git: 1728d26682c6 - stable/14 - sound: Implement AFMT_FLOAT support
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Date: Sun, 06 Apr 2025 00:28:28 UTC
The branch stable/14 has been updated by christos:
URL: https://cgit.FreeBSD.org/src/commit/?id=1728d26682c65cb878971f55b4e87e24d0050524
commit 1728d26682c65cb878971f55b4e87e24d0050524
Author: Christos Margiolis <christos@FreeBSD.org>
AuthorDate: 2025-03-30 17:45:38 +0000
Commit: Christos Margiolis <christos@FreeBSD.org>
CommitDate: 2025-04-06 00:28:14 +0000
sound: Implement AFMT_FLOAT support
Even though the OSS manual [1] advises against using AFMT_FLOAT, there
are applications that expect the sound driver to support it, and might
not work properly without it.
This patch adds AFMT_F32_LE|BE (as well as AFMT_FLOAT for OSS
compatibility) in sys/soundcard.h and implements AFMT_F32_LE|BE <->
AFMT_S32_LE|BE conversion functions. As a result, applications can
write/read floats to/from sound(4), but internally, because sound(4)
works with integers, we convert floating point samples to integer ones,
before doing any processing.
The reason for encoding/decoding IEEE754s manually, instead of using
fpu_kern(9), is that fpu_kern(9) is not supported by all architectures,
and also introduces significant overhead.
The IEEE754 encoding/decoding implementation has been written by Ariff
Abdullah [2].
[1] http://manuals.opensound.com/developer/AFMT_FLOAT.html
[2] https://people.freebsd.org/~ariff/utils/ieee754.c
PR: 157050, 184380, 264973, 280612, 281390
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Reviewed by: emaste
Differential Revision: https://reviews.freebsd.org/D47638
(cherry picked from commit e1bbaa71d62c8681a576f9f5bedf475c7541bd35)
---
sys/dev/sound/pcm/channel.c | 4 +++
sys/dev/sound/pcm/feeder_chain.c | 2 ++
sys/dev/sound/pcm/feeder_rate.c | 4 +++
sys/dev/sound/pcm/feeder_volume.c | 2 ++
sys/dev/sound/pcm/pcm.h | 67 +++++++++++++++++++++++++++++++++++++--
sys/dev/sound/pcm/sound.h | 13 +++++---
sys/sys/soundcard.h | 8 +++++
tests/sys/sound/pcm_read_write.c | 6 ++++
8 files changed, 98 insertions(+), 8 deletions(-)
diff --git a/sys/dev/sound/pcm/channel.c b/sys/dev/sound/pcm/channel.c
index 4a96505ada66..3aa7cf219d81 100644
--- a/sys/dev/sound/pcm/channel.c
+++ b/sys/dev/sound/pcm/channel.c
@@ -977,9 +977,13 @@ static const struct {
#if BYTE_ORDER == LITTLE_ENDIAN
{ "s32le", "s32", "32", AFMT_S32_LE },
{ "s32be", NULL, NULL, AFMT_S32_BE },
+ { "f32le", "f32", NULL, AFMT_F32_LE },
+ { "f32be", NULL, NULL, AFMT_F32_BE },
#else
{ "s32le", NULL, NULL, AFMT_S32_LE },
{ "s32be", "s32", "32", AFMT_S32_BE },
+ { "f32le", NULL, NULL, AFMT_F32_LE },
