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{{short description|High-fidelity digital video signal}} |
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{{expand|date=September 2008}} |
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{{More citations needed|date=March 2023}} |
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'''Uncompressed video''' is [[video]] that has no [[video compression|compression]] on it when capturing directly from a camera. It has variable data transfer rates. Native digital video capture rates are roughly 30Mbits/s. |
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'''Uncompressed video''' is [[digital video]] that either has never been [[video compression|compressed]] or was generated by decompressing previously compressed digital video. It is commonly used by video cameras, video monitors, video recording devices (including general-purpose computers), and in video processors that perform functions such as image resizing, image rotation, [[deinterlacing]], and text and graphics overlay. It is conveyed over various types of baseband digital video interfaces, such as [[HDMI]], [[DVI]], [[DisplayPort]] and [[Serial digital interface|SDI]]. Standards also exist for the carriage of uncompressed video over [[computer network]]s. |
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Some [[HD video]] cameras output uncompressed video, whereas others compress the video using a lossy compression method such as [[MPEG]] or [[H.264]]. In any lossy compression process, some of the video information is removed, which creates [[compression artifact]]s and reduces the quality of the resulting decompressed video. When editing video, it is preferred to work with video that has never been compressed (or was losslessly compressed) as this maintains the best possible quality, with compression performed after completion of editing.<ref>[http://msdn.microsoft.com/en-us/library/windows/desktop/dd743961(v=vs.85).aspx Using Uncompressed Audio and Video Streams] Microsoft</ref> |
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{{stub}} |
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Uncompressed video should not be confused with [[Raw image format|raw video]]. Raw video represents largely unprocessed data (e.g. without [[demosaicing]]) captured by an imaging device. |
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==Recording== |
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A standalone video recorder is a device that receives uncompressed video and stores it in either uncompressed or compressed form. These devices typically have a video output that can be used to monitor or playback recorded video. When playing back compressed video, the compressed video is uncompressed by the device before being output. Such devices may also have a communication interface, such as Ethernet or USB, which can used to exchange video files with an external computer, and in some cases control the recorder from an external computer as well. |
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Recording to a computer is a relatively inexpensive alternative to implementing a digital video recorder, but the computer and its video storage device (e.g., [[solid-state drive]], [[RAID]]) must be fast enough to keep up with the high video data rate, which in some cases may be [[HD video]] or multiple video sources, or both. Due to the extreme computational and storage system performance demands of real-time video processing, other unnecessary [[Computer program|program]] activity (e.g., [[background process]]es, [[virus scanner]]s) and asynchronous hardware interfaces (e.g., [[computer networks]]) may be disabled, and the [[Computer multitasking|process priority]] of the recording [[Real-time computing|realtime process]] may be increased, to avoid disruption of the recording process. |
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HDMI, DVI and HD-SDI inputs are available as [[PCI Express]] (partly multi-channel) or [[ExpressCard]], [[USB 3.0]]<ref>[http://www.epiphan.com/products/compare-usb-video-grabbers/ Compare USB Video Grabbers] Epiphan</ref> and [[Thunderbolt (interface)|Thunderbolt]] interface<ref>[http://www.blackmagicdesign.com/products/intensity/ Intensity models] Blackmagic</ref><ref>[http://www.imperx.com/frame-grabbers/hd-sdi-express34 HD-SDI Express/34] Imperx</ref><ref>[http://www.deltacast.tv/Products/DELTA-hd-SDI-OEM-video-input-output-PCI-Express-card.asp OEM video card for 8-10-12-bit HD-SD SDI digital video to PCI Express] Deltacast</ref> also for [[2160p]] ([[4K resolution]]).<ref>[http://www.magewell.com/hardware?lang=en Capture Card Series] Magewell</ref><ref>[http://www.blackmagicdesign.com/products/decklink/models DeckLink models] Blackmagic</ref> |
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Software for recording uncompressed video is often supplied with suitable hardware or available for free e.g. [[Ingex]].<ref>[http://ingex.sourceforge.net/studio/ Ingex Studio - Multi-camera Tapeless Recording]</ref> |
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==Network transmission== |
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[[SMPTE 2022]] and [[SMPTE 2110|2110]] are standards for professional digital video over [[IP network]]s. SMPTE 2022 includes provisions for both compressed and uncompressed video formats. SMPTE 2110 carries uncompressed video, audio, and [[ancillary data]] as separate [[streaming media|streams]]. |
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[[wireless network|Wireless interfaces]] such as [[Wireless LAN]] (WLAN, [[Wi-Fi]]), [[WiDi]], and [[Wireless Home Digital Interface]] can be used to transmit uncompressed standard definition (SD) video but not HD video because the HD bit rates would exceed the network bandwidth. HD can be transmitted using higher-speed interfaces such as [[WirelessHD]] and [[WiGig]]. In all cases, when video is conveyed over a network, communication disruptions or diminished bandwidth can corrupt the video or prevent its transmission. |
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==Data rates== |
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Uncompressed video has a [[constant bitrate]] that is based on pixel representation, image resolution, and frame rate: |
