audio: common rate control code for timer based outputs

This commit removes the ad-hoc rate-limiting code from noaudio and
wavaudio, and replaces them with a (slightly modified) code from
spiceaudio.  This way multiple write calls (for example when the
circular buffer wraps around) do not cause problems.

Signed-off-by: Kővágó, Zoltán <DirtY.iCE.hu@gmail.com>
Message-id: fd0fe5b95b13fa26d09ae77a72f99d0ea411de14.1568927990.git.DirtY.iCE.hu@gmail.com
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

1 files changed, 8 insertions, 43 deletions

diff --git a/audio/spiceaudio.c b/audio/spiceaudio.c
index ff4e4dcbb0..4ce4f94c6d 100644
--- a/audio/spiceaudio.c
+++ b/audio/spiceaudio.c
@@ -40,15 +40,10 @@
 #define LINE_IN_SAMPLES (256 * 4)
 #endif
 
-typedef struct SpiceRateCtl {
-    int64_t               start_ticks;
-    int64_t               bytes_sent;
-} SpiceRateCtl;
-
 typedef struct SpiceVoiceOut {
     HWVoiceOut            hw;
     SpicePlaybackInstance sin;
-    SpiceRateCtl          rate;
+    RateCtl               rate;
     int                   active;
     uint32_t              *frame;
     uint32_t              fpos;
@@ -58,7 +53,7 @@ typedef struct SpiceVoiceOut {
 typedef struct SpiceVoiceIn {
     HWVoiceIn             hw;
     SpiceRecordInstance   sin;
-    SpiceRateCtl          rate;
+    RateCtl               rate;
     int                   active;
 } SpiceVoiceIn;
 
@@ -89,32 +84,6 @@ static void spice_audio_fini (void *opaque)
     /* nothing */
 }
 
-static void rate_start (SpiceRateCtl *rate)
-{
-    memset (rate, 0, sizeof (*rate));
-    rate->start_ticks = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
-}
-
-static int rate_get_samples (struct audio_pcm_info *info, SpiceRateCtl *rate)
-{
-    int64_t now;
-    int64_t ticks;
-    int64_t bytes;
-    int64_t samples;
-
-    now = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
-    ticks = now - rate->start_ticks;
-    bytes = muldiv64(ticks, info->bytes_per_second, NANOSECONDS_PER_SECOND);
-    samples = (bytes - rate->bytes_sent) >> info->shift;
-    if (samples < 0 || samples > 65536) {
-        error_report("Resetting rate control (%" PRId64 " samples)", samples);
-        rate_start(rate);
-        samples = 0;
-    }
-    rate->bytes_sent += samples << info->shift;
-    return samples;
-}
-
 /* playback */
 
 static int line_out_init(HWVoiceOut *hw, struct audsettings *as,
@@ -154,7 +123,6 @@ static void line_out_fini (HWVoiceOut *hw)
 static void *line_out_get_buffer(HWVoiceOut *hw, size_t *size)
 {
     SpiceVoiceOut *out = container_of(hw, SpiceVoiceOut, hw);
-    size_t decr;
 
     if (!out->frame) {
         spice_server_playback_get_buffer(&out->sin, &out->frame, &out->fsize);
@@ -162,12 +130,10 @@ static void *line_out_get_buffer(HWVoiceOut *hw, size_t *size)
     }
 
     if (out->frame) {
-        decr = rate_get_samples(&hw->info, &out->rate);
-        decr = MIN(out->fsize - out->fpos, decr);
-
-        *size = decr << hw->info.shift;
+        *size = audio_rate_get_bytes(
+            &hw->info, &out->rate, (out->fsize - out->fpos) << hw->info.shift);
     } else {
-        rate_start(&out->rate);
+        audio_rate_start(&out->rate);
     }
     return out->frame + out->fpos;
 }
@@ -197,7 +163,7 @@ static int line_out_ctl (HWVoiceOut *hw, int cmd, ...)
             break;
         }
         out->active = 1;
-        rate_start (&out->rate);
+        audio_rate_start(&out->rate);
         spice_server_playback_start (&out->sin);
         break;
     case VOICE_DISABLE:
@@ -273,8 +239,7 @@ static void line_in_fini (HWVoiceIn *hw)
 static size_t line_in_read(HWVoiceIn *hw, void *buf, size_t len)
 {
     SpiceVoiceIn *in = container_of (hw, SpiceVoiceIn, hw);
-    uint64_t delta_samp = rate_get_samples(&hw->info, &in->rate);
-    uint64_t to_read = MIN(len >> 2, delta_samp);
+    uint64_t to_read = audio_rate_get_bytes(&hw->info, &in->rate, len) >> 2;
     size_t ready = spice_server_record_get_samples(&in->sin, buf, to_read);
 
     /* XXX: do we need this? */
@@ -296,7 +261,7 @@ static int line_in_ctl (HWVoiceIn *hw, int cmd, ...)
             break;
         }
         in->active = 1;
-        rate_start (&in->rate);
+        audio_rate_start(&in->rate);
         spice_server_record_start (&in->sin);
         break;
     case VOICE_DISABLE: