Uncompressed video, also called Clean HDMI, is digital video information that has not been compressed, or was not processed with compression on it when the video was captured directly via video capture (e.g. from a digital camera). It stands for the related data stream or the file format used in the video capture process. The purpose is significantly higher quality compared to lossy compression, allowing even resolution upscaling.
This article over focuses on HDMI, the reality is uncompressed video can be cared over several data paths including SDI and other standards. The HDMI specification specifies several modes of uncompressed digital video. Although often HD video capable cameras include a HDMI interface for playback or even live preview, the image processor and the video processor of cameras usable for uncompressed video must be able to deliver the full image resolution at the specified frame rate in realtime without any missing frames causing judder. Therefore usable uncompressed video out of HDMI is often called "Clean HDMI".
Currently uncompressed video is supported by Nikon DSLRs with the Expeed 3 (FR) and Expeed 4 image/video processor (currently Nikon D4, D4S, D800/D800E, D600, D610, D7100, D5200 and D5300), the Canon EOS-1D C, the Canon 5D Mark III with firmware 1.2.1 and professional video cameras (see list of video cameras supporting a raw format), which use proprietary raw video formats like CinemaDNG (open format) or ArriRaw with similarities to the raw image format.
- 1 Characteristics
- 2 Uncompressed video recording
- 3 Storage and Data Rates for Uncompressed Video
- 4 HDMI 1.3a Specifications
- 5 See also
- 6 References
- 7 External links
Currently there is no standardized uncompressed video file format except for HDMI, which uses the YCbCr and RGB formats listed below. This makes it necessary to store it best with a related description file about the used resolution and video mode. These files can be combined with lossless compression with the use of file archivers.
Lossless video compression
Uncompressed video recording
Setting up the camera is often new especially for DSLR users. The built in video interface in cameras is mostly an HDMI or, in professional cameras, a Serial digital interface (SDI or HD-SDI); converters between both are available.
Uncompressed video recorder
Portable recorders are an easy, reliable and complete solution for receiving and storing uncompressed video. Partly they receive uncompressed video, but only record lossy compressed video, often in the lossy Apple ProRes 422 or DNxHD codecs. Professional recorders support multiple channels of uncompressed HDMI, DVI or (HD-)SDI recording, but are limited by the total data rate.
Recording to a computer
Recording to a computer enables low-cost to highest performance solutions for laptop or desktop computers, but the computer should be prepared as it must act like a real-time operating system (RTOS). Any other significant program activity including background processes - for example not needed Windows startup processes (use for example Autoruns) or Windows services (use Service Control Manager), including automatic updates or virus scanners - may disrupt, distort or stop the video recording. Disconnection of not needed computer networks and increasing the process priority of the recording realtime process often helps to use most of the computer speed. Hard disk drives have to be fast solid-state drives (SSDs) and/or RAID to be capable of the data-rate of HD videos and/or multiple channels.
Video capture interface
Wireless video interface
Wireless interfaces like Wireless LAN (WLAN, Wi-Fi) are only usable for Full HD with highest speed (IEEE 802.11n-2009). Alternatives are (partly future) interfaces like WirelessHD, WiDi, Wireless Home Digital Interface (WHDI), Wireless HDMI and Wireless Gigabit Alliance. A disadvantage is that any - even shorttime - disruption or bandwidth decrease of the wireless connection will disrupt, distort or stop the video recording.
Uncompressed video recording software
Storage and Data Rates for Uncompressed Video
24bit @ 1080i @ 60fps :24*1920*1080*60/2=1.49 Gbps.
24bit @ 1080p @ 60fps :24*1920*1080*60=2.98 Gbit/s.
- 525 NTSC uncompressed
8 bit @ 720 x 486 @ 29.97fps = 20 MB per/sec, or 70 GB per/hr.
10 bit @ 720 x 486 @ 29.97fps = 27 MB per/sec, or 94 GB per/hr.
- 625 PAL uncompressed
8 bit @ 720 x 576 @ 25fps = 20 MB per/sec, or 70 GB per/hr.
10 bit @ 720 x 576 @ 25fps = 26 MB per/sec, or 93 GB per/hr.
- 720p HDTV uncompressed
8 bit @ 1280 x 720 @ 59.94fps = 105 MB per/sec, or 370 GB per/hr.
10 bit @ 1280 x 720 @ 59.94fps = 140 MB per/sec, or 494 GB per/hr.
