{
  "ok": true,
  "mode": "JS8",
  "tool": "webftr-js8-real-ldpc-matrix-syndrome-probe",
  "tool_version": "step51-source-aligned-tone-offset-cli-fix",
  "input_wav": null,
  "candidate_json": "/decoders/js8_decoder/runtime/timing_boundary_sweep/step51_source_aligned_best_timing_fec_candidate.json",
  "rx_only": true,
  "safety": {
    "tx": false,
    "ptt": false,
    "tune": false,
    "send": false,
    "js8call_runtime_control": false
  },
  "implementation_stage": "step43_bounded_gray_interleaver_matrix_ranking_no_message_unpack",
  "matrix": {
    "code": "(174,91) LDPC generator matrix",
    "generator_rows": 83,
    "generator_cols": 91,
    "message_bits": 91,
    "parity_bits": 83,
    "source_file": "ldpc_174_91_c_generator.f90"
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    "total_transform_rows_before_limit": 865,
    "max_rows": 72,
    "repair_rows": 10,
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        "tone_mapping": "ft8_gray_primary",
        "gray_direction": "inverse_observed_to_plain",
        "reverse_bits_within_tone_before_gray": true,
        "interleaver": "none",
        "polarity": "inverted"
      },
      "hard_weight_174": 127,
      "llr_avg_abs": 1.2983798793103447,
      "syndrome": {
        "bits_len": 174,
        "message91": "1111111001111111110011101101111000101111111000010011111111101110011001111111111011101111111",
        "parity83_observed": "11111001100111111110111111100001001100111100110111110111001111100001111110111111111",
        "parity83_expected": "10110001101001101110011110000001101010111101010101010001110111000111101100101000101",
        "syndrome83": "01001000001110010000100001100000100110000001100010100110111000100110010010010111010",
        "syndrome_weight": 31,
        "valid_codeword_hard_decision": false,
        "message91_sha256_16": "332fb0dabe874c89",
        "codeword174_sha256_16": "b69cc7a7a2c9cfc9"
      },
      "repair": {
        "attempted": false,
        "flip_count": 0,
        "repair_success": false,
        "final_syndrome_weight": 31,
        "trace": [],
        "repaired_message91_sha256_16": "332fb0dabe874c89"
      }
    },
    {
      "variant": "mapped_ft8_gray_primary_demap_msb_input+ft8_bitrev_deinterleave_rx_to_codeword",
      "transform": "ft8_gray_alt_high_demap_lsb_input+no_interleaver+inverted_bits",
      "mapping_meta": {
        "tone_mapping": "ft8_gray_alt_high",
        "gray_direction": "inverse_observed_to_plain",
        "reverse_bits_within_tone_before_gray": true,
        "interleaver": "none",
        "polarity": "inverted"
      },
      "hard_weight_174": 127,
      "llr_avg_abs": 1.2560504137931032,
      "syndrome": {
        "bits_len": 174,
        "message91": "1111111001111111110011101101111000101111111000010011111111101110011001111111111011101111111",
        "parity83_observed": "11111001100111111110111111100001001100111100110111110111001111100001111110111111111",
        "parity83_expected": "10110001101001101110011110000001101010111101010101010001110111000111101100101000101",
        "syndrome83": "01001000001110010000100001100000100110000001100010100110111000100110010010010111010",
        "syndrome_weight": 31,
        "valid_codeword_hard_decision": false,
        "message91_sha256_16": "332fb0dabe874c89",
        "codeword174_sha256_16": "b69cc7a7a2c9cfc9"
      },
      "repair": {
        "attempted": false,
        "flip_count": 0,
        "repair_success": false,
        "final_syndrome_weight": 31,
        "trace": [],
        "repaired_message91_sha256_16": "332fb0dabe874c89"
      }
    },
    {
      "variant": "mapped_ft8_gray_primary_demap_msb_input+ft8_bitrev_interleave_codeword_to_rx_inverse",
      "transform": "ft8_gray_alt_high_demap_lsb_input+ft8_bitrev_deinterleave_rx_to_codeword",
      "mapping_meta": {
        "tone_mapping": "ft8_gray_alt_high",
        "gray_direction": "inverse_observed_to_plain",
        "reverse_bits_within_tone_before_gray": true,
        "interleaver": "ft8_bitrev",
        "direction": "deinterleave_rx_to_codeword",
        "order_len": 174
      },
      "hard_weight_174": 37,
      "llr_avg_abs": 1.2423823563218392,
      "syndrome": {
        "bits_len": 174,
        "message91": "0100010011001000000000000111000000100000000000010001110000000010000000100000000000011000010",
        "parity83_observed": "01000000000010010010000000100010000110100011000011001010000000000001000000011000001",
        "parity83_expected": "01001001001001100010101001101110001000001011100010111111100001000101001010000000000",
        "syndrome83": "00001001001011110000101001001100001110101000100001110101100001000100001010011000001",
        "syndrome_weight": 31,
        "valid_codeword_hard_decision": false,
        "message91_sha256_16": "24f38de55dffa50e",
