Update extras.

extras/dr_flac.h

 /*
 FLAC audio decoder. Choice of public domain or MIT-0. See license statements at the end of this file.
-dr_flac - v0.12.11 - 2020-04-19
+dr_flac - v0.12.12 - 2020-04-30
 
 David Reid - mackron@gmail.com
 
@@ -2809,7 +2809,7 @@ static drflac_result drflac__read_utf8_coded_number(drflac_bs* bs, drflac_uint64
 {
     drflac_uint8 crc;
     drflac_uint64 result;
-    unsigned char utf8[7] = {0};
+    drflac_uint8 utf8[7] = {0};
     int byteCount;
     int i;
 
@@ -4749,7 +4749,7 @@ static drflac_bool32 drflac__decode_samples_with_residual(drflac_bs* bs, drflac_
                 return DRFLAC_FALSE;
             }
         } else {
-            unsigned char unencodedBitsPerSample = 0;
+            drflac_uint8 unencodedBitsPerSample = 0;
             if (!drflac__read_uint8(bs, 5, &unencodedBitsPerSample)) {
                 return DRFLAC_FALSE;
             }
@@ -4841,7 +4841,7 @@ static drflac_bool32 drflac__read_and_seek_residual(drflac_bs* bs, drflac_uint32
                 return DRFLAC_FALSE;
             }
         } else {
-            unsigned char unencodedBitsPerSample = 0;
+            drflac_uint8 unencodedBitsPerSample = 0;
             if (!drflac__read_uint8(bs, 5, &unencodedBitsPerSample)) {
                 return DRFLAC_FALSE;
             }
@@ -5190,7 +5190,7 @@ static drflac_bool32 drflac__read_subframe_header(drflac_bs* bs, drflac_subframe
         if (!drflac__seek_past_next_set_bit(bs, &wastedBitsPerSample)) {
             return DRFLAC_FALSE;
         }
-        pSubframe->wastedBitsPerSample = (unsigned char)wastedBitsPerSample + 1;
+        pSubframe->wastedBitsPerSample = (drflac_uint8)wastedBitsPerSample + 1;
     }
 
     return DRFLAC_TRUE;
@@ -5313,7 +5313,7 @@ static drflac_bool32 drflac__seek_subframe(drflac_bs* bs, drflac_frame* frame, i
 
         case DRFLAC_SUBFRAME_LPC:
         {
-            unsigned char lpcPrecision;
+            drflac_uint8 lpcPrecision;
 
             unsigned int bitsToSeek = pSubframe->lpcOrder * subframeBitsPerSample;
             if (!drflac__seek_bits(bs, bitsToSeek)) {
@@ -8505,7 +8505,7 @@ DRFLAC_API drflac* drflac_open_memory(const void* pData, size_t dataSize, const
     drflac__memory_stream memoryStream;
     drflac* pFlac;
 
-    memoryStream.data = (const unsigned char*)pData;
+    memoryStream.data = (const drflac_uint8*)pData;
     memoryStream.dataSize = dataSize;
     memoryStream.currentReadPos = 0;
     pFlac = drflac_open(drflac__on_read_memory, drflac__on_seek_memory, &memoryStream, pAllocationCallbacks);
@@ -8536,7 +8536,7 @@ DRFLAC_API drflac* drflac_open_memory_with_metadata(const void* pData, size_t da
     drflac__memory_stream memoryStream;
     drflac* pFlac;
 
-    memoryStream.data = (const unsigned char*)pData;
+    memoryStream.data = (const drflac_uint8*)pData;
     memoryStream.dataSize = dataSize;
     memoryStream.currentReadPos = 0;
     pFlac = drflac_open_with_metadata_private(drflac__on_read_memory, drflac__on_seek_memory, onMeta, drflac_container_unknown, &memoryStream, pUserData, pAllocationCallbacks);
@@ -11705,6 +11705,9 @@ DRFLAC_API drflac_bool32 drflac_next_cuesheet_track(drflac_cuesheet_track_iterat
 /*
 REVISION HISTORY
 ================
+v0.12.12 - 2020-04-30
+  - Fix compilation errors with VC6.
+
 v0.12.11 - 2020-04-19
   - Fix some pedantic warnings.
   - Fix some undefined behaviour warnings.

extras/dr_mp3.h

 /*
 MP3 audio decoder. Choice of public domain or MIT-0. See license statements at the end of this file.
-dr_mp3 - v0.6.8 - 2020-04-26
+dr_mp3 - v0.6.9 - 2020-04-30
 
 David Reid - mackron@gmail.com
 
@@ -249,14 +249,14 @@ typedef struct
 {
     float mdct_overlap[2][9*32], qmf_state[15*2*32];
     int reserv, free_format_bytes;
-    unsigned char header[4], reserv_buf[511];
+    drmp3_uint8 header[4], reserv_buf[511];
 } drmp3dec;
 
 /* Initializes a low level decoder. */
 DRMP3_API void drmp3dec_init(drmp3dec *dec);
 
 /* Reads a frame from a low level decoder. */
-DRMP3_API int drmp3dec_decode_frame(drmp3dec *dec, const unsigned char *mp3, int mp3_bytes, void *pcm, drmp3dec_frame_info *info);
+DRMP3_API int drmp3dec_decode_frame(drmp3dec *dec, const drmp3_uint8 *mp3, int mp3_bytes, void *pcm, drmp3dec_frame_info *info);
 
 /* Helper for converting between f32 and s16. */
 DRMP3_API void drmp3dec_f32_to_s16(const float *in, drmp3_int16 *out, size_t num_samples);
@@ -2182,7 +2182,7 @@ DRMP3_API void drmp3dec_init(drmp3dec *dec)
     dec->header[0] = 0;
 }
 
-DRMP3_API int drmp3dec_decode_frame(drmp3dec *dec, const unsigned char *mp3, int mp3_bytes, void *pcm, drmp3dec_frame_info *info)
+DRMP3_API int drmp3dec_decode_frame(drmp3dec *dec, const drmp3_uint8 *mp3, int mp3_bytes, void *pcm, drmp3dec_frame_info *info)
 {
     int i = 0, igr, frame_size = 0, success = 1;
     const drmp3_uint8 *hdr;
@@ -4390,6 +4390,9 @@ counts rather than sample counts.
 /*
 REVISION HISTORY
 ================
+v0.6.9 - 2020-04-30
+  - Change the `pcm` parameter of drmp3dec_decode_frame() to a `const drmp3_uint8*` for consistency with internal APIs.
+
 v0.6.8 - 2020-04-26
   - Optimizations to decoding when initializing from memory.