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:[[Data signaling rate|data rate]] = [[color depth]]{{efn|Most of the time color depth can be calculated as 3 × single color depth. For example, values of a single color can be represented with a range from 0 to 255 (8 bits) which gives a total color depth as 3 × 8 <nowiki>=</nowiki> 24.}} × vertical [[Image resolution|resolution]] × horizontal resolution × [[refresh frequency]] {{Citation needed|date=January 2024}} |
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For example: |
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*16-bit, 480i @ 24 [[Frame rate|fps]]: 16 × {{resx|640|240}}{{efn|[[Interlaced video]] formats transmit every other line, half the picture content, per field period. Two fields are required for a full frame so the vertical resolution is halved in this calculation.}} × 24 = 58.9 [[megabit per second|Mbit/s]] |
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*24-bit, 480p @ 30 fps: 24 × {{resx|640|480}} × 30 = 221 Mbit/s. |
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*24-bit, 720p @ 30 fps: 24 × {{resx|1280|720}} × 30 = 663 Mbit/s. |
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*24-bit, 720p @ 60 fps: 24 × {{resx|1280|720}} × 60 = 1.32 [[gigabit per second|Gbit/s]] |
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*24-bit, 1080i @ 60 fps: 24 × {{resx|1920|540}} × 60 = 1.49 Gbit/s. |
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*24-bit, 1080p @ 60 fps: 24 × {{resx|1920|1080}} × 60 = 2.98 Gbit/s. |
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*24-bit, [[4K UHD]] @ 60 fps: 24 × {{resx|3840|2160}} × 60 = 11.9 Gbit/s. |
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*24-bit, 4K UHD @ 120 fps: 24 × {{resx|3840|2160}} × 120 = 23.8 Gbit/s. |
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*[[High color|48-bit]], [[DCI 4K]] @ 144 fps: 48 × {{resx|4096|2160}} × 144 = 61.1 Gbit/s. |
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The actual data rate may be higher because some transmission media for uncompressed video require defined [[Raster_scan#Video_timing|blanking intervals]], which effectively add unused pixels around the visible image. |
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==See also== |
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* [[Data compression#Video|Data compression]] |
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* [[Digital Picture Exchange|DPX]] and [[Material Exchange Format|MXF]] files – used in professional video files systems |
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* [[List of cameras supporting a raw format]] |
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* {{Section link|List of codecs|Lossless video compression}} |
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* [[Expeed#Video processor|Nikon Expeed Video processor]] |
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* [[TIFF]] files – used in AV and professional video files systems |
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* [[Uncompressed audio]] |
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==Notes== |
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{{notelist}} |
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==References== |
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{{reflist}} |
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==External links== |
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* [https://toolstud.io/video/bitrate.php Video bitrate calculator] |
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* [http://www.creativeplanetnetwork.com/dcp/news/uncompressed-digital-video/45959 Uncompressed Digital Video], Creative Planet Network |
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* [http://www.creativeplanetnetwork.com/dcp/news/uncompressed-vs-compressed/45625 Uncompressed vs. Compressed Video], Creative Planet Network |
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* [http://wolfcrow.com/blog/master-guide-to-rigging-a-nikon-d800-or-d800e-part-12/ Master Guide to Rigging a Nikon D800 or D800E for Video], Wolfcrow |
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{{VideoProcessing}} |
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{{High-definition|state=collapsed}} |
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[[Category:High-definition television]] |
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[[Category:Video compression]] |
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[[Category:Film and video technology]] |
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[[Category:Video signal]] |
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[[Category:Data compression]] |
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[[Category:Digital television]] |
Latest revision as of 07:04, 1 May 2024
Uncompressed video is digital video that either has never been compressed or was generated by decompressing previously compressed digital video. It is commonly used by video cameras, video monitors, video recording devices (including general-purpose computers), and in video processors that perform functions such as image resizing, image rotation, deinterlacing, and text and graphics overlay. It is conveyed over various types of baseband digital video interfaces, such as HDMI, DVI, DisplayPort and SDI. Standards also exist for the carriage of uncompressed video over computer networks.
Some HD video cameras output uncompressed video, whereas others compress the video using a lossy compression method such as MPEG or H.264. In any lossy compression process, some of the video information is removed, which creates compression artifacts and reduces the quality of the resulting decompressed video. When editing video, it is preferred to work with video that has never been compressed (or was losslessly compressed) as this maintains the best possible quality, with compression performed after completion of editing.[1]
Uncompressed video should not be confused with raw video. Raw video represents largely unprocessed data (e.g. without demosaicing) captured by an imaging device.