        "codeword174_sha256_16": "a5cef5b3b7fef29e"
      },
      "repair": {
        "attempted": false,
        "flip_count": 0,
        "repair_success": false,
        "final_syndrome_weight": 31,
        "trace": [],
        "repaired_message91_sha256_16": "24f38de55dffa50e"
      }
    },
    {
      "variant": "mapped_ft8_gray_alt_high_demap_msb_input+ft8_bitrev_deinterleave_rx_to_codeword",
      "transform": "ft8_gray_alt_high_demap_lsb_input+no_interleaver+inverted_bits",
      "mapping_meta": {
        "tone_mapping": "ft8_gray_alt_high",
        "gray_direction": "inverse_observed_to_plain",
        "reverse_bits_within_tone_before_gray": true,
        "interleaver": "none",
        "polarity": "inverted"
      },
      "hard_weight_174": 127,
      "llr_avg_abs": 1.217521729885057,
      "syndrome": {
        "bits_len": 174,
        "message91": "1111111001111111110011101101111000101111111000010011111111101110011001111111111011101111111",
        "parity83_observed": "11111001100111111110111111100001001100111100110111110111001111100001111110111111111",
        "parity83_expected": "10110001101001101110011110000001101010111101010101010001110111000111101100101000101",
        "syndrome83": "01001000001110010000100001100000100110000001100010100110111000100110010010010111010",
        "syndrome_weight": 31,
        "valid_codeword_hard_decision": false,
        "message91_sha256_16": "332fb0dabe874c89",
        "codeword174_sha256_16": "b69cc7a7a2c9cfc9"
      },
      "repair": {
        "attempted": false,
        "flip_count": 0,
        "repair_success": false,
        "final_syndrome_weight": 31,
        "trace": [],
        "repaired_message91_sha256_16": "332fb0dabe874c89"
      }
    },
    {
      "variant": "mapped_ft8_gray_primary_demap_lsb_input+ft8_bitrev_deinterleave_rx_to_codeword",
      "transform": "ft8_gray_primary_demap_msb_input+ft8_bitrev_interleave_codeword_to_rx_inverse",
      "mapping_meta": {
        "tone_mapping": "ft8_gray_primary",
        "gray_direction": "inverse_observed_to_plain",
        "reverse_bits_within_tone_before_gray": false,
        "interleaver": "ft8_bitrev",
        "direction": "interleave_codeword_to_rx_inverse",
        "order_len": 174
      },
      "hard_weight_174": 57,
      "llr_avg_abs": 1.208058896551724,
      "syndrome": {
        "bits_len": 174,
        "message91": "0010100010100001100000001000010000001000000010100010100000001111110000001001001011100101100",
        "parity83_observed": "00110000000100110100000010000100010000101101001010000101100110001000000100110111110",
        "parity83_expected": "01110111010100110100100110000000011111000100011001001110001010001011101100110010100",
        "syndrome83": "01000111010000000000100100000100001111101001010011001011101100000011101000000101010",
        "syndrome_weight": 31,
        "valid_codeword_hard_decision": false,
        "message91_sha256_16": "678915ad8b5b531e",
        "codeword174_sha256_16": "0bfb984669bc190f"
      },
      "repair": {
        "attempted": false,
        "flip_count": 0,
        "repair_success": false,
        "final_syndrome_weight": 31,
        "trace": [],
        "repaired_message91_sha256_16": "678915ad8b5b531e"
      }
    },
    {
      "variant": "mapped_ft8_gray_alt_high_demap_msb_input+ft8_bitrev_interleave_codeword_to_rx_inverse",
      "transform": "ft8_gray_alt_high_demap_lsb_input+ft8_bitrev_deinterleave_rx_to_codeword",
      "mapping_meta": {
        "tone_mapping": "ft8_gray_alt_high",
        "gray_direction": "inverse_observed_to_plain",
        "reverse_bits_within_tone_before_gray": true,
        "interleaver": "ft8_bitrev",
        "direction": "deinterleave_rx_to_codeword",
        "order_len": 174
      },
      "hard_weight_174": 37,
      "llr_avg_abs": 1.2055921379310346,
      "syndrome": {
        "bits_len": 174,
        "message91": "0100010011001000000000000111000000100000000000010001110000000010000000100000000000011000010",
        "parity83_observed": "01000000000010010010000000100010000110100011000011001010000000000001000000011000001",
        "parity83_expected": "01001001001001100010101001101110001000001011100010111111100001000101001010000000000",
        "syndrome83": "00001001001011110000101001001100001110101000100001110101100001000100001010011000001",
        "syndrome_weight": 31,
        "valid_codeword_hard_decision": false,
        "message91_sha256_16": "24f38de55dffa50e",
        "codeword174_sha256_16": "a5cef5b3b7fef29e"
      },
      "repair": {
        "attempted": false,
        "flip_count": 0,
        "repair_success": false,
        "final_syndrome_weight": 31,
        "trace": [],
        "repaired_message91_sha256_16": "24f38de55dffa50e"
      }
    },
    {
