CyberLink MediaEspresso 6.5
MediaEspresso is the more expensive of the two commercial video conversion applications we tested. The full version will set you back $39.99 from CyberLink's website. It has a big, friendly interface with built-in profiles for smartphones, handheld media players, game consoles, and social networking sites. Using MediaEspresso is simply a matter of dragging and dropping a video into the main window, choosing a profile from the toolbar, and clicking OK. It's also possible to set your own profiles, which we did, since we wanted to keep things consistent across our different encoders.
MediaEspresso 6.5 supports QuickSync and shader-based encoding on Nvidia and AMD GPUs, as well as the VCE block on 7000-series Radeons and Trinity APUs. The particular beta build we tested, numbered 6.5.2811.44122, also supports the NVENC block on Kepler-based Nvidia cards like the GeForce GT 640.
We measured performance using our stopwatch, timing how long it took for the encoding progress bar to disappear once we'd clicked the "OK" button. MediaEspresso reports its own encoding time, as well, so we also jotted down that figure. Along with performance, we recorded power consumption at the wall, file sizes, and actual bit rates as reported by Windows. Each configuration produced slightly different output, so those last three data points are important.
Note that we enabled both hardware decoding and encoding, and when the option was available, we selected "better quality" instead of "faster conversion." Our preliminary testing showed that "faster conversion" increased the delta between our selected bitrate (4000Kbps) and the bitrate of the output file. We wanted to keep the output as consistent as possible across the board, so "better quality" won out.
Here are our results, with encoding times reported in seconds and the fastest configuration highlighted. Keep in mind that, since the output differs between the various solutions, encoding speed isn't everything. Oh, and lower encoding times are better, obviously.
|Idle wattage||37 W||37 W||43 W||46 W|
|Peak wattage||86 W||78 W||86 W||95 W|
QuickSync wins this race, pulling off the lowest encoding time by a few seconds and the lowest power consumption. Strangely, though, the output file of our QuickSync config also had the lowest actual bitrate of the bunch: only 3828Kbps, a fair bit below our 4000Kbps target. NVENC, which had the second-lowest encoding time, also missed the mark, but by a smaller margin. In both cases, the resulting file sizes were lower than with our other two configs. (The unassisted CPU and the VCE-enabled Radeon both stuck more closely to our prescribed bitrate setting, so it's no wonder that they produced bigger files.) The file size differences were relatively minor, though, and we're still looking at a nice slimming down from the 177MB source file.
Let's now take a quick look at image quality. We isolated two frames in our video: one showing fast camera panning and motion blur in a scene with high contrast, and another showing a relatively still scene with a high amount of detail. We took one screenshot of each frame from each output file, as well as from the source file. Since the screenshots from the source video were larger, we resized them to match the others using Photoshop with the default bicubic interpolation setting. These are two frames in a video that's two minutes and 34 seconds long, so they quite literally don't show the whole picture. They also don't account for how things appear in motion. That said, the shots do give us some very useful clues about differences between the various implementations.
Click the buttons under each screenshot to toggle between the different solutions. You might have to wait a second or two for a new image to load after each click.
Predictably, the QuickSync and NVENC output files look the worst in our action scene. Blocky compression artifacts obscure detail, make smooth lines appear lumpy, and create a sort of shimmering around moving objects. VCE doesn't fare much better; while it produces fewer artifacts, it jacks up the gamma and makes the picture look washed-out. The software encoder does the best job here by far. That said, color saturation is off across the board. Our source video has brighter reds and more vivid yellows than all of the output files.
The still scene shows more subtle differences, and it highlights another issue with the QuickSync output. Look at the frame of the actor's glasses against the wall on the right. The frame should appear as a smooth line, but it's oddly jagged in the QuickSync screenshot. We noticed similar pixelation in other scenes and on text throughout the trailer. In motion, the jaggies appeared to dance around objects. Clearly, there's something wrong here. Perhaps the scaling from 1080p to 720p isn't being done using the right interpolation method.
Meanwhile, NVENC continues to display more artifacting—you can see a big green smudge above the intersection of the characters' shoulders—and the VCE output remains washed out. The software encoder once again produces the best output of the bunch.