z80em.c

/* z80em.c: Routines for handling Z80Em raw audio files
   Copyright (c) 2015 Stuart Brady
   Copyright (c) 2002 Darren Salt
   Based on tap.c, copyright (c) 2001 Philip Kendall

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License along
   with this program; if not, write to the Free Software Foundation, Inc.,
   51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.

   Author contact information:

   E-mail: linux@youmustbejoking.demon.co.uk

*/

#include <config.h>
#include <string.h>

#include "internals.h"
#include "tape_block.h"


libspectrum_error libspectrum_z80em_read(libspectrum_tape *tape, const libspectrum_byte *buffer, size_t length)
{
    libspectrum_tape_block *block;
    libspectrum_tape_rle_pulse_block *z80em_block;

    static const char id[] = "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0"
                             "\0\0\0\0\0\0\0\0\0\0Raw tape sample";

    if (length < sizeof(id)) {
        libspectrum_print_error(LIBSPECTRUM_ERROR_CORRUPT, "libspectrum_z80em_read: not enough data in buffer");
        return LIBSPECTRUM_ERROR_CORRUPT;
    }

    if (memcmp(id, buffer, sizeof(id))) {
        libspectrum_print_error(LIBSPECTRUM_ERROR_SIGNATURE, "libspectrum_z80em_read: wrong signature");
        return LIBSPECTRUM_ERROR_SIGNATURE;
    }

    block = libspectrum_tape_block_alloc(LIBSPECTRUM_TAPE_BLOCK_RLE_PULSE);

    z80em_block = &block->types.rle_pulse;
    z80em_block->scale = 7; // 1 time unit == 7 clock ticks

    buffer += sizeof(id);
    length -= sizeof(id);

    // Claim memory for the data (it's one big lump)
    z80em_block->length = length;
    z80em_block->data = libspectrum_new(libspectrum_byte, length);

    // Copy the data across
    memcpy(z80em_block->data, buffer, length);

    libspectrum_tape_append_block(tape, block);

    return LIBSPECTRUM_ERROR_NONE;
}