src/pcm_sint16_converter.c

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