In Need of Best Practices

[ewr]

Hello all. New member to the forums. I am the eBusiness Manager for a financial services company, and I want to beef up the degree to which we leverage online video for external communications (via our Web site). We have dabbled lately, but we don't have best practices in place on which to build this effort. What I need is some insight on what the current, most appropriate specs are for deploying online video. We're not selling a product, and most of the video is of people talking, panel discussions, interviews, etc. Specifically, what I'm looking for is current appropriate specs for frame size (pixels), bit rate (kbps), 4:3 vs. 16:9, format and any other info. you might have. My expectation is for broadband delivery (T1, cable, perhaps some DSL). I want good quality, but I also don't want to crash anyone's computer. Any help would be most appreciated. Thanks.

[Dave]

Unfortunately there is no real simple answer to your question.

One of the great problems with streaming media is that the audience (and their computer / network spec) is usually an unknown factor. Often you have to use trial and error by putting some media out there and then analysing the log files to see the responses. One person may struggle to playback a stream encoded at 200kbps, whereas the next person may be able to handle 2Mbps with room to spare. You may have to encode at multiple rates / sizes if you want to keep everyone happy.

However, on a more positive note, if _produced properly_, then the type of video you are looking at is highly compressible, and should stand a better chance compared with higher motion stuff. For this type of subject, don't skimp on the audio quality, as it is likely to be far more important to the viewer than the video.

If you check out Jan Ozer's video 'Shooting for Streaming' presentation (SM West 2006) on streamingmedia.com, you will get some good tips on how to start optimising the production side (reducing motion/backgrounds/lighting/etc) . He also covers this material in his Critical Skills DVDs which are available for purchase.

As for aspect ratio, then use what best fits the subject. One of the plus sides to online video - you don't have to stick with TV aspect ratios. For example, a panel session could be re-created as four headshots side-by-side in an extreme widescreen type aspect ratio with all the redundant dead space cropped out, or it could be four headshots in a square ratio. Either way, when scaled down to smaller frame sizes then you are optimising the subject information in the frame, than would typically be possible with a single 4:3 ratio of four people at a desk with lots of dead space and the faces unrecognisable.

You may want to stick with specific sizes though as this may simplify the web interface if you are planning embedding multiple clips into the one template.

To put you in the right ball park, then if produced properly, a 384x288 25fps (or 320x240 30fps) head & shoulders shot, will easily encode at 200kbps, and if you allow 40kbps for a mono 48kHz audio track, you will get the show on the road for around 250kbps.

Dave

[ewr]

Thanks Dave. Very helpful. What are your thoughts on how CNN.com and ESPN.com deliver their online video? Now, I realized that these are media outlets and have substantial resources at their disposal for capturing, producing and rendering video. Nontheless, I'm more interested in your (or anyone's) thoughts on what they are using for bit rate and frame size, quality level, etc. Is this approapriate for mass audiences (I assume yes because of their larger user base)? I'm using these sites as examples because their presentation approach would fit well with my firm's environment. Thanks again!

[Dave]

A lot of these larger organisations are using content delivery networks (CDN) to distribute the content around the globe in a more controlled manner than is possible than solely relying on the internet. By doing so, they can remove most bottlenecks on the way apart from the 'last mile' between the ISP and the end viewer.

I feel that this 'last mile' is becomming more critical with residential users as often they are reliant on old analogue telecoms infrastructures for ADSL. To put this in perspective, over here in the UK I subscribe to a 8Mbps ADSL service, however my physical telephone line can only handle up to 3.5Mbps and in normal use, any streams encoded above 700kbps or so (even via a CDN) won't play back smoothly. A colleague a few miles away, struggles to get anything over 300kbps. So, if you are looking at the likes of streaming video in these two circumstances, then you need to be looking at limiting your bitrates to less than 300kbps in order for both connections to receive it.

However you may want to provide two streams, one at around 300kbps which may perhaps have a smaller frame size and one at around 700kbps which may be slightly larger. Alternatively you could keep the same frame size but opt for two different qualities of video.

( 300kbps can produce good quality low motion content at a resonable size, however for high motion content, you would need to significantly sacrifice quality or frame size. )

Other people located nearer to capital cities can now get ADSL2 services up to 24Mbps, and in these cases you can pretty much throw any bit rate you like at them.

News networks probably aren't producing content specifically for streaming and are more likely to be encoding footage produced for broadcast, so the content isn't necesserily optimised. They probably use variable bit rate CODECs which means that on slower connections, low motion scenes appear to play back fine, however once the action steps up the playback quality degrades rapidly. I've seen content here which averages at around 700kbps but peaks at rates of nearer 2Mbps.

Commercial news also has the advantage that the content also tends to be made available via broadcast television / radio / newspapers, so the content can reach the end user in a number of ways, so is less likely to be a problem if the stream cannot be viewed. With other types of content this isn't always the case and the end viewer may be dependent on the streamed content.

Another issue to consider is that someone, somewhere is paying for all that bandwidth, so the higher the bit rate used for the encode, the more it is going to cost to make available. However you have to offset that against the perhaps higher production costs in optimising for low bit rate streaming. Often higher bit rate content is simply 'robotically' encoded with everything encoded with the same set of profiles irrespective of the subject content. It's quick and simple to do, but is less likely to maintain a perceived level of quality.

Dave

[cata12]

Hello:
I am doing Live HD broadcasting on the Internet and its just a matter of minutes guys. My recommendation will be at least 250 kbs for upload speed. I am using blinkoTV as software because the broadcaster alllows me to setup the bitrate, fps and video quality (SD or HD). You will need a computer, a video source (video camera HD compliable for HD streaming) and a broadcasting software. Its not complicated and you can start in a few minutes. I can show you some demos if you are interested.