+Nageru and Futatabi 2.3.0, October 5th, 2023
+
+ - Support SRT output of the encoded stream, including
+ output to YouTube if your account is enabled for this
+ (beta testers only as of this release). This is useful
+ for push, and for bad networks (e.g. 4G).
+
+ - Fix various deprecation warnings with newer FFmpeg
+ (Nageru should now be warning-free with FFmpeg 6.0).
+ This also means that Nageru now requires FFmpeg 5.1
+ or newer.
+
+ - Fix crashes with newer SVT-AV1.
+
+
+Nageru and Futatabi 2.2.3, July 24th, 2023
+
+ - Fix startup crashes with newer libsrt.
+
+ - Fix an issue where checkable theme menus would get the wrong
+ starting state. Reported by Stefano Rivera.
+
+
+Nageru and Futatabi 2.2.2, July 15th, 2023
+
+ - Fix build breaks with newer GCC and SVT-AV1.
+
+
+Nageru and Futatabi 2.2.1, April 17th, 2023
+
+ - Work around an issue with OpenGL on Wayland, causing all
+ displays to be blank.
+
+ - Several fixes related to video inputs; in particular:
+ - Fix crashes when the master clock goes faster than 60 Hz
+ (which could happen primarily if an SRT input is the master).
+ - Be more resilient to errors in hardware video decoding
+ when the stream starts out broken (e.g., not on a key frame)
+ but recovers.
+ - Multiple fixes related to hardware acceleration on nVidia.
+ - Incoming frames of too high resolution (larger than 8 MB)
+ will be refused instead of crashing. Such videos may be
+ supported better in the future.
+
+
+Nageru and Futatabi 2.2.0, November 15th, 2022
+
+ - Support AV1 output, via SVT-AV1. Note that this is still somewhat
+ experimental, not the least because SVT-AV1's streaming support
+ is not as mature as x264.
+
+ - Remove the dependency on QCustomPlot.
+
+ - Expose BlurEffect and UnsharpMaskEffect to the theme.
+
+ - Clean up several rarely-unused command-line flags:
+ - All the 10-bit flags are now collapsed to --10-bit.
+ - Remove --http-uncompressed-video.
+ - Remove the x264 VBV flags.
+ - Hide --x264-speedcontrol-verbose.
+ - Hide --no-flush-pbos.
+
+ - Make a workaround for audio monitoring output under PipeWire.
+
+ - Update CEF compatibility (tested with CEF 107).
+
+
+Nageru and Futatabi 2.1.0, February 6th, 2022
+
+ - Support unsynchronized HDMI/SDI output.
+
+ This is for if you want just a monitor output without synchronizing
+ your entire stream chain to the output card (ie., you want to keep
+ some other camera as the master). Sound support is untested, and is
+ probably going to crackle a fair bit.
+
+ There's no GUI support for changing this currently (you enable it
+ by using --output-card-unsynchronized and then using HDMI/SDI output
+ as usual).
+
+ - Support sending a separate x264 encode to disk
+ (--separate-x264-disk-encode and associated --x264-separate-disk-*
+ flags).
+
+ This is useful for machines that don't have Quick Sync, but where
+ you want to have an archival copy on disk in higher quality
+ than what you streamed out.
+
+ - Fix compilation issues with FFmpeg 5.0.
+
+
+Nageru and Futatabi 2.0.2, September 3rd, 2021
+
+ - Fix issues with various upstream software:
+ DeckLink 11.7 (and newer) drivers, FFmpeg 4.4, newer CEF.
+
+ - Add a --no-transcode-video flag to Kaeru.
+
+ This is useful primarily if you want Kaeru to rewrap the stream into
+ Metacube (for Cubemap) and do nothing else with it. Only H.264
+ is supported for now, since everything else assumes that.
+
+
+Nageru and Futatabi 2.0.1, July 9th, 2020
+
+ - Upgrade DeckLink SDK to 10.11.4.
+
+ - Various bugfixes.
