mpd/src/chunk.c

100 lines
2.6 KiB
C

/*
* Copyright (C) 2003-2009 The Music Player Daemon Project
* http://www.musicpd.org
*
* 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.
*/
#include "chunk.h"
#include "audio_format.h"
#include "tag.h"
#include <assert.h>
void
music_chunk_init(struct music_chunk *chunk)
{
chunk->length = 0;
chunk->tag = NULL;
}
void
music_chunk_free(struct music_chunk *chunk)
{
if (chunk->tag != NULL)
tag_free(chunk->tag);
}
#ifndef NDEBUG
bool
music_chunk_check_format(const struct music_chunk *chunk,
const struct audio_format *audio_format)
{
assert(chunk != NULL);
assert(audio_format != NULL);
assert(audio_format_valid(audio_format));
return chunk->length == 0 ||
audio_format_equals(&chunk->audio_format, audio_format);
}
#endif
void *
music_chunk_write(struct music_chunk *chunk,
const struct audio_format *audio_format,
float data_time, uint16_t bit_rate,
size_t *max_length_r)
{
const size_t frame_size = audio_format_frame_size(audio_format);
size_t num_frames;
assert(music_chunk_check_format(chunk, audio_format));
assert(chunk->length == 0 || audio_format_valid(&chunk->audio_format));
if (chunk->length == 0) {
/* if the chunk is empty, nobody has set bitRate and
times yet */
chunk->bit_rate = bit_rate;
chunk->times = data_time;
}
num_frames = (sizeof(chunk->data) - chunk->length) / frame_size;
if (num_frames == 0)
return NULL;
#ifndef NDEBUG
chunk->audio_format = *audio_format;
#endif
*max_length_r = num_frames * frame_size;
return chunk->data + chunk->length;
}
bool
music_chunk_expand(struct music_chunk *chunk,
const struct audio_format *audio_format, size_t length)
{
const size_t frame_size = audio_format_frame_size(audio_format);
assert(chunk != NULL);
assert(chunk->length + length <= sizeof(chunk->data));
assert(audio_format_equals(&chunk->audio_format, audio_format));
chunk->length += length;
return chunk->length + frame_size > sizeof(chunk->data);
}