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/*-*- mode:c;indent-tabs-mode:t;c-basic-offset:4;tab-width:4;coding:utf-8 -*-│
│vi: set et ft=c ts=4 sw=4 fenc=utf-8 :vi│
╞══════════════════════════════════════════════════════════════════════════════╡
│ PL_MPEG - MPEG1 Video decoder, MP2 Audio decoder, MPEG-PS demuxer │
│ Dominic Szablewski - https://phoboslab.org │
│ │
│ The MIT License(MIT) │
│ Copyright(c) 2019 Dominic Szablewski │
│ │
│ 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 "dsp/mpeg/buffer.h"
#include "dsp/mpeg/mpeg.h"
#include "libc/calls/calls.h"
#include "libc/log/check.h"
#include "libc/mem/mem.h"
#include "libc/stdio/stdio.h"
#include "libc/str/str.h"
#include "libc/sysv/consts/madv.h"
asm(".ident\t\"\\n\\n\
PL_MPEG (MIT License)\\n\
Copyright(c) 2019 Dominic Szablewski\\n\
https://phoboslab.org\"");
asm(".include \"libc/disclaimer.inc\"");
/* clang-format off */
// -----------------------------------------------------------------------------
// plm_buffer implementation
plm_buffer_t *plm_buffer_create_with_filename(const char *filename) {
FILE *fh = fopen(filename, "rb");
if (!fh) {
return NULL;
}
fadvise(fileno(fh), 0, 0, MADV_SEQUENTIAL);
return plm_buffer_create_with_file(fh, true);
}
plm_buffer_t *plm_buffer_create_with_file(FILE *fh, int close_when_done) {
plm_buffer_t *b;
b = plm_buffer_create_with_capacity(PLM_BUFFER_DEFAULT_SIZE);
b->fh = fh;
b->close_when_done = close_when_done;
b->mode = PLM_BUFFER_MODE_FILE;
plm_buffer_set_load_callback(b, plm_buffer_load_file_callback, NULL);
return b;
}
plm_buffer_t *plm_buffer_create_with_memory(unsigned char *bytes, size_t length, int free_when_done) {
plm_buffer_t *b;
b = memalign(alignof(plm_buffer_t), sizeof(plm_buffer_t));
memset(b, 0, sizeof(plm_buffer_t));
b->capacity = length;
b->length = length;
b->free_when_done = free_when_done;
b->bytes = bytes;
b->mode = PLM_BUFFER_MODE_FIXED_MEM;
return b;
}
plm_buffer_t * plm_buffer_create_with_capacity(size_t capacity) {
plm_buffer_t *b;
b = memalign(alignof(plm_buffer_t), sizeof(plm_buffer_t));
memset(b, 0, sizeof(plm_buffer_t));
b->capacity = capacity;
b->free_when_done = true;
b->bytes = (unsigned char *)malloc(capacity);
b->mode = PLM_BUFFER_MODE_DYNAMIC_MEM;
return b;
}
void plm_buffer_destroy(plm_buffer_t *self) {
if (self->fh && self->close_when_done) {
fclose(self->fh);
}
if (self->free_when_done) {
free(self->bytes);
}
free(self);
}
size_t plm_buffer_write(plm_buffer_t *self, unsigned char *bytes, size_t length) {
if (self->mode == PLM_BUFFER_MODE_FIXED_MEM) {
return 0;
}
// This should be a ring buffer, but instead it just shifts all unread data
// to the beginning of the buffer and appends new data at the end. Seems
// to be good enough.
plm_buffer_discard_read_bytes(self);
// Do we have to resize to fit the new data?
size_t bytes_available = self->capacity - self->length;
if (bytes_available < length) {
size_t new_size = self->capacity;
do {
new_size *= 2;
} while (new_size - self->length < length);
self->bytes = (unsigned char *)realloc(self->bytes, new_size);
self->capacity = new_size;
}
memcpy(self->bytes + self->length, bytes, length);
self->length += length;
return length;
}
void plm_buffer_set_load_callback(plm_buffer_t *self, plm_buffer_load_callback fp, void *user) {
self->load_callback = fp;
self->load_callback_user_data = user;
}
void plm_buffer_rewind(plm_buffer_t *self) {
if (self->fh) {
fseek(self->fh, 0, SEEK_SET);
self->length = 0;
}
if (self->mode != PLM_BUFFER_MODE_FIXED_MEM) {
self->length = 0;
}
self->bit_index = 0;
}
void plm_buffer_discard_read_bytes(plm_buffer_t *self) {
size_t byte_pos = self->bit_index >> 3;
if (byte_pos == self->length) {
self->bit_index = 0;
self->length = 0;
}
else if (byte_pos > 0) {
memmove(self->bytes, self->bytes + byte_pos, self->length - byte_pos);
self->bit_index -= byte_pos << 3;
self->length -= byte_pos;
}
}
void plm_buffer_load_file_callback(plm_buffer_t *self, void *user) {
plm_buffer_discard_read_bytes(self);
unsigned bytes_available = self->capacity - self->length;
unsigned bytes_read = fread(self->bytes + self->length, 1, bytes_available, self->fh);
self->length += bytes_read;
}