Merge tag 'v0.19.11'

NEWS

@@ -42,6 +42,17 @@ ver 0.20 (not yet released)
 * update
   - apply .mpdignore matches to subdirectories
 
+ver 0.19.11 (2015/10/27)
+* tags
+  - ape: fix buffer overflow
+* decoder
+  - ffmpeg: fix crash due to wrong avio_alloc_context() call
+  - gme: don't loop forever, fall back to GME's default play length
+* encoder
+  - flac: fix crash with 32 bit playback
+* mixer
+  - fix mixer lag after enabling/disabling output
+
 ver 0.19.10 (2015/06/21)
 * input
   - curl: fix deadlock on small responses

doc/user.xml

@@ -1025,6 +1025,58 @@ database {
         plugin).
       </para>
     </section>
+
+    <section id="realtime">
+      <title>Real-Time Scheduling</title>
+
+      <para>
+        On Linux, <application>MPD</application> attempts to configure
+        <ulink
+        url="https://en.wikipedia.org/wiki/Real-time_computing">real-time
+        scheduling</ulink> for some threads that benefit from it.
+      </para>
+
+      <para>
+        This is only possible you allow <application>MPD</application>
+        to do it.  This privilege is controlled by
+        <varname>RLIMIT_RTPRIO</varname>
+        <varname>RLIMIT_RTTIME</varname>.  You can configure this
+        privilege with <command>ulimit</command> before launching
+        <application>MPD</application>:
+      </para>
+
+      <programlisting>ulimit -HS -r 50; mpd</programlisting>
+
+      <para>
+        Or you can use the <command>prlimit</command> program from the
+        <application>util-linux</application> package:
+      </para>
+
+      <programlisting>prlimit --rtprio=50 --rttime=unlimited mpd</programlisting>
+
+      <para>
+        The <application>systemd</application> service file shipped
+        with <application>MPD</application> comes with this setting.
+      </para>
+
+      <para>
+        This works only if the Linux kernel was compiled with
+        <varname>CONFIG_RT_GROUP_SCHED</varname> disabled.  Use the
+        following command to check this option for your current
+        kernel:
+      </para>
+
+      <programlisting>zgrep ^CONFIG_RT_GROUP_SCHED /proc/config.gz</programlisting>
+
+      <note>
+        <para>
+          There is a rumor that real-time scheduling improves audio
+          quality.  That is not true.  All it does is reduce the
+          probability of skipping (audio buffer xruns) when the
+          computer is under heavy load.
+        </para>
+      </note>
+    </section>
   </chapter>
 
   <chapter id="use">

src/decoder/plugins/FfmpegIo.cxx

@@ -28,7 +28,10 @@
 
 AvioStream::~AvioStream()
 {
-	av_free(io);
+	if (io != nullptr) {
+		av_free(io->buffer);
+		av_free(io);
+	}
 }
 
 inline int
@@ -90,9 +93,18 @@ AvioStream::_Seek(void *opaque, int64_t pos, int whence)
 bool
 AvioStream::Open()
 {
-	io = avio_alloc_context(buffer, sizeof(buffer),
+	constexpr size_t BUFFER_SIZE = 8192;
+	auto buffer = (unsigned char *)av_malloc(BUFFER_SIZE);
+	if (buffer == nullptr)
+		return false;
+
+	io = avio_alloc_context(buffer, BUFFER_SIZE,
 				false, this,
 				_Read, nullptr,
 				input.IsSeekable() ? _Seek : nullptr);
+	/* If avio_alloc_context() fails, who frees the buffer?  The
+	   libavformat API documentation does not specify this, it
+	   only says that AVIOContext.buffer must be freed in the end,
+	   however no AVIOContext exists in that failure code path. */
 	return io != nullptr;
 }

src/decoder/plugins/FfmpegIo.hxx

@@ -37,8 +37,6 @@ struct AvioStream {
 
 	AVIOContext *io;
 
-	uint8_t buffer[8192];
-
 	AvioStream(Decoder *_decoder, InputStream &_input)
 		:decoder(_decoder), input(_input), io(nullptr) {}
 

src/decoder/plugins/GmeDecoderPlugin.cxx

@@ -157,8 +157,11 @@ gme_file_decode(Decoder &decoder, Path path_fs)
 		return;
 	}
 
-	const SignedSongTime song_len = ti->length > 0
-		? SignedSongTime::FromMS(ti->length)
+	const int length = ti->play_length;
+	gme_free_info(ti);
+
+	const SignedSongTime song_len = length > 0
+		? SignedSongTime::FromMS(length)
 		: SignedSongTime::Negative();
 
 	/* initialize the MPD decoder */
@@ -169,7 +172,6 @@ gme_file_decode(Decoder &decoder, Path path_fs)
 				       SampleFormat::S16, GME_CHANNELS,
 				       error)) {
 		LogError(error);
-		gme_free_info(ti);
 		gme_delete(emu);
 		return;
 	}
@@ -180,8 +182,8 @@ gme_file_decode(Decoder &decoder, Path path_fs)
 	if (gme_err != nullptr)
 		LogWarning(gme_domain, gme_err);
 
