camlib

This is a Picture Transfer Protocol (PTP) library written in C.

Documentation

Design

• Data parsing, packet building, and I/O is all done in a single buffer (grows as needed)
• Will not perform memory allocations between operations
• Thread safe (optional)
• Portable, works well on many different platforms
• No macros, API uses only C ABI
• Regression tested against https://github.com/petabyt/vcam

Checklist

• [x] Complete working implemention of PTP as per ISO 15740
• [x] Working PTP/IP implementation
• [x] Working natively on Linux, MacOS, Windows, and Android
• [x] Can convert most data structures to JSON
• [x] Camera liveviews
• [x] Implements most EOS/Canon vendor OCs
• [x] Optional lua bindings
• [x] Thread safe (optional)
• [x] Regression testing (vcam)
• [ ] Sony support
• [ ] Pentax support

Sample

Get device info:

#include <camlib.h>
 
int main() {
    struct PtpRuntime *r = ptp_new(PTP_USB);
 
    if (ptp_device_init(r)) {
        printf("Device connection error\n");
        return 0;
    }
 
    struct PtpDeviceInfo di;
 
    char buffer[2048];
    ptp_get_device_info(r, &di);
    ptp_device_info_json(&di, buffer, sizeof(buffer));
    printf("%s\n", buffer);
 
    ptp_device_close(r);
    ptp_close(r);
    return 0;
}

Calling a custom opcode:

// Send a command, and recieve packet(s)
struct PtpCommand cmd;
cmd.code = 0x1234;
cmd.param_length = 3;
cmd.params[0] = 420;
cmd.params[1] = 420;
cmd.params[2] = 420;
return ptp_send(r, &cmd);
 
// Send a command with data payload
struct PtpCommand cmd;
cmd.code = 0x1234;
cmd.param_length = 1;
cmd.params[0] = 1234;
uint32_t dat[2] = {123, 123};
return ptp_send_data(r, &cmd, dat, sizeof(dat));

Explore the filesystem:

struct PtpArray *arr;
int rc = ptp_get_storage_ids(r, &arr);
int id = arr->data[0];
free(arr);
rc = ptp_get_object_handles(r, id, PTP_OF_JPEG, 0, &arr);
 
for (int i = 0; i < arr->length; i++) {
    struct PtpObjectInfo oi;
    ptp_get_object_info(r, arr->data[i], &oi);
    printf("Filename: %s\n", oi.filename);
}
 
free(arr);

License

Camlib is licensed under the Apache License 2.0.
lua-cjson: http://tools.ietf.org/html/rfc4627 (MIT License)