Rework the libvorbis and libopus custom decoders.

These decoders have been moved into their own subfolders under the
extras/decoders folder:

  extras/decoders/libvorbis
  extras/decoders/libopus

In addition to being relocated, they have also been split into separate
.c/h pairs. They now work like a more conventional library. The
implementation of these libraries have also been decoupled from the
miniaudio implementation which means they depend only on the header
section of miniaudio.h now.

With this change the custom_decoder and custom_decoder_engine examples
have been updated. To compile these you now need to link in the
miniaudio_libvorbis.c and miniaudio_libopus.c files via your build
tool. For your own code, you can still include the .c files directly
into your code if you want to compile as a single translation unit.

examples/custom_decoder.c

@@ -15,12 +15,14 @@ the decoder via the decoder config (`ma_decoder_config`). You need to implement
 of your custom decoders. See `ma_decoding_backend_vtable` for the functions you need to implement.
 The `onInitFile`, `onInitFileW` and `onInitMemory` functions are optional.
 */
-#define MA_NO_VORBIS    /* Disable the built-in Vorbis decoder to ensure the libvorbis decoder is picked. */
-#define MA_NO_OPUS      /* Disable the (not yet implemented) built-in Opus decoder to ensure the libopus decoder is picked. */
-#define MINIAUDIO_IMPLEMENTATION
-#include "../miniaudio.h"
-#include "../extras/miniaudio_libvorbis.h"
-#include "../extras/miniaudio_libopus.h"
+
+/*
+For now these need to be declared before miniaudio.c due to some compatibility issues with the old
+MINIAUDIO_IMPLEMENTATION system. This will change from version 0.12.
+*/
+#include "../extras/decoders/libvorbis/miniaudio_libvorbis.h"
+#include "../extras/decoders/libopus/miniaudio_libopus.h"
+#include "../miniaudio.c"
 
 #include <stdio.h>
 
@@ -80,15 +82,6 @@ static void ma_decoding_backend_uninit__libvorbis(void* pUserData, ma_data_sourc
     ma_free(pVorbis, pAllocationCallbacks);
 }
 
-static ma_result ma_decoding_backend_get_channel_map__libvorbis(void* pUserData, ma_data_source* pBackend, ma_channel* pChannelMap, size_t channelMapCap)
-{
-    ma_libvorbis* pVorbis = (ma_libvorbis*)pBackend;
-
-    (void)pUserData;
-
-    return ma_libvorbis_get_data_format(pVorbis, NULL, NULL, NULL, pChannelMap, channelMapCap);
-}
-
 static ma_decoding_backend_vtable g_ma_decoding_backend_vtable_libvorbis =
 {
     ma_decoding_backend_init__libvorbis,
@@ -156,15 +149,6 @@ static void ma_decoding_backend_uninit__libopus(void* pUserData, ma_data_source*
     ma_free(pOpus, pAllocationCallbacks);
 }
 
-static ma_result ma_decoding_backend_get_channel_map__libopus(void* pUserData, ma_data_source* pBackend, ma_channel* pChannelMap, size_t channelMapCap)
-{
-    ma_libopus* pOpus = (ma_libopus*)pBackend;
-
-    (void)pUserData;
-
-    return ma_libopus_get_data_format(pOpus, NULL, NULL, NULL, pChannelMap, channelMapCap);
-}
-
 static ma_decoding_backend_vtable g_ma_decoding_backend_vtable_libopus =
 {
     ma_decoding_backend_init__libopus,

examples/custom_decoder_engine.c

@@ -5,12 +5,14 @@ This is the same as the custom_decoder example, only it's used with the high lev
 rather than the low level decoding API. You can use this to add support for Opus to your games, for
 example (via libopus).
 */
-#define MA_NO_VORBIS    /* Disable the built-in Vorbis decoder to ensure the libvorbis decoder is picked. */
-#define MA_NO_OPUS      /* Disable the (not yet implemented) built-in Opus decoder to ensure the libopus decoder is picked. */
-#define MINIAUDIO_IMPLEMENTATION
-#include "../miniaudio.h"
-#include "../extras/miniaudio_libvorbis.h"
-#include "../extras/miniaudio_libopus.h"
+
+/*
+For now these need to be declared before miniaudio.c due to some compatibility issues with the old
+MINIAUDIO_IMPLEMENTATION system. This will change from version 0.12.
+*/
+#include "../extras/decoders/libvorbis/miniaudio_libvorbis.h"
+#include "../extras/decoders/libopus/miniaudio_libopus.h"
+#include "../miniaudio.c"
 
 #include <stdio.h>
 
@@ -70,15 +72,6 @@ static void ma_decoding_backend_uninit__libvorbis(void* pUserData, ma_data_sourc
     ma_free(pVorbis, pAllocationCallbacks);
 }
 
-static ma_result ma_decoding_backend_get_channel_map__libvorbis(void* pUserData, ma_data_source* pBackend, ma_channel* pChannelMap, size_t channelMapCap)
-{
-    ma_libvorbis* pVorbis = (ma_libvorbis*)pBackend;
-
-    (void)pUserData;
-
-    return ma_libvorbis_get_data_format(pVorbis, NULL, NULL, NULL, pChannelMap, channelMapCap);
-}
-
 static ma_decoding_backend_vtable g_ma_decoding_backend_vtable_libvorbis =
 {
     ma_decoding_backend_init__libvorbis,
@@ -146,15 +139,6 @@ static void ma_decoding_backend_uninit__libopus(void* pUserData, ma_data_source*
     ma_free(pOpus, pAllocationCallbacks);
 }
 
