Fixed audio on RPI frontend

.github/workflows/libretro.yml

@@ -11,9 +11,11 @@ on:
 env:
   VXT_VERSION: 1.2.0
   ZIG_VERSION: 0.10.1
-  ZIG_ARCHS: "x86_64-linux-gnu i386-linux-gnu aarch64-linux-gnu arm-linux-gnueabi x86_64-macos-none aarch64-macos-none"
+  #ZIG_ARCHS: "x86_64-linux-gnu i386-linux-gnu aarch64-linux-gnu arm-linux-gnueabi x86_64-macos-none aarch64-macos-none"
+  ZIG_ARCHS: "x86_64-linux-gnu"
   NDK_VERSION: r20
-  NDK_ARCHS: "aarch64-linux-android armv7a-linux-androideabi x86_64-linux-android i686-linux-android"
+  #NDK_ARCHS: "aarch64-linux-android armv7a-linux-androideabi x86_64-linux-android i686-linux-android"
+  NDK_ARCHS: "aarch64-linux-android"
 
 jobs:
   libretro-build:
@@ -92,7 +94,7 @@ jobs:
             cp build/libretro/*.so package/virtualxt/${arch}
           done
 
-      - name: Package & Deploy
-        env:
-          BUTLER_API_KEY: ${{ secrets.BUTLER_API_KEY }}
-        run: if [[ $GITHUB_REF_NAME =~ ^(edge|release)$ ]]; then ./tools/package/itch/push-libretro.sh; fi
+      #- name: Package & Deploy
+      #  env:
+      #    BUTLER_API_KEY: ${{ secrets.BUTLER_API_KEY }}
+      #  run: if [[ $GITHUB_REF_NAME =~ ^(edge|release)$ ]]; then ./tools/package/itch/push-libretro.sh; fi

front/rpi/Makefile

@@ -5,6 +5,7 @@ endif
 
 LIBCHOME = $(VXTHOME)/../scanf
 
+C_STANDARD = -std=c11
 CFLAGS = -DVXT_NO_LIBC -DFRONTEND_VIDEO_RED=2 -DFRONTEND_VIDEO_GREEN=1 -DFRONTEND_VIDEO_BLUE=0 -DFRONTEND_VIDEO_ALPHA=3 -I$(VXTHOME)/include -I../common
 
 OBJS_VXT = $(VXTHOME)/cpu.o \
@@ -24,7 +25,7 @@ EXTRACLEAN = $(VXTHOME)/*.o $(VXTHOME)/*.d
 OBJS_LIBC = $(LIBCHOME)/scanf.o
 EXTRACLEAN += $(LIBCHOME)/*.o $(LIBCHOME)/*.d
 
-OBJS = main.o kernel.o ethernet.o cga.o mouse.o ems.o vga.o $(OBJS_VXT) $(OBJS_LIBC)
+OBJS = main.o kernel.o ethernet.o cga.o vga.o mouse.o ems.o adlib.o $(OBJS_VXT) $(OBJS_LIBC)
 
 LIBS = $(CIRCLEHOME)/lib/usb/libusb.a \
 	$(CIRCLEHOME)/lib/sound/libsound.a \

front/rpi/adlib.c

@@ -0,0 +1,30 @@
+// Copyright (c) 2019-2024 Andreas T Jonsson <mail@andreasjonsson.se>
+//
+// This software is provided 'as-is', without any express or implied
+// warranty. In no event will the authors be held liable for any damages
+// arising from the use of this software.
+//
+// Permission is granted to anyone to use this software for any purpose,
+// including commercial applications, and to alter it and redistribute it
+// freely, subject to the following restrictions:
+//
+// 1. The origin of this software must not be misrepresented; you must not
+//    claim that you wrote the original software. If you use this software
+//    in a product, an acknowledgment in the product documentation would be
+//    appreciated but is not required.
+//
+// 2. Altered source versions must be plainly marked as such, and must not be
+//    misrepresented as being the original software.
+//
+// 3. This notice may not be removed or altered from any source
+//    distribution.
+
+#include "../../modules/adlib/nuked-opl3/opl3.c"
+#include "../../modules/adlib/adlib.c"
+
+struct vxt_peripheral *adlib_create(vxt_allocator *alloc, struct frontend_audio_adapter *aa) {
+    struct vxt_peripheral *p = create(alloc, NULL, NULL);
+    if (p)
+		*aa = (struct frontend_audio_adapter){p, &generate_sample};
+    return p;
+}

