我想创建 lirc 命令来停止录制。我有3个文件：
文件：record.c
...
#include "rec_tech.h"
...
void stop_rec_button_clicked_cb(GtkButton *button, gpointer data)
{
Recording *recording = data;
close_status_window();
recording_stop(recording);
}
...
文件：rec_tech.c
...
void recording_stop(Recording *recording)
{
g_assert(recording);
GstState state;
gst_element_get_state(recording->pipeline, &state, NULL, GST_CLOCK_TIME_NONE);
if (state != GST_STATE_PLAYING) {
GST_DEBUG ("pipeline in wrong state: %s", gst_element_state_get_name (state));
} else {
gst_element_set_state(recording->pipeline, GST_STATE_NULL);
}
gst_object_unref(GST_OBJECT(recording->pipeline));
g_free(recording->filename);
g_free(recording->station);
g_free(recording);
}
...
文件 rec_tech.h
...
#ifndef _REC_TECH_H
#define _REC_TECH_H
#include <gst/gst.h>
....
typedef struct {
GstElement* pipeline;
char* filename;
char* station;
} Recording;
Recording*
recording_start(const char* filename);
void
recording_stop(Recording* recording);
...
文件：lirc.c
...
#include <lirc/lirc_client.h>
#include "lirc.h"
#include "rec_tech.h"
#include "record.h"
static void execute_lirc_command (char *cmd)
{
printf("lirc command: %s\n", cmd);
if (strcasecmp (cmd, "stop recording") == 0) {
stop_rec_button_clicked_cb(NULL, data);
}
...
当我尝试编译文件 lirc.c 时出现错误
error: 'data' undeclared (first use in this function)
更新
如果在 lirc.c 添加行 Recording *data;
...
#include <lirc/lirc_client.h>
#include "lirc.h"
#include "rec_tech.h"
#include "record.h"
Recording *data;
static void execute_lirc_command (char *cmd)
{
printf("lirc command: %s\n", cmd);
if (strcasecmp (cmd, "stop recording") == 0) {
stop_rec_button_clicked_cb(NULL, data);
}
...
得到这个运行时错误：
ERROR:rec_tech.c:recording_stop: assertion failed: (recording)
为什么？