diff --git a/src/decoder/DecoderAPI.cxx b/src/decoder/DecoderAPI.cxx
index 354fed9a3..3d45cb325 100644
--- a/src/decoder/DecoderAPI.cxx
+++ b/src/decoder/DecoderAPI.cxx
@@ -41,7 +41,7 @@
 void
 decoder_initialized(Decoder &decoder,
 		    const AudioFormat audio_format,
-		    bool seekable, float total_time)
+		    bool seekable, SignedSongTime duration)
 {
 	DecoderControl &dc = decoder.dc;
 	struct audio_format_string af_string;
@@ -59,9 +59,7 @@ decoder_initialized(Decoder &decoder,
 	dc.out_audio_format = getOutputAudioFormat(audio_format);
 
 	dc.seekable = seekable;
-	dc.total_time = total_time > 0
-		? SignedSongTime::FromS(total_time)
-		: SignedSongTime::Negative();
+	dc.total_time = duration;
 
 	FormatDebug(decoder_domain, "audio_format=%s, seekable=%s",
 		    audio_format_to_string(dc.in_audio_format, &af_string),
diff --git a/src/decoder/DecoderAPI.hxx b/src/decoder/DecoderAPI.hxx
index ca33e26c7..b756331d9 100644
--- a/src/decoder/DecoderAPI.hxx
+++ b/src/decoder/DecoderAPI.hxx
@@ -53,12 +53,13 @@ class Error;
  * @param audio_format the audio format which is going to be sent to
  * decoder_data()
  * @param seekable true if the song is seekable
- * @param total_time the total number of seconds in this song; -1 if unknown
+ * @param duration the total duration of this song; negative if
+ * unknown
  */
 void
 decoder_initialized(Decoder &decoder,
 		    AudioFormat audio_format,
-		    bool seekable, float total_time);
+		    bool seekable, SignedSongTime duration);
 
 /**
  * Determines the pending decoder command.
diff --git a/src/decoder/plugins/AdPlugDecoderPlugin.cxx b/src/decoder/plugins/AdPlugDecoderPlugin.cxx
index 32a2432f4..6c8edfe02 100644
--- a/src/decoder/plugins/AdPlugDecoderPlugin.cxx
+++ b/src/decoder/plugins/AdPlugDecoderPlugin.cxx
@@ -62,7 +62,7 @@ adplug_file_decode(Decoder &decoder, Path path_fs)
 	assert(audio_format.IsValid());
 
 	decoder_initialized(decoder, audio_format, false,
-		player->songlength() / 1000.);
+			    SongTime::FromMS(player->songlength()));
 
 	int16_t buffer[2048];
 	const unsigned frames_per_buffer = ARRAY_SIZE(buffer) / 2;
diff --git a/src/decoder/plugins/AudiofileDecoderPlugin.cxx b/src/decoder/plugins/AudiofileDecoderPlugin.cxx
index 412cda1e3..8d04f9596 100644
--- a/src/decoder/plugins/AudiofileDecoderPlugin.cxx
+++ b/src/decoder/plugins/AudiofileDecoderPlugin.cxx
@@ -64,13 +64,11 @@ struct AudioFileInputStream {
 };
 
 gcc_pure
-static double
+static SongTime
 audiofile_get_duration(AFfilehandle fh)
 {
-	double frame_count = afGetFrameCount(fh, AF_DEFAULT_TRACK);
-	double rate = afGetRate(fh, AF_DEFAULT_TRACK);
-
-	return frame_count / rate;
+	return SongTime::FromScale<uint64_t>(afGetFrameCount(fh, AF_DEFAULT_TRACK),
+					     afGetRate(fh, AF_DEFAULT_TRACK));
 }
 
 static ssize_t
@@ -208,10 +206,10 @@ audiofile_stream_decode(Decoder &decoder, InputStream &is)
 		return;
 	}
 
-	const double total_time = audiofile_get_duration(fh);
+	const auto total_time = audiofile_get_duration(fh);
 
 	const uint16_t kbit_rate = (uint16_t)
-		(is.GetSize() * 8.0 / total_time / 1000.0 + 0.5);
+		(is.GetSize() * uint64_t(8000) / total_time.ToMS());
 
 	const unsigned frame_size = (unsigned)
 		afGetVirtualFrameSize(fh, AF_DEFAULT_TRACK, true);
@@ -258,7 +256,7 @@ audiofile_get_duration(InputStream &is)
 	if (fh == AF_NULL_FILEHANDLE)
 		return -1;
 