- 1080i and 1080p HDTV uncompressed
8 bit @ 1920 x 1080 @ 24fps = 95 MB per/sec, or 334 GB per/hr.
10 bit @ 1920 x 1080 @ 24fps = 127 MB per/sec, or 445 GB per/hr.
8 bit @ 1920 x 1080 @ 25fps = 99 MB per/sec, or 348 GB per/hr.
10 bit @ 1920 x 1080 @ 25fps = 132 MB per/sec, or 463 GB per/hr.
8 bit @ 1920 x 1080 @ 29.97fps = 119 MB per/sec, or 417 GB per/hr.
10 bit @ 1920 x 1080 @ 29.97fps = 158 MB per/sec, or 556 GB per/hr.
1080i and 1080p HDTV RGB (4:4:4) uncompressed
10 bit @ 1280 x 720p @ 60fps = 211 MB per/sec, or 742 GB per/hr.
10 bit @ 1920 x 1080 @ 24fps = 190 MB per/sec, or 667 GB per/hr.
10 bit @ 1920 x 1080 @ 50i = 198 MB per/sec, or 695 GB per/hr.
10 bit @ 1920 x 1080 @ 60i = 237 MB per/sec, or 834 GB per/hr.
HDMI 1.3a Specifications
According to HDMI 1.3a Spec.
Detailed timing is found in CEA-861-D or a later version of CEA-861 for the following video format timings.
Cameras mostly use the progressive segmented frame format: for example a 25p/30p progressive scan is transported in a 50i/60i interlaced format respectively, but with identical information: No deinterlacing should be used.
- Primary Video Format Timings
• 640x480p @ 59.94/60 Hz
• 1280x720p @ 59.94/60 Hz
• 1920x1080i @ 59.94/60 Hz
• 720x480p @ 59.94/60 Hz
• 720(1440)x480i @ 59.94/60 Hz
• 1280x720p @ 50 Hz
• 1920x1080i @ 50 Hz
• 720x576p @ 50 Hz
• 720(1440)x576i @ 50 Hz
- Secondary Video Format Timings
• 720(1440)x240p @ 59.94/60 Hz
• 2880x480i @ 59.94/60 Hz
• 2880x240p @ 59.94/60 Hz
• 1440x480p @ 59.94/60 Hz
• 1920x1080p @ 59.94/60 Hz
• 720(1440)x288p @ 50 Hz
• 2880x576i @ 50 Hz
• 2880x288p @ 50 Hz
• 1440x576p @ 50 Hz
• 1920x1080p @ 50 Hz
• 1920x1080p @ 23.98/24 Hz
• 1920x1080p @ 25 Hz
• 1920x1080p @ 29.97/30 Hz
• 2880x480p @ 59.94/60 Hz
• 2880x576p @ 50 Hz
• 1920x1080i (1250 total) @ 50 Hz
• 720(1440)x480i @ 119.88/120 Hz
• 720x480p @ 119.88/120 Hz
• 1920x1080i @ 119.88/120 Hz
• 1280x720p @ 119.88/120 Hz
• 720(1440)x480i @ 239.76/240 Hz
• 720x480p @ 239.76/240 Hz
• 720(1440)x576i @ 100 Hz
• 720x576p @ 100 Hz
• 1920x1080i @ 100 Hz
• 1280x720p @ 100 Hz
• 720(1440)x576i @ 200 Hz
• 720X576p @ 200 Hz
- Pixel Encodings and Color Depth
There are three different pixel encodings that may be sent across an HDMI cable: YCbCr 4:4:4 (chroma subsampling), YCbCr 4:2:2 and RGB 4:4:4.
There are four color depths supported: 24-, 30-, 36- and 48-bits per pixel.
- List of video cameras supporting a raw format
- Data compression
- Nikon Expeed Video processor
- Uncompressed audio
- Using Uncompressed Audio and Video Streams Microsoft
- Lossless Codecs Comparison ‘2007 PDF
- Capturing HDMI Video: A quick guide to getting the best video from a D4 or D800 Tom Hogan
- Master Guide to Rigging a Nikon D800 or D800E for Video Wolfcrow
- HD-SDI / HDMI digital video converters Atomos
- The world's smallest uncompressed video recorder Blackmagic
- Portable HD Field Recorder, Monitor, Playback And Playout Devices Atomos
- Video Recorders Sound Devices
- Video Disk Recorder KEISOKU GIKEN
- 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
- Video bitrate calculator Forret
- 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