-static ma_result ma_decoding_backend_get_channel_map__libopus(void* pUserData, ma_data_source* pBackend, ma_channel* pChannelMap, size_t channelMapCap)
-{
-    ma_libopus* pOpus = (ma_libopus*)pBackend;
-
-    (void)pUserData;
-
-    return ma_libopus_get_data_format(pOpus, NULL, NULL, NULL, pChannelMap, channelMapCap);
-}
-
 static ma_decoding_backend_vtable g_ma_decoding_backend_vtable_libopus =
 {
     ma_decoding_backend_init__libopus,

extras/decoders/libopus/miniaudio_libopus.h

+/*
+This implements a data source that decodes Opus streams via libopus + libopusfile
+
+This object can be plugged into any `ma_data_source_*()` API and can also be used as a custom
+decoding backend. See the custom_decoder example.
+*/
+#ifndef miniaudio_libopus_h
+#define miniaudio_libopus_h
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include "../../../miniaudio.h"
+
+typedef struct
+{
+    ma_data_source_base ds;     /* The libopus decoder can be used independently as a data source. */
+    ma_read_proc onRead;
+    ma_seek_proc onSeek;
+    ma_tell_proc onTell;
+    void* pReadSeekTellUserData;
+    ma_format format;           /* Will be either f32 or s16. */
+    /*OggOpusFile**/ void* of;  /* Typed as void* so we can avoid a dependency on opusfile in the header section. */
+} ma_libopus;
+
+MA_API ma_result ma_libopus_init(ma_read_proc onRead, ma_seek_proc onSeek, ma_tell_proc onTell, void* pReadSeekTellUserData, const ma_decoding_backend_config* pConfig, const ma_allocation_callbacks* pAllocationCallbacks, ma_libopus* pOpus);
+MA_API ma_result ma_libopus_init_file(const char* pFilePath, const ma_decoding_backend_config* pConfig, const ma_allocation_callbacks* pAllocationCallbacks, ma_libopus* pOpus);
+MA_API void ma_libopus_uninit(ma_libopus* pOpus, const ma_allocation_callbacks* pAllocationCallbacks);
+MA_API ma_result ma_libopus_read_pcm_frames(ma_libopus* pOpus, void* pFramesOut, ma_uint64 frameCount, ma_uint64* pFramesRead);
+MA_API ma_result ma_libopus_seek_to_pcm_frame(ma_libopus* pOpus, ma_uint64 frameIndex);
+MA_API ma_result ma_libopus_get_data_format(ma_libopus* pOpus, ma_format* pFormat, ma_uint32* pChannels, ma_uint32* pSampleRate, ma_channel* pChannelMap, size_t channelMapCap);
+MA_API ma_result ma_libopus_get_cursor_in_pcm_frames(ma_libopus* pOpus, ma_uint64* pCursor);
+MA_API ma_result ma_libopus_get_length_in_pcm_frames(ma_libopus* pOpus, ma_uint64* pLength);
+
+#ifdef __cplusplus
+}
+#endif
+#endif  /* miniaudio_libopus_h */
+

extras/decoders/libvorbis/miniaudio_libvorbis.h

+/*
+This implements a data source that decodes Vorbis streams via libvorbis + libvorbisfile
+
+This object can be plugged into any `ma_data_source_*()` API and can also be used as a custom
+decoding backend. See the custom_decoder example.
+*/
+#ifndef miniaudio_libvorbis_h
+#define miniaudio_libvorbis_h
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include "../../../miniaudio.h"
+
+typedef struct
+{
+    ma_data_source_base ds;     /* The libvorbis decoder can be used independently as a data source. */
+    ma_read_proc onRead;
+    ma_seek_proc onSeek;
+    ma_tell_proc onTell;
+    void* pReadSeekTellUserData;
+    ma_format format;           /* Will be either f32 or s16. */
+    /*OggVorbis_File**/ void* vf;   /* Typed as void* so we can avoid a dependency on opusfile in the header section. */
+} ma_libvorbis;
+
+MA_API ma_result ma_libvorbis_init(ma_read_proc onRead, ma_seek_proc onSeek, ma_tell_proc onTell, void* pReadSeekTellUserData, const ma_decoding_backend_config* pConfig, const ma_allocation_callbacks* pAllocationCallbacks, ma_libvorbis* pVorbis);
+MA_API ma_result ma_libvorbis_init_file(const char* pFilePath, const ma_decoding_backend_config* pConfig, const ma_allocation_callbacks* pAllocationCallbacks, ma_libvorbis* pVorbis);
+MA_API void ma_libvorbis_uninit(ma_libvorbis* pVorbis, const ma_allocation_callbacks* pAllocationCallbacks);
+MA_API ma_result ma_libvorbis_read_pcm_frames(ma_libvorbis* pVorbis, void* pFramesOut, ma_uint64 frameCount, ma_uint64* pFramesRead);
+MA_API ma_result ma_libvorbis_seek_to_pcm_frame(ma_libvorbis* pVorbis, ma_uint64 frameIndex);
+MA_API ma_result ma_libvorbis_get_data_format(ma_libvorbis* pVorbis, ma_format* pFormat, ma_uint32* pChannels, ma_uint32* pSampleRate, ma_channel* pChannelMap, size_t channelMapCap);
+MA_API ma_result ma_libvorbis_get_cursor_in_pcm_frames(ma_libvorbis* pVorbis, ma_uint64* pCursor);
+MA_API ma_result ma_libvorbis_get_length_in_pcm_frames(ma_libvorbis* pVorbis, ma_uint64* pLength);
+
+#ifdef __cplusplus
+}
+#endif
+#endif  /* miniaudio_libvorbis_h */