audio/mixeng: replace redundant pcm_info fields with AudioFormat
The audio_pcm_info structure stored three fields (bits, is_signed, is_float) that were always derived from the AudioFormat enum. This redundancy meant the same information was represented twice, with no type-level guarantee that they stayed in sync. Replace these fields with a single AudioFormat field, and add helper functions to extract the derived properties when needed: - audio_format_bits() - audio_format_is_signed() - audio_format_is_float() This improves type safety by making AudioFormat the single source of truth, eliminating the possibility of inconsistent state between the format enum and its derived boolean/integer representations. Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com> Reviewed-by: Akihiko Odaki <odaki@rsg.ci.i.u-tokyo.ac.jp> Reviewed-by: Mark Cave-Ayland <mark.caveayland@nutanix.com>
Marc-André Lureau committed
Jan 20, 2026 at 23:23 UTC
42061a14358c4a26b2104c47ba1ff2adb14bbd63
6 files changed
+126
-171
audio/audio-mixeng-be.c
+63
-155
@@ -62,23 +62,28 @@ int audio_bug (const char *funcname, int cond)
62
return cond;
63
}
64
65
-static inline int audio_bits_to_index (int bits)
65
+/*
66
+ * Convert audio format to mixeng_clip index. Used by audio_pcm_sw_init_ and
67
+ * audio_mixeng_backend_add_capture()
68
+ */
69
+static int audio_format_to_index(AudioFormat af)
70
{
67
- switch (bits) {
68
- case 8:
71
+ switch (af) {
72
+ case AUDIO_FORMAT_U8:
73
+ case AUDIO_FORMAT_S8:
74
return 0;
70
-
71
- case 16:
75
+ case AUDIO_FORMAT_U16:
76
+ case AUDIO_FORMAT_S16:
77
return 1;
73
-
74
- case 32:
78
+ case AUDIO_FORMAT_U32:
79
+ case AUDIO_FORMAT_S32:
80
return 2;
76
-
77
- default:
78
- audio_bug ("bits_to_index", 1);
79
- AUD_log (NULL, "invalid bits %d\n", bits);
80
- return 0;
81
+ case AUDIO_FORMAT_F32:
82
+ case AUDIO_FORMAT__MAX:
83
+ break;
84
}
85
+
86
+ g_assert_not_reached();
87
}
88
89
void AUD_vlog (const char *cap, const char *fmt, va_list ap)
@@ -172,141 +177,68 @@ static int audio_validate_settings (const struct audsettings *as)
177
178
static int audio_pcm_info_eq (struct audio_pcm_info *info, const struct audsettings *as)
179
{
175
- int bits = 8;
176
- bool is_signed = false, is_float = false;
177
-
178
- switch (as->fmt) {
179
- case AUDIO_FORMAT_S8:
180
- is_signed = true;
181
- /* fall through */
182
- case AUDIO_FORMAT_U8:
183
- break;
184
-
185
- case AUDIO_FORMAT_S16:
186
- is_signed = true;
187
- /* fall through */
188
- case AUDIO_FORMAT_U16:
189
- bits = 16;
190
- break;
191
-
192
- case AUDIO_FORMAT_F32:
193
- is_float = true;
194
- /* fall through */
195
- case AUDIO_FORMAT_S32:
196
- is_signed = true;
197
- /* fall through */
198
- case AUDIO_FORMAT_U32:
199
- bits = 32;
200
- break;
201
-
202
- default:
203
- abort();
204
- }
205
- return info->freq == as->freq
180
+ return info->af == as->fmt
181
+ && info->freq == as->freq
182
&& info->nchannels == as->nchannels
207
- && info->is_signed == is_signed
208
- && info->is_float == is_float
209
- && info->bits == bits
183
&& info->swap_endianness == (as->endianness != HOST_BIG_ENDIAN);
184
}
185
186
void audio_pcm_init_info (struct audio_pcm_info *info, const struct audsettings *as)
187
{
215
