#include "module_geoscan_decoder.h" #include "common/utils.h" #include "imgui/imgui.h" #include "logger.h" #include "../common/scrambling.h" #include namespace geoscan { GEOSCANDecoderModule::GEOSCANDecoderModule(std::string input_file, std::string output_file_hint, nlohmann::json parameters) : satdump::pipeline::base::FileStreamToFileStreamModule(input_file, output_file_hint, parameters), d_frame_length(parameters["frame_length"].get()), d_thresold(parameters["thresold"].get()) { input_buffer = new int8_t[256]; deframer = std::make_unique(0x930B51DE, 32, (int)((d_frame_length + 4) * 8), d_thresold, false, true); fsfsm_file_ext = ".frm"; } GEOSCANDecoderModule::~GEOSCANDecoderModule() { delete[] input_buffer; } const uint8_t *GEOSCANDecoderModule::PN9_MASK_Generator() { uint8_t mask[8192] = {0}; uint16_t buffer = 0x1FF; uint8_t xor_state = 0; uint8_t *mask_bytes = (uint8_t *)malloc(1024 * sizeof(uint8_t)); memset(mask_bytes, 0, 1024); for (int i = 0; i < 8192; i++) { mask[i] = buffer & 0b1; xor_state = (buffer & 0b1) ^ (buffer >> 5 & 0b1); if (xor_state) { buffer = (buffer >> 1) | 0x0100; } else { buffer = (buffer >> 1); } } for (int i = 0; i < 1024; i++) { for (int j = 0; j < 8; j++) { mask_bytes[i] |= (mask[i * 8 + j] & 0x01) << (0 + j); } } return mask_bytes; } void GEOSCANDecoderModule::process() { const uint8_t *pn9_scrambling = GEOSCANDecoderModule::PN9_MASK_Generator(); while (should_run()) { // Read buffer read_data((uint8_t *)input_buffer, 256); auto frames = deframer->work((uint8_t *)input_buffer, 256 / 8); for (auto &framebuf : frames) { for (int i = 0; i < (int)d_frame_length; i++) framebuf[4 + i] ^= pn9_scrambling[i]; uint16_t crc_frm1 = crc_check.compute(&framebuf[4], (int)(d_frame_length - 2)); uint16_t crc_frm2 = framebuf[4 + (int)(d_frame_length - 2) + 0] << 8 | framebuf[4 + (int)(d_frame_length - 2) + 1]; if (crc_frm1 == crc_frm2) { write_data((uint8_t *)framebuf.data(), framebuf.size()); frm_cnt++; } } } logger->info("Decoding finished"); cleanup(); } nlohmann::json GEOSCANDecoderModule::getModuleStats() { auto v = satdump::pipeline::base::FileStreamToFileStreamModule::getModuleStats(); v["frm_cnt"] = frm_cnt; return v; } void GEOSCANDecoderModule::drawUI(bool window) { ImGui::Begin("GEOSCAN Decoder", NULL, window ? 0 : NOWINDOW_FLAGS); ImGui::Button("Deframer", {200 * ui_scale, 20 * ui_scale}); { ImGui::Text("Frames : "); ImGui::SameLine(); ImGui::TextColored(style::theme.green, UITO_C_STR(frm_cnt)); } drawProgressBar(); ImGui::End(); } std::string GEOSCANDecoderModule::getID() { return "geoscan_decoder"; } std::shared_ptr GEOSCANDecoderModule::getInstance(std::string input_file, std::string output_file_hint, nlohmann::json parameters) { return std::make_shared(input_file, output_file_hint, parameters); } } // namespace geoscan