+
+
+Nageru and Futatabi 2.0.0, June 2nd, 2020
+
+ - Native support for SRT inputs; by default, Nageru will listen
+ for incoming connections on port 9710 and treat them as hotplugged
+ cameras. They do not need any special handling in the theme,
+ and can pick up e.g. the SRT stream ID to be used in the UI.
+ They generally have fewer limitations than using an srt:// URL
+ on an FFmpeg capture; e.g., there is no forced scaling, and they
+ can be used as master clock (although this is not generally
+ recommended).
+
+ For license reaseons, please be sure that libsrt does not link to
+ OpenSSL when building Nageru.
+
+ - You do no longer need to set up a fixed amount of capture cards
+ at startup; by default, at least two will be created for you
+ (fake capture cards) as before, but if you have more, or hotplug
+ more, more slots will be automatically available, and will go
+ away (not take up any resources like fake capture cards do)
+ when unplugged. If you wish to artificially limit the maximum
+ number of cards like before, you can use the new switch
+ --max-num-cards.
+
+ - MJPEG handling now includes 4:2:0 support in both Nageru and
+ Futatabi, as SRT inputs are often 4:2:0 and not 4:2:2.
+
+ - FFmpeg capture cards (including SRT cards) now use VA-API
+ hardware acceleration for decoding whenever available.
+
+
+Nageru and Futatabi 1.9.3, April 12th, 2020
+
+ - Support (video-only) V4L2 output. The intended use case is output into
+ v4l2loopback to get into videoconferencing or the likes:
+
+ sudo apt install v4l2loopback-dkms
+ sudo modprobe v4l2loopback video_nr=2 card_label='Nageru loopback' max_width=1280 max_height=720 exclusive_caps=1
+ nageru --v4l-output /dev/video2
+
+ Start Nageru before any readers.
+
+
+Nageru and Futatabi 1.9.2, March 29th, 2020
+
+ - Support handling white balance directly in Nageru, without themes
+ manually inserting a WhiteBalanceEffect or handling set_wb().
+ To use it, call scene:add_white_balance() instead of
+ scene:add_effect(WhiteBalanceEffect.new()). If using this functionality,
+ white balance will be properly propagated to the MJPEG feed and
+ through Futatabi, so that replays get the correct white balance.
+ Futatabi's UI will still be uncorrected, though.
+
+ - Make it possible to siphon out a single MJPEG stream, for remote
+ debugging, single-camera recording, single-camera streaming via
+ Kaeru or probably other things. The URL for this is /feeds/N.mp4
+ where N is the card index (starting from zero).
+
+ - The theme can now access some audio settings; it can get (not set)
+ number of buses and names, get/set fader volume, get/set mute,
+ and get/set EQ parameters.
+
+ - In Futatabi, it is now possible to set custom source labels, with
+ the parameter --source-label NUM:LABEL (or -l NUM:LABEL).
+
+ - When the playback speed changes in Futatabi, ease into the new speed.
+ The easing period is nominally 200 ms, but it will be automatically
+ shortened or lengthened (up to as much as two seconds in extreme
+ cases, especially involving very slight speed change) if this
+ helps getting back into a cadence of hitting the original frames.
+ This can mean significant performance improvements when ramping
+ from higher speeds back into 100%.
+
+ - Updates for newer versions of CEF (tested with Chrome 80).
+
+ - Various bugfixes and performance improvements.
+
+
+Nageru and Futatabi 1.9.1, November 17th, 2019
+
+ - Support disabling optional effects if a given other effect is _enabled_
+ (typically for mutually exclusive effects).
+
+ - Make it possible for the theme to override the status line, by declaring
+ a function format_status_line() in the theme. Inspired by a C++ patch by
+ Alex Thomazo in the Breizhcamp repository.
+
+ - Various bugfixes.
