V2.9.5.7 – Bug fixes and enhancements

Version 2.9.5.7 contains general bug fixes and enhancements for some special situations.

Bug Fixes

• Getting delay and latency information from the alsa subsystem has been improved -- bugs fixed, error codes handled better, arithmetic handling (hopefully) better.
• If latency information is temporarily unavailable from the alsa subsystem, skip trying to synchronise until the next time.
• Some condition variables and a mutex were uninitialised, yikes! Fixed.
• A bug that set the output volume to maximum at the same time as muting the output has been fixed. AFAIK, this was inaudible, but it was scary looking.
• Recover from name collisions in Avahi.
• Detect and handle empty buffers better.

Enhancements

• Turn off synchronisation. This is an advanced feature and generally leads to buffer underrun or overrun.
• Set alsa buffer size and alsa period size. There are advanced features, mainly for debugging. They may be removed.
• Change the Zeroconf/Bonjour regtype to enable Shairport Sync to continue to run but to be invisible to AirPlay clients. Special purpose usage only.
• Output total number of packets and the play time of a session when statistics are enabled.

V2.9.5.2 – Modify Delay Check Version

This may be unstable, really.

This has a number of changes to how DAC delay information is handled and what happens if it isn't available on occasion. It corrects at least one error misinterpreting a return error code of -1 as 4,294,967,295.

It also tidies up and possibly corrects some arithmetic sign overflow type and type-promotion errors due to incomplete observance of the rule of type conversion and promotion in C.

A new alsa backend option to disable synchronisation is added: disable_synchronization = "yes" with a default of "no". This should be used with caution. Synchronisation is disabled, obviously, but also, sooner or later, the DAC will either overflow or underflow, giving audible glitches. They may happen only after a number of hours, however.

Some debug messages are tided up, some demoted to level 2 or 3, and some promoted to level 1.

V2.9.5 – Modify Delay Check Version

This is 2.9.4 but with a change in the way delay information is obtained from the alsa subsystem – it uses snd_pcm_delay rather than snd_pcm_avail_delay.

V2.9.4 – Development Version

Version 2.9.4 corrects some bugs in how Avahi error conditions are handled.

Bug Fix

• If the network disappears, Avahi will occasionally report an error. This will cause Shairport Sync to attempt to terminate gracefully (which is the wrong thing to do in the circumstances). However, the termination attempt actually causes an assertion violation crash. These errors are now simply logged.

V2.9.3 – Development Version

This is release version 2.8.1, with documentation and version changes to indicate that it's a development version.

V2.8.1 – Stability Improvements and Bug Fixes

Version 2.8.1 is derived from development version 2.9.2 and has stability improvements and important bug fixes.

It is recommended for all installations.

No changes in settings are necessary.

V2.9.2 – Development Version

Version 2.9.2 focusses on further bug fixes and stability improvements.

• An important bug has been fixed in the handling of missing audio frames – i.e. what happens when a frame of audio is truly missing, in spite of having been re-requested. The bug would cause Shairport Sync to do an unnecessary resynchronisation, or, if resync was turned off, to jump out of sync. This is a long-standing bug – thanks to Jörg Krause for identifying it.
• An extra diagnostic has been added which gives the mean, standard deviation and maximum values for inter-packet reception time on the audio port. It may be useful for exploring line quality. Available at log verbosity level 3.

V2.9.1 – Development Version

Version 2.9.1 focusses on bug fixes and stability improvements.

• Stability improvements are concentrated on what happens when a play sessions ends and is followed immediately by a new session. This happens in iOS 9.2 when you click to the next track or to the previous track. It also happens playing YouTube videos when a Mac's System Audio is routed through AirPlay. Thanks to Tim Curtis for help with these issues.
• A workaround for an apparent flushing issue in TuneBlade has been included. Thanks to gibman for reporting this issue.
• A number of bug fixes have been made to configure.ac – thanks to Jörg Krause.

V2.8.0 – Stable Version

The version number of Shairport Sync in release 2.8 was incorrectly left at 2.7.10. In this release, the release number and the version number match – 2.8.0.

V2.8 – Stable Version

Version 2.8 is the next stable release after Version 2.6.

Version 2.8 is derived from Version 2.7.10 with slight documentation updates. Here is a summary of changes between the last stable version – 2.6 – and this version. For full details, refer to the release notes.

New Feature

• For hardware mixers with a restricted range (including many cheaper USB DACS), the general volume_range_db can be used to specify a wider range than the hardware provides – the extra range is provided by software.

Enhancements

• Volume-setting metadata is now sent even when the volume level is to be ignored by Shairport Sync itself.
• Shairport Sync waits a little longer before asking for missing packets to be resent. Sometimes packets are just arriving slightly out of order and don't need to be asked for again.
• The build scripts have been modified to be a little more compatible with standard practice.
• The man manual and the html version of it are automagically rebuilt if xml2man and friends are available.
• A Continuous Integration (CI) system – Travis CI – is now used to do some limited build checking (thanks guys!).
• Support added for compiling on Cygwin.
• Added rtptime tags to metadata and picture metadata.
• Replaced and improved the dither algorithm used with the software volume control. The new dither code gives a two bit peak-to-peak dither based on a Triangular Probability Distribution Function (TPDF).
• Disabled picture sending if pictures haven’t been asked for.

Bug fixes

• Fixed a bug that prevented Shairport Sync from correctly setting the hardware mixer volume if it had been altered externally.
• Modified the shutdown behaviour so that a shutdown followed immediately by a play request is handled properly. This was causing iOS 9.2 sometimes to drop the Airplay link between tunes.
• Fixed a data-alignment bug that would cause a crash in certain circumstances on ARM processors with metadata enabled.
• Corrected the names for a few settings tags.
• Fixed some typos and misspellings.
• Miscellaneous small bug fixes.