x264 Compression Artifacts

[zcream]

Using Mpeg Streamclip with x264Encoder.component ..
Any idea what is causing these artifacts ? I am trying to compress a film to upload to vimeo. Using CRF 19. Its only 2 secs in a 1hour 41min film. Frustrating..

[LoRd_MuldeR]

This very much looks like a decoding error! (or corrupted stream)

So, either your source file already is corrupted, at least at that position. Or your encoding software (Mpeg Streamclip?) is not correctly decoding your source file. Or whatever playback software you are using to look at the re-encoded clip is not correctly decoding the stream created by x264. In the first two cases "corrupted" images are sent to x264 encoder and then "baked" into the re-encoded stream; in the latter case it's a pure playback issue.

Anyhow, I would first check your source clip, preferably with different players (MPC-HC, VLC Player, MPlayer, etc), to ensure that the source isn't corrupted already. If it turns out the source is corrupted, there is not much you can do. Otherwise, if the source looks okay, I would try re-encoding it with x264 CLI directly. Or with FFmpeg. In both cases be sure to use an up-to-date version! And, once again, use different players to check the re-encoded stream.

[zcream]

It shows the same problem on QT, QT7 and VLC. VLC shows 1 lost frame in properties.
I had encoded this file - had no idea that a software encoder could even corrupt a frame..

Problem is that my source is a QT ref in Cineform. And the newest ffmpeg has only rudimentary support for CF - and none for QT ref.

[smok3]

I do convert Cineform to x264 daily (using ffmpeg), what do you mean with rudimentary?

[zcream]

@smok3 ffmpeg does not recognize any changes made using FirstLight - or Remaster as the case may be. So no LUTs.

[zcream]

I re-encoded using film-slow preset and everything is fine now. Thanks for all the help.

[zcream]

I do convert Cineform to x264 daily (using ffmpeg), what do you mean with rudimentary?
How do you avoid gamma shift during export for vimeo?
I tried pix_fmt and I still get washed out colors.