CD audio optimizations and buffer zero-copy

.github/workflows/windows.yml

@@ -98,7 +98,7 @@ jobs:
       - name:  Install packages
         shell: pwsh
         run: |
-          vcpkg install libpng sdl1 sdl1-net opusfile speexdsp
+          vcpkg install libpng sdl1 sdl1-net opusfile
           vcpkg integrate install
       - name:  Build
         shell: pwsh
@@ -120,7 +120,7 @@ jobs:
       - name:  Install packages
         shell: pwsh
         run: |
-          vcpkg install libpng sdl1 sdl1-net opusfile speexdsp
+          vcpkg install libpng sdl1 sdl1-net opusfile
           vcpkg integrate install
       - name:  Build
         shell: pwsh

configure.ac

@@ -466,15 +466,11 @@ else
    AC_MSG_WARN([Can't find SDL_net, internal modem and ipx disabled])
 fi
 
-# Check for required Opus decoding libraries
+# Check for the Opus file-handling library
 PKG_CHECK_MODULES([OPUSFILE], [opusfile],
   [ LIBS="$LIBS ${OPUSFILE_LIBS}"
     CPPFLAGS="$CPPFLAGS ${OPUSFILE_CFLAGS}" ], [])
 
-PKG_CHECK_MODULES([SPEEXDSP], [speexdsp],
-  [ LIBS="$LIBS ${SPEEXDSP_LIBS}"
-    CPPFLAGS="$CPPFLAGS ${SPEEXDSP_CFLAGS}" ], [])
-
 AH_TEMPLATE(C_X11_XKB,[define to 1 if you have XKBlib.h and X11 lib])
 AC_CHECK_LIB(X11, main, have_x11_lib=yes, have_x11_lib=no, )
 AC_CHECK_HEADER(X11/XKBlib.h, have_x11_h=yes, have_x11_h=no, )

include/mixer.h

@@ -46,8 +46,11 @@ extern Bit8u MixTemp[MIXER_BUFSIZE];
 
 class MixerChannel {
 public:
+	MixerChannel(MIXER_Handler _handler, Bitu _freq, const char * _name);
 	void SetVolume(float _left,float _right);
-	void SetScale( float f );
+	void SetScale(float f);
+	void SetScale(float _left, float _right);
+	void MapChannels(Bit8u _left, Bit8u _right);
 	void UpdateVolume(void);
 	void SetFreq(Bitu _freq);
 	void Mix(Bitu _needed);
@@ -77,24 +80,25 @@ class MixerChannel {
 
 	void FillUp(void);
 	void Enable(bool _yesno);
-	MIXER_Handler handler;
-	float volmain[2];
-	float scale;
-	Bit32s volmul[2];
-
-	//This gets added the frequency counter each mixer step
-	Bitu freq_add;
-	//When this flows over a new sample needs to be read from the device
-	Bitu freq_counter;
-	//Timing on how many samples have been done and were needed by th emixer
-	Bitu done, needed;
-	//Previous and next samples
-	Bits prevSample[2];
-	Bits nextSample[2];
-	const char * name;
-	bool interpolate;
-	bool enabled;
-	MixerChannel * next;
+
+	float          volmain[2];
+	MixerChannel*  next;
+	const char*    name;
+	Bitu           done;           //Timing on how many samples have been done by the mixer
+	bool           enabled;
+
+private:
+	MixerChannel();
+	MIXER_Handler  handler;
+	Bitu           freq_add;       //This gets added the frequency counter each mixer step
+	Bitu           freq_counter;   //When this flows over a new sample needs to be read from the device
+	Bitu           needed; 	       //Timing on how many samples were needed by the mixer
+	Bits           prev_sample[2]; //Previous and next samples
+	Bits           next_sample[2];
+	Bit32s         volmul[2];
+	float          scale[2];
+	Bit8u          channel_map[2]; //Output channel mapping
+	bool           interpolate;
 };
 
 MixerChannel * MIXER_AddChannel(MIXER_Handler handler,Bitu freq,const char * name);

scripts/list-build-dependencies.sh

@@ -105,31 +105,31 @@ function list_packages() {
 			if [[ "${COMPILER}" == "gcc" ]]; then
 				COMPILER="g++"
 			fi
-			PACKAGES=(libtool build-essential autoconf-archive libsdl1.2-dev libsdl-net1.2-dev libopusfile-dev libspeexdsp-dev)
+			PACKAGES=(libtool build-essential autoconf-archive libsdl1.2-dev libsdl-net1.2-dev libopusfile-dev)
 			;;
 
 		dnf)
 			VERSION_DELIM="-"
-			PACKAGES=(libtool autoconf-archive SDL SDL_net-devel opusfile-devel speexdsp-devel)
+			PACKAGES=(libtool autoconf-archive SDL SDL_net-devel opusfile-devel)
 			;;
 