+ { "f32be", "f32", NULL, AFMT_F32_BE },
#endif
{ "u32le", NULL, NULL, AFMT_U32_LE },
{ "u32be", NULL, NULL, AFMT_U32_BE },
diff --git a/sys/dev/sound/pcm/feeder_chain.c b/sys/dev/sound/pcm/feeder_chain.c
index 1c4ddca6cdd5..56de32441de7 100644
--- a/sys/dev/sound/pcm/feeder_chain.c
+++ b/sys/dev/sound/pcm/feeder_chain.c
@@ -102,6 +102,7 @@ static uint32_t feeder_chain_formats_multi[] = {
AFMT_S16_LE, AFMT_S16_BE, AFMT_U16_LE, AFMT_U16_BE,
AFMT_S24_LE, AFMT_S24_BE, AFMT_U24_LE, AFMT_U24_BE,
AFMT_S32_LE, AFMT_S32_BE, AFMT_U32_LE, AFMT_U32_BE,
+ AFMT_F32_LE, AFMT_F32_BE,
0
};
@@ -111,6 +112,7 @@ static uint32_t feeder_chain_formats_fullmulti[] = {
AFMT_S16_LE, AFMT_S16_BE, AFMT_U16_LE, AFMT_U16_BE,
AFMT_S24_LE, AFMT_S24_BE, AFMT_U24_LE, AFMT_U24_BE,
AFMT_S32_LE, AFMT_S32_BE, AFMT_U32_LE, AFMT_U32_BE,
+ AFMT_F32_LE, AFMT_F32_BE,
0
};
diff --git a/sys/dev/sound/pcm/feeder_rate.c b/sys/dev/sound/pcm/feeder_rate.c
index 1610211ff5f5..9ea454cdee1e 100644
--- a/sys/dev/sound/pcm/feeder_rate.c
+++ b/sys/dev/sound/pcm/feeder_rate.c
@@ -639,6 +639,8 @@ Z_DECLARE(U, 32, LE)
Z_DECLARE(U, 16, BE)
Z_DECLARE(U, 24, BE)
Z_DECLARE(U, 32, BE)
+Z_DECLARE(F, 32, LE)
+Z_DECLARE(F, 32, BE)
#endif
enum {
@@ -687,6 +689,8 @@ static const struct {
Z_RESAMPLER_ENTRY(U, 16, BE),
Z_RESAMPLER_ENTRY(U, 24, BE),
Z_RESAMPLER_ENTRY(U, 32, BE),
+ Z_RESAMPLER_ENTRY(F, 32, LE),
+ Z_RESAMPLER_ENTRY(F, 32, BE),
#endif
};
diff --git a/sys/dev/sound/pcm/feeder_volume.c b/sys/dev/sound/pcm/feeder_volume.c
index f72c6aa7ef4f..2d35bb56ef8f 100644
--- a/sys/dev/sound/pcm/feeder_volume.c
+++ b/sys/dev/sound/pcm/feeder_volume.c
@@ -93,6 +93,8 @@ FEEDVOLUME_DECLARE(U, 32, LE)
FEEDVOLUME_DECLARE(U, 16, BE)
FEEDVOLUME_DECLARE(U, 24, BE)
FEEDVOLUME_DECLARE(U, 32, BE)
+FEEDVOLUME_DECLARE(F, 32, LE)
+FEEDVOLUME_DECLARE(F, 32, BE)
#endif
struct feed_volume_info {
diff --git a/sys/dev/sound/pcm/pcm.h b/sys/dev/sound/pcm/pcm.h
index 1de686b04097..7d0a8f0f431b 100644
--- a/sys/dev/sound/pcm/pcm.h
+++ b/sys/dev/sound/pcm/pcm.h
@@ -128,7 +128,8 @@ static const struct {
static __always_inline __unused intpcm_t
pcm_sample_read(const uint8_t *src, uint32_t fmt)
{
- intpcm_t v;
+ intpcm_t v, e, m;
+ bool s;
fmt = AFMT_ENCODING(fmt);
@@ -190,6 +191,34 @@ pcm_sample_read(const uint8_t *src, uint32_t fmt)
v = INTPCM_T(src[3] | src[2] << 8 | src[1] << 16 |
(int8_t)(src[0] ^ 0x80) << 24);
break;
+ case AFMT_F32_LE: /* FALLTHROUGH */
+ case AFMT_F32_BE:
+ if (fmt == AFMT_F32_LE) {
+ v = INTPCM_T(src[0] | src[1] << 8 | src[2] << 16 |
+ (int8_t)src[3] << 24);
+ } else {
+ v = INTPCM_T(src[3] | src[2] << 8 | src[1] << 16 |
+ (int8_t)src[0] << 24);
+ }
+ e = (v >> 23) & 0xff;