-	int duration = int(audiofile_get_duration(fh));
+	int duration = audiofile_get_duration(fh).RoundS();
 	afCloseFile(fh);
 	return duration;
 }
diff --git a/src/decoder/plugins/DsdiffDecoderPlugin.cxx b/src/decoder/plugins/DsdiffDecoderPlugin.cxx
index 112de8b90..617d34ae4 100644
--- a/src/decoder/plugins/DsdiffDecoderPlugin.cxx
+++ b/src/decoder/plugins/DsdiffDecoderPlugin.cxx
@@ -437,8 +437,10 @@ dsdiff_stream_decode(Decoder &decoder, InputStream &is)
 
 	/* calculate song time from DSD chunk size and sample frequency */
 	offset_type chunk_size = metadata.chunk_size;
-	float songtime = ((chunk_size / metadata.channels) * 8) /
-			 (float) metadata.sample_rate;
+
+	uint64_t n_frames = chunk_size / audio_format.channels;
+	auto songtime = SongTime::FromScale<uint64_t>(n_frames,
+						      audio_format.sample_rate);
 
 	/* success: file was recognized */
 	decoder_initialized(decoder, audio_format, is.IsSeekable(), songtime);
diff --git a/src/decoder/plugins/DsfDecoderPlugin.cxx b/src/decoder/plugins/DsfDecoderPlugin.cxx
index c92c276fc..b84eadf66 100644
--- a/src/decoder/plugins/DsfDecoderPlugin.cxx
+++ b/src/decoder/plugins/DsfDecoderPlugin.cxx
@@ -318,8 +318,8 @@ dsf_stream_decode(Decoder &decoder, InputStream &is)
 	}
 	/* Calculate song time from DSD chunk size and sample frequency */
 	const auto n_blocks = metadata.n_blocks;
-	float songtime = float(n_blocks * DSF_BLOCK_BITS) /
-			 (float) metadata.sample_rate;
+	auto songtime = SongTime::FromScale<uint64_t>(n_blocks * DSF_BLOCK_SIZE,
+						      audio_format.sample_rate);
 
 	/* success: file was recognized */
 	decoder_initialized(decoder, audio_format, is.IsSeekable(), songtime);
diff --git a/src/decoder/plugins/FaadDecoderPlugin.cxx b/src/decoder/plugins/FaadDecoderPlugin.cxx
index 83fab7f9e..5b352c9f4 100644
--- a/src/decoder/plugins/FaadDecoderPlugin.cxx
+++ b/src/decoder/plugins/FaadDecoderPlugin.cxx
@@ -107,13 +107,13 @@ adts_find_frame(DecoderBuffer *buffer)
 	}
 }
 
-static float
+static SignedSongTime
 adts_song_duration(DecoderBuffer *buffer)
 {
 	const InputStream &is = decoder_buffer_get_stream(buffer);
 	const bool estimate = !is.CheapSeeking();
 	if (estimate && !is.KnownSize())
-		return -1;
+		return SignedSongTime::Negative();
 
 	unsigned sample_rate = 0;
 
@@ -146,7 +146,7 @@ adts_song_duration(DecoderBuffer *buffer)
 			const auto offset = is.GetOffset()
 				- decoder_buffer_available(buffer);
 			if (offset <= 0)
-				return -1;
+				return SignedSongTime::Negative();
 
 			const auto file_size = is.GetSize();
 			frames = (frames * file_size) / offset;
@@ -155,20 +155,18 @@ adts_song_duration(DecoderBuffer *buffer)
 	}
 
 	if (sample_rate == 0)
-		return -1;
+		return SignedSongTime::Negative();
 
-	float frames_per_second = (float)sample_rate / 1024.0;
-	assert(frames_per_second > 0);
-
-	return (float)frames / frames_per_second;
+	return SignedSongTime::FromScale<uint64_t>(frames * uint64_t(1024),
+						   sample_rate);
 }
 
-static float
+static SignedSongTime
 faad_song_duration(DecoderBuffer *buffer, InputStream &is)
 {
 	auto data = ConstBuffer<uint8_t>::FromVoid(decoder_buffer_need(buffer, 5));
 	if (data.IsNull())
-		return -1;
+		return SignedSongTime::Negative();
 
 	size_t tagsize = 0;
 	if (data.size >= 10 && !memcmp(data.data, "ID3", 3)) {
@@ -180,20 +178,20 @@ faad_song_duration(DecoderBuffer *buffer, InputStream &is)
 		tagsize += 10;
 
 		if (!decoder_buffer_skip(buffer, tagsize))
-			return -1;
+			return SignedSongTime::Negative();
 
 		data = ConstBuffer<uint8_t>::FromVoid(decoder_buffer_need(buffer, 5));
 		if (data.IsNull())
-			return -1;
+			return SignedSongTime::Negative();
 	}
 
 	if (data.size >= 8 && adts_check_frame(data.data) > 0) {
 		/* obtain the duration from the ADTS header */
 
 		if (!is.IsSeekable())
-			return -1;
+			return SignedSongTime::Negative();
 
