From e3973967d2fa330df578164ed2e9020e59d4ee4f Mon Sep 17 00:00:00 2001
From: Nils Daumann <nils_daumann@slindev.com>
Date: Wed, 24 May 2017 22:57:35 +0200
Subject: [PATCH] Fixed WASAPI input stream releasing a different buffer size
 than it got.

This caused a SoundIOErrorStreaming error and all following reads would fail. It took a while in the microphone sample, but after ~30 seconds it would always fail for me.
---
 src/wasapi.c | 19 ++++++++++++++-----
 src/wasapi.h |  1 +
 2 files changed, 15 insertions(+), 5 deletions(-)

diff --git a/src/wasapi.c b/src/wasapi.c
index 9637f64..5556a6b 100644
--- a/src/wasapi.c
+++ b/src/wasapi.c
@@ -2084,7 +2084,9 @@ static int instream_begin_read_wasapi(struct SoundIoPrivate *si, struct SoundIoI
         {
             return SoundIoErrorStreaming;
         }
-        isw->read_buf_frames_left = frames_to_read;
+		isw->opened_buf_frames = frames_to_read;
+		isw->read_buf_frames_left = frames_to_read;
+
         if (flags & AUDCLNT_BUFFERFLAGS_SILENT)
             isw->read_buf = NULL;
     }
@@ -2096,6 +2098,8 @@ static int instream_begin_read_wasapi(struct SoundIoPrivate *si, struct SoundIoI
         for (int ch = 0; ch < instream->layout.channel_count; ch += 1) {
             isw->areas[ch].ptr = isw->read_buf + ch * instream->bytes_per_sample;
             isw->areas[ch].step = instream->bytes_per_frame;
+
+			isw->areas[ch].ptr += instream->bytes_per_frame * (isw->opened_buf_frames - isw->read_buf_frames_left);
         }
 
         *out_areas = isw->areas;
@@ -2109,10 +2113,15 @@ static int instream_begin_read_wasapi(struct SoundIoPrivate *si, struct SoundIoI
 static int instream_end_read_wasapi(struct SoundIoPrivate *si, struct SoundIoInStreamPrivate *is) {
     struct SoundIoInStreamWasapi *isw = &is->backend_data.wasapi;
     HRESULT hr;
-    if (FAILED(hr = IAudioCaptureClient_ReleaseBuffer(isw->audio_capture_client, isw->read_frame_count))) {
-        return SoundIoErrorStreaming;
-    }
-    isw->read_buf_frames_left -= isw->read_frame_count;
+
+	isw->read_buf_frames_left -= isw->read_frame_count;
+
+	if (isw->read_buf_frames_left <= 0) {
+		if (FAILED(hr = IAudioCaptureClient_ReleaseBuffer(isw->audio_capture_client, isw->opened_buf_frames))) {
+			return SoundIoErrorStreaming;
+		}
+	}
+
     return 0;
 }
 
diff --git a/src/wasapi.h b/src/wasapi.h
index 5860f86..e27b3f8 100644
--- a/src/wasapi.h
+++ b/src/wasapi.h
@@ -100,6 +100,7 @@ struct SoundIoInStreamWasapi {
     bool started;
     char *read_buf;
     int read_buf_frames_left;
+	int opened_buf_frames;
     struct SoundIoChannelArea areas[SOUNDIO_MAX_CHANNELS];
 };