srnx2rnx.c

/** srnx2rnx.c - Succinct RINEX decompressor.
 * Copyright 2020 Michael Poole.
 *
 * Permission is hereby granted, free of charge, to any person
 * obtaining a copy of this software and associated documentation
 * files (the "Software"), to deal in the Software without
 * restriction, including without limitation the rights to use, copy,
 * modify, merge, publish, distribute, sublicense, and/or sell copies
 * of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>

/* SRNX reading functions:
 * - Open file.
 * - Read RINEX header.
 * - Decompress all epochs.
 * - Retrieve list of satellites observed.
 * - Decompress a given satellite's signals.
 *   - Select signals by name and/or index.
 *   - Conditionally omit the LLI and/or SSI.
 * - Read a signal value-by-value.
 * - Read next special event record (?).
 *
 * Internal state:
 * - RINEX header version (2 vs 3).
 * - Cached signal directory (two offsets, arrays of SV name + offset).
 * - For each satellite system, number and names of signals.
 * - For per-signal reader: Cache of up to 256 observation values,
 *   along with SSI and LLI.  Size of, and index into, array.  File
 *   offset of next block.  Delta decoder state.
 * - For event reader: Buffer of event contents, file offset of next
 *   block to consider.
 *
 * Decompression algorithm:
 * - Load and decompress epochs.
 * - Load the next special event record.
 * - For each epoch:
 *   - If epoch RLE count > 0, increment epoch timestamp, else read next
 *     epoch RLE run.
 *   - Emit any special events before this record.
 *   - Find satellites with observations in this epoch, along with
 *     their observation values.
 *   - Emit the epoch record.
 */

int main(int argc, char *argv[])
{
    struct srnx_reader *srnx;
    int err;

    return EXIT_FAILURE;
}