March 10, 2011

It’s working, but different (Apple Compressor)

Filed under: video,workflow — Erik Dobberkau @ 13:59

This week I’ve been quite busy converting a series of videos into iPad-compatible format (which is h.264 video with AAC audio in an MP4 container), and I encountered an annoying glitch in Apple’s Compressor 3.5.x which is part of Final Cut Studio 3.

It’s been reported that when working with interlaced footage, de-nterlacing and downscaling leads to bad results. My experience and the solution I’m giving here has worked with DVCpro 1080i50 material, I can’t say if it works for other formats as well. Here’s the thing: When deinterlacing, you have to leave the Deinterlace Filter off. Here are some screenshots to show the massive differences between Compressor’s Preview and the actual results.

Compressor Preview with Deinterlace on

Fig. 1 — Compressor Preview with Deinterlace on

Compressor Preview with Deinterlace off

Fig. 2 — Compressor Preview with Deinterlace off

Once again, the source is 1080i, and I want the output to be 720p. The Image Processing settings are “better” for both Scaling and Deinterlacing, because “Optimum” takes ages to render. The output fields are set to “Progressive”.

In Fig.1, the Deinterlace filter in the Filters Tab has been added with the “even” setting. As you can see, the result (right side) is promised to look very smooth. In Fig. 2 the Deinterlace filter is off, all other settings are the same. Notice the jagged edges and compression artifacts on the right side.

Compressor Output with Deinterlace on

Fig. 3 — Compressor Output with Deinterlace on

Compressor Output with Deinterlace off

Fig. 4 — Compressor Output with Deinterlace off

But the results are just the other way round. In Fig. 3, which is the output from the processing with the filter enabled, the edges are all jagged and the whole image looks like a blow-up from one with half the resolution. But the file with the filter disabled (Fig. 4) looks all sweet.

Oh, by the way, should you experience Compressor abort encoding with a “NewMovieFromFile failed” error when converting WMV with Flip4Mac 2.2.x, my current workaround is to export the WMV from QuicktimePlayer 7 with a ProRes 422 Setting and then use Compressor on the ProRes file to make whatever format.


No Comments

No comments yet.

RSS feed for comments on this post.

Sorry, the comment form is closed at this time.

Powered by WordPress