alsa-utils/axfer/frame-cache.c

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// SPDX-License-Identifier: GPL-2.0
//
// frame-cache.c - maintainer of cache for data frame.
//
// Copyright (c) 2018 Takashi Sakamoto <o-takashi@sakamocchi.jp>
//
// Licensed under the terms of the GNU General Public License, version 2.
#include "frame-cache.h"
static void align_frames_in_i(struct frame_cache *cache,
unsigned int consumed_count)
{
char *buf = cache->buf;
unsigned int offset;
unsigned int size;
cache->remained_count -= consumed_count;
offset = cache->bytes_per_sample * cache->samples_per_frame *
consumed_count;
size = cache->bytes_per_sample * cache->samples_per_frame *
cache->remained_count;
memmove(buf, buf + offset, size);
cache->buf_ptr = buf + size;
}
static void align_frames_in_n(struct frame_cache *cache,
unsigned int consumed_count)
{
char **bufs = cache->buf;
char **buf_ptrs = cache->buf_ptr;
unsigned int offset;
unsigned int size;
int i;
cache->remained_count -= consumed_count;
for (i = 0; i < cache->samples_per_frame; ++i) {
offset = cache->bytes_per_sample * consumed_count;
size = cache->bytes_per_sample * cache->remained_count;
memmove(bufs[i], bufs[i] + offset, size);
buf_ptrs[i] = bufs[i] + size;
}
}
int frame_cache_init(struct frame_cache *cache, snd_pcm_access_t access,
unsigned int bytes_per_sample,
unsigned int samples_per_frame,
unsigned int frames_per_cache)
{
cache->access = access;
cache->remained_count = 0;
cache->bytes_per_sample = bytes_per_sample;
cache->samples_per_frame = samples_per_frame;
cache->frames_per_cache = frames_per_cache;
if (access == SND_PCM_ACCESS_RW_INTERLEAVED)
cache->align_frames = align_frames_in_i;
else if (access == SND_PCM_ACCESS_RW_NONINTERLEAVED)
cache->align_frames = align_frames_in_n;
else
return -EINVAL;
if (access == SND_PCM_ACCESS_RW_INTERLEAVED) {
char *buf;
buf = calloc(frames_per_cache,
bytes_per_sample * samples_per_frame);
if (buf == NULL)
goto nomem;
cache->buf = buf;
cache->buf_ptr = buf;
} else {
char **bufs = calloc(samples_per_frame, sizeof(*bufs));
char **buf_ptrs = calloc(samples_per_frame, sizeof(*buf_ptrs));
int i;
cache->buf = bufs;
cache->buf_ptr = buf_ptrs;
if (bufs == NULL || buf_ptrs == NULL)
goto nomem;
for (i = 0; i < samples_per_frame; ++i) {
bufs[i] = calloc(frames_per_cache, bytes_per_sample);
if (bufs[i] == NULL)
goto nomem;
buf_ptrs[i] = bufs[i];
}
}
return 0;
nomem:
frame_cache_destroy(cache);
return -ENOMEM;
}
void frame_cache_destroy(struct frame_cache *cache)
{
if (cache->access == SND_PCM_ACCESS_RW_NONINTERLEAVED) {
char **bufs = cache->buf;
if (bufs) {
int i;
for (i = 0; i < cache->samples_per_frame; ++i)
free(bufs[i]);
}
free(cache->buf_ptr);
}
free(cache->buf);
memset(cache, 0, sizeof(*cache));
}