axfer/frame-cache.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 //
   3 // frame-cache.c - maintainer of cache for data frame.
   4 //
   5 // Copyright (c) 2018 Takashi Sakamoto <o-takashi@sakamocchi.jp>
   6 //
   7 // Licensed under the terms of the GNU General Public License, version 2.
   8
   9 #include "frame-cache.h"
  10
  11 static void align_frames_in_i(struct frame_cache *cache,
  12                               unsigned int consumed_count)
  13 {
  14         char *buf = cache->buf;
  15         unsigned int offset;
  16         unsigned int size;
  17
  18         cache->remained_count -= consumed_count;
  19
  20         offset = cache->bytes_per_sample * cache->samples_per_frame *
  21                  consumed_count;
  22         size = cache->bytes_per_sample * cache->samples_per_frame *
  23                cache->remained_count;
  24         memmove(buf, buf + offset, size);
  25
  26         cache->buf_ptr = buf + size;
  27 }
  28
  29 static void align_frames_in_n(struct frame_cache *cache,
  30                               unsigned int consumed_count)
  31 {
  32         char **bufs = cache->buf;
  33         char **buf_ptrs = cache->buf_ptr;
  34         unsigned int offset;
  35         unsigned int size;
  36         int i;
  37
  38         cache->remained_count -= consumed_count;
  39
  40         for (i = 0; i < cache->samples_per_frame; ++i) {
  41                 offset = cache->bytes_per_sample * consumed_count;
  42                 size = cache->bytes_per_sample * cache->remained_count;
  43                 memmove(bufs[i], bufs[i] + offset, size);
  44                 buf_ptrs[i] = bufs[i] + size;
  45         }
  46 }
  47
  48 int frame_cache_init(struct frame_cache *cache, snd_pcm_access_t access,
  49                      unsigned int bytes_per_sample,
  50                      unsigned int samples_per_frame,
  51                      unsigned int frames_per_cache)
  52 {
  53         if (access == SND_PCM_ACCESS_RW_INTERLEAVED)
  54                 cache->align_frames = align_frames_in_i;
  55         else if (access == SND_PCM_ACCESS_RW_NONINTERLEAVED)
  56                 cache->align_frames = align_frames_in_n;
  57         else
  58                 return -EINVAL;
  59         cache->access = access;
  60
  61         if (access == SND_PCM_ACCESS_RW_INTERLEAVED) {
  62                 char *buf;
  63
  64                 buf = calloc(frames_per_cache,
  65                              bytes_per_sample * samples_per_frame);
  66                 if (buf == NULL)
  67                         return -ENOMEM;
  68                 cache->buf = buf;
  69                 cache->buf_ptr = buf;
  70         } else {
  71                 char **bufs;
  72                 char **buf_ptrs;
  73                 int i;
  74
  75                 bufs = calloc(samples_per_frame, sizeof(*bufs));
  76                 if (bufs == NULL)
  77                         return -ENOMEM;
  78                 buf_ptrs = calloc(samples_per_frame, sizeof(*buf_ptrs));
  79                 if (buf_ptrs == NULL)
  80                         return -ENOMEM;
  81                 for (i = 0; i < samples_per_frame; ++i) {
  82                         bufs[i] = calloc(frames_per_cache, bytes_per_sample);
  83                         if (bufs[i] == NULL)
  84                                 return -ENOMEM;
  85                         buf_ptrs[i] = bufs[i];
  86                 }
  87                 cache->buf = bufs;
  88                 cache->buf_ptr = buf_ptrs;
  89         }
  90
  91         cache->remained_count = 0;
  92         cache->bytes_per_sample = bytes_per_sample;
  93         cache->samples_per_frame = samples_per_frame;
  94         cache->frames_per_cache = frames_per_cache;
  95
  96         return 0;
  97 }
  98
  99 void frame_cache_destroy(struct frame_cache *cache)
 100 {
 101         if (cache->access == SND_PCM_ACCESS_RW_NONINTERLEAVED) {
 102                 int i;
 103                 for (i = 0; i < cache->samples_per_frame; ++i) {
 104                         char **bufs = cache->buf;
 105                         free(bufs[i]);
 106                 }
 107                 free(cache->buf_ptr);
 108         }
 109         free(cache->buf);
 110         memset(cache, 0, sizeof(*cache));
 111 }