-		float song_length = adts_song_duration(buffer);
+		auto song_length = adts_song_duration(buffer);
 
 		is.LockSeek(tagsize, IgnoreError());
 
@@ -204,14 +202,14 @@ faad_song_duration(DecoderBuffer *buffer, InputStream &is)
 		/* obtain the duration from the ADIF header */
 
 		if (!is.KnownSize())
-			return -1;
+			return SignedSongTime::Negative();
 
 		size_t skip_size = (data.data[4] & 0x80) ? 9 : 0;
 
 		if (8 + skip_size > data.size)
 			/* not enough data yet; skip parsing this
 			   header */
-			return -1;
+			return SignedSongTime::Negative();
 
 		unsigned bit_rate = ((data.data[4 + skip_size] & 0x0F) << 19) |
 			(data.data[5 + skip_size] << 11) |
@@ -220,11 +218,11 @@ faad_song_duration(DecoderBuffer *buffer, InputStream &is)
 
 		const auto size = is.GetSize();
 		if (bit_rate == 0)
-			return -1;
+			return SignedSongTime::Negative();
 
-		return size * 8.0 / bit_rate;
+		return SongTime::FromScale(size, bit_rate / 8);
 	} else
-		return -1;
+		return SignedSongTime::Negative();
 }
 
 static NeAACDecHandle
@@ -301,19 +299,21 @@ faad_decoder_decode(NeAACDecHandle decoder, DecoderBuffer *buffer,
 }
 
 /**
- * Get a song file's total playing time in seconds, as a float.
- * Returns 0 if the duration is unknown, and a negative value if the
- * file is invalid.
+ * Determine a song file's total playing time.
+ *
+ * The first return value specifies whether the file was recognized.
+ * The second return value is the duration.
  */
-static float
-faad_get_file_time_float(InputStream &is)
+static std::pair<bool, SignedSongTime>
+faad_get_file_time(InputStream &is)
 {
 	DecoderBuffer *buffer =
 		decoder_buffer_new(nullptr, is,
 				   FAAD_MIN_STREAMSIZE * MAX_CHANNELS);
-	float length = faad_song_duration(buffer, is);
+	auto duration = faad_song_duration(buffer, is);
+	bool recognized = !duration.IsNegative();
 
-	if (length < 0) {
+	if (!recognized) {
 		NeAACDecHandle decoder = faad_decoder_new();
 
 		decoder_buffer_fill(buffer);
@@ -321,36 +321,21 @@ faad_get_file_time_float(InputStream &is)
 		AudioFormat audio_format;
 		if (faad_decoder_init(decoder, buffer, audio_format,
 				      IgnoreError()))
-			length = 0;
+			recognized = true;
 
 		NeAACDecClose(decoder);
 	}
 
 	decoder_buffer_free(buffer);
 
-	return length;
-}
-
-/**
- * Get a song file's total playing time in seconds, as an int.
- * Returns 0 if the duration is unknown, and a negative value if the
- * file is invalid.
- */
-static int
-faad_get_file_time(InputStream &is)
-{
-	float length = faad_get_file_time_float(is);
-	if (length < 0)
-		return -1;
-
-	return int(length + 0.5);
+	return std::make_pair(recognized, duration);
 }
 
 static void
 faad_stream_decode(Decoder &mpd_decoder, InputStream &is,
 		   DecoderBuffer *buffer, const NeAACDecHandle decoder)
 {
-	const float total_time = faad_song_duration(buffer, is);
+	const auto total_time = faad_song_duration(buffer, is);
 
 	if (adts_find_frame(buffer) == 0)
 		return;
@@ -449,11 +434,15 @@ static bool
 faad_scan_stream(InputStream &is,
 		 const struct tag_handler *handler, void *handler_ctx)
 {
-	int file_time = faad_get_file_time(is);
-	if (file_time < 0)
+	auto result = faad_get_file_time(is);
+	if (!result.first)
 		return false;
 
-	tag_handler_invoke_duration(handler, handler_ctx, file_time);
+	unsigned duration = result.second.IsNegative()
+		? 0
+		: result.second.RoundS();
+
+	tag_handler_invoke_duration(handler, handler_ctx, duration);
 	return true;
 }
 
diff --git a/src/decoder/plugins/FfmpegDecoderPlugin.cxx b/src/decoder/plugins/FfmpegDecoderPlugin.cxx
index e328da24b..0693ffd43 100644
--- a/src/decoder/plugins/FfmpegDecoderPlugin.cxx
+++ b/src/decoder/plugins/FfmpegDecoderPlugin.cxx
@@ -514,9 +514,11 @@ ffmpeg_decode(Decoder &decoder, InputStream &input)
 		return;
 	}
 
