Review: Elgato Systems Turbo.264 HD H.264 Encoder/Accelerator
Ever since Apple announced the fifth-generation "video" iPod back in 2005, users have struggled to create iPod-, and later iPhone- and Apple TV-compatible H.264 video files. Even today, H.264 encoding demands a powerful computer -- notably, even a current-generation mid-range MacBook can take longer to convert a file into H.264 than to play it all the way through. So companies such as Elgato System has emerged with solutions: USB-connecting H.264 accelerators that plug into computers and help them to convert video files faster. Back in August, 2007, we reviewed and highly recommended Elgato's original Turbo.264 video encoder hardware and software package for the Mac; now the company has returned with a more powerful and more expensive version called Turbo.264 HD ($150). Updated: We updated this review on April 2, 2008 with additional notes on Turbo.264 HD's support for high-bitrate encoding, discussed at the bottom of the original text, as well as a correction to the text regarding the software's editing functionality.
Both of Elgato’s packages come with the same basic three pieces: a black USB dongle, an extension cable, and a CD containing both Elgato’s own speedy conversion software and a plug-in that works with programs such as iMovie to help them create H.264 files faster, too. For Turbo.264 HD, the dongle’s a little smaller, the cable’s a little fancier, and the software’s been updated: it now offers direct-from-HD camcorder transfers, simplifying the process of locating the video clips on a connected camcorder and offering them up for conversion. More importantly, the Turbo.264 HD software adds the option of higher-resolution H.264 hardware encoding assistance, enabling both 720p (1280x720) and 1080p (1920x1080) transcoding with simple presets. The prior Turbo.264 tapped out at 960x540, enough to theoretically do anamorphic DVD conversions but not true HD encoding.
It’s hard to overstate just how easy Turbo.264 HD is to install and use. Within minutes of unpacking the parts and installing the included software, we successfully connected an AVCHD video camera to our computer, had Elgato’s software automatically locate the videos stored on it, and begun the process of encoding files we’d recorded. Average users will find the process extremely simple, and by comparison with using iMovie, incredibly fast at taking videos from a camcorder and rendering them viewable on a computer.
That said, several points need to be made up front about Turbo.264 HD’s real-world utility. First, Turbo.264 HD is primarily designed to serve as a transcoder, transforming various types of video into H.264-compliant files that can be played back on recent computers, iPods, iPhones, and Apple TVs, as well as game consoles such as the Sony PlayStation 3. It actually does include its own simple editor feature to let you snip out sections of videos, a feature we missed in our initial testing of the software, though the editor is a blunt tool by comparison with Apple’s included iMovie software—for gentle transitions and virtually any type of edit other than a snip, you’ll want to use iMovie rather than the Turbo.264 HD application, and will suffer a speed penalty by doing so. Additionally, sheer speed comparisons don’t tell the full story of Turbo.264 HD’s abilities, or lack thereof. There’s more to consider in video conversion—namely, quality of the finished product—than just how fast it’s churned out.
For our comparison tests, we used a 2.4GHz 13” MacBook computer, a three-minute, seven-second video clip created in 1920x1080 resolution on a Canon HF100 AVCHD camcorder, and three pieces of software: iMovie ‘09, Turbo.264 version 1.3, and Turbo.264 HD 1.0.1. We gave all three pieces of software the same tasks: convert the clip into a 480x270 iPhone-ready file, and then, convert it into a file at the maximum resolution permitted by the software.
Unlike the Elgato software, the unassisted iMovie ‘09 initially required a 6:32 (six-minute, 32-second) importation of the full 3:07 video clip—plus creation of thumbnails—before it could start the conversion process into either of the formats. Once that was finished, it took 5:53 to create the 21MB iPhone-ready file, and 28:28 to create what was supposed to be a 1080p (1920x1080) output file. However, in viewing the second file—suspiciously only 40MB in size—we found that iMovie ‘09’s settings hadn’t been optimized; essentially, we’d wasted 30 minutes creating something unwatchable. We went back, plugged in the settings that are used automatically by Turbo.264 HD, and ran the conversion again. This time, again without hardware assistance, it took 37:36, and created a properly sized 214MB file.
Users should note that Apple’s focus on helping users create content for comparatively low-resolution iPods, iPhones, and Apple TVs has resulted in an iMovie ‘09 that makes little mention of high-resolution 1080p files—iMovie ‘09 has settings that are optimized for its devices, but you need to dig around a bit to properly create videos in 1080p, the maximum possible output offered by today’s consumer camcorders. Elgato actually aids iMovie ‘09 users by offering a plug-in that’s automatically installed with the Turbo.264 HD software, speeding up encoding whenever the USB dongle is attached and a Turbo.264 HD setting is selected in iMovie’s QuickTime Export menu. The 37:36 encoding time for the 1080p video shrunk to 8:04—4.6 times faster, even on a relatively recent computer. Once again, iMovie’s initial 6:32 importation period needs to be taken into account, as well, and it should be noted that Turbo.264 HD’s plug-in is limited to the same output characteristics as the standalone Elgato software. More on that in a moment.
By comparison, Elgato’s original Turbo.264 software had no initial import time. Instead, it created an iPhone-format 23MB video in a slightly-better-than-iMovie speed of 5:36. When it came to high-resolution output, however, the first Turbo.264 was capped at an output resolution of 960x540, and took 7:04 to create a 78MB file; it could not create true HD videos.
