The municipal television channel I work for is preparing to offer our signal on AT&Ts U-Verse system. Unfortunately, due to some short-sighted state legislation we will be responsible for providing our own encoder. AT&T has provided the following specifications:
Video Encoding Format: Windows Media Video 9 VC-1 Main Profile
Video Streaming Bandwidth: 1.25 Mbps
Input Video Format: NTSC
Frame Rate: 30/29.97 fps
Scanning Type: Non-interlaced
Key Frame Distance: 4 Seconds
Buffer Size: 2 Seconds
Output Resolution: 480x480
Captioning: Open Captions
Audio Encoding Format: WMA (Windows Media Audio)
Audio Streaming Bandwidth: 96 kbps
Audio Sample Rate: 48 kHz
Streaming Protocol: HTTP
Streaming Mode: Constant Bit Rate
Streaming Format: Unicast
Addressing: Public IP Address
Output: ASF Network Pull
Input Physical Connection: Component, Composite or SDI
I'm assuming the 480x480 resolution is incorrect.
They listed a number of hardware encoders that are known to be compatible with their system. These models ranged in price from $3900 to $17,000. That seems like a huge range and I'm not sure what separates a $4K encoder from a $17K encoder.
Although they strongly discourage it, I'm also considering building a high-end PC (dual Xeon or Opteron) with a high-quality capture card (Aja, Black Magic, etc.) and encoding via software. Assuming a fast machine and a high-quality capture card, is there any reason why something like this couldn't put out a compliant stream that is just as good as a stream generated by a hardware encoder? Would the software used matter? Microsoft, for example, says their Expression encoder offers better VC-1 encodes than their free Windows Media encoder.