-	int total_time = format_context->duration != (int64_t)AV_NOPTS_VALUE
-		? format_context->duration / AV_TIME_BASE
-		: 0;
+	const SignedSongTime total_time =
+		format_context->duration != (int64_t)AV_NOPTS_VALUE
+		? SignedSongTime::FromScale<uint64_t>(format_context->duration,
+						      AV_TIME_BASE)
+		: SignedSongTime::Negative();
 
 	decoder_initialized(decoder, audio_format,
 			    input.IsSeekable(), total_time);
diff --git a/src/decoder/plugins/FlacCommon.cxx b/src/decoder/plugins/FlacCommon.cxx
index f06a52cf8..76762bdf9 100644
--- a/src/decoder/plugins/FlacCommon.cxx
+++ b/src/decoder/plugins/FlacCommon.cxx
@@ -136,10 +136,12 @@ flac_got_first_frame(struct flac_data *data, const FLAC__FrameHeader *header)
 
 	data->frame_size = data->audio_format.GetFrameSize();
 
+	const auto duration = SongTime::FromScale<uint64_t>(data->total_frames,
+							    data->audio_format.sample_rate);
+
 	decoder_initialized(data->decoder, data->audio_format,
 			    data->input_stream.IsSeekable(),
-			    (float)data->total_frames /
-			    (float)data->audio_format.sample_rate);
+			    duration);
 
 	data->initialized = true;
 
diff --git a/src/decoder/plugins/FlacDecoderPlugin.cxx b/src/decoder/plugins/FlacDecoderPlugin.cxx
index 60772398c..eea813401 100644
--- a/src/decoder/plugins/FlacDecoderPlugin.cxx
+++ b/src/decoder/plugins/FlacDecoderPlugin.cxx
@@ -144,10 +144,14 @@ flac_decoder_initialize(struct flac_data *data, FLAC__StreamDecoder *sd,
 
 	if (data->initialized) {
 		/* done */
+
+		const auto duration2 =
+			SongTime::FromScale<uint64_t>(data->total_frames,
+						      data->audio_format.sample_rate);
+
 		decoder_initialized(data->decoder, data->audio_format,
 				    data->input_stream.IsSeekable(),
-				    (float)data->total_frames /
-				    (float)data->audio_format.sample_rate);
+				    duration2);
 		return true;
 	}
 
diff --git a/src/decoder/plugins/FluidsynthDecoderPlugin.cxx b/src/decoder/plugins/FluidsynthDecoderPlugin.cxx
index bdf30baea..f19ac5bf4 100644
--- a/src/decoder/plugins/FluidsynthDecoderPlugin.cxx
+++ b/src/decoder/plugins/FluidsynthDecoderPlugin.cxx
@@ -166,7 +166,8 @@ fluidsynth_file_decode(Decoder &decoder, Path path_fs)
 	   MPD core */
 
 	const AudioFormat audio_format(sample_rate, SampleFormat::S16, 2);
-	decoder_initialized(decoder, audio_format, false, -1);
+	decoder_initialized(decoder, audio_format, false,
+			    SignedSongTime::Negative());
 
 	DecoderCommand cmd;
 	while (fluid_player_get_status(player) == FLUID_PLAYER_PLAYING) {
diff --git a/src/decoder/plugins/GmeDecoderPlugin.cxx b/src/decoder/plugins/GmeDecoderPlugin.cxx
index 5588e2a1e..e1b281f93 100644
--- a/src/decoder/plugins/GmeDecoderPlugin.cxx
+++ b/src/decoder/plugins/GmeDecoderPlugin.cxx
@@ -156,9 +156,9 @@ gme_file_decode(Decoder &decoder, Path path_fs)
 		return;
 	}
 
-	const float song_len = ti->length > 0
-		? ti->length / 1000.0
-		: -1.0;
+	const SignedSongTime song_len = ti->length > 0
+		? SignedSongTime::FromMS(ti->length)
+		: SignedSongTime::Negative();
 
