2009 Encoder Shootout

Wow! Another year has passed. 因此，是时候进行另一轮编码工具更新了. In this roundup, I’ll compare the output quality, speed, 与编解码器相关的功能集最突出的作物低于1美元,000 encoders and provide the results in report-card form. 在大多数情况下，每个类别中最好的被评为A，最差的被评为C，其余的被评为B. Though this will vary by the encoding tool and category, 如果你目前正在使用或计划使用编码工具，那么C级应该是一个问题. 在某个特定的编码器中，某个特性受到很大的限制, 我已经在表格中标注了星号，并在正文中解释了这个问题.

Briefly, for quality tests, 我制作了标清(640x480, 30 fps, 468Kbps视频/32Kbps音频)和高清(1280x720, 29帧).97 fps at 800Kbps video/128Kbps audio) files using H.264, VP6, and VC-1 codecs; I compared output quality with other encoding tools using the same operating system. I produced all comparative quality tests from prescaled, 预去隔行文件以隔离编码质量，而不是各自工具的缩放和去隔行质量. To test scaling and deinterlacing quality, 我使用了一个1分钟的DV文件，其中包含多个边缘锐利的场景, diagonal lines, and other jaggy magnets; I then compared the output of the respective tools.

To test performance, 我计算了一个1分钟文件的编码时间，然后计算了编码5个1分钟文件所需的时间, deploying all available techniques to speed encoding time, 比如在Mac和Windows平台上同时运行On2 Flix Pro和Sorenson Squeeze的多个实例，进行5个文件编码试验. For Windows, I tested using a 2.8 ghz双处理器，四核HP xw6600工作站运行XP与3MB RAM. For the Mac encodes, I tested on a 3.2ghz双处理器，四核Mac Pro运行Leopard，内存为8MB.

In terms of supported features, this varied by codec. For H.264, I looked at features such as access to the baseline, main, and high profiles; support for context-adaptive binary arithmetic coding (CABAC) entropy encoding; and the breadth of B-frame configuration options. 对于VP6，我研究了访问双通道编码以及VP6- s和VP6- e选项. For VC-1, 我查看了WMV SDK 11中启用的调整参数和对Silverlight输出的支持.

Adobe Media Encoder CS4
CS4 was a great release for the Adobe Media Encoder (AME), 由于该程序获得了批处理能力和独立操作能力, 这意味着你可以独立于Premiere Pro(或其他CS4应用程序)运行程序，并插入文件或Premiere Pro序列进行编码. Even more impressive, 您可以将序列从Premiere Pro发送到AME，并在Premiere Pro中继续编辑, 一个梦想的功能，很容易证明套件升级价格为大多数严肃的Premiere Pro编辑器.

There are some limitations, however. For example, the new watch folder functionality doesn’t trigger automatically when a file gets dropped into the folder; you have to start the encoding process manually, 这个限制有望在未来的版本中得到解决. 另一个缺点是，您不能打开多个AME实例来提高多个文件编码的速度, which you can do with many other programs, including Microsoft Expression Encoder 2, On2 Flix Pro, 和Sorenson squeeze——后两者都适用于Mac和Windows. Adobe也没有提供像苹果Qmaster这样的工具来提高多核计算机(如我们的8核惠普xw6600)的编码效率. Since AME is very fast with Windows Media and H.264输出，这主要影响VP6编码时间，我在下面详细说明.

In terms of output quality, it was a different story for the Mac and Windows versions, with Windows offering better H.264的质量和生成WMV文件的能力，这是AME在Mac上做不到的. On both platforms, H.264 configurability is limited. You can choose the baseline, main, and high profiles, 但不能选择CABAC熵编码或控制b帧排序. 不过，你可以用新的F4V格式输出Flash，这并不奇怪.

Still, in Windows, H.264的质量相当好，非常接近Sorenson Squeeze制作的质量, 在被审查的项目中，哪个项目的质量最好. Mac H.264的质量参差不齐，虽然在我们的SD测试中很差，但在高清测试中非常好. AME was a screamer in our performance trials, 在Mac和Windows上都是最快的5个文件编码时间. Overall, if you’re a casual H.264的生产者，AME在Windows中很好，但你可能希望在其他地方寻找Mac.

VP6最重要的一点是AME获得了双通道编码能力, which boosted output quality to the top tier, and access to VP6-S, 这是一种“简单”版本的编解码器，非常适合高清视频或低功耗设备制作的视频. 如前所述，AME和Flash最大的缺点是编码时间. On our 8-core HP workstation, for example, Squeeze在10:28 (min:sec)内生成了5个1分钟的测试文件, while it took AME CS4 33:30 to accomplish the same task. The difference was even more stark on our 8-core Apple loaner: On2 Flix Pro took 6:22; AME took 47:20. 如果您想要匆忙地对Flash文件进行编码，那么AME在这两个平台上都不适合您. If you’re not in a hurry, it’s a great choice.

On the Windows platform, Windows Media quality is good and encoding times are quite good; AME should prove adequate for any producers not looking for the ability to tweak their Windows Media files or create a Silverlight player.