Bump SDL to 2.28.5 and add FFmpeg for AV1 parsing

libs/SDL2/include/SDL_audio.h

@@ -1,6 +1,6 @@
 /*
   Simple DirectMedia Layer
-  Copyright (C) 1997-2022 Sam Lantinga <slouken@libsdl.org>
+  Copyright (C) 1997-2023 Sam Lantinga <slouken@libsdl.org>
 
   This software is provided 'as-is', without any express or implied
   warranty.  In no event will the authors be held liable for any damages
@@ -169,13 +169,13 @@ typedef void (SDLCALL * SDL_AudioCallback) (void *userdata, Uint8 * stream,
  *  The calculated values in this structure are calculated by SDL_OpenAudio().
  *
  *  For multi-channel audio, the default SDL channel mapping is:
- *  2:  FL FR                       (stereo)
- *  3:  FL FR LFE                   (2.1 surround)
- *  4:  FL FR BL BR                 (quad)
- *  5:  FL FR FC BL BR              (quad + center)
- *  6:  FL FR FC LFE SL SR          (5.1 surround - last two can also be BL BR)
- *  7:  FL FR FC LFE BC SL SR       (6.1 surround)
- *  8:  FL FR FC LFE BL BR SL SR    (7.1 surround)
+ *  2:  FL  FR                          (stereo)
+ *  3:  FL  FR LFE                      (2.1 surround)
+ *  4:  FL  FR  BL  BR                  (quad)
+ *  5:  FL  FR LFE  BL  BR              (4.1 surround)
+ *  6:  FL  FR  FC LFE  SL  SR          (5.1 surround - last two can also be BL BR)
+ *  7:  FL  FR  FC LFE  BC  SL  SR      (6.1 surround)
+ *  8:  FL  FR  FC LFE  BL  BR  SL  SR  (7.1 surround)
  */
 typedef struct SDL_AudioSpec
 {
@@ -487,6 +487,7 @@ extern DECLSPEC int SDLCALL SDL_GetNumAudioDevices(int iscapture);
  * \since This function is available since SDL 2.0.0.
  *
  * \sa SDL_GetNumAudioDevices
+ * \sa SDL_GetDefaultAudioInfo
  */
 extern DECLSPEC const char *SDLCALL SDL_GetAudioDeviceName(int index,
                                                            int iscapture);
@@ -500,9 +501,7 @@ extern DECLSPEC const char *SDLCALL SDL_GetAudioDeviceName(int index,
  * hardware.
  *
  * `spec` will be filled with the sample rate, sample format, and channel
- * count. All other values in the structure are filled with 0. When the
- * supported struct members are 0, SDL was unable to get the property from the
- * backend.
+ * count.
  *
  * \param index the index of the audio device; valid values range from 0 to
  *              SDL_GetNumAudioDevices() - 1
@@ -514,12 +513,48 @@ extern DECLSPEC const char *SDLCALL SDL_GetAudioDeviceName(int index,
  * \since This function is available since SDL 2.0.16.
  *
  * \sa SDL_GetNumAudioDevices
+ * \sa SDL_GetDefaultAudioInfo
  */
 extern DECLSPEC int SDLCALL SDL_GetAudioDeviceSpec(int index,
                                                    int iscapture,
                                                    SDL_AudioSpec *spec);
 
 
+/**
+ * Get the name and preferred format of the default audio device.
+ *
+ * Some (but not all!) platforms have an isolated mechanism to get information
+ * about the "default" device. This can actually be a completely different
+ * device that's not in the list you get from SDL_GetAudioDeviceSpec(). It can
+ * even be a network address! (This is discussed in SDL_OpenAudioDevice().)
+ *
+ * As a result, this call is not guaranteed to be performant, as it can query
+ * the sound server directly every time, unlike the other query functions. You
+ * should call this function sparingly!
+ *
+ * `spec` will be filled with the sample rate, sample format, and channel
+ * count, if a default device exists on the system. If `name` is provided,
+ * will be filled with either a dynamically-allocated UTF-8 string or NULL.
+ *
+ * \param name A pointer to be filled with the name of the default device (can
+ *             be NULL). Please call SDL_free() when you are done with this
+ *             pointer!
+ * \param spec The SDL_AudioSpec to be initialized by this function.
+ * \param iscapture non-zero to query the default recording device, zero to
+ *                  query the default output device.
+ * \returns 0 on success, nonzero on error
+ *
+ * \since This function is available since SDL 2.24.0.
+ *
+ * \sa SDL_GetAudioDeviceName
+ * \sa SDL_GetAudioDeviceSpec
+ * \sa SDL_OpenAudioDevice
+ */
+extern DECLSPEC int SDLCALL SDL_GetDefaultAudioInfo(char **name,
+                                                    SDL_AudioSpec *spec,
+                                                    int iscapture);
+
+
 /**
  * Open a specific audio device.
  *
@@ -586,6 +621,7 @@ extern DECLSPEC int SDLCALL SDL_GetAudioDeviceSpec(int index,
  * - `SDL_AUDIO_ALLOW_FREQUENCY_CHANGE`
  * - `SDL_AUDIO_ALLOW_FORMAT_CHANGE`
  * - `SDL_AUDIO_ALLOW_CHANNELS_CHANGE`
+ * - `SDL_AUDIO_ALLOW_SAMPLES_CHANGE`
  * - `SDL_AUDIO_ALLOW_ANY_CHANGE`
  *
  * These flags specify how SDL should behave when a device cannot offer a