+
+
+Nageru and Futatabi 1.9.0, July 20th, 2019
+
+ - Significant reworking of the theme engine: Chains (now called scenes)
+ can now instantiate different versions behind-the-scenes instead of the
+ user having to worry about input types, low/high quality, or replacing
+ effects with others. Menus can have submenus and checkboxes. Finally, some
+ callbacks, such as num_channels(), have been replaced with easier-to-use
+ imperative functions, ie., an explicit call to Nageru.set_num_channels(N).
+
+ See the documentation for more information, or the included themes,
+ which have been ported to the new interfaces. Existing themes will continue
+ to run without modification, but the old interfaces are deprecated.
+
+ Martin Sandsmark contributed a bugfix to this work.
+
+ - Support cross-compilation. Patch from Helmut Grohne.
+
+ - Kaeru now has a parameter --disable-audio for transcoding streams
+ with no audio.
+
+ - Various bugfixes. In particular, work around an issue where Mesa's shader
+ cache interacts with Qt's EGL support to create a confusing crash with
+ “vertex shader lacks `main'”.
+
+
+Nageru and Futatabi 1.8.6, April 19th, 2019
+
+ - Filenames for the recordings are now without colons; it caused
+ too much problems with various software, including most players.
+
+ - Various bugfixes.
+
+
+Nageru and Futatabi 1.8.5, March 30th, 2019
+
+ - Experimental support for audio in Futatabi: The MJPEG export from
+ Nageru now supports audio, and Futatabi will store it and play it
+ back. Audio is currently only supported when playing at 100% speed
+ (no pitch shift or time stretching), and there is no audio output
+ to the Futatabi operator.
+
+ - Significant optimizations to MJPEG encoding, both when in use and when
+ not in use.
+
+ - Various bugfixes.
+
+
+Nageru and Futatabi 1.8.4, March 11th, 2019
+
+ - Various bugfixes, in particular for 32-bit platforms.
+
+
+Nageru and Futatabi 1.8.3, March 10th, 2019
+
+ - Allow controlling video mixing from MIDI events. Adapted from a patch
+ by Yann Dubreuil, from the BreizhCamp repository.
+
+ - Use ALSA hardware timestamps for input; gives more stable delay.
+ Patch by Yann Dubreuil, from the BreizhCamp repository.
+
+ - For FFmpeg inputs, add an option for playing as fast as possible
+ (set rate >= 10.0).
+
+ - In Futatabi, support queueing and playing clips with no cue-out point.
+ This opens up for new and even faster UI workflows.
+
+ - Many bugfixes.
+
+
+Nageru and Futatabi 1.8.2, January 19th, 2019
+
+ - Futatabi now supports MIDI controllers like Nageru, including an editor
+ and a sample mapping for the Behringer CMD PL-1.
+
+ - Futatabi now supports changing master speed during play, both via a
+ MIDI controller and the GUI.
+
+ - Various bugfixes.
+
+
+Nageru and Futatabi 1.8.1, December 30th, 2018
+
+ - Futatabi can now communicate its queue status through a subtitle track,
+ and Nageru can consume it. This allows Nageru themes to get precise
+ information programmatically, e.g. to show status or automatically
+ switch away when the queue is about to end.
+
+ - Futatabi can now reuse the computed flow across successive frames when
+ interpolating between the same frame pair. This significantly reduces
+ the GPU load when doing super-slow motion (slower than 0.5x).
+
+ - Various smaller fixes.
+
+
+Nageru and Futatabi 1.8.0, December 20th, 2018
+
+ - Initial release of Futatabi, a multicamera slow motion video server
+ designed to be used with Nageru. Futatabi is currently in alpha stage
+ and largely undocumented.
+
+ - Add support for multi-camera export from Nageru. A multi-camera stream
+ contains all frames from all camera inputs (unless overridden by
+ --mjpeg-export-cards), unprocessed except for MJPEG encoding.
+ MJPEG encoding is done in hardware (via VA-API) on Skylake or newer,
+ or using libjpeg otherwise. The intended user of this stream is Futatabi.
+
+
+Nageru 1.7.5, November 11th, 2018
+
+ - Fix a bug where --record-x264-video would not work when VA-API was
+ not present, making the option rather useless (broken in 1.7.2).