      "variant": "mapped_ft8_gray_alt_high_demap_lsb_input+ft8_bitrev_deinterleave_rx_to_codeword",
      "transform": "ft8_gray_primary_demap_msb_input+ft8_bitrev_interleave_codeword_to_rx_inverse",
      "mapping_meta": {
        "tone_mapping": "ft8_gray_primary",
        "gray_direction": "inverse_observed_to_plain",
        "reverse_bits_within_tone_before_gray": false,
        "interleaver": "ft8_bitrev",
        "direction": "interleave_codeword_to_rx_inverse",
        "order_len": 174
      },
      "hard_weight_174": 57,
      "llr_avg_abs": 1.1703414942528743,
      "syndrome": {
        "bits_len": 174,
        "message91": "0010100010100001100000001000010000001000000010100010100000001111110000001001001011100101100",
        "parity83_observed": "00110000000100110100000010000100010000101101001010000101100110001000000100110111110",
        "parity83_expected": "01110111010100110100100110000000011111000100011001001110001010001011101100110010100",
        "syndrome83": "01000111010000000000100100000100001111101001010011001011101100000011101000000101010",
        "syndrome_weight": 31,
        "valid_codeword_hard_decision": false,
        "message91_sha256_16": "678915ad8b5b531e",
        "codeword174_sha256_16": "0bfb984669bc190f"
      },
      "repair": {
        "attempted": false,
        "flip_count": 0,
        "repair_success": false,
        "final_syndrome_weight": 31,
        "trace": [],
        "repaired_message91_sha256_16": "678915ad8b5b531e"
      }
    },
    {
      "variant": "lsb_within_each_tone",
      "transform": "raw_msb+ft8_bitrev_deinterleave_rx_to_codeword",
      "mapping_meta": {
        "tone_mapping": "raw_msb",
        "interleaver": "ft8_bitrev",
        "direction": "deinterleave_rx_to_codeword",
        "order_len": 174
      },
      "hard_weight_174": 30,
      "llr_avg_abs": 2.2186752701149435,
      "syndrome": {
        "bits_len": 174,
        "message91": "0100000000000100011001000000000100000000000110000000001000000100000100010001001100000000001",
        "parity83_observed": "00001000000000010001100000010010001000010000000000110001010000100000000000000100000",
        "parity83_expected": "11010100100010100010111000111011101010000001011001100001100100010000100000001101000",
        "syndrome83": "11011100100010110011011000101001100010010001011001010000110100110000100000001001000",
        "syndrome_weight": 32,
        "valid_codeword_hard_decision": false,
        "message91_sha256_16": "770633de1c822554",
        "codeword174_sha256_16": "3605fe147cc4f9f8"
      },
      "repair": {
        "attempted": false,
        "flip_count": 0,
        "repair_success": false,
        "final_syndrome_weight": 32,
        "trace": [],
        "repaired_message91_sha256_16": "770633de1c822554"
      }
    },
    {
      "variant": "mapped_lsb_within_each_tone+ft8_bitrev_deinterleave_rx_to_codeword",
      "transform": "raw_msb+no_interleaver",
      "mapping_meta": {
        "tone_mapping": "raw_msb",
        "interleaver": "none"
      },
      "hard_weight_174": 30,
      "llr_avg_abs": 2.2186752701149435,
      "syndrome": {
        "bits_len": 174,
        "message91": "0100000000000100011001000000000100000000000110000000001000000100000100010001001100000000001",
        "parity83_observed": "00001000000000010001100000010010001000010000000000110001010000100000000000000100000",
        "parity83_expected": "11010100100010100010111000111011101010000001011001100001100100010000100000001101000",
        "syndrome83": "11011100100010110011011000101001100010010001011001010000110100110000100000001001000",
        "syndrome_weight": 32,
        "valid_codeword_hard_decision": false,
        "message91_sha256_16": "770633de1c822554",
        "codeword174_sha256_16": "3605fe147cc4f9f8"
      },
      "repair": {
        "attempted": false,
        "flip_count": 0,
        "repair_success": false,
        "final_syndrome_weight": 32,
        "trace": [],
        "repaired_message91_sha256_16": "770633de1c822554"
      }
    }
  ],
  "decodes": [],
  "outputs": {
    "ldpc_matrix_probe_json": "/decoders/js8_decoder/runtime/ldpc_matrix_probe/step43_ldpc_matrix_probe.json"
  },
  "warnings": [
    "Step 51 preserves the exact timing-sweep primary row in matrix ranking, then repairs only a bounded subset to avoid Raspberry Pi timeouts.",
    "This is still a diagnostic LDPC/FEC probe and does not unpack JS8 text yet.",
    "If best_matrix_probe reaches syndrome_weight 0, the next step can feed message91 into CRC/message unpack. Otherwise continue timing, symbol boundary, deinterleaver/order or LLR tuning using best mapping_meta."
  ],
  "next_action": "Upload Step35 logs. Inspect best_matrix_probe.mapping_meta and final_syndrome_weight; then either unpack message91 on syndrome 0 or continue bounded LDPC/timing tuning."
}