Recording
A standalone video recorder is a device that receives uncompressed video and stores it in either uncompressed or compressed form. These devices typically have a video output that can be used to monitor or playback recorded video. When playing back compressed video, the compressed video is uncompressed by the device before being output. Such devices may also have a communication interface, such as Ethernet or USB, which can used to exchange video files with an external computer, and in some cases control the recorder from an external computer as well.
Recording to a computer is a relatively inexpensive alternative to implementing a digital video recorder, but the computer and its video storage device (e.g., solid-state drive, RAID) must be fast enough to keep up with the high video data rate, which in some cases may be HD video or multiple video sources, or both. Due to the extreme computational and storage system performance demands of real-time video processing, other unnecessary program activity (e.g., background processes, virus scanners) and asynchronous hardware interfaces (e.g., computer networks) may be disabled, and the process priority of the recording realtime process may be increased, to avoid disruption of the recording process.
HDMI, DVI and HD-SDI inputs are available as PCI Express (partly multi-channel) or ExpressCard, USB 3.0[2] and Thunderbolt interface[3][4][5] also for 2160p (4K resolution).[6][7]
Software for recording uncompressed video is often supplied with suitable hardware or available for free e.g. Ingex.[8]
Network transmission
SMPTE 2022 and 2110 are standards for professional digital video over IP networks. SMPTE 2022 includes provisions for both compressed and uncompressed video formats. SMPTE 2110 carries uncompressed video, audio, and ancillary data as separate streams.
Wireless interfaces such as Wireless LAN (WLAN, Wi-Fi), WiDi, and Wireless Home Digital Interface can be used to transmit uncompressed standard definition (SD) video but not HD video because the HD bit rates would exceed the network bandwidth. HD can be transmitted using higher-speed interfaces such as WirelessHD and WiGig. In all cases, when video is conveyed over a network, communication disruptions or diminished bandwidth can corrupt the video or prevent its transmission.
Data rates
Uncompressed video has a constant bitrate that is based on pixel representation, image resolution, and frame rate:
- data rate = color depth[a] × vertical resolution × horizontal resolution × refresh frequency [citation needed]
For example:
- 16-bit, 480i @ 24 fps: 16 × 640 × 240[b] × 24 = 58.9 Mbit/s
- 24-bit, 480p @ 30 fps: 24 × 640 × 480 × 30 = 221 Mbit/s.
- 24-bit, 720p @ 30 fps: 24 × 1280 × 720 × 30 = 663 Mbit/s.
- 24-bit, 720p @ 60 fps: 24 × 1280 × 720 × 60 = 1.32 Gbit/s
- 24-bit, 1080i @ 60 fps: 24 × 1920 × 540 × 60 = 1.49 Gbit/s.
- 24-bit, 1080p @ 60 fps: 24 × 1920 × 1080 × 60 = 2.98 Gbit/s.
- 24-bit, 4K UHD @ 60 fps: 24 × 3840 × 2160 × 60 = 11.9 Gbit/s.
- 24-bit, 4K UHD @ 120 fps: 24 × 3840 × 2160 × 120 = 23.8 Gbit/s.
- 48-bit, DCI 4K @ 144 fps: 48 × 4096 × 2160 × 144 = 61.1 Gbit/s.
The actual data rate may be higher because some transmission media for uncompressed video require defined blanking intervals, which effectively add unused pixels around the visible image.
See also
- Data compression
- DPX and MXF files – used in professional video files systems
- List of cameras supporting a raw format
- List of codecs § Lossless video compression
- Nikon Expeed Video processor
- TIFF files – used in AV and professional video files systems
- Uncompressed audio
Notes
- ^ Most of the time color depth can be calculated as 3 × single color depth. For example, values of a single color can be represented with a range from 0 to 255 (8 bits) which gives a total color depth as 3 × 8 = 24.
- ^ Interlaced video formats transmit every other line, half the picture content, per field period. Two fields are required for a full frame so the vertical resolution is halved in this calculation.
References
- ^ Using Uncompressed Audio and Video Streams Microsoft
- ^ Compare USB Video Grabbers Epiphan
- ^ Intensity models Blackmagic
- ^ HD-SDI Express/34 Imperx
- ^ OEM video card for 8-10-12-bit HD-SD SDI digital video to PCI Express Deltacast
- ^ Capture Card Series Magewell
- ^ DeckLink models Blackmagic
- ^ Ingex Studio - Multi-camera Tapeless Recording
External links
- Video bitrate calculator
- Uncompressed Digital Video, Creative Planet Network
- Uncompressed vs. Compressed Video, Creative Planet Network
- Master Guide to Rigging a Nikon D800 or D800E for Video, Wolfcrow