- int bits = 8, mul;
216
- bool is_signed = false, is_float = false;
217
-
218
- switch (as->fmt) {
219
- case AUDIO_FORMAT_S8:
220
- is_signed = true;
221
- /* fall through */
222
- case AUDIO_FORMAT_U8:
223
- mul = 1;
224
- break;
225
-
226
- case AUDIO_FORMAT_S16:
227
- is_signed = true;
228
- /* fall through */
229
- case AUDIO_FORMAT_U16:
230
- bits = 16;
231
- mul = 2;
232
- break;
233
-
234
- case AUDIO_FORMAT_F32:
235
- is_float = true;
236
- /* fall through */
237
- case AUDIO_FORMAT_S32:
238
- is_signed = true;
239
- /* fall through */
240
- case AUDIO_FORMAT_U32:
241
- bits = 32;
242
- mul = 4;
243
- break;
244
-
245
- default:
246
- abort();
247
- }
248
-
188
+ info->af = as->fmt;
189
info->freq = as->freq;
250
- info->bits = bits;
251
- info->is_signed = is_signed;
252
- info->is_float = is_float;
190
info->nchannels = as->nchannels;
254
- info->bytes_per_frame = as->nchannels * mul;
191
+ info->bytes_per_frame = as->nchannels * audio_format_bits(as->fmt) / 8;
192
info->bytes_per_second = info->freq * info->bytes_per_frame;
193
info->swap_endianness = (as->endianness != HOST_BIG_ENDIAN);
194
}
195
259
-void audio_pcm_info_clear_buf (struct audio_pcm_info *info, void *buf, int len)
196
+void audio_pcm_info_clear_buf(struct audio_pcm_info *info, void *buf, int len)
197
{
198
if (!len) {
199
return;
200
}
201
265
- if (info->is_signed || info->is_float) {
266
- memset(buf, 0x00, len * info->bytes_per_frame);
267
- } else {
268
- switch (info->bits) {
269
- case 8:
270
- memset(buf, 0x80, len * info->bytes_per_frame);
271
- break;
272
-
273
- case 16:
274
- {
275
- int i;
276
- uint16_t *p = buf;
277
- short s = INT16_MAX;
278
-
279
- if (info->swap_endianness) {
280
- s = bswap16 (s);
281
- }
282
-
283
- for (i = 0; i < len * info->nchannels; i++) {
284
- p[i] = s;
285
- }
286
- }
287
- break;
202
+ switch (info->af) {
203
+ case AUDIO_FORMAT_U8:
204
+ memset(buf, 0x80, len * info->bytes_per_frame);
205
+ break;
206
+ case AUDIO_FORMAT_U16: {
207
+ int i;
208
+ uint16_t *p = buf;
209
+ short s = INT16_MAX;
210
289
- case 32:
290
- {
291
- int i;
292
- uint32_t *p = buf;
293
- int32_t s = INT32_MAX;
211
+ if (info->swap_endianness) {
212
+ s = bswap16(s);
213
+ }
214
295
- if (info->swap_endianness) {
296
- s = bswap32 (s);
297
- }
215
+ for (i = 0; i < len * info->nchannels; i++) {
216
+ p[i] = s;
217
+ }
218
+ break;
219
+ }
220
+ case AUDIO_FORMAT_U32: {
221
+ int i;
222
+ uint32_t *p = buf;
223
+ int32_t s = INT32_MAX;
224
299
- for (i = 0; i < len * info->nchannels; i++) {
300
- p[i] = s;
301
- }
302
- }
303
- break;
225
+ if (info->swap_endianness) {
226
+ s = bswap32(s);
227
+ }
228
305
- default:
306
- AUD_log (NULL, "audio_pcm_info_clear_buf: invalid bits %d\n",
307
- info->bits);
308
- break;
229
+ for (i = 0; i < len * info->nchannels; i++) {
230
+ p[i] = s;
231
}
232
+ break;
233
+ }
234
+ case AUDIO_FORMAT_S8:
235
+ case AUDIO_FORMAT_S16:
236
+ case AUDIO_FORMAT_S32:
237
+ case AUDIO_FORMAT_F32:
238
+ memset(buf, 0x00, len * info->bytes_per_frame);
239
+ break;
240
+ case AUDIO_FORMAT__MAX:
241
+ g_assert_not_reached();
242
}
243
}
244
@@ -719,8 +651,8 @@ static size_t audio_pcm_sw_write(SWVoiceOut *sw, void *buf, size_t buf_len)
651