 	/* initialize the MPD decoder */
 
diff --git a/src/decoder/plugins/MadDecoderPlugin.cxx b/src/decoder/plugins/MadDecoderPlugin.cxx
index 7509faabb..3175d4bf6 100644
--- a/src/decoder/plugins/MadDecoderPlugin.cxx
+++ b/src/decoder/plugins/MadDecoderPlugin.cxx
@@ -122,7 +122,7 @@ struct MadDecoder {
 	mad_timer_t timer;
 	unsigned char input_buffer[READ_BUFFER_SIZE];
 	int32_t output_buffer[MP3_DATA_OUTPUT_BUFFER_SIZE];
-	float total_time;
+	SignedSongTime total_time;
 	SongTime elapsed_time;
 	SongTime seek_time;
 	enum muteframe mute_frame;
@@ -713,11 +713,10 @@ parse_lame(struct lame *lame, struct mad_bitptr *ptr, int *bitlen)
 	return true;
 }
 
-static inline float
+static inline SongTime
 mp3_frame_duration(const struct mad_frame *frame)
 {
-	return mad_timer_count(frame->header.duration,
-			       MAD_UNITS_MILLISECONDS) / 1000.0;
+	return ToSongTime(frame->header.duration);
 }
 
 inline offset_type
@@ -745,13 +744,19 @@ MadDecoder::FileSizeToSongLength()
 	if (input_stream.KnownSize()) {
 		offset_type rest = RestIncludingThisFrame();
 
-		float frame_duration = mp3_frame_duration(&frame);
+		const SongTime frame_duration = mp3_frame_duration(&frame);
+		const SongTime duration =
+			SongTime::FromScale<uint64_t>(rest,
+						      frame.header.bitrate / 8);
+		total_time = duration;
 
-		total_time = (rest * 8.0) / frame.header.bitrate;
-		max_frames = total_time / frame_duration + FRAMES_CUSHION;
+		max_frames = (frame_duration.IsPositive()
+			      ? duration.count() / frame_duration.count()
+			      : 0)
+			+ FRAMES_CUSHION;
 	} else {
 		max_frames = FRAMES_CUSHION;
-		total_time = 0;
+		total_time = SignedSongTime::Negative();
 	}
 }
 
@@ -792,7 +797,7 @@ MadDecoder::DecodeFirstFrame(Tag **tag)
 		if ((xing.flags & XING_FRAMES) && xing.frames) {
 			mad_timer_t duration = frame.header.duration;
 			mad_timer_multiply(&duration, xing.frames);
-			total_time = ((float)mad_timer_count(duration, MAD_UNITS_MILLISECONDS)) / 1000;
+			total_time = ToSongTime(duration);
 			max_frames = xing.frames;
 		}
 
@@ -844,13 +849,13 @@ MadDecoder::~MadDecoder()
 }
 
 /* this is primarily used for getting total time for tags */
-static int
+static std::pair<bool, SignedSongTime>
 mad_decoder_total_file_time(InputStream &is)
 {
 	MadDecoder data(nullptr, is);
 	return data.DecodeFirstFrame(nullptr)
-		? data.total_time + 0.5
-		: -1;
+		? std::make_pair(true, data.total_time)
+		: std::make_pair(false, SignedSongTime::Negative());
 }
 
 long
@@ -1085,11 +1090,15 @@ static bool
 mad_decoder_scan_stream(InputStream &is,
 			const struct tag_handler *handler, void *handler_ctx)
 {
-	const int total_time = mad_decoder_total_file_time(is);
-	if (total_time < 0)
+	const auto result = mad_decoder_total_file_time(is);
+	if (!result.first)
 		return false;
 
-	tag_handler_invoke_duration(handler, handler_ctx, total_time);
+	unsigned duration = result.second.IsNegative()
+		? 0
+		: result.second.RoundS();
+
+	tag_handler_invoke_duration(handler, handler_ctx, duration);
 	return true;
 }
 
diff --git a/src/decoder/plugins/MikmodDecoderPlugin.cxx b/src/decoder/plugins/MikmodDecoderPlugin.cxx
index a1938617d..85633f1fc 100644
--- a/src/decoder/plugins/MikmodDecoderPlugin.cxx
+++ b/src/decoder/plugins/MikmodDecoderPlugin.cxx
@@ -170,7 +170,8 @@ mikmod_decoder_file_decode(Decoder &decoder, Path path_fs)
 	const AudioFormat audio_format(mikmod_sample_rate, SampleFormat::S16, 2);
 	assert(audio_format.IsValid());
 
-	decoder_initialized(decoder, audio_format, false, 0);
+	decoder_initialized(decoder, audio_format, false,
+			    SignedSongTime::Negative());
 
 	Player_Start(handle);
 
diff --git a/src/decoder/plugins/ModplugDecoderPlugin.cxx b/src/decoder/plugins/ModplugDecoderPlugin.cxx
index c88249fa5..279790b93 100644
--- a/src/decoder/plugins/ModplugDecoderPlugin.cxx
+++ b/src/decoder/plugins/ModplugDecoderPlugin.cxx
@@ -153,7 +153,7 @@ mod_decode(Decoder &decoder, InputStream &is)
 
 	decoder_initialized(decoder, audio_format,
 			    is.IsSeekable(),
-			    ModPlug_GetLength(f) / 1000.0);
+			    SongTime::FromMS(ModPlug_GetLength(f)));
 