 		pacman)
-			# Arch offers 32-bit versions of SDL and speexDSP (but not others)
+			# Arch offers 32-bit versions of SDL (but not others)
 			PACKAGES=(libtool autoconf-archive sdl_net opusfile)
 			if [[ "${BITS}" == 32 ]]; then
-				PACKAGES+=(lib32-sdl lib32-speexdsp)
+				PACKAGES+=(lib32-sdl)
 			else
-				PACKAGES+=(sdl speexdsp)
+				PACKAGES+=(sdl)
 			fi
 			;;
 
 		zypper)
-			# OpenSUSE offers 32-bit versions of SDL, SDL_net, and speexDSP (but not others)
+			# OpenSUSE offers 32-bit versions of SDL and SDL_net (but not others)
 			PACKAGES=(devel_basis libtool autoconf-archive opusfile)
 			if [[ "${BITS}" == 32 ]]; then
-				PACKAGES+=(libSDL-devel-32bit libSDL_net-devel-32bit libspeexdsp1-32bit)
+				PACKAGES+=(libSDL-devel-32bit libSDL_net-devel-32bit)
 			else
-				PACKAGES+=(SDL SDL_net speexdsp)
+				PACKAGES+=(SDL SDL_net)
 			fi
 			;;
 
@@ -142,7 +142,7 @@ function list_packages() {
 			echo "   sudo xcodebuild -license  # to accept Apple's license agreement"
 			echo ""
 			echo "Now download, build, and install the following manually to avoid using Homebrew or MacPorts:"
-			echo " - coreutils autogen autoconf automake pkg-config libpng sdl sdl_net opusfile speexdsp"
+			echo " - coreutils autogen autoconf automake pkg-config libpng sdl sdl_net opusfile"
 			;;
 
 		brew)
@@ -151,11 +151,11 @@ function list_packages() {
 			if [[ "${COMPILER}" == "clang" ]]; then
 				COMPILER=""
 			fi
-			PACKAGES=(coreutils autogen autoconf autoconf-archive automake pkg-config libpng sdl sdl_net opusfile speexdsp)
+			PACKAGES=(coreutils autogen autoconf autoconf-archive automake pkg-config libpng sdl sdl_net opusfile)
 			;;
 
 		macports)
-			PACKAGES=(coreutils autogen automake autoconf autoconf-archive pkgconfig libpng libsdl libsdl_net opusfile speexDSP)
+			PACKAGES=(coreutils autogen automake autoconf autoconf-archive pkgconfig libpng libsdl libsdl_net opusfile)
 			;;
 
 		msys2)
@@ -167,7 +167,7 @@ function list_packages() {
 				pkg_type="i686"
 			fi
 			PACKAGES=(autogen autoconf autoconf-archive base-devel automake-wrapper)
-			for pkg in pkg-config libtool libpng zlib SDL SDL_net opusfile speexdsp; do
+			for pkg in pkg-config libtool libpng zlib SDL SDL_net opusfile; do
 				PACKAGES+=("mingw-w64-${pkg_type}-${pkg}")
 			done
 			COMPILER="mingw-w64-${pkg_type}-${COMPILER}"
@@ -176,7 +176,7 @@ function list_packages() {
 		vcpkg)
 			# VCPKG doesn't provide Clang or GCC, so we knock out the compiler and just give packages
 			COMPILER=""
-			PACKAGES=(libpng sdl1 sdl1-net opusfile speexdsp)
+			PACKAGES=(libpng sdl1 sdl1-net opusfile)
 			;;
 		*)
 			usage "Unknown package manager ${1}"

src/dos/cdrom.h

@@ -36,13 +36,11 @@
 #include "mixer.h"
 #include "../libs/decoders/SDL_sound.h"
 
-#define RAW_SECTOR_SIZE		2352
-#define COOKED_SECTOR_SIZE	2048
-#define AUDIO_DECODE_BUFFER_SIZE 16512
-// 16512 is 16384 + 128, which enough for four 4KB decode audio chunks plus 128 bytes extra,
-// which accomodate the leftovers from typically callbacks, which also helps minimize
-// most of the time. This size is also an even multiple of 8-bytes, allowing the compiler to
-// use "large-D" SIMD instructions on it.
+// CDROM data and audio format constants
+#define RAW_SECTOR_SIZE         2352
+#define COOKED_SECTOR_SIZE      2048
+#define BYTES_PER_TRACK_FRAME      4
+#define REDBOOK_FRAMES_PER_SECOND 75
 
 enum { CDROM_USE_SDL, CDROM_USE_ASPI, CDROM_USE_IOCTL_DIO, CDROM_USE_IOCTL_DX, CDROM_USE_IOCTL_MCI };
 