front/rpi/kernel.cpp

@@ -30,9 +30,19 @@
 #include <frontend.h>
 #include "keymap.h"
 
+//#define LOGSERIAL
+
+#define DRIVE "SD:"
+#define BIOSIMAGE "GLABIOS.ROM"
+#define SAMPLE_RATE	22050
+#define CHUNK_SIZE 256
+#define AUDIO_LATENCY_MS 10
+
 volatile bool mouse_updated = false;
 struct frontend_mouse_event mouse_state;
-struct frontend_video_adapter video_adapter;
+
+struct frontend_video_adapter video_adapter = {0};
+struct frontend_audio_adapter audio_adapter = {0};
 
 unsigned cpu_frequency = VXT_DEFAULT_FREQUENCY;
 
@@ -41,19 +51,16 @@ int screen_height = 0;
 struct vxt_peripheral *ppi = 0;
 struct vxt_peripheral *mouse = 0;
 
+const unsigned audio_buffer_size = (SAMPLE_RATE / 1000) * AUDIO_LATENCY_MS;
+unsigned audio_buffer_len = 0;
+DMA_BUFFER(short, audio_buffer, audio_buffer_size);
+
 CKernel *CKernel::s_pThis = 0;
 CBcmFrameBuffer *pFrameBuffer = 0;
 CDevice *pUMSD1 = 0;
-volatile int pUMSD1_head = 0;
 
 FIL log_file = {0};
 
-//#define LOGSERIAL
-
-#define DRIVE "SD:"
-#define BIOSIMAGE "GLABIOS.ROM"
-#define SAMPLE_RATE	48000
-
 extern "C" {
 	// From joystick.c
 	bool joystick_push_event(struct vxt_peripheral *p, const struct frontend_joystick_event *ev);
@@ -69,6 +76,9 @@ extern "C" {
 	// From ems.c
 	struct vxt_peripheral *ems_create(vxt_allocator *alloc, const char *args);
 
+	// From adlib.c
+	struct vxt_peripheral *adlib_create(vxt_allocator *alloc, struct frontend_audio_adapter *aa);
+
 	// From cga.c
 	struct vxt_peripheral *cga_card_create(vxt_allocator *alloc, struct frontend_video_adapter *va);
 
@@ -259,6 +269,7 @@ CKernel::CKernel(void)
 
 	memset(&mouse_state, 0, sizeof(mouse_state));
 	memset(&video_adapter, 0, sizeof(video_adapter));
+	memset(audio_buffer, 0, audio_buffer_size * 2);
 	memset(m_RawKeys, 0, sizeof(m_RawKeys));
 	s_pThis = this;
 }
@@ -346,22 +357,35 @@ TShutdownMode CKernel::Run(void) {
 	if ((pUMSD1 = m_DeviceNameService.GetDevice("umsd1", TRUE)))
 		VXT_LOG("Found USB storage device!");
 
+	VXT_LOG("Initializing audio...");
 	const char *pSoundDevice = m_Options.GetSoundDevice();
-	if (!strcmp(pSoundDevice, "sndpwm")) {
-		m_pSound = new CPWMSoundBaseDevice(&m_Interrupt, SAMPLE_RATE, 1);
+	if (pSoundDevice) {
+		if (!strcmp(pSoundDevice, "sndhdmi"))
+			m_pSound = new CHDMISoundBaseDevice(&m_Interrupt, SAMPLE_RATE, CHUNK_SIZE);
 
