09 October, 2006


Got a set of questions from a gate keeper at some 800lb gorilla of a company on at least it’s 3rd attempt to control a portion of the glass teat (nod to Harlan Ellison), makes one wonder just how anything gets done there

1) What are the NTSC & PAL frame rates?

NTSC (color) is 29.97 Frames per second (Monochrome - B&W) is exactly 30 Frames per second
PAL (and SECAM) is 25 Frames per second

2) Are you familiar with Telecine?
an open question, a Telecine is a device for transferring motion picture images from film to video, when transferring to PAL from the typical 24 Frame Per Second (actually, modern film is "double shuttered" each frame is projected twice for 48 images per second) there is a one to one movie frame to video frame correspondence slightly slowing the run time of the film when viewed, for transfer to NTSC (other than film shot as Todd AO which is 30fps) a 3:2 pull down sequence is used where alternating frames of movie are 'written' as 3 fields then 2 fields maintaining a realtime correspondence between the movie and video

Most MPEG encoders have an 'inverse telecine' function where repeated fields are detected and only process the first instance of the image

3) What is full D-1 resolution for NTSC & PAL?
the question is not correctly phrased and shows ignorance of the subject matter at hand - thanks for playing - don't call us, we'll call you

image resolution is the result of a combination of factors determined primarily by objective size, lens MTF (Modulation Transfer Function), Imaging device type and size

D-1 is an un compressed component digital video tape format that records a 270Mbps serial digital stream

this stream specification is correctly specified as ITU-R BT.601 (formerly known as CCIR 601) or SMPTE 259M and supports both PAL and NTSC line and frame rates (PAL is 625 lines including Vertical blanking, NTSC is 525 lines at the frame rates noted above) sampling the luminance at 720 (with at least 8 bits of resolution) and the two chroma difference values (at least 4 bits of resolution) at 360 times Per line often referred to as YUV 4:2:2 encoding

4) Are you familiar with H.264?


we'll see if I get a call back, until then, I’m not holding my breath

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