 	DecoderCommand cmd;
 	do {
diff --git a/src/decoder/plugins/Mp4v2DecoderPlugin.cxx b/src/decoder/plugins/Mp4v2DecoderPlugin.cxx
index ef5284437..d59be7f09 100644
--- a/src/decoder/plugins/Mp4v2DecoderPlugin.cxx
+++ b/src/decoder/plugins/Mp4v2DecoderPlugin.cxx
@@ -149,7 +149,8 @@ mp4_file_decode(Decoder &mpd_decoder, Path path_fs)
 	/* initialize the MPD core */
 
 	const MP4Timestamp scale = MP4GetTrackTimeScale(handle, track);
-	const float duration = ((float)MP4GetTrackDuration(handle, track)) / scale + 0.5f;
+	const SongTime duration = SongTime::FromScale<uint64_t>(MP4GetTrackDuration(handle, track),
+								scale);
 	const MP4SampleId num_samples = MP4GetTrackNumberOfSamples(handle, track);
 
 	decoder_initialized(mpd_decoder, audio_format, true, duration);
diff --git a/src/decoder/plugins/MpcdecDecoderPlugin.cxx b/src/decoder/plugins/MpcdecDecoderPlugin.cxx
index 3ad4ff40d..08e060bee 100644
--- a/src/decoder/plugins/MpcdecDecoderPlugin.cxx
+++ b/src/decoder/plugins/MpcdecDecoderPlugin.cxx
@@ -180,7 +180,7 @@ mpcdec_decode(Decoder &mpd_decoder, InputStream &is)
 
 	decoder_initialized(mpd_decoder, audio_format,
 			    is.IsSeekable(),
-			    mpc_streaminfo_get_length(&info));
+			    SongTime::FromS(mpc_streaminfo_get_length(&info)));
 
 	DecoderCommand cmd = DecoderCommand::NONE;
 	do {
diff --git a/src/decoder/plugins/Mpg123DecoderPlugin.cxx b/src/decoder/plugins/Mpg123DecoderPlugin.cxx
index 8779a6568..798cc953d 100644
--- a/src/decoder/plugins/Mpg123DecoderPlugin.cxx
+++ b/src/decoder/plugins/Mpg123DecoderPlugin.cxx
@@ -131,9 +131,11 @@ mpd_mpg123_file_decode(Decoder &decoder, Path path_fs)
 
 	/* tell MPD core we're ready */
 
-	decoder_initialized(decoder, audio_format, true,
-			    (float)num_samples /
-			    (float)audio_format.sample_rate);
+	const auto duration =
+		SongTime::FromScale<uint64_t>(num_samples,
+					      audio_format.sample_rate);
+
+	decoder_initialized(decoder, audio_format, true, duration);
 
 	if (mpg123_info(handle, &info) != MPG123_OK) {
 		info.vbr = MPG123_CBR;
diff --git a/src/decoder/plugins/OpusDecoderPlugin.cxx b/src/decoder/plugins/OpusDecoderPlugin.cxx
index 18ccf8183..2de827c7f 100644
--- a/src/decoder/plugins/OpusDecoderPlugin.cxx
+++ b/src/decoder/plugins/OpusDecoderPlugin.cxx
@@ -253,9 +253,10 @@ MPDOpusDecoder::HandleBOS(const ogg_packet &packet)
 
 	eos_granulepos = LoadEOSGranulePos(input_stream, &decoder,
 					   opus_serialno);
-	const double duration = eos_granulepos >= 0
-		? double(eos_granulepos) / opus_sample_rate
-		: -1.0;
+	const auto duration = eos_granulepos >= 0
+		? SignedSongTime::FromScale<uint64_t>(eos_granulepos,
+						      opus_sample_rate)
+		: SignedSongTime::Negative();
 
 	const AudioFormat audio_format(opus_sample_rate,
 				       SampleFormat::S16, channels);
diff --git a/src/decoder/plugins/PcmDecoderPlugin.cxx b/src/decoder/plugins/PcmDecoderPlugin.cxx
index 0f41099f2..c07a7b9b1 100644
--- a/src/decoder/plugins/PcmDecoderPlugin.cxx
+++ b/src/decoder/plugins/PcmDecoderPlugin.cxx
@@ -40,12 +40,12 @@ pcm_stream_decode(Decoder &decoder, InputStream &is)
 	const bool reverse_endian = mime != nullptr &&
 		strcmp(mime, "audio/x-mpd-cdda-pcm-reverse") == 0;
 
