From 32835b29d9a5e911d5162184677ff21e960f639d Mon Sep 17 00:00:00 2001
From: Jean Pierre Cimalando <jp-dev@inbox.ru>
Date: Fri, 9 Oct 2020 15:41:08 +0200
Subject: [PATCH] Add MP3

---
 external/st_audiofile/src/st_audiofile.c      | 53 +++++++++++++++++++
 external/st_audiofile/src/st_audiofile.h      |  1 +
 .../st_audiofile/src/st_audiofile_common.c    |  3 ++
 external/st_audiofile/src/st_audiofile_libs.c |  1 +
 external/st_audiofile/src/st_audiofile_libs.h |  1 +
 5 files changed, 59 insertions(+)

diff --git a/external/st_audiofile/src/st_audiofile.c b/external/st_audiofile/src/st_audiofile.c
index efaccb85..671e8618 100644
--- a/external/st_audiofile/src/st_audiofile.c
+++ b/external/st_audiofile/src/st_audiofile.c
@@ -14,7 +14,12 @@ struct st_audio_file {
     union {
         drwav *wav;
         drflac *flac;
+        drmp3 *mp3;
     };
+
+    union {
+        struct { uint64_t frames; } mp3;
+    } cache;
 };
 
 enum {
@@ -47,6 +52,19 @@ st_audio_file* st_open_file(const char* filename)
             af->type = st_audio_file_flac;
     }
 
+    if (af->type == st_audio_file_null) {
+        af->mp3 = (drmp3*)malloc(sizeof(drmp3));
+        if (!af->mp3) {
+            free(af);
+            return NULL;
+        }
+        if (!drmp3_init_file(af->mp3, filename, NULL) ||
+            (af->cache.mp3.frames = drmp3_get_pcm_frame_count(af->mp3)) == 0)
+            free(af->mp3);
+        else
+            af->type = st_audio_file_mp3;
+    }
+
     if (af->type == st_audio_file_null) {
         free(af);
         af = NULL;
@@ -82,6 +100,19 @@ st_audio_file* st_open_file_w(const wchar_t* filename)
             af->type = st_audio_file_flac;
     }
 
+    if (af->type == st_audio_file_null) {
+        af->mp3 = (drmp3*)malloc(sizeof(drmp3));
+        if (!af->mp3) {
+            free(af);
+            return NULL;
+        }
+        if (!drmp3_init_file_w(af->mp3, filename, NULL) ||
+            (af->cache.mp3.frames = drmp3_get_pcm_frame_count(af->mp3)) == 0)
+            free(af->mp3);
+        else
+            af->type = st_audio_file_mp3;
+    }
+
     if (af->type == st_audio_file_null) {
         free(af);
         af = NULL;
@@ -101,6 +132,10 @@ void st_close(st_audio_file* af)
     case st_audio_file_flac:
         drflac_close(af->flac);
         break;
+    case st_audio_file_mp3:
+        drmp3_uninit(af->mp3);
+        free(af->mp3);
+        break;
     }
 
     af->type = st_audio_file_null;
@@ -122,6 +157,9 @@ uint32_t st_get_channels(st_audio_file* af)
     case st_audio_file_flac:
         channels = af->flac->channels;
         break;
+    case st_audio_file_mp3:
+        channels = af->mp3->channels;
+        break;
     }
 
     return channels;
@@ -138,6 +176,9 @@ float st_get_sample_rate(st_audio_file* af)
     case st_audio_file_flac:
         sample_rate = af->flac->sampleRate;
         break;
+    case st_audio_file_mp3:
+        sample_rate = af->mp3->sampleRate;
+        break;
     }
 
     return sample_rate;
@@ -154,6 +195,9 @@ uint64_t st_get_frame_count(st_audio_file* af)
     case st_audio_file_flac:
         frames = af->flac->totalPCMFrameCount;
         break;
+    case st_audio_file_mp3:
+        frames = af->cache.mp3.frames;
+        break;
     }
 
     return frames;
@@ -170,6 +214,9 @@ bool st_seek(st_audio_file* af, uint64_t frame)
     case st_audio_file_flac:
         success = drflac_seek_to_pcm_frame(af->flac, frame);
         break;
+    case st_audio_file_mp3:
+        success = drmp3_seek_to_pcm_frame(af->mp3, frame);
+        break;
     }
 
     return success;
@@ -184,6 +231,9 @@ uint64_t st_read_s16(st_audio_file* af, int16_t* buffer, uint64_t count)
     case st_audio_file_flac:
         count = drflac_read_pcm_frames_s16(af->flac, count, buffer);
         break;
+    case st_audio_file_mp3:
+        count = drmp3_read_pcm_frames_s16(af->mp3, count, buffer);
+        break;
     }
 
     return count;
@@ -198,6 +248,9 @@ uint64_t st_read_f32(st_audio_file* af, float* buffer, uint64_t count)
     case st_audio_file_flac:
         count = drflac_read_pcm_frames_f32(af->flac, count, buffer);
         break;
+    case st_audio_file_mp3:
+        count = drmp3_read_pcm_frames_f32(af->mp3, count, buffer);
+        break;
     }
 
     return count;
diff --git a/external/st_audiofile/src/st_audiofile.h b/external/st_audiofile/src/st_audiofile.h
index 704addb8..fd62c77f 100644
--- a/external/st_audiofile/src/st_audiofile.h
+++ b/external/st_audiofile/src/st_audiofile.h
@@ -24,6 +24,7 @@ typedef enum st_audio_file_type {
     st_audio_file_wav,
     st_audio_file_flac,
     st_audio_file_ogg,
+    st_audio_file_mp3,
     st_audio_file_other,
 } st_audio_file_type;
 
diff --git a/external/st_audiofile/src/st_audiofile_common.c b/external/st_audiofile/src/st_audiofile_common.c
index 2b6e5d34..d8e2ac6e 100644
--- a/external/st_audiofile/src/st_audiofile_common.c
+++ b/external/st_audiofile/src/st_audiofile_common.c
@@ -26,6 +26,9 @@ const char* st_type_string(int type)
     case st_audio_file_ogg:
         type_string = "OGG";
         break;
+    case st_audio_file_mp3:
+        type_string = "MP3";
+        break;
     case st_audio_file_other:
         type_string = "other";
         break;
diff --git a/external/st_audiofile/src/st_audiofile_libs.c b/external/st_audiofile/src/st_audiofile_libs.c
index 77ae28c2..4c39e703 100644
--- a/external/st_audiofile/src/st_audiofile_libs.c
+++ b/external/st_audiofile/src/st_audiofile_libs.c
@@ -6,4 +6,5 @@
 
 #define DR_WAV_IMPLEMENTATION
 #define DR_FLAC_IMPLEMENTATION
+#define DR_MP3_IMPLEMENTATION
 #include "st_audiofile_libs.h"
diff --git a/external/st_audiofile/src/st_audiofile_libs.h b/external/st_audiofile/src/st_audiofile_libs.h
index 8620cdce..16f329b0 100644
--- a/external/st_audiofile/src/st_audiofile_libs.h
+++ b/external/st_audiofile/src/st_audiofile_libs.h
@@ -7,3 +7,4 @@
 #pragma once
 #include "dr_wav.h"
 #include "dr_flac.h"
+#include "dr_mp3.h"