ReClock DirectShow Filter 1.9.0.7 beta

ReClock is a free DirectShow audio renderer that removes judder from video on a PC by matching playback speed to your screen.

It was a favourite of home theatre PC owners for more than a decade.

Development stopped with version 1.9.0.7 beta in April 2018, so on a current PC there are usually better ways to get the same result.

What ReClock Actually Does

Most films run at 23.976 frames per second, while most screens refresh 60 times a second. The two numbers do not divide evenly, so some frames stay on screen longer than others, and slow camera pans look jerky. That stutter is called judder.

ReClock takes over as the audio renderer in your player and becomes the clock that the whole playback follows. It then speeds the video up or slows it down very slightly, so the frame rate fits the refresh rate exactly, and resamples the sound to stay in sync. The change is far too small to hear, but the picture stops stuttering.

The same trick fixes PAL speed-up. European DVDs and broadcasts often play films at 25 frames per second, about 4 percent too fast, with voices a little higher than normal. ReClock can slow them back to the original speed and correct the pitch.

It also offers multi-channel audio output, dynamic range compression for late-night listening, and an AC3 encoder for sending surround sound over an S/PDIF or optical cable.

Why It Is Not The Easy Answer Any More

ReClock began in the early 2000s as a hobby project, later passed to SlySoft and then to RedFox, which released the 1.9 series. The last update, 1.9.0.7 beta from 3 April 2018, only added support for PowerDVD 18.

Three things make it awkward now. It is a 32-bit filter, so it only loads in 32-bit players such as MPC-HC x86. It only works with DirectShow players, not with mpv, VLC or Kodi. And users report problems on newer Windows 10 releases, including ReClock not showing up as an audio renderer at all.

Meanwhile, the job it did has been built into the players themselves.

What To Use Instead

• mpv has the closest match. Its display-resample sync mode does exactly what ReClock did: it times playback to the screen and adjusts the audio to keep up.
• Kodi has two settings for this, Adjust display refresh rate and Sync playback to display, and both work on Windows, Android TV and Linux.
• madVR can switch your screen to a matching refresh rate automatically and has a smooth motion option for screens that cannot.
• MPC-BE and MPC-HC can change the refresh rate when a video goes fullscreen, and pair well with MPC Video Renderer.
• JRiver Media Center, a paid player, has its own clock adjustment that works much like ReClock.

If you want motion that looks smoother than the original film, rather than just steady, that is a different tool. SVP adds new in-between frames, and our guide to Bluesky Frame Rate Converter covers a free way to do the same with an AMD graphics card.

If You Still Want ReClock

It can still be useful on an older Windows 7 or 8 media PC with a 32-bit player you already know. Install it, then add it as the audio renderer in your player's settings or as an external filter in MPC-HC.

It needs DirectShow decoders such as LAV Filters, which the K-Lite Codec Pack installs for you. For a modern audio renderer that still gets updates, try MPC Audio Renderer instead.

ReClock also had special support for disc players such as PowerDVD and ArcSoft TMT, but it never needed them. Any DirectShow player could use it.

Quick questions

Download ReClock 1.9.0.7 for an older setup, or tell us how it worked for you if you still use it.