-	const double time_to_size = audio_format.GetTimeToSize();
 	const auto frame_size = audio_format.GetFrameSize();
 
-	float total_time = -1;
-	if (is.KnownSize())
-		total_time = is.GetSize() / time_to_size;
+	const auto total_time = is.KnownSize()
+		? SignedSongTime::FromScale<uint64_t>(is.GetSize() / frame_size,
+						      audio_format.sample_rate)
+		: SignedSongTime::Negative();
 
 	decoder_initialized(decoder, audio_format,
 			    is.IsSeekable(), total_time);
diff --git a/src/decoder/plugins/SidplayDecoderPlugin.cxx b/src/decoder/plugins/SidplayDecoderPlugin.cxx
index b0a398f56..2adfa6df9 100644
--- a/src/decoder/plugins/SidplayDecoderPlugin.cxx
+++ b/src/decoder/plugins/SidplayDecoderPlugin.cxx
@@ -159,11 +159,11 @@ get_song_num(const char *path_fs)
 }
 
 /* get the song length in seconds */
-static int
+static SignedSongTime
 get_song_length(Path path_fs)
 {
 	if (songlength_database == nullptr)
-		return -1;
+		return SignedSongTime::Negative();
 
 	char *sid_file = get_container_name(path_fs);
 	SidTuneMod tune(sid_file);
@@ -171,7 +171,7 @@ get_song_length(Path path_fs)
 	if(!tune) {
 		LogWarning(sidplay_domain,
 			   "failed to load file for calculating md5 sum");
-		return -1;
+		return SignedSongTime::Negative();
 	}
 	char md5sum[SIDTUNE_MD5_LENGTH+1];
 	tune.createMD5(md5sum);
@@ -183,7 +183,7 @@ get_song_length(Path path_fs)
 		"Database", md5sum, &num_items, nullptr);
 	if(!values || song_num>num_items) {
 		g_strfreev(values);
-		return -1;
+		return SignedSongTime::Negative();
 	}
 
 	int minutes=strtol(values[song_num-1], nullptr, 10);
@@ -199,7 +199,7 @@ get_song_length(Path path_fs)
 
 	g_strfreev(values);
 
-	return (minutes*60)+seconds;
+	return SignedSongTime::FromS((minutes * 60) + seconds);
 }
 
 static void
@@ -220,8 +220,9 @@ sidplay_file_decode(Decoder &decoder, Path path_fs)
 	const int song_num = get_song_num(path_fs.c_str());
 	tune.selectSong(song_num);
 
-	int song_len=get_song_length(path_fs);
-	if(song_len==-1) song_len=default_songlength;
+	auto duration = get_song_length(path_fs);
+	if (duration.IsNegative() && default_songlength > 0)
+		duration = SongTime::FromS(default_songlength);
 
 	/* initialize the player */
 
@@ -292,12 +293,14 @@ sidplay_file_decode(Decoder &decoder, Path path_fs)
 	const AudioFormat audio_format(48000, SampleFormat::S16, channels);
 	assert(audio_format.IsValid());
 
-	decoder_initialized(decoder, audio_format, true, (float)song_len);
+	decoder_initialized(decoder, audio_format, true, duration);
 
 	/* .. and play */
 
 	const unsigned timebase = player.timebase();
-	song_len *= timebase;
+	const unsigned end = duration.IsNegative()
+		? 0u
+		: duration.ToScale<uint64_t>(timebase);
 
 	DecoderCommand cmd;
 	do {
@@ -334,7 +337,7 @@ sidplay_file_decode(Decoder &decoder, Path path_fs)
 			decoder_command_finished(decoder);
 		}
 
-		if (song_len > 0 && player.time() >= (unsigned)song_len)
+		if (end > 0 && player.time() >= end)
 			break;
 
 	} while (cmd != DecoderCommand::STOP);
@@ -382,9 +385,10 @@ sidplay_scan_file(Path path_fs,
 	tag_handler_invoke_tag(handler, handler_ctx, TAG_TRACK, track);
 
