virtualcam-module: Clarify resolution variables

The `cx`/`cy`/`interval` variables specifically specify the
OBS/placeholder resolution/interval. The resolution may not be the same
as the filter's resolution (when scaling is used).

Instead, prefix these variables with `obs_` to improve clarity.

plugins/win-dshow/virtualcam-module/virtualcam-filter.cpp

@@ -49,15 +49,15 @@ VCamFilter::VCamFilter()
 	/* ---------------------------------------- */
 	/* add last/current obs res/interval        */
 
-	uint32_t new_cx = cx;
-	uint32_t new_cy = cy;
-	uint64_t new_interval = interval;
+	uint32_t new_obs_cx = obs_cx;
+	uint32_t new_obs_cy = obs_cy;
+	uint64_t new_obs_interval = obs_interval;
 
 	vq = video_queue_open();
 	if (vq) {
 		if (video_queue_state(vq) == SHARED_QUEUE_STATE_READY) {
-			video_queue_get_info(vq, &new_cx, &new_cy,
-					     &new_interval);
+			video_queue_get_info(vq, &new_obs_cx, &new_obs_cy,
+					     &new_obs_interval);
 		}
 
 		/* don't keep it open until the filter actually starts */
@@ -79,13 +79,15 @@ VCamFilter::VCamFilter()
 			if (ReadFile(file, res, sizeof(res) - 1, &len,
 				     nullptr)) {
 				res[len] = 0;
-				int vals = sscanf(
-					res, "%" PRIu32 "x%" PRIu32 "x%" PRIu64,
-					&new_cx, &new_cy, &new_interval);
+				int vals = sscanf(res,
+						  "%" PRIu32 "x%" PRIu32
+						  "x%" PRIu64,
+						  &new_obs_cx, &new_obs_cy,
+						  &new_obs_interval);
 				if (vals != 3) {
-					new_cx = cx;
-					new_cy = cy;
-					new_interval = interval;
+					new_obs_cx = obs_cx;
+					new_obs_cy = obs_cy;
+					new_obs_interval = obs_interval;
 				}
 			}
 
@@ -93,14 +95,20 @@ VCamFilter::VCamFilter()
 		}
 	}
 
-	if (new_cx != cx || new_cy != cy || new_interval != interval) {
-		AddVideoFormat(VideoFormat::NV12, new_cx, new_cy, new_interval);
-		AddVideoFormat(VideoFormat::I420, new_cx, new_cy, new_interval);
-		AddVideoFormat(VideoFormat::YUY2, new_cx, new_cy, new_interval);
-		SetVideoFormat(VideoFormat::NV12, new_cx, new_cy, new_interval);
-		cx = new_cx;
-		cy = new_cy;
-		interval = new_interval;
+	if (new_obs_cx != obs_cx || new_obs_cy != obs_cy ||
+	    new_obs_interval != obs_interval) {
+		AddVideoFormat(VideoFormat::NV12, new_obs_cx, new_obs_cy,
+			       new_obs_interval);
+		AddVideoFormat(VideoFormat::I420, new_obs_cx, new_obs_cy,
+			       new_obs_interval);
+		AddVideoFormat(VideoFormat::YUY2, new_obs_cx, new_obs_cy,
+			       new_obs_interval);
+		SetVideoFormat(VideoFormat::NV12, new_obs_cx, new_obs_cy,
+			       new_obs_interval);
+
+		obs_cx = new_obs_cx;
+		obs_cy = new_obs_cy;
+		obs_interval = new_obs_interval;
 	}
 
 	/* ---------------------------------------- */
@@ -178,9 +186,9 @@ void VCamFilter::Thread()
 	uint64_t cur_time = gettime_100ns();
 	uint64_t filter_time = GetTime();
 
-	cx = GetCX();
-	cy = GetCY();
-	interval = GetInterval();
+	obs_cx = (uint32_t)GetCX();
+	obs_cy = (uint32_t)GetCY();
+	obs_interval = (uint64_t)GetInterval();
 
 	/* ---------------------------------------- */
 	/* load placeholder image                   */
@@ -195,8 +203,9 @@ void VCamFilter::Thread()
 	/* Created dynamically based on output resolution changes */
 	placeholder.scaled_data = nullptr;
 
-	nv12_scale_init(&scaler, TARGET_FORMAT_NV12, cx, cy, cx, cy);
-	nv12_scale_init(&placeholder.scaler, TARGET_FORMAT_NV12, cx, cy,
+	nv12_scale_init(&scaler, TARGET_FORMAT_NV12, obs_cx, obs_cy, obs_cx,
+			obs_cy);
+	nv12_scale_init(&placeholder.scaler, TARGET_FORMAT_NV12, obs_cx, obs_cy,
 			placeholder.cx, placeholder.cy);
 
