If only computer inputs were plentiful and camera outputs simply matched those inputs. Each camera type has its own set of benefits and liabilities and matching them to the computer inputs compounds the challenge. Once I explain the compromises you’ll at least have the puzzle pieces clearly laid out before you. So what are my choices?
High Definition or Standard Def Video Frame Sizes
Video cameras coming to market have been Hi Def for some time, although most also allow for Standard Def. HD video is either 1920×1080 or 1280×720. SD video is generally 720×480 (NTSC) or 720×576 (PAL) or stretched to 854×480 (NTSC 16×9 square pixels from anamorphic) or 1024×576 (PAL 16×9 square pixels from anamorphic). Webcams are square pixel only, so you’ll see SD as 640×480. I will leave a more detailed explanation of what those SD frame sizes mean to a future post, but it’s important to know those are the options.
Web Frame Sizes
HD and SD are much harder to define as they’re not locked into the sizes available on a TV set. Some might define an HD stream as anything larger than 640×480. Others might define it as 960×540, which is half of 1920×1080. Some will stick to the smallest HDTV size of 1280×720.
Streaming HD vs SD
Whichever way you define HD, the larger the frame size, the higher the upload speed you’ll need and the higher the download speed your viewers will need. A recent FCC report stated that the median download speed in the USA was 3Mbps. This means half the connections are slower than that. NetIndex, by the same folks who brought you speedtest and pingtest are now reporting averages worldwide.
You might think we’re getting close to the point where everyone should be streaming in HD, but consider the following factors:
- Download speeds over longer distances tend to be lower so viewers farther away from the server may have much less bandwidth than they show locally.
- Upload speeds tend to be much lower so your ability rests on that
- If you’re paying by bandwidth used, your costs go up considerably
- Your computer resources must be greater since you’re decoding and encoding more data
- If you’re using one of the free services, the default player frame size is usually SD and smaller
So SD is a practical choice, and for most people it’s still far more practical to stream SD. This means, for the time being, having a video camera that has an SD mode can be more practical. Certainly evaluate your specific circumstances and target viewers. Cameras that shoot both SD and HD will give you room to grow. Also remember that cameras that have both modes can generally shoot SD 16:9 so you can still have the widescreen look.
Recently a few webcams are coming to market that are 720 (1280×720) 30fps. Most have been 640×480 or smaller and 30fps or 15fps. Relative to other cameras they’re inexpensive and always connect by USB. Generally all computers have USB connections so there’s not much of a quandary over connecting them. There are some noteworthy drawbacks: Most computers only have a single USB bus. Often you can put two cameras on a bus but the newer HD webcams use more bandwidth. Desktops with PCIe buses and laptops with Express ports can allow you to add buses. Often webcams don’t achieve their best frame rates except under very limited circumstances. All too often you’ll find webcams rated at 30fps actually working at 15fps in many situations.
Webcam Mac Limitations
The feature options and performance may be even more limited on the Mac. Most Macs and new Mac monitors have built in iSight web cams which tend to be mediocre and SD. While most third party webcams will work on Macs, they depend on a standard and limited function Mac driver. This will often mean limited or no control over frame size (generally no HD support), as well as exposure (which can impact frame rate). There’s not much motivation for webcam manufacturers to overcome these limitations since, outside of us live streamers, most people find the built in iSights adequate. This certainly makes the Windows version of Wirecast the better choice if you decide to use webcams and want quality and flexibility.
Generally HDV cameras also support DV in 16:9 mode. They can output live over Firewire which most computers have either through a 400 connector or an 800 to 400 cable. These cameras have you covered if you want to stream SD now and HD in the future. If you’re on a limited budge DV only cameras can be very inexpensive although not all have 16:9 modes.
Be aware that if you use the camera in HDV mode you’ll want to get the Wirecast HDV plugin ($99) but it’s not needed if you’re sticking with DV mode for now. Also important is that HDV uses considerable computer resources so generally it’s not recommended to use more than two camera in HDV mode on a system. Like USB, most computers only have a single Firewire bus regardless of the number and types of inputs so you’ll still need to add PCIe or Express cards adapters for additional cameras.
While some people manage to put two DV cameras on one firewire bus, there are considerable reliability issues. Camera manufacturers often implement bus control in ways that conflict with other cameras on the same bus. You’re best bet is one camera per bus.
One thing to be mindful of is that these tape based firewire out cameras are being phased out of production. Investing your money in soon-to-be-obsolete camera technology may not be a choice you want to make, even if firewire connectors will probably be around a bit longer.