#ifdef DEBUG_AUDIO
652
static void audio_pcm_print_info (const char *cap, struct audio_pcm_info *info)
653
{
722
- dolog("%s: bits %d, sign %d, float %d, freq %d, nchan %d\n",
723
- cap, info->bits, info->is_signed, info->is_float, info->freq,
654
+ dolog("%s: %s, freq %d, nchan %d\n",
655
+ cap, AudioFormat_str(info->af), info->freq,
656
info->nchannels);
657
}
658
#endif
@@ -1759,15 +1691,15 @@ static CaptureVoiceOut *audio_mixeng_backend_add_capture(
1691
1692
cap->buf = g_malloc0_n(hw->mix_buf.size, hw->info.bytes_per_frame);
1693
1762
- if (hw->info.is_float) {
1694
+ if (audio_format_is_float(hw->info.af)) {
1695
hw->clip = mixeng_clip_float[hw->info.nchannels == 2]
1696
[hw->info.swap_endianness];
1697
} else {
1698
hw->clip = mixeng_clip
1699
[hw->info.nchannels == 2]
1768
- [hw->info.is_signed]
1700
+ [audio_format_is_signed(hw->info.af)]
1701
[hw->info.swap_endianness]
1770
- [audio_bits_to_index(hw->info.bits)];
1702
+ [audio_format_to_index(hw->info.af)];
1703
}
1704
1705
QLIST_INSERT_HEAD (&s->cap_head, cap, entries);
@@ -1869,29 +1801,6 @@ audsettings audiodev_to_audsettings(AudiodevPerDirectionOptions *pdo)
1801
};
1802
}
1803
1872
-int audioformat_bytes_per_sample(AudioFormat fmt)
1873
-{
1874
- switch (fmt) {
1875
- case AUDIO_FORMAT_U8:
1876
- case AUDIO_FORMAT_S8:
1877
- return 1;
1878
-
1879
- case AUDIO_FORMAT_U16:
1880
- case AUDIO_FORMAT_S16:
1881
- return 2;
1882
-
1883
- case AUDIO_FORMAT_U32:
1884
- case AUDIO_FORMAT_S32:
1885
- case AUDIO_FORMAT_F32:
1886
- return 4;
1887
-
1888
- case AUDIO_FORMAT__MAX:
1889
- ;
1890
- }
1891
- abort();
1892
-}
1893
-
1894
-
1804
/* frames = freq * usec / 1e6 */
1805
int audio_buffer_frames(AudiodevPerDirectionOptions *pdo,
1806
audsettings *as, int def_usecs)
@@ -1914,8 +1823,7 @@ int audio_buffer_samples(AudiodevPerDirectionOptions *pdo,
1823
int audio_buffer_bytes(AudiodevPerDirectionOptions *pdo,
1824
audsettings *as, int def_usecs)
1825
{
1917
- return audio_buffer_samples(pdo, as, def_usecs) *
1918
- audioformat_bytes_per_sample(as->fmt);
1826
+ return audio_buffer_samples(pdo, as, def_usecs) * audio_format_bits(as->fmt) / 8;
1827
}
1828
1829
void audio_rate_start(RateCtl *rate)
audio/audio_int.h
+1
-3
@@ -45,9 +45,7 @@ struct audio_callback {
45
};
46
47
struct audio_pcm_info {
48
- int bits;
49
- bool is_signed;
50
- bool is_float;
48
+ AudioFormat af;
49
int freq;
50
int nchannels;
51
int bytes_per_frame;
audio/audio_template.h
+6
-6
@@ -173,7 +173,7 @@ static int glue (audio_pcm_sw_init_, TYPE) (
173
sw->empty = true;
174
#endif
175
176
- if (sw->info.is_float) {
176
+ if (audio_format_is_float(hw->info.af)) {
177
#ifdef DAC
178
sw->conv = mixeng_conv_float[sw->info.nchannels == 2]
179
[sw->info.swap_endianness];
@@ -188,9 +188,9 @@ static int glue (audio_pcm_sw_init_, TYPE) (
188
sw->clip = mixeng_clip
189
#endif
190
[sw->info.nchannels == 2]
191
- [sw->info.is_signed]
191
+ [audio_format_is_signed(hw->info.af)]
192
[sw->info.swap_endianness]
193
- [audio_bits_to_index(sw->info.bits)];
193
+ [audio_format_to_index(hw->info.af)];
194
}
195
196
sw->name = g_strdup (name);
@@ -300,7 +300,7 @@ static HW *glue(audio_pcm_hw_add_new_, TYPE)(AudioMixengBackend *s,
300
goto err1;
301
}
302
303
