Clang warns for the uint32_t clip_ instantiations because HALF cannot be
represented with mixeng_real:
[1115/2559] Compiling C object libqemuaudio.a.p/audio_mixeng.c.o
In file included from ../../qemu/audio/mixeng.c:147:
../../qemu/audio/mixeng_template.h:68:70: warning: implicit conversion from 'unsigned int' to 'float' changes value from 2147483647 to 2147483648 [-Wimplicit-const-int-float-conversion]
68 | return ENDIAN_CONVERT((IN_T)((v * ((mixeng_real)IN_MAX / 2.f)) + HALF));
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~
../../qemu/audio/mixeng_template.h:31:22: note: expanded from macro 'HALF'
31 | #define HALF (IN_MAX >> 1)
| ^
../../qemu/audio/mixeng.c:146:28: note: expanded from macro 'ENDIAN_CONVERT'
146 | #define ENDIAN_CONVERT(v) (v)
| ^
In file included from ../../qemu/audio/mixeng.c:152:
../../qemu/audio/mixeng_template.h:68:70: warning: implicit conversion from 'unsigned int' to 'float' changes value from 2147483647 to 2147483648 [-Wimplicit-const-int-float-conversion]
68 | return ENDIAN_CONVERT((IN_T)((v * ((mixeng_real)IN_MAX / 2.f)) + HALF));
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~
../../qemu/audio/mixeng_template.h:31:22: note: expanded from macro 'HALF'
31 | #define HALF (IN_MAX >> 1)
| ^
../../qemu/audio/mixeng.c:151:36: note: expanded from macro 'ENDIAN_CONVERT'
151 | #define ENDIAN_CONVERT(v) bswap32 (v)
| ~~~~~~~~~^~
/Users/person/v/qemu/include/qemu/bswap.h:10:39: note: expanded from macro 'bswap32'
10 | #define bswap32(_x) __builtin_bswap32(_x)
| ^~
2 warnings generated.
HALF is not the right value here anyway. IN_MAX is odd, so the integer
sample range has two middle codes. Unsigned PCM normally uses the upper
middle code as the "bias": 0x80, 0x8000, or 0x80000000. HALF is instead
defined as the lower middle code: 0x7f, 0x7fff, or 0x7fffffff.
Replace HALF with BIAS, defined as the upper middle code. This fixes the
warnings, since the value can be exactly represented with mixeng_real.
Signed-off-by: Akihiko Odaki <odaki@rsg.ci.i.u-tokyo.ac.jp>
Acked-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20260423-audio-v1-3-e1d6b65c76f9@rsg.ci.i.u-tokyo.ac.jp>
clip_*_uint32_t() returns 0 when v == 1.f because it computes the result
as (IN_T)((v * ((mixeng_real)IN_MAX / 2.f)) + HALF):
- (v * ((mixeng_real)IN_MAX / 2.f)) + HALF == 0x100000000.f, which does
not fit in uint32_t.
- (v * ((mixeng_real)IN_MAX / 2.f)) == 0x80000000.f
- ((mixeng_real)IN_MAX / 2.f) == 0x80000000.f
- (mixeng_real)IN_MAX == 0x100000000.f because 0xffffffff cannot be
represented exactly in float.
- HALF == 0x7fffffff, which is implicitly converted to 0x80000000.f.
Clamp the result to avoid the overflow.
Signed-off-by: Akihiko Odaki <odaki@rsg.ci.i.u-tokyo.ac.jp>
Acked-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20260423-audio-v1-2-e1d6b65c76f9@rsg.ci.i.u-tokyo.ac.jp>
When !defined(SIGNED), nv - HALF will wrap around if nv < HALF because
nv and HALF are unsigned. Fix it by casting nv to mixeng_real, which is
signed.
Signed-off-by: Akihiko Odaki <odaki@rsg.ci.i.u-tokyo.ac.jp>
Acked-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20260423-audio-v1-1-e1d6b65c76f9@rsg.ci.i.u-tokyo.ac.jp>
Currently the internal float range of the mixing engine is
[-.5f, .5f]. PulseAudio, SDL2 and libasound use a [-1.f, 1.f]
range. This means with float samples the audio playback volume
is 6dB too low and audio recording signals will be clipped in
most cases.
To avoid another scaling factor in the conv_natural_float_* and
clip_natural_float_* functions with FLOAT_MIXENG defined this
patch changes the mixing engine float range to [-1.f, 1.f].
Signed-off-by: Volker Rümelin <vr_qemu@t-online.de>
Message-id: 20200308193321.20668-4-vr_qemu@t-online.de
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Fix error: ‘inline’ is not at beginning of declaration
[-Werror=old-style-declaration]
Signed-off-by: Alex Bligh <alex@alex.org.uk>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
Split IN_T into BSIZE and ITYPE, to avoid expansion if the OS has
defined macros for the intX_t and uintX_t types. The IN_T constant is
then defined in mixeng_template.h so it can be used by the
functions/macros on this header file.
This change has been tested successfully under Debian Linux and NetBSD
6.0BETA.
Cc: Vassili Karpov (malc) <av1474@comtv.ru>
Signed-off-by: Roger Pau Monne <roger.pau@citrix.com>
Signed-off-by: malc <av1474@comtv.ru>
Fix an integer overflow that can happen for signed 32 bit types
when using FLOAT_MIXENG. (Note that at the moment this is only true
when using the MacOSX coreaudio audio driver.)
Signed-off-by: Juha Riihim?ki <juha.riihimaki@nokia.com>
[Peter Maydell: Removed unnecessary casts]
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: malc <av1474@comtv.ru>
Refactor the volume mixing, so it can be reused for capturing devices.
Additionally, it removes superfluous multiplications with the nominal
volume within the hardware voice code path.
Signed-off-by: Michael Walle <michael@walle.cc>
Signed-off-by: malc <av1474@comtv.ru>
