Skip to content

Libretro: add USE_LOW_GBA_RESAMPLE_RATE flag to force GBA resample rate to 32768 (65536/2) in low-end platforms #312

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
saulfabregwiivc wants to merge 2 commits into
base: master
Choose a base branch
from
Open

Libretro: add USE_LOW_GBA_RESAMPLE_RATE flag to force GBA resample rate to 32768 (65536/2) in low-end platforms #312

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
fc16472
libretro: force GBA resample rate to 32768 if specific flag USE_LOW_G…
saulfabregwiivc Aug 11, 2025
05aa2bf
add flag USE_LOW_GBA_RESAMPLE_RATE in some low-end platforms
saulfabregwiivc Aug 11, 2025
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
8 changes: 4 additions & 4 deletions Makefile.libretro
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -268,7 +268,7 @@ else ifneq (,$(filter $(platform), psl1ght))
TARGET := $(TARGET_NAME)_libretro_$(platform).a
CC = $(PS3DEV)/ppu/bin/ppu-gcc$(EXE_EXT)
AR = $(PS3DEV)/ppu/bin/ppu-ar$(EXE_EXT)
PLATFORM_DEFINES := -D__PPC__ -D__BIG_ENDIAN__
PLATFORM_DEFINES := -D__PPC__ -D__BIG_ENDIAN__ -DUSE_LOW_GBA_RESAMPLE_RATE
STATIC_LINKING = 1
DEFINES += -std=gnu99 -fms-extensions
HAVE_VFS_FD = 0
Expand All @@ -279,7 +279,7 @@ else ifeq ($(platform), ps2)
CC = mips64r5900el-ps2-elf-gcc$(EXE_EXT)
AR = mips64r5900el-ps2-elf-ar$(EXE_EXT)
PLATFORM_DEFINES := -DPS2 -DCC_RESAMPLER
CFLAGS += -G0 -DHAVE_NO_LANGEXTRA -DHAVE_STRTOF_L -D_GNU_SOURCE -DHAVE_LOCALE
CFLAGS += -G0 -DHAVE_NO_LANGEXTRA -DHAVE_STRTOF_L -D_GNU_SOURCE -DHAVE_LOCALE -DUSE_LOW_GBA_RESAMPLE_RATE
STATIC_LINKING = 1
DEFINES += -std=c99
HAVE_VFS_FD = 0
Expand All @@ -290,7 +290,7 @@ else ifeq ($(platform), psp1)
CC = psp-gcc$(EXE_EXT)
AR = psp-ar$(EXE_EXT)
PLATFORM_DEFINES := -DPSP -DCC_RESAMPLER -DHAVE_STRTOF_L
CFLAGS += -G0 -I$(shell psp-config --pspsdk-path)/include
CFLAGS += -G0 -I$(shell psp-config --pspsdk-path)/include -DUSE_LOW_GBA_RESAMPLE_RATE
STATIC_LINKING = 1
DEFINES += -std=c99
HAVE_VFS_FD = 0
Expand Down Expand Up @@ -337,7 +337,7 @@ else ifneq (,$(filter $(platform), ngc wii wiiu))
CC = $(DEVKITPPC)/bin/powerpc-eabi-gcc$(EXE_EXT)
AR = $(DEVKITPPC)/bin/powerpc-eabi-ar$(EXE_EXT)
PLATFORM_DEFINES += -DGEKKO -mcpu=750 -meabi -mhard-float -DHAVE_STRTOF_L
PLATFORM_DEFINES += -U__INT32_TYPE__ -U __UINT32_TYPE__ -D__INT32_TYPE__=int -D_GNU_SOURCE
PLATFORM_DEFINES += -U__INT32_TYPE__ -U __UINT32_TYPE__ -D__INT32_TYPE__=int -D_GNU_SOURCE -DUSE_LOW_GBA_RESAMPLE_RATE
STATIC_LINKING = 1
DEFINES += -std=c99
HAVE_VFS_FD = 0
Expand Down
8 changes: 8 additions & 0 deletions src/platform/libretro/libretro.c
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -43,7 +43,15 @@ FS_Archive sdmcArchive;

#include "libretro_core_options.h"

/* 65536 is too high for low-end platforms (such the
* NGC, Wii, Wii U) resulting in a very slow
* GBA emulation performance...
* so let's revert to 32768 for these platforms */
#if !defined(USE_LOW_GBA_RESAMPLE_RATE)
#define GBA_RESAMPLED_RATE 65536
#else
#define GBA_RESAMPLED_RATE 32768
#endif
#define GB_SAMPLES 512
/* An alpha factor of 1/180 is *somewhat* equivalent
* to calculating the average for the last 180
Expand Down