- if (hw->info.is_float) {
303
+ if (audio_format_is_float(hw->info.af)) {
304
#ifdef DAC
305
hw->clip = mixeng_clip_float[hw->info.nchannels == 2]
306
[hw->info.swap_endianness];
@@ -315,9 +315,9 @@ static HW *glue(audio_pcm_hw_add_new_, TYPE)(AudioMixengBackend *s,
315
hw->conv = mixeng_conv
316
#endif
317
[hw->info.nchannels == 2]
318
- [hw->info.is_signed]
318
+ [audio_format_is_signed(hw->info.af)]
319
[hw->info.swap_endianness]
320
- [audio_bits_to_index(hw->info.bits)];
320
+ [audio_format_to_index(hw->info.af)];
321
}
322
323
glue(audio_pcm_hw_alloc_resources_, TYPE)(hw);
audio/coreaudio.m
+1
-1
@@ -359,7 +359,7 @@ static OSStatus init_out_device(coreaudioVoiceOut *core)
359
AudioValueRange frameRange;
360
361
AudioStreamBasicDescription streamBasicDescription = {
362
- .mBitsPerChannel = core->hw.info.bits,
362
+ .mBitsPerChannel = audio_format_bits(core->hw.info.af),
363
.mBytesPerFrame = core->hw.info.bytes_per_frame,
364
.mBytesPerPacket = core->hw.info.bytes_per_frame,
365
.mChannelsPerFrame = core->hw.info.nchannels,
audio/dbusaudio.c
+6
-6
@@ -147,9 +147,9 @@ dbus_init_out_listener(QemuDBusDisplay1AudioOutListener *listener,
147
qemu_dbus_display1_audio_out_listener_call_init(
148
listener,
149
(uintptr_t)hw,
150
- hw->info.bits,
151
- hw->info.is_signed,
152
- hw->info.is_float,
150
+ audio_format_bits(hw->info.af),
151
+ audio_format_is_signed(hw->info.af),
152
+ audio_format_is_float(hw->info.af),
153
hw->info.freq,
154
hw->info.nchannels,
155
hw->info.bytes_per_frame,
@@ -273,9 +273,9 @@ dbus_init_in_listener(QemuDBusDisplay1AudioInListener *listener, HWVoiceIn *hw)
273
qemu_dbus_display1_audio_in_listener_call_init(
274
listener,
275
(uintptr_t)hw,
276
- hw->info.bits,
277
- hw->info.is_signed,
278
- hw->info.is_float,
276
+ audio_format_bits(hw->info.af),
277
+ audio_format_is_signed(hw->info.af),
278
+ audio_format_is_float(hw->info.af),
279
hw->info.freq,
280
hw->info.nchannels,
281
hw->info.bytes_per_frame,
include/qemu/audio.h
+49
@@ -185,6 +185,55 @@ bool audio_be_set_dbus_server(AudioBackend *be,
185
186
const char *audio_application_name(void);
187
188
+static inline int audio_format_bits(AudioFormat fmt)
189
+{
190
+ switch (fmt) {
191
+ case AUDIO_FORMAT_S8:
192
+ case AUDIO_FORMAT_U8:
193
+ return 8;
194
+
195
+ case AUDIO_FORMAT_S16:
196
+ case AUDIO_FORMAT_U16:
197
+ return 16;
198
+
199
+ case AUDIO_FORMAT_F32:
200
+ case AUDIO_FORMAT_S32:
201
+ case AUDIO_FORMAT_U32:
202
+ return 32;
203
+
204
+ case AUDIO_FORMAT__MAX:
205
+ break;
206
+ }
207
+
208
+ g_assert_not_reached();
209
+}
210
+
211
+static inline bool audio_format_is_float(AudioFormat fmt)
212
+{
213
+ return fmt == AUDIO_FORMAT_F32;
214
+}
215
+
216
+static inline bool audio_format_is_signed(AudioFormat fmt)
217
+{
218
+ switch (fmt) {
219
+ case AUDIO_FORMAT_S8:
220
+ case AUDIO_FORMAT_S16:
221
+ case AUDIO_FORMAT_S32:
222
+ case AUDIO_FORMAT_F32:
223
+ return true;
224
+
225
+ case AUDIO_FORMAT_U8:
226
+ case AUDIO_FORMAT_U16:
227
+ case AUDIO_FORMAT_U32:
228
+ return false;
229
+
230
+ case AUDIO_FORMAT__MAX:
231
+ break;
232
+ }
233
+
234
+ g_assert_not_reached();
235
+}
236
+
237
#define DEFINE_AUDIO_PROPERTIES(_s, _f) \
238
DEFINE_PROP_AUDIODEV("audiodev", _s, _f)
239