+ /* NaN, +/- Inf or too small */
+ if (e == 0xff || e < 96) {
+ v = INTPCM_T(0);
+ break;
+ }
+ s = v & 0x80000000U;
+ if (e > 126) {
+ v = INTPCM_T((s == 0) ? PCM_S32_MAX : PCM_S32_MIN);
+ break;
+ }
+ m = 0x800000 | (v & 0x7fffff);
+ e += 8 - 127;
+ if (e < 0)
+ m >>= -e;
+ else
+ m <<= e;
+ v = INTPCM_T((s == 0) ? m : -m);
+ break;
default:
v = 0;
printf("%s(): unknown format: 0x%08x\n", __func__, fmt);
@@ -241,8 +270,38 @@ pcm_sample_read_calc(const uint8_t *src, uint32_t fmt)
static __always_inline __unused void
pcm_sample_write(uint8_t *dst, intpcm_t v, uint32_t fmt)
{
+ intpcm_t r, e;
+
fmt = AFMT_ENCODING(fmt);
+ if (fmt & (AFMT_F32_LE | AFMT_F32_BE)) {
+ if (v == 0)
+ r = 0;
+ else if (v == PCM_S32_MAX)
+ r = 0x3f800000;
+ else if (v == PCM_S32_MIN)
+ r = 0x80000000U | 0x3f800000;
+ else {
+ r = 0;
+ if (v < 0) {
+ r |= 0x80000000U;
+ v = -v;
+ }
+ e = 127 - 8;
+ while ((v & 0x7f000000) != 0) {
+ v >>= 1;
+ e++;
+ }
+ while ((v & 0x7f800000) == 0) {
+ v <<= 1;
+ e--;
+ }
+ r |= (e & 0xff) << 23;
+ r |= v & 0x7fffff;
+ }
+ v = r;
+ }
+
switch (fmt) {
case AFMT_AC3:
*(int16_t *)dst = 0;
@@ -295,13 +354,15 @@ pcm_sample_write(uint8_t *dst, intpcm_t v, uint32_t fmt)
dst[1] = v >> 8;
dst[0] = (v >> 16) ^ 0x80;
break;
- case AFMT_S32_LE:
+ case AFMT_S32_LE: /* FALLTHROUGH */
+ case AFMT_F32_LE:
dst[0] = v;
dst[1] = v >> 8;
dst[2] = v >> 16;
dst[3] = v >> 24;
break;
- case AFMT_S32_BE:
+ case AFMT_S32_BE: /* FALLTHROUGH */
+ case AFMT_F32_BE:
dst[3] = v;
dst[2] = v >> 8;
dst[1] = v >> 16;
diff --git a/sys/dev/sound/pcm/sound.h b/sys/dev/sound/pcm/sound.h
index 74c710f6f843..f7411ee096c9 100644
--- a/sys/dev/sound/pcm/sound.h
+++ b/sys/dev/sound/pcm/sound.h
@@ -451,15 +451,17 @@ int sound_oss_card_info(oss_card_info *);
#endif /* _KERNEL */
/* make figuring out what a format is easier. got AFMT_STEREO already */
-#define AFMT_32BIT (AFMT_S32_LE | AFMT_S32_BE | AFMT_U32_LE | AFMT_U32_BE)
+#define AFMT_32BIT (AFMT_S32_LE | AFMT_S32_BE | AFMT_U32_LE | AFMT_U32_BE | \
+ AFMT_F32_LE | AFMT_F32_BE)
#define AFMT_24BIT (AFMT_S24_LE | AFMT_S24_BE | AFMT_U24_LE | AFMT_U24_BE)
#define AFMT_16BIT (AFMT_S16_LE | AFMT_S16_BE | AFMT_U16_LE | AFMT_U16_BE)
#define AFMT_G711 (AFMT_MU_LAW | AFMT_A_LAW)
#define AFMT_8BIT (AFMT_G711 | AFMT_U8 | AFMT_S8)
-#define AFMT_SIGNED (AFMT_S32_LE | AFMT_S32_BE | AFMT_S24_LE | AFMT_S24_BE | \
+#define AFMT_SIGNED (AFMT_S32_LE | AFMT_S32_BE | AFMT_F32_LE | AFMT_F32_BE | \
+ AFMT_S24_LE | AFMT_S24_BE | \
AFMT_S16_LE | AFMT_S16_BE | AFMT_S8)
-#define AFMT_BIGENDIAN (AFMT_S32_BE | AFMT_U32_BE | AFMT_S24_BE | AFMT_U24_BE | \
- AFMT_S16_BE | AFMT_U16_BE)
