aja: Only allow output formats matching OBS framerate

plugins/aja/aja-common.cpp

@@ -146,7 +146,8 @@ void populate_io_selection_output_list(const std::string &cardID,
 }
 
 void populate_video_format_list(NTV2DeviceID deviceID, obs_property_t *list,
-				NTV2VideoFormat genlockFormat, bool want4KHFR)
+				NTV2VideoFormat genlockFormat, bool want4KHFR,
+				bool matchFPS)
 {
 	VideoFormatList videoFormats = {};
 	VideoStandardList orderedStandards = {};
@@ -179,6 +180,20 @@ void populate_video_format_list(NTV2DeviceID deviceID, obs_property_t *list,
 		if (genlockFormat != NTV2_FORMAT_UNKNOWN)
 			addFormat = IsMultiFormatCompatible(genlockFormat, vf);
 
+		struct obs_video_info ovi;
+		if (matchFPS && obs_get_video_info(&ovi)) {
+			NTV2FrameRate frameRate =
+				GetNTV2FrameRateFromVideoFormat(vf);
+			ULWord fpsNum = 0;
+			ULWord fpsDen = 0;
+			GetFramesPerSecond(frameRate, fpsNum, fpsDen);
+			uint32_t obsFrameTime =
+				1000000 * ovi.fps_den / ovi.fps_num;
+			uint32_t ajaFrameTime = 1000000 * fpsDen / fpsNum;
+			if (obsFrameTime != ajaFrameTime)
+				addFormat = false;
+		}
+
 		if (addFormat) {
 			std::string name = NTV2VideoFormatToString(vf, true);
 			obs_property_list_add_int(list, name.c_str(), (int)vf);

plugins/aja/aja-common.hpp

@@ -42,7 +42,7 @@ extern void populate_io_selection_output_list(const std::string &cardID,
 extern void
 populate_video_format_list(NTV2DeviceID deviceID, obs_property_t *list,
 			   NTV2VideoFormat genlockFormat = NTV2_FORMAT_UNKNOWN,
-			   bool want4KHFR = false);
+			   bool want4KHFR = false, bool matchFPS = false);
 extern void populate_pixel_format_list(NTV2DeviceID deviceID,
 				       obs_property_t *list);
 extern void populate_sdi_transport_list(obs_property_t *list,

plugins/aja/aja-output.cpp

@@ -19,6 +19,8 @@
 // Log AJA Output video/audio delay and av-sync
 // #define AJA_OUTPUT_STATS
 
+#define MATCH_OBS_FRAMERATE true
+
 static constexpr uint32_t kNumCardFrames = 3;
 static const int64_t kDefaultStatPeriod = 3000000000;
 static const int64_t kAudioSyncAdjust = 20000;
@@ -849,7 +851,7 @@ bool aja_output_device_changed(void *data, obs_properties_t *props,
 
 	obs_property_list_clear(vid_fmt_list);
 	populate_video_format_list(deviceID, vid_fmt_list, videoFormatChannel1,
-				   false);
+				   false, MATCH_OBS_FRAMERATE);
 
 	obs_property_list_clear(pix_fmt_list);
 	populate_pixel_format_list(deviceID, pix_fmt_list);