Fix AV1 encoder availability for custom RTMP streaming services. (#1690)

Author: aleksandr-voitenko

obs-studio-server/source/osn-encoders.cpp

@@ -23,6 +23,8 @@
 #include <util/dstr.h>
 #include "utility.hpp"
 
+static bool codecListContains(const char **codecs, const char *codec);
+static const char *getStreamOutputType(const obs_service_t *service);
 static bool isNvencAvailableForSimpleMode();
 static bool containerSupportsCodec(const std::string &container, const std::string &codec);
 static void convert_nvenc_h264_presets(obs_data_t *data);
@@ -104,18 +106,81 @@ bool osn::EncoderUtils::isCodecAvailableForService(const char *encoder, obs_serv
 	auto supportedCodecs = obs_service_get_supported_video_codecs(service);
 	auto encoderCodec = obs_get_encoder_codec(encoder);
 
-	if (!supportedCodecs || !encoderCodec)
+	if (!encoderCodec)
 		return false;
 
-	while (*supportedCodecs) {
-		if (strcmp(*supportedCodecs, encoderCodec) == 0)
+	if (supportedCodecs)
+		return codecListContains(supportedCodecs, encoderCodec);
+
+	// Custom services do not expose codec lists, so mirror OBS and fall back to the output type.
+	auto outputType = getStreamOutputType(service);
+	if (!outputType)
+		return false;
+
+	auto outputSupportedCodecs = obs_get_output_supported_video_codecs(outputType);
+	if (!outputSupportedCodecs)
+		return false;
+
+	auto splitOutputSupportedCodecs = strlist_split(outputSupportedCodecs, ';', false);
+	bool supported = codecListContains((const char **)splitOutputSupportedCodecs, encoderCodec);
+	strlist_free(splitOutputSupportedCodecs);
+
+	return supported;
+}
+
+static bool codecListContains(const char **codecs, const char *codec)
+{
+	if (!codecs || !codec)
+		return false;
+
+	while (*codecs) {
+		if (strcmp(*codecs, codec) == 0)
 			return true;
-		supportedCodecs++;
+		codecs++;
 	}
 
 	return false;
 }
 
+// Resolves the OBS output type used by a streaming service.
+// Returns a non-owned output type ID, such as "rtmp_output", or nullptr if no compatible output is registered.
+static const char *getStreamOutputType(const obs_service_t *service)
+{
+	const char *protocol = obs_service_get_protocol(service);
+
+	if (!protocol)
+		return nullptr;
+
+	if (!obs_is_output_protocol_registered(protocol))
+		return nullptr;
+
+	const char *output = obs_service_get_preferred_output_type(service);
+	if (output && (obs_get_output_flags(output) & OBS_OUTPUT_SERVICE) != 0)
+		return output;
+
+	auto canUseOutput = [](const char *prot, const char *output, const char *prot_test1, const char *prot_test2 = nullptr) {
+		return (strcmp(prot, prot_test1) == 0 || (prot_test2 && strcmp(prot, prot_test2) == 0)) &&
+		       (obs_get_output_flags(output) & OBS_OUTPUT_SERVICE) != 0;
+	};
+
+	if (canUseOutput(protocol, "rtmp_output", "RTMP", "RTMPS")) {
+		return "rtmp_output";
+	} else if (canUseOutput(protocol, "ffmpeg_hls_muxer", "HLS")) {
+		return "ffmpeg_hls_muxer";
+	} else if (canUseOutput(protocol, "ffmpeg_mpegts_muxer", "SRT", "RIST")) {
+		return "ffmpeg_mpegts_muxer";
+	}
+
+	auto returnFirstOutputId = [](void *data, const char *id) {
+		const char **output = (const char **)data;
+
+		*output = id;
+		return false;
+	};
+	obs_enum_output_types_with_protocol(protocol, &output, returnFirstOutputId);
+	return output;
+}
+
 bool osn::EncoderUtils::isEncoderCompatible(std::string encoderName, obs_service_t *service, bool simpleMode, bool recording, const std::string &container,
 					    int checkIndex)
 {
@@ -517,4 +582,4 @@ static void convert_nvenc_hevc_presets(obs_data_t *data)
 		obs_data_set_string(data, "tune", "ll");
 		obs_data_set_string(data, "multipass", "disabled");
 	}
-}
+}

tests/osn-tests/src/test_osn_get_available_encoders.ts

@@ -9,6 +9,21 @@ import { ERecordingFormat } from '../osn';
 import path = require('path');
 
 const testName = 'osn-get-available-encoders';
+const av1EncoderNames = new Set([
+    'ffmpeg_aom_av1',
+    'ffmpeg_svt_av1',
+    'obs_nvenc_av1_tex',
+    'obs_qsv11_av1',
+    'av1_texture_amf',
+]);
+
+function getEncoderNames(encoders: { name: string }[]): string[] {
+    return encoders.map(encoder => encoder.name);
+}
+
+function getAv1EncoderNames(encoders: { name: string }[]): string[] {
+    return getEncoderNames(encoders).filter(name => av1EncoderNames.has(name));
+}
 
 describe(testName, () => {
     let obs: OBSHandler;
@@ -142,6 +157,41 @@ describe(testName, () => {
         osn.AdvancedStreamingFactory.destroy(stream);
     });
 
+    it('Get available AV1 encoders for custom RTMP streaming using output codec fallback', async () => {
+        const youtubeService = osn.ServiceFactory.create('rtmp_common', 'youtube-service', {
+            service: 'YouTube - RTMPS',
+            server: 'rtmps://a.rtmps.youtube.com:443/live2',
+            key: 'test',
+        });
+        const customService = osn.ServiceFactory.create('rtmp_custom', 'custom-service', {
+            server: 'rtmps://a.rtmps.youtube.com:443/live2',
+            key: 'test',
+        });
+        const youtubeStream = osn.AdvancedStreamingFactory.create();
+        const customStream = osn.AdvancedStreamingFactory.create();
+
+        try {
+            youtubeStream.service = youtubeService;
+            customStream.service = customService;
+
+            const youtubeAv1Encoders = getAv1EncoderNames(youtubeStream.getAvailableEncoders());
+            const customEncoderNames = getEncoderNames(customStream.getAvailableEncoders());
+
+            expect(youtubeAv1Encoders.length).to.be.greaterThan(0,
+                'Test requires at least one registered AV1 encoder for YouTube');
+
+            for (const encoder of youtubeAv1Encoders) {
+                expect(customEncoderNames).to.include(encoder,
+                    `Custom RTMP service should allow ${encoder} when the output supports AV1`);
+            }
+        } finally {
+            osn.AdvancedStreamingFactory.destroy(customStream);
+            osn.AdvancedStreamingFactory.destroy(youtubeStream);
+            osn.ServiceFactory.destroy(customService);
+            osn.ServiceFactory.destroy(youtubeService);
+        }
+    });
+
     it('Get available encoders for simple recording', async () => {
         const recording = osn.SimpleRecordingFactory.create();
         expect(recording).to.not.equal(