Review: Sorenson Squeeze 5
Returning to the xw4600, I then compressed the same eight source files to Windows Media format using four simultaneous encoding sessions, which took 18.38, more than 10 minutes faster than the eight core xw8400. Clearly, if a user is buying an encoding station for Squeeze, a fast four-core system is a smarter buy than a slower eight-core system.
Deinterlacing Quality
Since many of us still work with interlaced source video, the deinterlacing quality produced by a batch-encoding tool is a key comparison metric. To test this, a while ago I created a 1-minute DV test file containing short clips of hard-to-deinterlace scenes, which typically involve high motion, diagonal lines, great detail, or all of the above. I’ve since deinterlaced this file with virtually all video editors and batch-encoding tools, creating a QuickTime file I can compare to new products and updates, such as Squeeze 5.
Squeeze has never been a star performer in deinterlacing tests, and I was psyched when I learned that one of the new features in Squeeze 5 was multiple deinterlacing options. To make sure I produced the optimal results, I sent my test file to Sorenson and asked them to recommend the best deinterlacing routine for the file. Sorenson recommended Discard Even Field, which I used to create a video. This particular scene, with the "jaggies" highlighted in the diagonal lines shown on the right, has been a challenge for Squeeze in the past, and it remains so. There are also several other scenes in the test file that display similar problems.
Overall, when shooting for streaming, it’s good practice to eliminate fine detail and diagonal lines whenever possible, and if users do so, deinterlacing in Squeeze won’t be a problem. But for real-world shoots, when users often can’t tailor their content for streaming, they should deinterlace in their video editors before producing the intermediate file to be encoded with Squeeze.
General Encoding Parameters
With this as background, let’s tackle the encoding configuration options and output quality. With all encoding presets, Squeeze presents both a simple and advanced view, shielding novices from the minutiae of encoding though occasionally leaving out some encoding parameters that advanced compressionists might want to see. For most codecs, Squeeze presents both single and dual pass VBR and CBR with several format-specific variations, such as Quality VBR.
For output resolution, users can check Same As Source or specify a frame size. When changing the resolution, they can select via radio button to leave the display aspect ratio unconstrained, to maintain the aspect ratio, or to insert a letter box or pillar. Leaving it unconstrained is usually the correct option. Frame rate options are expressed by frames per second or ratio, with 1:1 meaning 1 frame in the encoded file for each frame in the source.
Squeeze 5 applies an auto crop deinterlace effect to all files before encoding, which users can disable in the preferences field. These controls worked intelligently in my tests, deinterlacing interlaced source footage, leaving progressive footage alone, and not cropping any pixel that I didn’t want cropped.
Sorenson actually performed these same functions in earlier versions, which was immensely helpful because, otherwise, users could ruin a long encoding run by simply forgetting to deinterlace. In Squeeze 5, Sorenson simply brought the controls out from under the hood. These touches make Squeeze by far the most approachable program for novices, and it has the easiest learning curve.
Windows Media Encoding
Sorenson made few changes to Windows Media Video encoding in version 5. From a configuration perspective, users can access all the controls available in the Windows Media Encoder with several additional options. Specifically, they can produce WMV files in 1-Pass or 2-Pass CBR, 1-Pass Quality VBR, and 2-Pass Data Rate VBR, to which they can assign a target data rate and maximum data rate, the latter control available only in the advanced view of the preset.
The advanced view also reveals the smoothness versus quality slider, which is active only for CBR encoding, and a quality slider active for the 1-Pass Quality VBR. The only other control available in the advanced view is the Maximum Startup Latency, which sets buffer time before the clip begins to play.