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Digital Cinema Concepts
Digital Cinema Concepts review: DVB
In Europe, 1080p25 signals have been supported by the DVB suite of broadcasting standards. The 1080p50 is considered to be a future-proof production format and, eventually, a future broadcasting format. 1080p50 broadcasting should require the same bandwidth as 1080i50 signal and only 15�20% more than that of 720p50 signal due to increased compression efficiency, though 1080p50 production requires more bandwidth and/or more efficient codecs such as JPEG 2000, high-bitrate MPEG-2, or H.264/AVC and HEVC.
From September 2009, ETSI and EBU, the maintainers of the DVB suite, added support for 1080p50 signal coded with MPEG-4 AVC High Profile Level 4.2 with Scalable Video Coding extensions or VC-1 Advanced Profile compression; DVB also supports 1080p encoded at ATSC frame rates of 23.976, 24, 29.97, 30, 59.94 and 60.
EBU requires that legacy MPEG-4 AVC decoders should avoid crashing in the presence of SVC and/or 1080p50 (and higher resolution) packets. SVC enables forward compatibility with 1080p50 and 1080p60 broadcasting for older MPEG-4 AVC receivers, so they will only recognize baseline SVC stream coded at a lower resolution or frame rate (such as 720p60 or 1080i60) and will gracefully ignore additional packets, while newer hardware will be able to decode full-resolution signal (such as 1080p60).
Interlacing problems
When someone watches interlaced video on a progressive monitor with poor deinterlacing, they can see "combing" in movement between two fields of one frame.
Interlaced video is designed to be captured, stored, transmitted, and displayed in the same interlaced format. Because each interlaced video frame is two fields captured at different moments in time, interlaced video frames can exhibit motion artifacts known as interlacing effects, or combing, if recorded objects move fast enough to be in different positions when each individual field is captured. These artifacts may be more visible when interlaced video is displayed at a slower speed than it was captured, or in still frames.Digital Cinema Concepts HD979
Digital Cinema Concepts HD979 for sale: Over-the-air broadcasts
In the United States, 1080p over-the-air broadcasts still do not exist as of November 2014; all major networks use either 720p60 or 1080i60 encoded with MPEG-2. However, satellite services (e.g., DirecTV, XstreamHD and Dish Network) utilize the 1080p/24-30 format with MPEG-4 AVC/H.264 encoding for pay-per-view movies that are downloaded in advance via satellite or on-demand via broadband. At this time, no pay service channel such as USA, HDNET, etc. nor premium movie channel such as HBO, etc., stream their services live to their distributors (MVPD) in this format because many MVPDs, especially DBS and cable, do not have sufficient bandwidth to provide the format streaming live to their subscribers without negatively impacting their current services. In addition is the high "cost" of using more bandwidth for one 1080p/24 channel than that necessary for a 1080i or even a 720p channel and for only those relatively few subscribers who have HDTV devices that can display 1080p/24 being an efficient use of their limited bandwidth.
Static contrast
Static contrast ratio is the luminosity ratio comparing the brightest and darkest color the system is capable of producing simultaneously at any instant of time, while dynamic contrast ratio is the luminosity ratio comparing the brightest and darkest color the system is capable of producing over time (while the picture is moving). Moving from a system that displays a static motionless image to a system that displays a dynamic, changing picture slightly complicates the definition of the contrast ratio, due to the need to take into account the extra temporal dimension to the measuring process. Digital Cinema Concepts
Digital Cinema Concepts HD979:The ANSI contrast
The ANSI contrast - the measurement is done with a checker board patterned test image where the black and white luminosity values are measured simultaneously. This is a more realistic measure of system capability, but includes the potential of including the effects of the room into the measurement, if the test is not performed in a room that is close to ideal.
It is useful to note that the full on/full off method effectively measures the dynamic contrast ratio of a display, while the ANSI contrast measures the static contrast ratio.
In Europe, 1080p25 signals have been supported by the DVB suite of broadcasting standards. The 1080p50 is considered to be a future-proof production format and, eventually, a future broadcasting format. 1080p50 broadcasting should require the same bandwidth as 1080i50 signal and only 15�20% more than that of 720p50 signal due to increased compression efficiency, though 1080p50 production requires more bandwidth and/or more efficient codecs such as JPEG 2000, high-bitrate MPEG-2, or H.264/AVC and HEVC.
From September 2009, ETSI and EBU, the maintainers of the DVB suite, added support for 1080p50 signal coded with MPEG-4 AVC High Profile Level 4.2 with Scalable Video Coding extensions or VC-1 Advanced Profile compression; DVB also supports 1080p encoded at ATSC frame rates of 23.976, 24, 29.97, 30, 59.94 and 60.
EBU requires that legacy MPEG-4 AVC decoders should avoid crashing in the presence of SVC and/or 1080p50 (and higher resolution) packets. SVC enables forward compatibility with 1080p50 and 1080p60 broadcasting for older MPEG-4 AVC receivers, so they will only recognize baseline SVC stream coded at a lower resolution or frame rate (such as 720p60 or 1080i60) and will gracefully ignore additional packets, while newer hardware will be able to decode full-resolution signal (such as 1080p60).
Interlacing problems
When someone watches interlaced video on a progressive monitor with poor deinterlacing, they can see "combing" in movement between two fields of one frame.
Interlaced video is designed to be captured, stored, transmitted, and displayed in the same interlaced format. Because each interlaced video frame is two fields captured at different moments in time, interlaced video frames can exhibit motion artifacts known as interlacing effects, or combing, if recorded objects move fast enough to be in different positions when each individual field is captured. These artifacts may be more visible when interlaced video is displayed at a slower speed than it was captured, or in still frames.Digital Cinema Concepts HD979
Digital Cinema Concepts HD979 for sale: Over-the-air broadcasts
In the United States, 1080p over-the-air broadcasts still do not exist as of November 2014; all major networks use either 720p60 or 1080i60 encoded with MPEG-2. However, satellite services (e.g., DirecTV, XstreamHD and Dish Network) utilize the 1080p/24-30 format with MPEG-4 AVC/H.264 encoding for pay-per-view movies that are downloaded in advance via satellite or on-demand via broadband. At this time, no pay service channel such as USA, HDNET, etc. nor premium movie channel such as HBO, etc., stream their services live to their distributors (MVPD) in this format because many MVPDs, especially DBS and cable, do not have sufficient bandwidth to provide the format streaming live to their subscribers without negatively impacting their current services. In addition is the high "cost" of using more bandwidth for one 1080p/24 channel than that necessary for a 1080i or even a 720p channel and for only those relatively few subscribers who have HDTV devices that can display 1080p/24 being an efficient use of their limited bandwidth.
Digital Cinema Concepts sell
Static contrast
Static contrast ratio is the luminosity ratio comparing the brightest and darkest color the system is capable of producing simultaneously at any instant of time, while dynamic contrast ratio is the luminosity ratio comparing the brightest and darkest color the system is capable of producing over time (while the picture is moving). Moving from a system that displays a static motionless image to a system that displays a dynamic, changing picture slightly complicates the definition of the contrast ratio, due to the need to take into account the extra temporal dimension to the measuring process. Digital Cinema Concepts
Digital Cinema Concepts HD979:The ANSI contrast
The ANSI contrast - the measurement is done with a checker board patterned test image where the black and white luminosity values are measured simultaneously. This is a more realistic measure of system capability, but includes the potential of including the effects of the room into the measurement, if the test is not performed in a room that is close to ideal.
It is useful to note that the full on/full off method effectively measures the dynamic contrast ratio of a display, while the ANSI contrast measures the static contrast ratio.
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