test/run_decoder: add option --seek

test/run_decoder.cxx

@@ -47,16 +47,20 @@ struct CommandLine {
 	Path config_path = nullptr;
 
 	bool verbose = false;
+
+	SongTime seek_where{};
 };
 
 enum Option {
 	OPTION_CONFIG,
 	OPTION_VERBOSE,
+	OPTION_SEEK,
 };
 
 static constexpr OptionDef option_defs[] = {
 	{"config", 0, true, "Load a MPD configuration file"},
 	{"verbose", 'v', false, "Verbose logging"},
+	{"seek", 0, true, "Seek to this position"},
 };
 
 static CommandLine
@@ -74,6 +78,10 @@ ParseCommandLine(int argc, char **argv)
 		case OPTION_VERBOSE:
 			c.verbose = true;
 			break;
+
+		case OPTION_SEEK:
+			c.seek_where = SongTime::FromS(strtod(o.value, nullptr));
+			break;
 		}
 	}
 
@@ -102,6 +110,85 @@ public:
 	}
 };
 
+class MyDecoderClient final : public DumpDecoderClient {
+	SongTime seek_where;
+
+	unsigned sample_rate;
+
+	bool seekable, seek_error = false;
+
+public:
+	explicit MyDecoderClient(SongTime _seek_where) noexcept
+		:seek_where(_seek_where) {}
+
+	void Finish() {
+		if (!IsInitialized())
+			throw "Unrecognized file";
+
+		if (seek_error)
+			throw "Seek error";
+
+		if (seek_where != SongTime{}) {
+			if (!seekable)
+				throw "Not seekable";
+
+			throw "Did not seek";
+		}
+	}
+
+	/* virtual methods from DecoderClient */
+	void Ready(AudioFormat audio_format,
+		   bool _seekable, SignedSongTime duration) noexcept override {
+		assert(!IsInitialized());
+
+		DumpDecoderClient::Ready(audio_format, _seekable, duration);
+		sample_rate = audio_format.sample_rate;
+		seekable = _seekable;
+	}
+
+	DecoderCommand GetCommand() noexcept override {
+		assert(IsInitialized());
+
+		if (seek_where != SongTime{}) {
+			if (!seekable)
+				return DecoderCommand::STOP;
+
+			return DecoderCommand::SEEK;
+		} else if (seek_error)
+			return DecoderCommand::STOP;
+		else
+			return DumpDecoderClient::GetCommand();
+	}
+
+	void CommandFinished() noexcept override {
+		assert(!seek_error);
+
+		if (seek_where != SongTime{})
+			seek_where = {};
+		else
+			DumpDecoderClient::CommandFinished();
+	}
+
+	SongTime GetSeekTime() noexcept override {
+		assert(seek_where != SongTime{});
+
+		return seek_where;
+	}
+
+	uint64_t GetSeekFrame() noexcept override {
+		assert(seek_where != SongTime{});
+
+		return GetSeekTime().ToScale<uint64_t>(sample_rate);
+	}
+
+	void SeekError() noexcept override {
+		assert(seek_where != SongTime{});
+
+		seek_error = true;
+		seek_where = {};
+	}
+};
+
 int main(int argc, char **argv)
 try {
 	const auto c = ParseCommandLine(argc, argv);
@@ -115,7 +202,7 @@ try {
 		return EXIT_FAILURE;
 	}
 
-	DumpDecoderClient client;
+	MyDecoderClient client(c.seek_where);
 	if (plugin->file_decode != nullptr) {
 		try {
 			plugin->FileDecode(client, Path::FromFS(c.uri));
@@ -132,10 +219,7 @@ try {
 		return EXIT_FAILURE;
 	}
 
-	if (!client.IsInitialized()) {
-		fprintf(stderr, "Decoding failed\n");
-		return EXIT_FAILURE;
-	}
+	client.Finish();
 
 	return EXIT_SUCCESS;
 } catch (...) {