@@ -53,17 +51,16 @@ typedef struct SMSF {
 } TMSF;
 
 typedef struct SCtrl {
-	Bit8u	out[4];			// output channel
-	Bit8u	vol[4];			// channel volume
+	Bit8u	out[4];			// output channel mapping
+	Bit8u	vol[4];			// channel volume (0 to 255)
 } TCtrl;
 
 // Conversion function from frames to Minutes/Second/Frames
 //
 template<typename T>
 inline void frames_to_msf(int frames, T *m, T *s, T *f) {
-	const int cd_fps = 75;
-	*f = frames % cd_fps;
-	frames /= cd_fps;
+	*f = frames % REDBOOK_FRAMES_PER_SECOND;
+	frames /= REDBOOK_FRAMES_PER_SECOND;
 	*s = frames % 60;
 	frames /= 60;
 	*m = frames;
@@ -72,8 +69,7 @@ inline void frames_to_msf(int frames, T *m, T *s, T *f) {
 // Conversion function from Minutes/Second/Frames to frames
 //
 inline int msf_to_frames(int m, int s, int f) {
-	const int cd_fps = 75;
-	return m * 60 * cd_fps + s * cd_fps + f;
+	return m * 60 * REDBOOK_FRAMES_PER_SECOND + s * REDBOOK_FRAMES_PER_SECOND + f;
 }
 
 extern int CDROM_GetMountType(char* path, int force);
@@ -161,7 +157,7 @@ class CDROM_Interface_Image : public CDROM_Interface
 	public:
 		virtual bool    read(Bit8u *buffer, int seek, int count) = 0;
 		virtual bool    seek(Bit32u offset) = 0;
-		virtual Bit16u  decode(Bit8u *buffer) = 0;
+		virtual Bit32u  decode(Bit16s *buffer, Bit32u desired_track_frames) = 0;
 		virtual Bit16u  getEndian() = 0;
 		virtual Bit32u  getRate() = 0;
 		virtual Bit8u   getChannels() = 0;
@@ -175,7 +171,7 @@ class CDROM_Interface_Image : public CDROM_Interface
 		BinaryFile      (const char *filename, bool &error);
 		bool            read(Bit8u *buffer, int seek, int count);
 		bool            seek(Bit32u offset);
-		Bit16u          decode(Bit8u *buffer);
+		Bit32u          decode(Bit16s *buffer, Bit32u desired_track_frames);
 		Bit16u          getEndian();
 		Bit32u          getRate() { return 44100; }
 		Bit8u           getChannels() { return 2; }
@@ -191,7 +187,7 @@ class CDROM_Interface_Image : public CDROM_Interface
 		AudioFile       (const char *filename, bool &error);
 		bool            read(Bit8u *buffer, int seek, int count) { return false; }
 		bool            seek(Bit32u offset);
-		Bit16u          decode(Bit8u *buffer);
+		Bit32u          decode(Bit16s *buffer, Bit32u desired_track_frames);
 		Bit16u          getEndian();
 		Bit32u          getRate();
 		Bit8u           getChannels();
@@ -237,26 +233,21 @@ static	CDROM_Interface_Image* images[26];
 
 private:
 	// player
-static	void	CDAudioCallBack(Bitu len);
+static	void	CDAudioCallBack(Bitu desired_frames);
 	int	GetTrack(int sector);
 
 static  struct imagePlayer {
-		Bit8u                 buffer[AUDIO_DECODE_BUFFER_SIZE];
-		TCtrl                 ctrlData;
+		Bit16s                buffer[MIXER_BUFSIZE * 2]; // 2 channels (max)
 		TrackFile             *trackFile;
 		MixerChannel          *channel;
 		CDROM_Interface_Image *cd;
-		void                  (MixerChannel::*addSamples) (Bitu, const Bit16s*);
-		Bit32u                startFrame;
-		Bit32u                currFrame;
-		Bit32u                numFrames;
-		Bit32u                playbackTotal;
-		Bit32s                playbackRemaining;
-		Bit16u                bufferPos;
-		Bit16u                bufferConsumed;
+		void                  (MixerChannel::*addFrames) (Bitu, const Bit16s*);
+		Bit32u                startRedbookFrame;
+		Bit32u                totalRedbookFrames;
+		Bit32u                playedTrackFrames;
+		Bit32u                totalTrackFrames;
 		bool                  isPlaying;
 		bool                  isPaused;
-		bool                  ctrlUsed;
 	} player;
 
 	void  ClearTracks();
@@ -407,7 +398,7 @@ class CDROM_Interface_Ioctl : public CDROM_Interface
 		SDL_mutex		*mutex;
 		Bit8u   buffer[8192];
 		int     bufLen;
-		int     currFrame;	
+		int     currFrame;
 		int     targetFrame;
 		bool    isPlaying;
 		bool    isPaused;