2010年4月5日
By 1月时特约编辑
专题文章

制作视频案例研究

Many organizations use video case studies to help market their products and services. I recently analyzed eleven video case studies, focusing on high level production techniques, 视频是如何编码的, and how the video was presented on the companies' web pages. 这篇文章展示了我的发现, and should be useful to marketing professionals, 视频制作人, 压缩师和web开发人员.

I'll present the findings in four sections:

有用的数据
值得模仿的好技巧
要避免的错误
案例研究的最佳实践

作为概述, I identified the case studies by Googling "video case studies" and trolling through the results. 使用案例研究, 我必须能够下载它, it must have been created after 1/1/2009 (to the best that I could determine) and had to be used to sell a product or service.

最终, I found videos from companies like Xerox, 康卡斯特公司, 松下, 富士通, Tandberg和黑莓, 仅举几个例子. 对我来说, it looked like all the videos were professionally produced and edited; none appeared to be the work of an ambitious marketing director with a camcorder and no budget.

再一次。, when analyzing the videos for this article, I focused primarily on video encoding and web site presentation. 在以后的文章中, I'll examine the actual content and discuss issues like the how the marketing claims were presented and proved, B-roll和A-roll的使用, how and w在这里 background music was used and the like.

Let's start with some useful stats about encoding and presentation.

有用的数据

Here are some useful stats from the videos that I analyzed.

持续时间: The average duration was 4:04 (min:sec) with the longest at 8:20 and the shortest at 1:33.

解决方法: The average resolution was 413x258, with the largest at 640x480, and the smallest at 220x164.

视频数据速率: The average video data rate was 466 kbps, with a high of 917 kbps, and a low of 200Kbps.

位/像素/框架: The average bits per pixel per frame was .24、用高的 .557和最低的 .061. This is a measure of how much data was applied for each pixel in the video and it lets you compare, 例如, the compression applied to a file encoded at 640x360@448 kbps (b/p/f = .065) and a video encoded at 220x164@250 kbps (b/p/f = .577). The easiest way to derive this number is to download the free, cross-platform MediaInfo utility from 在这里 and analyze your file within the program. What's the significance of the bits/pixel/frame? My rule of thumb is that any value over .1 is likely to be a waste of bandwidth, though at resolutions below 400x300, .15 is acceptable, since codecs are less efficient at lower resolutions. 如果你看到一个值 .557, you can pretty much assume that the data rate is way higher than it needs to be. Click the Figure to see a larger view of MediaInfo, a tool I have installed on all of my computers.

编解码器: Six of the ten videos used the VP6 codec, while three used the antiquated H.263 codec, for which t在这里 is no explanation if the videos were encoded post 2008. Three others, which the respective web site produced and displayed via YouTube, were encoded with H.264. All the videos were presented in the Flash Player. 公平地说, Microsoft and Cisco both presented case studies in the Windows Media Video format, but both were produced prior to 1/1/2009 so missed the cut.
音频数据速率: The average audio data rate was 102 kbps, with a low of 16 kbps and high of 256 kbps, with nine of eleven streams produced in stereo, 二人一体. 我对案例研究的经验法则, which is primarily recorded monoaural speech, is 32Kbps for AAC audio and 64Kbps for MP3 audio. Obviously, my thumb was not familiar to most of these producers.
使用社交媒体: Here's a surprise; if you don't count videos embedded via YouTube (which are all linkable and embeddable), only one of the case studies was linkable and embeddable, and one other offered the ability to email the page into which the video was embedded. None of the other videos offered any social media or sharing links whatsoever. Obviously, some room for improvement 在这里.
号召行动: Another surprise was that five of the eleven videos didn't have any special call to action, and several were blank players with no links at all. We learned in Marketing 101 that all marketing documents must have a call to action; it makes no sense to spend thousands on a case study and not make it easy for the inspired viewer to take the next step.