Last but not least, the newer Turbo.264 HD software demonstrated some interesting differences in speed. When tasked with creating the iPhone-format video, it took 4:49, spitting out a 22MB file—a hint smaller than the prior Turbo.264 and a little larger than the iMovie video, but at least a bit faster in output speed than both. In creating a 213MB 1080p video, however, its speed was stunning. What took iMovie ‘09 over 37 minutes, or around 12 times realtime before considering the initial import process, took Turbo.264 HD a total of 6:25, running at roughly 17 frames per second, or around 2 times realtime. Another way to look at Turbo.264 HD’s performance is this: it may offer only a small improvement in speed versus iMovie or the prior Turbo.264 when creating low-resolution output, but for high-resolution output, it’s a speed demon, and offers HD resolution support that the first Turbo.264 can’t match. Used alone, the Turbo.264 HD software makes the 1080p creation process much easier than iMovie ‘09, and it even accelerates iMovie ‘09, besides. That’s all good news.
Unfortunately, there’s one piece of bad news and one piece of so-so news to share as well. In direct comparisons between the iPhone-formatted video clips, there wasn’t any question as to which ones actually looked the best or the worst to us, and the iMovie version came out on top, followed by the original Turbo.264, and then Turbo.264 HD. Despite possessing the smallest file size of the bunch—attributable perhaps to its CD-quality 44.1KHz audio sampling rate rather than the 48KHz rate preferred by the T264 software—the iMovie file was the sharpest in detail and the most vivid in color. By comparison, the Turbo.264 HD version was still watchable and listenable, but looked softer and less vibrant at all points; the screenshots don’t do the videos full justice. Original Turbo.264 users mightn’t have noticed a major difference between iMovie output and their software, but Turbo.264 HD users will, at least, unless Elgato tweaks the software.
On the other hand, Turbo.264 HD’s 1080p video output was at least somewhat impressive: it was unmistakably better looking in both color and detail than the maximum-resolution file created by the original Turbo.264—the latter almost a given, the former not necessarily so—and the differences were even noticeable when the windows were scaled to the same 960x540 size. The HD version isn’t just creating a bigger, higher-resolution file; it’s actually preserving more of the detail and color from the original within its pixels. Additionally, though iMovie ‘09 doesn’t do users any favors in creating 1080p files, Elgato’s software and plug-in make it easier and faster to do so. The first video we attempted to output in 1080p with iMovie ‘09 took almost a half hour to create, and was unwatchable; within 6.5 minutes, the Turbo.264 HD standalone software made something that looked very good. The second iMovie ‘09 1080p video, created without Turbo.264 HD’s assistance, was a toss-up in quality versus the one created with the Turbo.264 HD software. iMovie’s renderer produced more vivid, accurate colors, but also far more noticeable artifacting within shadows, resulting in a video that looked better in stills but less impressive in motion. All things considered, we’d go with the Turbo.264 HD version if all other things were equal.
But they’re not. Whether it’s hardware- or software-based, the 10Mbps bitrate cap* on Turbo.264 output is going to be a non-starter for many professional or prosumer users, particularly those with the latest generation of 24Mbps 1080p AVCHD camcorders. This isn’t merely a theoretical issue, since last year’s AVCHD models, including the HF100 we tested with, run at a maximum of 17Mbps, which is to say that using Turbo.264 HD currently means losing around 40% of the data in a 17Mbps file, or nearly 60% of the data in a 24Mbps file. How much of an actual impact this has on the video quality of files you transcode will vary, but it’s a fact worth noting before making a purchase. Bear in mind that you can come closer to the best of both worlds by using Turbo.264 HD to accelerate iMovie ‘09, resulting in improved picture quality at the cost of some speed, though you still can’t increase the accelerator’s bitrate to 24Mbps.
All in all, Turbo.264 HD offers a consumer-grade H.264 acceleration solution with several clear advantages over both its predecessor and an unaided Mac—speed, tremendous ease of use, and in certain cases, higher-resolution output, though it also has a few consequences: a higher price, low-resolution output that’s a step back from other alternatives, and a cap on its maximum bitrate that prevents it from making the best possible output from recent 1080p-ready camcorders. From where we stand, Elgato has crafted a product that will immediately satisfy users in the middle, specifically those who are more concerned about fast conversion speeds than optimal visual quality, but may disappoint those looking for truly pixel-optimized low- or high-resolution videos. Unless Elgato releases updated software, low-end users will be better off with the original Turbo.264, and high-end ones may need to continue to suffer slower conversion speeds to squeeze the most detail out of their camcorders.
Update: The 10Mbps Bitrate Cap
Following publication of our review, Elgato contacted us to let us know that the 10Mbps bitrate limitation—currently noted on everything from Turbo.264 HD’s packaging to its web pages—may not in fact be set in stone after all. According to the company, “20Mbps is possible,” though users will “need to delve quite (extremely) deeply into the customer settings to get to it,” and a software update will likely improve access to this functionality “in the future.” Having attempted without success to change the manual settings of Turbo.264 HD’s software to enable 17Mbps encoding from our 17Mbps source, it’s obvious that Elgato has some tweaks left to make before the higher bitrate feature is as easy to use as the rest of its software. We will update this review with additional details when they become available.