Downloading Image to a specific folder using gp_filesystem_get_file() - libgphoto2

Question

Trying my hands on libgphoto2 library examples and while going through simple-capture.c file. Can i download foo.jpg captured image to a specified folder on my computer?
As far as i understood, in capture_to_file() camera_file_path.folder is the folder in which the file can be found on the camera. So open() should specify the host(computer) location. But nothing worked, i get following error:
You need to specify a folder starting with /store_xxxxxxxxx/
Am i missing something here? Any help would be appreciated, thanks!

Answer 1

I got this working.
Written small application for multiple cameras. Including main() for about question.
int main(int argc, char **argv)
{
CameraList *list;
Camera **cams;
int retval, count, i;
GPContext *context;
FILE *f;
char *data;
unsigned long size;
const char *name, *value;
/*
* Create context
*/
context = sample_create_context();
/*
* Setup Images DB directory.
*/
char* home = getenv("HOME");
if (home == NULL)
{
printf("Error: Unable to fetch home env! \n");
exit(1);
}
char* path = "/Desktop/mw/";
size_t len = strlen(home) + strlen(path) + 1;
char* imgdb = malloc(len);
if (imgdb == NULL)
{
printf("Error: Unable to malloc(). \n");
exit(1);
}
strcpy(imgdb, home);
strcat(imgdb, path);
directory_exists_or_create(imgdb);
/*
* Logs
*/
gp_log_add_func(GP_LOG_ERROR, errordumper, NULL);
/*
* Detect all the cameras that can be autodetected
*/
retval = gp_list_new(&list);
if (retval < GP_OK)
{
printf("Unable to create camera list.\n");
return 1;
}
count = sample_autodetect(list, context);
if (count < GP_OK)
{
printf("No cameras detected.\n");
return 1;
}
/*
* Now open all the cameras we autodetected for usage.
*/
printf("Number of cameras: %d\n", count);
cams = calloc(sizeof(Camera*), count);
for (i = 0; i < count; i++)
{
gp_list_get_name(list, i, &name);
gp_list_get_value(list, i, &value);
retval = sample_open_camera(&cams[i], name, value, context);
if (retval < GP_OK)
{
fprintf(stderr, "Camera %s on port %s failed to open\n", name, value);
}
}
if (argc > 0)
{
while ((++argv)[0])
{
if (argv[0][0] == '-')
{
switch (argv[0][1])
{
case 'h':
case 'H':
{
/* Now call a simple function in each of those cameras. */
for (i = 0; i < count; i++)
{
CameraText text;
char *owner;
retval = gp_camera_get_summary (cams[i], &text, context);
if (retval < GP_OK)
{
fprintf (stderr, "Failed to get summary.\n");
continue;
}
gp_list_get_name (list, i, &name);
gp_list_get_value (list, i, &value);
printf("%-30s %-16s\n", name, value);
printf("Summary:\n%s\n", text.text);
/* Query a simple string configuration variable. */
retval = get_config_value_string (cams[i], "owner", &owner, context);
if (retval >= GP_OK)
{
printf("Owner: %s\n", owner);
free (owner);
}
else
{
printf("Owner: No owner found.\n");
}
}
}
/* Graceful exit from the program */
goto exit_;;
default:
printf("Unknown option -%c\n\n", argv[0][1]);
break;
}
}
}
}
/* When I set GP_LOG_DEBUG instead of GP_LOG_ERROR above, I noticed that the
* init function seems to traverse the entire filesystem on the camera. This
* is partly why it takes so long.
* (Marcus: the ptp2 driver does this by default currently.)
*/
printf("Cameras init. Takes about 10 seconds each.\n");
for (i = 0; i < count; i++)
{
retval = gp_camera_init(cams[i], context);
if (retval != GP_OK)
{
printf(" Camera [%d] init failed with retval %d\n", i, retval);
exit (1);
}
}
printf(" ----------------\n");
printf(" Sampler is ready \n");
printf(" ----------------\n");
printf("Usage : \n");
printf(" ESC - Exit the program\n");
printf(" i/I - Insert new product barcode manually\n");
#if defined(BARCODE_ENABLED)
printf(" b/B - Insert new product barcode using barcode-scanner\n");
#endif
char get_key;
char exit_key = 0;
char bcr_buf[128] = {0};
int hemispheres_counts = 0;
int rotar_steps = 0;
do
{
get_key = getchar();
switch (get_key)
{
// Gracefull Exit
case _ESC_:
exit_key = 1;
break;
// Manual insert mode
case 'i':
case 'I':
printf("ACTION: Type in the name.\n");
scanf("%128s", bcr_buf);
process:
press_enter();
printf("ACTION: Shall we start? press return key.\n");
press_enter();
hemispheres_counts = 0;
rotar_steps = 0;
char product_filename[256] = {0};
strcpy(product_filename, imgdb);
strcat(product_filename, bcr_buf);
if (directory_exists_or_create(product_filename))
{
printf("\n\n!!! ATTENTION: The product already exists !!!\n\n");
printf("\nEnter options:\n");
printf(" ESC - Exit the program\n");
printf(" i/I - Insert new product barcode manually\n");
#if defined(BARCODE_ENABLED)
printf(" b/B - Insert new product barcode using barcode-scanner\n");
#endif
break;
}
while (hemispheres_counts < MAX_HEMISPHERES)
{
while (rotar_steps < MAX_ROTAR_STEPS)
{
for (i = 0; i < count; i++)
{
capture_to_memory(cams[i], context, (const char**)&data, &size);
char fname[64] = {0};
char mk_filename[256] = {0};
strcpy(mk_filename, product_filename);
snprintf(fname, sizeof(fname), "/%d-%d-%d.jpg", i, hemispheres_counts, rotar_steps);
strcat(mk_filename, fname);
printf("file name %s\n", mk_filename);
f = fopen(mk_filename, "wb");
if (f)
{
retval = fwrite (data, size, 1, f);
if (retval != size)
{
printf(" fwrite size %ld, written %d\n", size, retval);
}
fclose(f);
}
else
{
printf(" fopen *.jpg failed. %s\n", strerror(errno));
}
usleep(500*1000);
}
rotar_steps++;
}
rotar_steps = 0;
hemispheres_counts++;
if (hemispheres_counts < MAX_HEMISPHERES)
{
printf("Flip the product and hit 'RETURN' key\n");
press_enter(); // This expect some input from user, thats it.
printf("Started capturing other hemisphere!\n");
} else {
printf("Sampling Done for barcode: %s\n", bcr_buf);
printf(" -------------------------------------\n");
printf("\nEnter options:\n");
printf(" ESC - Exit the program\n");
printf(" i/I - Insert new product barcode manually\n");
#if defined(BARCODE_ENABLED)
printf(" b/B - Insert new product barcode using barcode-scanner\n");
#endif
break;
}
}
break;
}
} while (exit_key != 1);
exit_:
/*
* Release all the resources.
*/
printf("\nReleasing all the resources ... \n");
for (i = 0; i < count; i++)
{
gp_camera_exit(cams[i], context);
}
if (cams) {
free(cams);
}
free(imgdb);
#if defined(BARCODE_ENABLED)
close_bcr();
#endif
printf("Done.\n");
return 0;
}