-	if (ti->length > 0)
-		gme_set_fade(emu, ti->length);
+	if (length > 0)
+		gme_set_fade(emu, length);
 
 	/* play */
 	DecoderCommand cmd;
@@ -197,16 +199,17 @@ gme_file_decode(Decoder &decoder, Path path_fs)
 		if (cmd == DecoderCommand::SEEK) {
 			unsigned where = decoder_seek_time(decoder).ToMS();
 			gme_err = gme_seek(emu, where);
-			if (gme_err != nullptr)
+			if (gme_err != nullptr) {
 				LogWarning(gme_domain, gme_err);
-			decoder_command_finished(decoder);
+				decoder_seek_error(decoder);
+			} else
+				decoder_command_finished(decoder);
 		}
 
 		if (gme_track_ended(emu))
 			break;
 	} while (cmd != DecoderCommand::STOP);
 
-	gme_free_info(ti);
 	gme_delete(emu);
 }
 
@@ -214,9 +217,9 @@ static void
 ScanGmeInfo(const gme_info_t &info, unsigned song_num, int track_count,
 	    const struct tag_handler *handler, void *handler_ctx)
 {
-	if (info.length > 0)
+	if (info.play_length > 0)
 		tag_handler_invoke_duration(handler, handler_ctx,
-					    SongTime::FromMS(info.length));
+					    SongTime::FromMS(info.play_length));
 
 	if (info.song != nullptr) {
 		if (track_count > 1) {

src/encoder/plugins/FlacEncoderPlugin.cxx

@@ -157,8 +157,6 @@ flac_encoder_open(Encoder *_encoder, AudioFormat &audio_format, Error &error)
 	struct flac_encoder *encoder = (struct flac_encoder *)_encoder;
 	unsigned bits_per_sample;
 
-	encoder->audio_format = audio_format;
-
 	/* FIXME: flac should support 32bit as well */
 	switch (audio_format.format) {
 	case SampleFormat::S8:
@@ -178,6 +176,8 @@ flac_encoder_open(Encoder *_encoder, AudioFormat &audio_format, Error &error)
 		audio_format.format = SampleFormat::S24_P32;
 	}
 
+	encoder->audio_format = audio_format;
+
 	/* allocate the encoder */
 	encoder->fse = FLAC__stream_encoder_new();
 	if (encoder->fse == nullptr) {

src/output/OutputCommand.cxx

@@ -30,6 +30,7 @@
 #include "Internal.hxx"
 #include "player/Control.hxx"
 #include "mixer/MixerControl.hxx"
+#include "mixer/Volume.hxx"
 #include "Idle.hxx"
 
 extern unsigned audio_output_state_version;
@@ -47,6 +48,11 @@ audio_output_enable_index(MultipleOutputs &outputs, unsigned idx)
 	ao.enabled = true;
 	idle_add(IDLE_OUTPUT);
 
+	if (ao.mixer != nullptr) {
+		InvalidateHardwareVolume();
+		idle_add(IDLE_MIXER);
+	}
+
 	ao.player_control->UpdateAudio();
 
 	++audio_output_state_version;
@@ -70,6 +76,7 @@ audio_output_disable_index(MultipleOutputs &outputs, unsigned idx)
 	Mixer *mixer = ao.mixer;
 	if (mixer != nullptr) {
 		mixer_close(mixer);
+		InvalidateHardwareVolume();
 		idle_add(IDLE_MIXER);
 	}
 
@@ -94,6 +101,7 @@ audio_output_toggle_index(MultipleOutputs &outputs, unsigned idx)
 		Mixer *mixer = ao.mixer;
 		if (mixer != nullptr) {
 			mixer_close(mixer);
+			InvalidateHardwareVolume();
 			idle_add(IDLE_MIXER);
 		}
 	}

src/output/plugins/PipeOutputPlugin.cxx

@@ -51,7 +51,6 @@ public:
 	}
 
 	size_t Play(const void *chunk, size_t size, Error &error);
-
 };
 
 inline bool

src/tag/ApeLoader.cxx

@@ -79,12 +79,12 @@ ape_scan_internal(FILE *fp, ApeTagCallback callback)
 
 		/* get the key */
 		const char *key = p;
-		while (remaining > size && *p != '\0') {
-			p++;
-			remaining--;
-		}
-		p++;
-		remaining--;
+		const char *key_end = (const char *)memchr(p, '\0', remaining);
+		if (key_end == nullptr)
+			break;
+
+		p = key_end + 1;
+		remaining -= p - key;
 
 		/* get the value */
 		if (remaining < size)

systemd/mpd.service.in

@@ -10,15 +10,6 @@ ExecStart=@prefix@/bin/mpd --no-daemon
 LimitRTPRIO=50
 LimitRTTIME=-1
 
-# move MPD to a top-level cgroup, as real-time budget assignment fails
-# in cgroup /system/mpd.service, because /system has a zero real-time
-# budget; see
-# http://www.freedesktop.org/wiki/Software/systemd/MyServiceCantGetRealtime/
-ControlGroup=cpu:/mpd
-
-# assign a real-time budget
-ControlGroupAttribute=cpu.rt_runtime_us 500000
-
 # disallow writing to /usr, /bin, /sbin, ...
 ProtectSystem=yes