent of the new node.
+ * \param child The child of the new node.
+ * \param params Default values and options.
+ * \param cw_btrn A pointer to the check wav node is returned here.
+ *
+ * This function also sets up the ->execute handler of the btrn so that all
+ * children of this node can figure out channel count, sample rate, etc.
+ *
+ * \return The (opaque) handle of the newly created check_wav instance. It is
+ * supposed to be passed to \ref check_wav_pre_monitor() and \ref
+ * check_wav_post_monitor().
+ *
+ * \sa \ref btr_new_node.
+ */
struct check_wav_context *check_wav_init(struct btr_node *parent,
struct btr_node *child, struct wav_params *params,
struct btr_node **cw_btrn)
{
- struct check_wav_context *cwc = para_calloc(sizeof(*cwc));
+ struct check_wav_context *cwc = zalloc(sizeof(*cwc));
cwc->state = CWS_NEED_HEADER;
cwc->min_iqs = WAV_HEADER_LEN;
return cwc;
}
+/**
+ * Dellocate all ressources of a check_wav instance.
+ *
+ * \param cwc Determines the instance to shut down.
+ *
+ * This function may only be called after check_wav_post_monitor() has returned
+ * negative.
+ */
void check_wav_shutdown(struct check_wav_context *cwc)
{
free(cwc);
projects / paraslash.git / blobdiff