src/pcm_sint16_converter.c

   1 /*
   2  * Copyright (C) 2013 nu774
   3  * For conditions of distribution and use, see copyright notice in COPYING
   4  */
   5 #if HAVE_CONFIG_H
   6 #  include "config.h"
   7 #endif
   8 #include <stdlib.h>
   9 #include <string.h>
  10 #if HAVE_STDINT_H
  11 #  include <stdint.h>
  12 #endif
  13 #include "pcm_reader.h"
  14
  15 typedef struct pcm_sint16_converter_t {
  16     pcm_reader_vtbl_t *vtbl;
  17     pcm_reader_t *src;
  18     pcm_sample_description_t format;
  19     void *pivot;
  20     unsigned capacity;
  21 } pcm_sint16_converter_t;
  22
  23 static inline pcm_reader_t *get_source(pcm_reader_t *reader)
  24 {
  25     return ((pcm_sint16_converter_t *)reader)->src;
  26 }
  27
  28 static const
  29 pcm_sample_description_t *get_format(pcm_reader_t *reader)
  30 {
  31     return &((pcm_sint16_converter_t *)reader)->format;
  32 }
  33
  34 static int64_t get_length(pcm_reader_t *reader)
  35 {
  36     return pcm_get_length(get_source(reader));
  37 }
  38
  39 static int64_t get_position(pcm_reader_t *reader)
  40 {
  41     return pcm_get_position(get_source(reader));
  42 }
  43
  44 static int read_frames(pcm_reader_t *reader, void *buffer, unsigned nframes)
  45 {
  46     pcm_sint16_converter_t *self = (pcm_sint16_converter_t *)reader;
  47     const pcm_sample_description_t *sfmt = pcm_get_format(self->src);
  48     unsigned bytes = nframes * sfmt->bytes_per_frame;
  49
  50     if (self->capacity < bytes) {
  51         void *p = realloc(self->pivot, bytes);
  52         if (!p) return -1;
  53         self->pivot = p;
  54         self->capacity = bytes;
  55     }
  56     nframes = pcm_read_frames(self->src, self->pivot, nframes);
  57     if (pcm_convert_to_native_sint16(sfmt, self->pivot, nframes, buffer) < 0)
  58         return -1;
  59     return nframes;
  60 }
  61
  62 static void teardown(pcm_reader_t **reader)
  63 {
  64     pcm_sint16_converter_t *self = (pcm_sint16_converter_t *)*reader;
  65     pcm_teardown(&self->src);
  66     free(self->pivot);
  67     free(self);
  68     *reader = 0;
  69 }
  70
  71 static pcm_reader_vtbl_t my_vtable = {
  72     get_format, get_length, get_position, read_frames, teardown
  73 };
  74
  75 pcm_reader_t *pcm_open_sint16_converter(pcm_reader_t *reader)
  76 {
  77     pcm_sint16_converter_t *self = 0;
  78     pcm_sample_description_t *fmt;
  79
  80     if ((self = calloc(1, sizeof(pcm_sint16_converter_t))) == 0)
  81         return 0;
  82     self->src = reader;
  83     self->vtbl = &my_vtable;
  84     memcpy(&self->format, pcm_get_format(reader), sizeof(self->format));
  85     fmt = &self->format;
  86 #if WORDS_BIGENDIAN
  87     fmt->sample_type = PCM_TYPE_SINT_BE;
  88 #else
  89     fmt->sample_type = PCM_TYPE_SINT;
  90 #endif
  91     fmt->bits_per_channel = 16;
  92     fmt->bytes_per_frame = 2 * fmt->channels_per_frame;
  93     return (pcm_reader_t *)self;
  94 }