 	UpdatePlaceholder();
@@ -204,16 +213,16 @@ void VCamFilter::Thread()
 	while (!stopped()) {
 		if (os_atomic_load_bool(&active))
 			Frame(filter_time);
-		sleepto_100ns(cur_time += interval);
-		filter_time += interval;
+		sleepto_100ns(cur_time += obs_interval);
+		filter_time += obs_interval;
 	}
 }
 
 void VCamFilter::Frame(uint64_t ts)
 {
-	uint32_t new_cx = cx;
-	uint32_t new_cy = cy;
-	uint64_t new_interval = interval;
+	uint32_t new_obs_cx = obs_cx;
+	uint32_t new_obs_cy = obs_cy;
+	uint64_t new_obs_interval = obs_interval;
 
 	/* cx, cy and interval are the resolution and frame rate of the
 	   virtual camera _source_, ie OBS' output. Do not confuse cx / cy
@@ -229,8 +238,8 @@ void VCamFilter::Frame(uint64_t ts)
 		if (state == SHARED_QUEUE_STATE_READY) {
 			/* The virtualcam output from OBS has started, get
 			   the actual cx / cy of the data stream */
-			video_queue_get_info(vq, &new_cx, &new_cy,
-					     &new_interval);
+			video_queue_get_info(vq, &new_obs_cx, &new_obs_cy,
+					     &new_obs_interval);
 		} else if (state == SHARED_QUEUE_STATE_STOPPING) {
 			video_queue_close(vq);
 			vq = nullptr;
@@ -242,28 +251,29 @@ void VCamFilter::Frame(uint64_t ts)
 	if (state != SHARED_QUEUE_STATE_READY) {
 		/* Virtualcam output not yet started, assume it's
 		   the same resolution as the filter output */
-		new_cx = GetCX();
-		new_cy = GetCY();
-		new_interval = GetInterval();
+		new_obs_cx = GetCX();
+		new_obs_cy = GetCY();
+		new_obs_interval = GetInterval();
 	}
 
-	if (new_cx != cx || new_cy != cy || new_interval != interval) {
+	if (new_obs_cx != obs_cx || new_obs_cy != obs_cy ||
+	    new_obs_interval != obs_interval) {
 		/* The res / FPS of the video coming from OBS has
 		   changed, update parameters as needed */
 		if (in_obs) {
 			/* If the vcam is being used inside obs, adjust
 			   the format we present to match */
-			SetVideoFormat(GetVideoFormat(), new_cx, new_cy,
-				       new_interval);
+			SetVideoFormat(GetVideoFormat(), new_obs_cx, new_obs_cy,
+				       new_obs_interval);
 		}
 
 		/* Re-initialize the main scaler to use the new resolution */
 		nv12_scale_init(&scaler, scaler.format, GetCX(), GetCY(),
-				new_cx, new_cy);
+				new_obs_cx, new_obs_cy);
 
-		cx = new_cx;
-		cy = new_cy;
-		interval = new_interval;
+		obs_cx = new_obs_cx;
+		obs_cy = new_obs_cy;
+		obs_interval = new_obs_interval;
 
 		UpdatePlaceholder();
 	}
@@ -295,7 +305,7 @@ void VCamFilter::Frame(uint64_t ts)
 		else
 			ShowDefaultFrame(ptr);
 
-		UnlockSampleData(ts, ts + interval);
+		UnlockSampleData(ts, ts + obs_interval);
 	}
 }
 

plugins/win-dshow/virtualcam-module/virtualcam-filter.hpp

@@ -30,10 +30,10 @@ class VCamFilter : public DShow::OutputFilter {
 	bool in_obs = false;
 	enum queue_state prev_state = SHARED_QUEUE_STATE_INVALID;
 	placeholder_t placeholder;
-	uint32_t cx = DEFAULT_CX;
-	uint32_t cy = DEFAULT_CY;
+	uint32_t obs_cx = DEFAULT_CX;
+	uint32_t obs_cy = DEFAULT_CY;
+	uint64_t obs_interval = DEFAULT_INTERVAL;
 	DShow::VideoFormat format;
-	uint64_t interval = DEFAULT_INTERVAL;
 	WinHandle thread_start;
 	WinHandle thread_stop;
 	volatile bool active = false;