-		if (!m_pSound->AllocateQueueFrames(1))
-			VXT_LOG("Cannot allocate sound queue!");
+		#if RASPPI >= 4
+			if (!m_pSound && !strcmp(pSoundDevice, "sndusb"))
+				m_pSound = new CUSBSoundBaseDevice(SAMPLE_RATE);
+		#endif
+	}
 
+	// Use PWM as default audio device.
+	if (!m_pSound) {
+		pSoundDevice = "sndpwm";
+		m_pSound = new CPWMSoundBaseDevice(&m_Interrupt, SAMPLE_RATE, CHUNK_SIZE);
+	}
+
+	if (m_pSound) {
+		VXT_LOG("Sound device: %s", pSoundDevice);
 		m_pSound->SetWriteFormat(SoundFormatSigned16, 1);
-
-		//unsigned nQueueSizeFrames = m_pSound->GetQueueSizeFrames();
-		//WriteSoundData(nQueueSizeFrames);
+		
+		if (!m_pSound->AllocateQueue(AUDIO_LATENCY_MS))
+			VXT_LOG("Cannot allocate sound queue!");
 
 		if (!m_pSound->Start())
 			VXT_LOG("Cannot start sound device!");
 	} else {
-		VXT_LOG("No supported audio device!");
+		VXT_LOG("Sound device is not supported!");
 	}
 
 	struct vxtu_disk_interface2 intrf = {
@@ -385,6 +409,7 @@ TShutdownMode CKernel::Run(void) {
 		(disk = vxtu_disk_create2(&allocator, &intrf)),
 		(mouse = mouse_create(&allocator, NULL, "0x3F8")),
 		//(joystick = joystick_create(&allocator, NULL, "0x201")),
+		adlib_create(&allocator, &audio_adapter),
 		use_cga ? cga_card_create(&allocator, &video_adapter) : vga_card_create(&allocator, &video_adapter),
 		use_cga ? NULL : load_bios("vgabios.bin", 0xC0000),
 		NULL
@@ -469,12 +494,27 @@ TShutdownMode CKernel::Run(void) {
 	    	video_adapter.render(video_adapter.device, &render_callback, &m_Options);
 		}
 
-		if ((ticks - audioTicks) >= (CLOCKHZ / SAMPLE_RATE)) {
-			audioTicks = ticks;
-			if (m_pSound && m_pSound->IsActive()) {
+		while ((ticks - audioTicks) >= (CLOCKHZ / SAMPLE_RATE)) {
+			audioTicks += CLOCKHZ / SAMPLE_RATE;
+
+			// Generate audio.
+			if (audio_buffer_len < audio_buffer_size) {
 				short sample = vxtu_ppi_generate_sample(ppi, SAMPLE_RATE);
-				m_pSound->Write((u8*)&sample, 2);
-			}			
+				if (audio_adapter.device)
+					sample += audio_adapter.generate_sample(audio_adapter.device, SAMPLE_RATE);
+				audio_buffer[audio_buffer_len++] = sample;
+			}
+
+			// Write audio data to output device.
+			if (m_pSound && m_pSound->IsActive()) {
+				const unsigned samples_needed = m_pSound->GetQueueSizeFrames() - m_pSound->GetQueueFramesAvail();
+
+				if ((audio_buffer_len == audio_buffer_size) || (samples_needed > audio_buffer_len)) {
+					unsigned num_samples = (samples_needed < audio_buffer_len) ? samples_needed : audio_buffer_len;
+					m_pSound->Write((u8*)audio_buffer, num_samples * 2);
+					audio_buffer_len = 0;
+				}
+			}
 		}
 
 		u64	cpuTicks = ticks * (cpu_frequency / 1000000);

front/rpi/kernel.h

@@ -34,6 +34,8 @@
 #include <circle/logger.h>
 #include <circle/sound/soundbasedevice.h>
 #include <circle/sound/pwmsoundbasedevice.h>
+#include <circle/sound/hdmisoundbasedevice.h>
+#include <circle/sound/usbsoundbasedevice.h>
 #include <circle/usb/usbhcidevice.h>
 #include <circle/usb/usbkeyboard.h>
 #include <circle/input/mouse.h>

modules/adlib/adlib.c

@@ -88,14 +88,16 @@ static const char *name(struct adlib *a) {
     (void)a; return "AdLib Music Synthesizer";
 }
 
