3.0 changelog:
- Another HUGE change of the codebase, too many changes to list. Here are the major ones:
- Now uses ffmpeg to encode rather than x264.exe. Supports many more input files directly.
- Supports both 8-bit and 10-bit video encoding, as well as support for x86 and x64 processors, all in one package.
- Supports FLAC for lossless audio encoding when using the MKV container.
- More settings for improving compatibility with hardware devices
- Includes some basic filtering options such as resizing.
- Includes a help file to explain all settings. Just press F1.
- Many more small tweaks and improvements.

2.0 changelog:
- Almost a total rewrite of the code which eliminated many of the external dependancies
- Now uses Qaac audio encoder. This is the highest quality AAC encoder, and should keep sync well. Required quicktime installed on your system. If quicktime is not installed, the libvoaac encoder will be used instead, but quality and sync may not be great.
- Files are loaded directly into x264 rather than generating avs scripts for them.
- Option between mp4 and mkv container.
- New "video info" button in the Command Line tab gives you info that can be useful for troubleshooting.
- The output log now displays everything exactly as if you were running from the commandline. All output is captured.
- Demuxer selection in the advanced options.
- Batch processing support.
- Outputs a log file after encoding (located in the same folder as the exe)

1.41 changelog:
- Using x264 r1924 Jeeb's build
- Supports MKV output.

1.4 changelog:
- Using x264 r1900 Jeeb's build
- Fixed bug which caused AQ settings to not be applied
- Automatically checks for new versions - Normal updates will be indicated by unobtrusive red text on the advanced options screen. Critical updates will present a popup box.
- Default settings can be configured using a settings.xml file.

1.33 changelog:
- Using x264 r1732 Jeeb's build
- When loading a non-avs file, it will ask if you want to load via DirectShowSource, AviSource, or directly through x264.
- Supports quality based AAC encoding as default
- Now muxing MP4 with L-SMASH instead of MP4Box. Should fix issues where the encode would hang at 99%.
- "Keep intermediate files" option was removed, because its no longer useful with the removal of MP4Box.
- Removed 1-pass bitrate mode option, because I couldn't think of any logical reason to use it.
- When doing a 2-pass encode, the progress bar now displays the progress of the current pass, rather than of the entire encode
- "veryslow" preset is now the default
- Replaced "profile" setting with "level" setting. Currently supports 3 settings: unrestricted, 4.1, and 3.0 baseline. The 4.1 setting should make your encodes compatable with xbox360 and ps3. The 3.0 Baseline setting should make your encodes compatible with iPhone/iPod (at the expense of quality). I don't guarantee that these settings actually work, because I don't own any of these devices.

1.32 changelog:
- Using x264 r1703, with fade compensation patch
- Fade compensation added to advanced settings. This setting increases the bitrate during fades. If fades look bad in your encodes, try setting this to about .6
- Threads setting removed, as it was mostly useless. If you still need to access this setting you can use the custom commandline option under the commandline tab
- When starting, checks to see if AviSynth is installed, and warns the user if it isn't
- Files can now be dragged directly onto Zarx264gui.exe

1.31 changelog:
- Undid much of the work that went into the previous version. Avs2yuv was causing lots of issues, so I felt that the best thing to do would be to go back to how things were handled in previous versions. 64bit x264 is no longer supported, unfortunately.
- using x264 r1538
- removed warning message when encoding without audio
- outputs shorter commandlines
- batch scripts now contain a "Pause" command at the end
- added 'superfast' preset
- added 'fastdecode' tune

1.3 changelog:
- Using x264 r1373
- Pipes input through avs2avi rather than loading avs scripts directly. x264 and avisynth no longer share the same pool of memory.
- If a 64bit operating system is detected, the 64-bit version of x264 will be used.
- fixed an issue where it would calculate bitrate for audio, even if you weren't encoding audio.
- removed the interlaced checkbox. This option was pretty useless.
- reverted to old color scheme.
- specify a temp folder for mp4box. Should prevent errors where an output file was not created.
- fixed a bug where psy-rdo settings were disabled when using the "slow" preset.
- added support for loading image sequences. (broken, will be removed in next version)
- "keep intermediate files" option should work now
- new icon
- taskbar will light up when encoding is complete

1.22 Changelog:
- Using x264 r1251
- Medium & Slow profiles were mixed up
- Fixed an issue where audio wouldn't be recognized when your audio source was dragged onto the form.
- When generating avs scripts, it will now always use DirectShowSource. This should fix problems for people using windows movie maker.
- Modified the colors of the gui a bit so it should look better on Vista and Windows 7.
- Auto VAQ is no longer enabled by default, as there is some debate as to whether it is better.
- Fixed an issue where it would complain about the colorspace, when using FFVideoSource.

1.21 Changelog:
- Using x264 r1206
- Added "very slow" and "faster" presets
- No longer enable b-pyramid on some presets

1.20 Changelog:
- Using x264 r1184
- Now supports Presets/Tune/Profiles from x264
- Default settings have changed
- Supports "AutoVAQ" (enabled by default)
- Allow 16-bit values for Sample Aspect Ratio
- Support for custom commandline options
- Fixed an issue that caused the gui to use lots of CPU while encoding audio
- Various minor fixes and improvements