 	/* time */
-	int song_len=get_song_length(path_fs);
-	if (song_len >= 0)
-		tag_handler_invoke_duration(handler, handler_ctx, song_len);
+	const auto duration = get_song_length(path_fs);
+	if (!duration.IsNegative())
+		tag_handler_invoke_duration(handler, handler_ctx,
+					    duration.RoundS());
 
 	return true;
 }
diff --git a/src/decoder/plugins/SndfileDecoderPlugin.cxx b/src/decoder/plugins/SndfileDecoderPlugin.cxx
index 96e61d088..78897da58 100644
--- a/src/decoder/plugins/SndfileDecoderPlugin.cxx
+++ b/src/decoder/plugins/SndfileDecoderPlugin.cxx
@@ -140,10 +140,11 @@ static SF_VIRTUAL_IO vio = {
 /**
  * Converts a frame number to a timestamp (in seconds).
  */
-static float
+static SongTime
 frame_to_time(sf_count_t frame, const AudioFormat *audio_format)
 {
-	return (float)frame / (float)audio_format->sample_rate;
+	return SongTime::FromScale<uint64_t>(frame,
+					     audio_format->sample_rate);
 }
 
 static void
diff --git a/src/decoder/plugins/VorbisDecoderPlugin.cxx b/src/decoder/plugins/VorbisDecoderPlugin.cxx
index e740cede6..8348407d6 100644
--- a/src/decoder/plugins/VorbisDecoderPlugin.cxx
+++ b/src/decoder/plugins/VorbisDecoderPlugin.cxx
@@ -202,6 +202,16 @@ vorbis_init(gcc_unused const config_param &param)
 	return true;
 }
 
+gcc_pure
+static SignedSongTime
+vorbis_duration(OggVorbis_File &vf)
+{
+	auto total = ov_time_total(&vf, -1);
+	return total >= 0
+		? SignedSongTime::FromS(total)
+		: SignedSongTime::Negative();
+}
+
 static void
 vorbis_stream_decode(Decoder &decoder,
 		     InputStream &input_stream)
@@ -237,11 +247,8 @@ vorbis_stream_decode(Decoder &decoder,
 		return;
 	}
 
-	float total_time = ov_time_total(&vf, -1);
-	if (total_time < 0)
-		total_time = 0;
-
-	decoder_initialized(decoder, audio_format, vis.seekable, total_time);
+	decoder_initialized(decoder, audio_format, vis.seekable,
+			    vorbis_duration(vf));
 
 #ifdef HAVE_TREMOR
 	char buffer[4096];
diff --git a/src/decoder/plugins/WavpackDecoderPlugin.cxx b/src/decoder/plugins/WavpackDecoderPlugin.cxx
index 870a1a80d..1efd49850 100644
--- a/src/decoder/plugins/WavpackDecoderPlugin.cxx
+++ b/src/decoder/plugins/WavpackDecoderPlugin.cxx
@@ -160,8 +160,9 @@ wavpack_decode(Decoder &decoder, WavpackContext *wpc, bool can_seek)
 		? format_samples_float
 		: format_samples_int;
 
-	const float total_time = float(WavpackGetNumSamples(wpc))
-		/ audio_format.sample_rate;
+	const auto total_time =
+		SongTime::FromScale<uint64_t>(WavpackGetNumSamples(wpc),
+					      audio_format.sample_rate);
 
 	const int bytes_per_sample = WavpackGetBytesPerSample(wpc);
 	const int output_sample_size = audio_format.GetFrameSize();
diff --git a/src/decoder/plugins/WildmidiDecoderPlugin.cxx b/src/decoder/plugins/WildmidiDecoderPlugin.cxx
index 08078a792..221f7433b 100644
--- a/src/decoder/plugins/WildmidiDecoderPlugin.cxx
+++ b/src/decoder/plugins/WildmidiDecoderPlugin.cxx
@@ -86,8 +86,11 @@ wildmidi_file_decode(Decoder &decoder, Path path_fs)
 		return;
 	}
 
-	decoder_initialized(decoder, audio_format, true,
-			    info->approx_total_samples / WILDMIDI_SAMPLE_RATE);
+	const auto duration =
+		SongTime::FromScale<uint64_t>(info->approx_total_samples,
+					      WILDMIDI_SAMPLE_RATE);
+
+	decoder_initialized(decoder, audio_format, true, duration);
 
 	DecoderCommand cmd;
 	do {
diff --git a/test/FakeDecoderAPI.cxx b/test/FakeDecoderAPI.cxx
index 2516e9e62..dcc78125b 100644
--- a/test/FakeDecoderAPI.cxx
+++ b/test/FakeDecoderAPI.cxx
@@ -30,7 +30,7 @@ void
 decoder_initialized(Decoder &decoder,
 		    const AudioFormat audio_format,
 		    gcc_unused bool seekable,
-		    float duration)
+		    SignedSongTime duration)
 {
 	struct audio_format_string af_string;
 
@@ -39,7 +39,7 @@ decoder_initialized(Decoder &decoder,
 
 	fprintf(stderr, "audio_format=%s duration=%f\n",
 		audio_format_to_string(audio_format, &af_string),
-		duration);
+		duration.ToDoubleS());
 
 	decoder.initialized = true;
 }