+ Bug reported by Peter De Schrijver.
+
+ - The build system has been switched to Meson; see the README for new
+ build instructions.
+
+ - Various smaller fixes.
+
+
+Nageru 1.7.4, August 31st, 2018
+
+ - Rework the x264 speedcontrol presets, again. (They earlier assumed
+ we could control B-frame settings on the fly, which we cannot with
+ threaded lookahead.) Also support x264 >= 153, which can support
+ multiple bit depths in the same library.
+
+ - Default to SDI inputs instead of HDMI.
+
+ - Add a mode to run in full screen (--fullscreen). Adapted from a patch
+ by Yoann Dubreuil.
+
+ - Add support for lift/gamma/gain in the theme. Patch by Alexandre Thomazo.
+
+
+Nageru 1.7.3, May 22nd, 2018
+
+ - When using multichannel audio, add a control for adjusting the
+ stereo width (from normal stereo to mono, all the way to
+ inverted stereo).
+
+ - Removed --http-coarse-timebase (it is now always on).
+
+ - Various bugfixes.
+
+
+Nageru 1.7.2, April 28th, 2018
+
+ - Several improvements to video (FFmpeg) inputs: You can now use
+ them as audio sources, you can right-click on video channels
+ to change URL/filename on-the-fly, themes can ask for forced
+ disconnection (useful for network sources that are hanging),
+ and various other improvements. Be aware that the audio support
+ may still be somewhat rough, as A/V sync of arbitrary video
+ playout is a hard problem.
+
+ - The included themes have been fixed to properly make the returned
+ chain preparation functions independent of global state (e.g. if
+ the white balance for a channel was changed before the frame was
+ actually rendered). If you are using a custom theme, you may want
+ to apply similar fixes to it.
+
+ - In Metacube stream output, mark each keyframe with a pts metadata
+ block. This allows Cubemap 1.4.0 or newer to serve fMP4 fragments
+ for HLS from Nageru's output, without any further remuxing or
+ transcoding.
+
+ - If needed, Nageru will now automatically try to autodetect a
+ usable --va-display parameter by probing all DRM nodes for H.264
+ encoders. This removes the need to set --va-display in almost all
+ cases, and also removes the dependency on libpci.
+
+ - For GPUs that support querying available memory (in practice only
+ NVIDIA GPUs at the current time), expose the amount of used/total
+ GPU memory both on standard output and in the Prometheus metrics
+ (as well as included Grafana dashboard).
+
+ - The Grafana dashboard now supports heatmaps for the chosen x264
+ speedcontrol preset (requires Grafana 5.1 or newer). (There used to
+ be a heatmap earlier, but it was all broken.)
+
+ - Various bugfixes.
+
+
+Nageru 1.7.1, March 26th, 2018
+
+ - Various bugfixes, mostly related to HTML and video inputs.
+
+
+Nageru 1.7.0, March 8th, 2018
+
+ - Support for HTML5 graphics directly in Nageru, through CEF
+ (Chromium Embedded Framework). This performs better and is more
+ flexible than integrating with CasparCG over a socket. Note that
+ CEF is an optional component; see the documentation for more
+ information.
+
+ - Add an HTTP endpoint for enumerating channels and one for getting
+ only their colors. Intended for remote tally applications;
+ set the documentation.
+
+ - Add a video grid display that removes the audio controls and shows
+ the video channels only, potentially in multiple rows if that makes
+ for a larger viewing area.
+
+ - Themes can now present simple menus in the Nageru UI. See the
+ documentation for more information.
+
+ - Various bugfixes.
+
+
+Nageru 1.6.4, January 25th, 2018
+
+ - Fix compilation with the upcoming FFmpeg 3.5.
+
+ - Switch to LuaJIT for the theme engine, which is faster.
+
+ - Various bugfixes and smaller optimizations.
+
+
+Nageru 1.6.3, November 8th, 2017
+
+ - Add quick-cut keys (Q, W, E, etc.) below the preview keys.