+#define AFMT_BIGENDIAN (AFMT_S32_BE | AFMT_U32_BE | AFMT_F32_BE | \
+ AFMT_S24_BE | AFMT_U24_BE | AFMT_S16_BE | AFMT_U16_BE)
#define AFMT_CONVERTIBLE (AFMT_8BIT | AFMT_16BIT | AFMT_24BIT | \
AFMT_32BIT)
@@ -509,7 +511,8 @@ int sound_oss_card_info(oss_card_info *);
#define AFMT_U8_NE AFMT_U8
#define AFMT_S8_NE AFMT_S8
-#define AFMT_SIGNED_NE (AFMT_S8_NE | AFMT_S16_NE | AFMT_S24_NE | AFMT_S32_NE)
+#define AFMT_SIGNED_NE (AFMT_S8_NE | AFMT_S16_NE | AFMT_S24_NE | \
+ AFMT_S32_NE | AFMT_F32_NE)
#define AFMT_NE (AFMT_SIGNED_NE | AFMT_U8_NE | AFMT_U16_NE | \
AFMT_U24_NE | AFMT_U32_NE)
diff --git a/sys/sys/soundcard.h b/sys/sys/soundcard.h
index b5434b930215..a0342ebf58f0 100644
--- a/sys/sys/soundcard.h
+++ b/sys/sys/soundcard.h
@@ -184,6 +184,8 @@ struct snd_size {
#define AFMT_S24_BE 0x00020000 /* Big endian signed 24-bit */
#define AFMT_U24_LE 0x00040000 /* Little endian unsigned 24-bit */
#define AFMT_U24_BE 0x00080000 /* Big endian unsigned 24-bit */
+#define AFMT_F32_LE 0x10000000 /* Little endian 32-bit floating point */
+#define AFMT_F32_BE 0x20000000 /* Big endian 32-bit floating point */
/* Machine dependent AFMT_* definitions. */
#if BYTE_ORDER == LITTLE_ENDIAN
@@ -199,6 +201,8 @@ struct snd_size {
#define AFMT_U16_OE AFMT_U16_BE
#define AFMT_U24_OE AFMT_U24_BE
#define AFMT_U32_OE AFMT_U32_BE
+#define AFMT_F32_NE AFMT_F32_LE
+#define AFMT_F32_OE AFMT_F32_BE
#else
#define AFMT_S16_OE AFMT_S16_LE
#define AFMT_S24_OE AFMT_S24_LE
@@ -212,8 +216,12 @@ struct snd_size {
#define AFMT_U16_NE AFMT_U16_BE
#define AFMT_U24_NE AFMT_U24_BE
#define AFMT_U32_NE AFMT_U32_BE
+#define AFMT_F32_NE AFMT_F32_BE
+#define AFMT_F32_OE AFMT_F32_LE
#endif
+#define AFMT_FLOAT AFMT_F32_NE /* compatibility alias */
+
#define AFMT_STEREO 0x10000000 /* can do/want stereo */
/*
diff --git a/tests/sys/sound/pcm_read_write.c b/tests/sys/sound/pcm_read_write.c
index 2aba19840735..a77b953a78a0 100644
--- a/tests/sys/sound/pcm_read_write.c
+++ b/tests/sys/sound/pcm_read_write.c
@@ -70,6 +70,12 @@ static struct afmt_test_data {
{"u32be_1", {0x01, 0x02, 0x03, 0x04}, 4, AFMT_U32_BE, 0x81020304},
{"u32be_2", {0x81, 0x82, 0x83, 0x84}, 4, AFMT_U32_BE, 0x01828384},
+ /* 32 bit floating point sample formats. */
+ {"f32le_1", {0x00, 0x00, 0x00, 0x3f}, 4, AFMT_F32_LE, 0x40000000},
+ {"f32le_2", {0x00, 0x00, 0x00, 0xbf}, 4, AFMT_F32_LE, 0xc0000000},
+ {"f32be_1", {0x3f, 0x00, 0x00, 0x00}, 4, AFMT_F32_BE, 0x40000000},
+ {"f32be_2", {0xbf, 0x00, 0x00, 0x00}, 4, AFMT_F32_BE, 0xc0000000},
+
/* u-law and A-law sample formats. */
{"mulaw_1", {0x01, 0x00, 0x00, 0x00}, 1, AFMT_MU_LAW, 0xffffff87},
{"mulaw_2", {0x81, 0x00, 0x00, 0x00}, 1, AFMT_MU_LAW, 0x00000079},