-VXTU_MODULE_CREATE(adlib, {
-    DEVICE->freq = 48000;
-    if (FRONTEND)
-        DEVICE->set_audio_adapter = ((struct frontend_interface*)FRONTEND)->set_audio_adapter;
+static struct vxt_peripheral *create(vxt_allocator *alloc, void *frontend, const char *args) VXT_PERIPHERAL_CREATE(alloc, adlib, {
+	if (frontend)
+		DEVICE->set_audio_adapter = ((struct frontend_interface*)frontend)->set_audio_adapter;
 
-    PERIPHERAL->install = &install;
-    PERIPHERAL->reset = &reset;
-    PERIPHERAL->name = &name;
-    PERIPHERAL->io.in = ∈
-    PERIPHERAL->io.out = &out;
+	DEVICE->freq = 48000;
+	PERIPHERAL->install = &install;
+	PERIPHERAL->reset = &reset;
+	PERIPHERAL->name = &name;
+	PERIPHERAL->io.in = ∈
+	PERIPHERAL->io.out = &out;
 })
+
+VXTU_MODULE_ENTRIES(&create)

premake5.lua

@@ -162,7 +162,7 @@ workspace "virtualxt"
 
                 cleancommands {
                     "{RMFILE} modules/" .. name .. ".*",
-                    "make clean %{cfg.buildcfg}"
+                    "${MAKE} clean %{cfg.buildcfg}"
                 }
 
                 filter {}
@@ -258,7 +258,7 @@ workspace "virtualxt"
 
         cleancommands {
             "{RMDIR} build/libretro",
-            "make clean %{cfg.buildcfg}"
+            "${MAKE} clean %{cfg.buildcfg}"
         }
 
         filter "toolset:clang or gcc"
@@ -320,7 +320,7 @@ workspace "virtualxt"
 
         cleancommands {
             "{RMDIR} build/web",
-            "make clean %{cfg.buildcfg}"
+            "${MAKE} clean %{cfg.buildcfg}"
         }
 
     project "sdl2-frontend"
@@ -349,7 +349,7 @@ workspace "virtualxt"
 
         cleancommands {
             "{RMDIR} build/sdl2",
-            "make clean %{cfg.buildcfg}"
+            "${MAKE} clean %{cfg.buildcfg}"
         }
 
         filter "action:vs*"
@@ -402,7 +402,7 @@ workspace "virtualxt"
 
         cleancommands {
             "{RMDIR} build/sdl3",
-            "make clean %{cfg.buildcfg}"
+            "${MAKE} clean %{cfg.buildcfg}"
         }
 
         filter "action:vs*"
@@ -452,7 +452,7 @@ workspace "virtualxt"
 
         cleancommands {
             "{RMDIR} build/terminal",
-            "make clean %{cfg.buildcfg}"
+            "${MAKE} clean %{cfg.buildcfg}"
         }
 
         filter "options:validator"
@@ -468,6 +468,11 @@ workspace "virtualxt"
         filter "toolset:gcc"
             buildoptions "-Wno-maybe-uninitialized"
 
+	project "rpi-frontend"
+		kind "Makefile"
+		buildcommands "${MAKE} -C front/rpi"
+		cleancommands "${MAKE} -C front/rpi clean"
+
 if _OPTIONS["test"] then
     project "test"
         kind "ConsoleApp"