+ Since it's easy to hit these by accident and put up a signal
+ you didn't want, they are disabled by default (they can be
+ enabled in the video menu, or with the command line flag
+ --quick-cut-keys).
+
+ - Rework the x264 speedcontrol presets to better match newer
+ x264 versions.
+
+ - Add an option for changing the HTTP port (--http-port).
+
+ - Various smaller bug and integration fixes.
+
+
+Nageru 1.6.2, July 16th, 2017
+
+ - Various smaller Kaeru fixes, mostly around metrics. Also,
+ you can now adjust the x264 bitrate in Kaeru (in 100 kbit/sec
+ increments) by sending SIGUSR1 (higher) or SIGUSR2 (lower).
+
+
+Nageru 1.6.1, July 9th, 2017
+
+ - Add native export of Prometheus metrics.
+
+ - Rework the frame queue drop algorithm. The new one should handle tricky
+ situations much better, especially when a card is drifting very slowly
+ against the master timer.
+
+ - Add Kaeru, an experimental transcoding tool based on Nageru code.
+ Kaeru can run headless on a server without a GPU to transcode a
+ Nageru stream into a lower-bitrate one, replacing VLC.
+
+ - Work around a bug in some versions of NVIDIA's OpenGL drivers that would
+ crash Nageru after about three hours (fix in cooperation with Movit).
+
+ - Fix a crash with i965-va-driver 1.8.x.
+
+ - Reduce mutex contention in certain critical places, causing lower tail
+ latency in the mixer.
+
+
+Nageru 1.6.0, May 29th, 2017
+
+ - Add support for having videos (from file or from URL) as a separate
+ input channels, albeit with some limitations. Apart from the obvious use of
+ looping pause clips or similar, this can be used to integrate with CasparCG;
+ see the manual for more details.
+
+ - Add a frame analyzer (accessible from the Video menu) containing an
+ RGB histogram and a color dropped tool. This is useful in calibrating
+ video chains by playing back a known signal. Note that this adds a
+ dependency on QCustomPlot.
+
+ - Allow overriding Y'CbCr input interpretation, for inputs that don't
+ use the correct settings. Also, Rec. 601 is now used by default instead
+ of Rec. 709 for SD resolutions.
+
+ - Support other sample rates than 48000 Hz from bmusb.
+
+
+Nageru 1.5.0, April 5th, 2017
+
+ - Support for low-latency HDMI/SDI output in addition to (or instead of) the
+ stream. This currently only works with DeckLink cards, not bmusb. See the
+ manual for more information.
+
+ - Support changing the resolution from the command line, instead of locking
+ everything to 1280x720.
+
+ - The A/V sync code has been rewritten to be more in line with Fons
+ Adriaensen's original paper. It handles several cases much better,
+ in particular when trying to match 59.94 and 60 Hz sources to each other.
+ However, it might occasionally need a few extra seconds on startup to
+ lock properly if startup is slow.
+
+ - Add support for using x264 for the disk recording. This makes it possible,
+ among other things, to run Nageru on a machine entirely without VA-API
+ support.
+
+ - Support for 10-bit Y'CbCr, both on input and output. (Output requires
+ x264 disk recording, as Quick Sync Video does not support 10-bit H.264.)
+ This requires compute shader support, and is in general a little bit
+ slower on input and output, due to the extra amount of data being shuffled
+ around. Intermediate precision is 16-bit floating-point or better,
+ as before.
+
+ - Enable input mode autodetection for DeckLink cards that support it.
+ (bmusb mode has always been autodetected.)
+
+ - Add functionality to add a time code to the stream; useful for debugging
+ latency.
+
+ - The live display is now both more performant and of higher image quality.
+
+ - Fix a long-standing issue where the preview displays would be too bright
+ when using an NVIDIA GPU. (This did not affect the finished stream.)
+
+ - Many other bugfixes and small improvements.
+
+
+Nageru 1.4.2, November 24th, 2016
+
+ - Fix a thread race that would sometimes cause x264 streaming to go awry.
+
+