AVCHD cameras, recording H.264 codec to SDHC cards are the norm now. They tend to be HD only. They’re relatively inexpensive too. But they are probably the heart of the quandary we Wirecasters face. If they have USB connections, they’re for data transfer only. They don’t have live Firewire connections either. Their live HDMI outputs have nearly uncompressed HD. The stunning quality is great for hooking up to your HDTV but, alas, computers don’t have live HDMI inputs. Oh what a pain that the camera and computer manufacturers don’t rectify this.
To connect these cameras to your computer, you have a couple of options. One method is to use an HDMI input card or box. This certainly adds to the cost of ownership. Telestream will be testing these devices for official support in Wirecast 4. It can be a challenge to find a way to use two of these cameras on a laptop. The other method is to use an analog to digital converter. These cameras always have some sort of analog out, so one might use devices that can convert to USB or, more reliably, Firewire. I’d recommend the latter.
For this Wirecaster, I’d love to see more affordable ways to get those great inexpensive HDMI cameras into computers, as well as cameras and computers adopting USB3 for connectivity as well. If only camera manufacturers and computer makers understood the importance of multi-camera easy connectivity. Certainly Telestream Wirecast does, as we continue to expand support for video input devices.
Excellent post, thanks. Wish I had read it a few years ago!
Just a few years ago those AVCHD/HDMI cameras were rare. It may all start to shift again depending on where USB3 goes. It might be a year or so before that picture becomes clearer.
It seems about the only source for FireWire Cams anymore is used on Ebay. And there are some good deals to be had. We go 3 Canons Opturas for less than $500 total.
Went to CanonExpo in NYC. Things are getting very interesting on the camera front. The “sleeper” feature is touch screen LCD. Canon Vixia S and less expensive M series have this, not the R series apparently.
Key is you can flip the LCD and put the camera in manual and have complete control of camera setup while being in front of the camera. This is important for show hosts of course.
They AVCHD cameras with HDMI out though. Component out would allow you to use less expensive A/D convertors though.
If only we can get past the connectivity hurdle. My ultimate hope is that both computers and and these inexpensive video cameras move to USB3 next year.
A novel idea inspired by the CanonExpo. The DSLR alternative. With their live video out and shallow Depth of Field, they’d be great if you want that messy background of the room you stream from to be out of focus.
Really great post – what you are offering with your blog is a good example for how to deliver meaningful content to your customers, not only marketing blah blah – I want to express my respect and thankfulness for doing this! Please continue this important work.
I would like to suggest another way: good old analog signal transmission! With many cams you get really good analog signal quality and with very cheap capture devices you can easily handle multiple input channels – of course driver problems apply, but it is not too hard to find mature products. I would like to recommend to take a look into the VJ scene and also learn a little bit from surveillance systems. If you combine the best pieces of these areas together you get good quality with reliable and cheap hardware.
Anyway, it would be nice to see Telestream engaging with hardware producers to make them better understand, what the web-caster of today is missing in modern hardware. Just look at all the netbooks – I do not know ONE netbook with firewire input – a real PITA!!!
Thanks for taking note of the blog work.
I have mixed feelings about the cheaper A/D devices. Those going to Firewire tend to be a bit more reliable than those going to USB. There are analog input cards for desktops as well. The challenge is that audio and video must remain in sync when switching between cameras and other sources and then must remain in sync over long durations and the cheaper devices are very hit and miss based in those regards based on user reports. It’s best to buy and test with the ability to return.
AVCHD cameras usually have composite and component video out in addition to HDMI so analog can be worth testing though. I do wish people wouldn’t have to look back to analog when the image of the sensors is so good especially with HDMI.
Analog in can work but due to the nature of real time encoding for live streaming, input quality is critical. Encoders tend to exaggerate issues in the source such as noise and other aberrations common to analog video.
I’m curious what you’re seeing in the VJ scene as far as video inputs that Wirecast doesn’t already work with. I think the issues are similar with the caveat the Wirecast must see all input sources simultaneously as a compositor/switcher.
Telestream is certainly is looking the surveillance field and that’s why IP camera support is part of the Wirecast 4 roadmap.
Thanks for your input and ff you’ve had success with specific analog hardware devices please do mention them.
Mike, there are certainly DV bargains to be found. This is especially true if someone is selling an used camera where the record and/or playback heads don’t work well anymore. Unless one is doing “ISO” recording, all you need is a live firewire port and the camera will work fine for streaming.
The price of some of the AVCHD/HDMI cameras are dropping nearly as low as some of the used DV cameras though. I do hope for future inexpensive connectivity between current cameras and computers.
I use to use usb webcam and if the conditions are right a very sharp picture.
But it was not very consistent, quality would constantly change.
I decided to change to two Sony HDR CX110 HD camcorders thru two Blackmagic Intensity Pro capture cards. Yea, a bit expensive, but get very hi quality consistent/stable video sources.
I have tried firewire but was not quite what im looking for.