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High Definition Video: Acquisition to Broadcast PowerPoint Presentation
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High Definition Video: Acquisition to Broadcast

High Definition Video: Acquisition to Broadcast

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High Definition Video: Acquisition to Broadcast

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  1. High Definition Video: Acquisition to Broadcast

  2. Overview • Defining the term “High Definition” • Pixel, frame and video formats • Image acquisition • Storage media • Compression • Post production • Transmission and the digital switchover • Reception and “HD Ready” • Home entertainment HD

  3. What is HD? • Anything providing more resolution than current standard definition (SD) video. • It is a generic term for “better” • It doesn’t specify how much better.

  4. Standard definition • For the UK, a system known as PAL • Broadcast systems comprising 625 lines • 25 frames per second • After signalling and data removed, a frame resolution of 768x576 pixels • Frame aspect of 4:3 (768:576 simplified to it’s lowest common factor)

  5. Standard definition SD, 4:3 3 576 4 768

  6. Standard definition • 768x576 assumes a square pixel • Pixels don’t have to be square and in SD video, they usually aren’t! • 4:3 PAL uses a pixel aspect of 1.066666:1 • Your TV “stretches” the frame horizontally • Anything that increases the size of a pixel reduces resolution

  7. Standard definition Standard definition 3 4

  8. Widescreen • A further extension of this kludge • Very un-square pixels • 16:9 broadcasts take the 720x576 frame and stretch it even more horizontally

  9. Standard definition Widescreen standard definition 3 9 16 4

  10. Standard definition • Uses anamorphic pixels • 4:3 – 1.0666:1 • 16:9 – 1.4222:1 • Results in resolution being lost due to the stretching process

  11. High Definition • Two common formats • 720p • 1080i • SD frame: 720 x 576 • 720p frame: 1280 x 720 (2.2 x SD) • 1080i frame: 1920 x 1080 (5 x SD)

  12. High Definition 1920x1080i, 16:9 1280x720p, 16:9 SD 720x576, 4:3

  13. High Definition(or “what all the fuss is about”) • 1080i provides almost five times the resolution of Standard Definition • Unencumbered by legacy technology • Native 16:9 aspect ratio • True 720p and 1080i are square pixel formats – no resolution-killing scaling when displayed

  14. Image Acquisition • Professional: anything with mechanical manual focus • “Prosumer” – Servo-operated focus / fixed lenses that provide similar functionality to pro cameras • Consumer - point-and-shoot cameras that do all of the hard work for you!

  15. Professional cameras Unlimited budget ARRI 320D • Can shoot film resolutions • CCD is the same size as a 35mm frame • Needs a huge amount of peripherals • Camera alone starts at £200,000 • Lenses £20,000 upwards

  16. Professional cameras

  17. Professional cameras Top-end HDC-1500L444 • Native 1080p • Variable frame rates (1 to 60fps) • Still needs lots of peripherals • Camera alone starts at £80,000

  18. Professional cameras Mainstream HD HDW-F900R • Native 1080i • Integral HDCAM recorder • More realistic price: £40,000

  19. Professional cameras Optical storage PDW-F350 • Native 1080i • Integral ProDisc recorder • £10,000

  20. Professional cameras Budget professional JVC GY-HD251E • Native 1080i • Integral 720p HDV recorder • Still uses “proper” lenses • £5000

  21. “Prosumer” cameras Canon XHA1 • Native 1080i • Integral 1080i HDV recorder • Internal focus lens • £2200

  22. “Prosumer” cameras Sony HVR-V1E • Native 1080i • Integral 1080i HDV recorder • Internal focus lens • £1500

  23. Consumer cameras Sony HDR-HC7E • Native 1080i • Integral 1080i HDV recorder • Internal focus lens • £800

  24. Consumer cameras Canon HV20 • Native 1080i • Integral 1080i HDV recorder • Internal focus lens • £650

  25. Consumer cameras Sanyo DMX-HD1000 • Native 1080i • Uses standard SD flash storage • 4.2 megapixel stills • £450

  26. Consumer cameras

  27. Image Acquisition • For home use, size and convenience are generally more important than features • “More expensive” doesn’t necessarily mean “better” or “more suited” • The manual functions on pro cameras just get in the way when you’re simply trying to shoot something

  28. Lens Image sensor Processing electronics Storage Image Acquisition

  29. Image Acquisition

  30. Video storage • Tape • Optical disc • Hard drives • Flash memory

  31. Video Tape Recorders

  32. Video Tape Recorders

  33. Video Tape Recorders

  34. Video Tape Recorders

  35. Principal HD tape formats

  36. Tape: pros • Relatively cheap • Universally accepted for interchange • Long shelf life when stored correctly • Long recording durations

  37. Tape: cons • Linear by nature • Limited record / playback cycles • No warning during recording of drop-out • Easily damaged if handled carelessly • Easily damaged by deck malfunction • Easily damaged by incorrect storage • Decks can be very expensive to maintain

  38. Tape: cons Deck malfunction Incorrect storage

  39. Tape: cons • Linear by nature • Limited record / playback cycles • No warning during recording of drop-out • Easily damaged if handled carelessly • Easily damaged by deck malfunction • Easily damaged by incorrect storage • Decks can be very expensive to maintain

  40. Tape: cons

  41. Video storage: Tape Q:Who won the VHS vs. Beta format war? A: Sony’s Beta! • Betacam SP • Betacam SX • MPEG IMX • Digital Betacam • HDCAM • HDCAM SR

  42. Video storage: Tape

  43. Video storage: optical disc

  44. Optical disc: pros • Robust • High number of read/write cycles • Non-linear: near instant access • Easy ingest to editing systems • Improved workflow • Supports multiple formats (SD & HD)

  45. Optical disc: cons • Read/write cycles not as high as expected • Harsh conditions can upset recording • Limited shelf-life – data degrades with time

  46. Video storage: hard discs

  47. Hard drives: pros • Fast – capable of recording uncompressed • Non-linear – instant access • Capacity – multi-terrabyte • Unlimited read/write cycles • Immediate ingest

  48. Hard drives: cons • Not portable • Camera-to-drive interfaces can be costly • Failures often catastrophic • Not practical for long-term storage • Can be noisy

  49. Video storage: hard discs