source/modules/audio_decoder/ad_dr_mp3.c

   1 /**
   2    Copyright (C) 2011-2013 Robin Gareus <robin@gareus.org>
   3    Copyright (C) 2014-2023 Filipe Coelho <falktx@falktx.com>
   4
   5    This program is free software; you can redistribute it and/or modify
   6    it under the terms of the GNU Lesser Public License as published by
   7    the Free Software Foundation; either version 2.1, or (at your option)
   8    any later version.
   9
  10    This program is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13    GNU Lesser Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with this library; if not, write to the Free Software
  17    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  18
  19 */
  20
  21 #include <stdio.h>
  22 #include <stdlib.h>
  23 #include <string.h>
  24 #include <math.h>
  25
  26 #include "ad_plugin.h"
  27
  28 #define DR_MP3_FLOAT_OUTPUT
  29 #define DR_MP3_IMPLEMENTATION
  30 #define DRMP3_DATA_CHUNK_SIZE DRMP3_MIN_DATA_CHUNK_SIZE*40
  31 #include "dr_mp3.h"
  32
  33 /* internal abstraction */
  34
  35 #define DR_MP3_MAX_SEEK_POINTS 500
  36
  37 #ifdef _MSC_VER
  38 #define strcasecmp stricmp
  39 #endif
  40
  41 typedef struct {
  42         drmp3 mp3;
  43         drmp3_seek_point seekPoints[DR_MP3_MAX_SEEK_POINTS];
  44 } drmp3_audio_decoder;
  45
  46 static int ad_info_dr_mp3(void *sf, struct adinfo *nfo) {
  47         drmp3_audio_decoder *priv = (drmp3_audio_decoder*) sf;
  48         if (!priv) return -1;
  49         if (nfo) {
  50                 nfo->channels = priv->mp3.channels;
  51                 nfo->frames = drmp3_get_pcm_frame_count(&priv->mp3);
  52                 nfo->sample_rate = priv->mp3.sampleRate;
  53                 nfo->length = nfo->sample_rate ? (nfo->frames * 1000) / nfo->sample_rate : 0;
  54                 nfo->bit_depth = 16;
  55                 nfo->bit_rate = priv->mp3.frameInfo.bitrate_kbps * 1000;
  56                 nfo->meta_data = NULL;
  57                 nfo->can_seek = 1;
  58         }
  59         return 0;
  60 }
  61
  62 static void *ad_open_dr_mp3(const char *filename, struct adinfo *nfo) {
  63         drmp3_audio_decoder *priv = (drmp3_audio_decoder*)calloc (1, sizeof(drmp3_audio_decoder));
  64         drmp3_bool32 res = drmp3_init_file(&priv->mp3, filename, NULL);
  65         if (res == DRMP3_FALSE) {
  66                 dbg(0, "unable to open file '%s'.", filename);
  67                 free (priv);
  68                 return NULL;
  69         }
  70         drmp3_uint32 seekPointCount = DR_MP3_MAX_SEEK_POINTS;
  71         drmp3_calculate_seek_points (&priv->mp3, &seekPointCount, priv->seekPoints);
  72         drmp3_bind_seek_table (&priv->mp3, seekPointCount, priv->seekPoints);
  73         ad_info_dr_mp3 (priv, nfo);
  74         return (void*) priv;
  75 }
  76
  77 static int ad_close_dr_mp3(void *sf) {
  78         drmp3_audio_decoder *priv = (drmp3_audio_decoder*) sf;
  79         if (!priv) return -1;
  80         if (!sf) {
  81                 dbg (0, "fatal: bad file close.\n");
  82                 return -1;
  83         }
  84         drmp3_uninit (&priv->mp3);
  85         free (priv);
  86         return 0;
  87 }
  88
  89 static int64_t ad_seek_dr_mp3(void *sf, int64_t pos)
  90 {
  91         drmp3_audio_decoder *priv = (drmp3_audio_decoder*) sf;
  92         if (!priv) return -1;
  93         return drmp3_seek_to_pcm_frame (&priv->mp3, pos);
  94 }
  95
  96 static ssize_t ad_read_dr_mp3(void *sf, float* d, size_t len)
  97 {
  98         drmp3_audio_decoder *priv = (drmp3_audio_decoder*) sf;
  99         if (!priv) return -1;
 100         return drmp3_read_pcm_frames_f32 (&priv->mp3, len / priv->mp3.channels, d) * priv->mp3.channels;
 101 }
 102
 103 static int ad_get_bitrate_dr_mp3(void *sf) {
 104         drmp3_audio_decoder *priv = (drmp3_audio_decoder*) sf;
 105         if (!priv) return -1;
 106         return priv->mp3.frameInfo.bitrate_kbps * 1000;
 107 }
 108
 109 static int ad_eval_dr_mp3(const char *f)
 110 {
 111         char *ext = strrchr(f, '.');
 112         if (strstr (f, "://")) return 0;
 113         if (!ext) return 5;
 114         if (!strcasecmp(ext, ".mp3")) return 100;
 115         return 0;
 116 }
 117
 118 static const ad_plugin ad_dr_mp3 = {
 119 #if 1
 120         &ad_eval_dr_mp3,
 121         &ad_open_dr_mp3,
 122         &ad_close_dr_mp3,
 123         &ad_info_dr_mp3,
 124         &ad_seek_dr_mp3,
 125         &ad_read_dr_mp3,
 126         &ad_get_bitrate_dr_mp3
 127 #else
 128         &ad_eval_null,
 129         &ad_open_null,
 130         &ad_close_null,
 131         &ad_info_null,
 132         &ad_seek_null,
 133         &ad_read_null,
 134         &ad_bit_rate_null
 135 #endif
 136 };
 137
 138 /* dlopen handler */
 139 const ad_plugin * adp_get_dr_mp3() {
 140         return &ad_dr_mp3;
 141 }