RetroArch/movie.c
2012-03-30 21:18:15 +02:00

235 lines
6.5 KiB
C

/* SSNES - A Super Nintendo Entertainment System (SNES) Emulator frontend for libsnes.
* Copyright (C) 2010-2012 - Hans-Kristian Arntzen
*
* Some code herein may be based on code found in BSNES.
*
* SSNES 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 Found-
* ation, either version 3 of the License, or (at your option) any later version.
*
* SSNES 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 SSNES.
* If not, see <http://www.gnu.org/licenses/>.
*/
#include "movie.h"
#include "hash.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "general.h"
#include "dynamic.h"
struct bsv_movie
{
FILE *file;
uint8_t *state;
size_t state_size;
size_t *frame_pos; // A ring buffer keeping track of positions in the file for each frame.
size_t frame_mask;
size_t frame_ptr;
bool playback;
size_t min_file_pos;
bool first_rewind;
bool did_rewind;
};
static bool init_playback(bsv_movie_t *handle, const char *path)
{
handle->playback = true;
handle->file = fopen(path, "rb");
if (!handle->file)
{
SSNES_ERR("Couldn't open BSV file \"%s\" for playback.\n", path);
return false;
}
uint32_t header[4] = {0};
if (fread(header, sizeof(uint32_t), 4, handle->file) != 4)
{
SSNES_ERR("Couldn't read movie header.\n");
return false;
}
// Compatibility with old implementation that used incorrect documentation.
if (swap_if_little32(header[MAGIC_INDEX]) != BSV_MAGIC && swap_if_big32(header[MAGIC_INDEX]) != BSV_MAGIC)
{
SSNES_ERR("Movie file is not a valid BSV1 file.\n");
return false;
}
if (swap_if_big32(header[CRC_INDEX]) != g_extern.cart_crc)
SSNES_WARN("CRC32 checksum mismatch between ROM file and saved ROM checksum in replay file header; replay highly likely to desync on playback.\n");
uint32_t state_size = swap_if_big32(header[STATE_SIZE_INDEX]);
if (state_size)
{
handle->state = (uint8_t*)malloc(state_size);
handle->state_size = state_size;
if (!handle->state)
return false;
if (fread(handle->state, 1, state_size, handle->file) != state_size)
{
SSNES_ERR("Couldn't read state from movie.\n");
return false;
}
if (psnes_serialize_size() == state_size)
psnes_unserialize(handle->state, state_size);
else
SSNES_WARN("Movie format seems to have a different serializer version. Will most likely fail.\n");
}
handle->min_file_pos = sizeof(header) + state_size;
return true;
}
static bool init_record(bsv_movie_t *handle, const char *path)
{
handle->file = fopen(path, "wb");
if (!handle->file)
{
SSNES_ERR("Couldn't open BSV \"%s\" for recording.\n", path);
return false;
}
uint32_t header[4] = {0};
// This value is supposed to show up as BSV1 in a HEX editor, big-endian.
header[MAGIC_INDEX] = swap_if_little32(BSV_MAGIC);
header[CRC_INDEX] = swap_if_big32(g_extern.cart_crc);
uint32_t state_size = psnes_serialize_size();
header[STATE_SIZE_INDEX] = swap_if_big32(state_size);
fwrite(header, 4, sizeof(uint32_t), handle->file);
handle->min_file_pos = sizeof(header) + state_size;
handle->state_size = state_size;
if (state_size)
{
handle->state = (uint8_t*)malloc(state_size);
if (!handle->state)
return false;
psnes_serialize(handle->state, state_size);
fwrite(handle->state, 1, state_size, handle->file);
}
return true;
}
void bsv_movie_free(bsv_movie_t *handle)
{
if (handle)
{
if (handle->file)
fclose(handle->file);
free(handle->state);
free(handle->frame_pos);
free(handle);
}
}
bool bsv_movie_get_input(bsv_movie_t *handle, int16_t *input)
{
if (fread(input, sizeof(int16_t), 1, handle->file) != 1)
return false;
*input = swap_if_big16(*input);
return true;
}
void bsv_movie_set_input(bsv_movie_t *handle, int16_t input)
{
input = swap_if_big16(input);
fwrite(&input, sizeof(int16_t), 1, handle->file);
}
bsv_movie_t *bsv_movie_init(const char *path, enum ssnes_movie_type type)
{
bsv_movie_t *handle = (bsv_movie_t*)calloc(1, sizeof(*handle));
if (!handle)
return NULL;
if (type == SSNES_MOVIE_PLAYBACK)
{
if (!init_playback(handle, path))
goto error;
}
else if (!init_record(handle, path))
goto error;
// Just pick something really large :D ~1 million frames rewind should do the trick.
if (!(handle->frame_pos = (size_t*)calloc((1 << 20), sizeof(size_t))))
goto error;
handle->frame_pos[0] = handle->min_file_pos;
handle->frame_mask = (1 << 20) - 1;
return handle;
error:
bsv_movie_free(handle);
return NULL;
}
void bsv_movie_set_frame_start(bsv_movie_t *handle)
{
handle->frame_pos[handle->frame_ptr] = ftell(handle->file);
}
void bsv_movie_set_frame_end(bsv_movie_t *handle)
{
handle->frame_ptr = (handle->frame_ptr + 1) & handle->frame_mask;
handle->first_rewind = !handle->did_rewind;
handle->did_rewind = false;
}
void bsv_movie_frame_rewind(bsv_movie_t *handle)
{
handle->did_rewind = true;
// If we're at the beginning ... :)
if ((handle->frame_ptr <= 1) && (handle->frame_pos[0] == handle->min_file_pos))
{
handle->frame_ptr = 0;
fseek(handle->file, handle->min_file_pos, SEEK_SET);
}
else
{
// First time rewind is performed, the old frame is simply replayed.
// However, playing back that frame caused us to read data, and push data to the ring buffer.
// Sucessively rewinding frames, we need to rewind past the read data, plus another.
handle->frame_ptr = (handle->frame_ptr - (handle->first_rewind ? 1 : 2)) & handle->frame_mask;
fseek(handle->file, handle->frame_pos[handle->frame_ptr], SEEK_SET);
}
// We rewound past the beginning. :O
if (ftell(handle->file) <= (long)handle->min_file_pos)
{
// If recording, we simply reset the starting point. Nice and easy.
if (!handle->playback)
{
fseek(handle->file, 4 * sizeof(uint32_t), SEEK_SET);
psnes_serialize(handle->state, handle->state_size);
fwrite(handle->state, 1, handle->state_size, handle->file);
}
else
fseek(handle->file, handle->min_file_pos, SEEK_SET);
}
}