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Final Cut Pro on an Apple G5 with 8-drive SATA array is fully capable of realtime capturing and editing HD material. Our editing package includes DVD Studio Pro, Compressor, Soundtrack Pro, and QMaster, which allows you to use other G5s on the network for faster rendering of files.
An Aja Kona LH on an Apple G5 supports 4:2:2 HD input and output as well as realtime down conversion to standard definition. Other features include analog recording and playback of SD and well as HD playback via analog down conversion for suites lacking HD monitoring capabilities. It works in conjunction with our Final Cut Pro systems that include a sata drive array for full recording and playback of HD 8bit or 10bit uncompressed in realtime. This system can be used with our Sony HDCAM, Panasonic AJ-HD1200A or Sony HDV decks. The system is fully mobile and easily integrates into any edit suite or MCR.
The Black Magic DeckLink HD on a Apple G5 supports 4:2:2 HD input and output as well as realtime down conversion to standard definition. It works in conjunction with our fully configured Final Cut Pro 5 systems that include a sata drive array for full recording and playback of HD 8bit or 10bit uncompressed in realtime. This system is fully integrated into our machine room for access to both our Sony HDCAM and our Panasonic HD1200 decks as well as all our other standard definition decks such as Digital Beta, Beta SP, and our standards conversion system.
Sony HDW-F500 HDCAM
Supports 24, 25, 29.97, 30, 50i, 59.94i frame rates at 1920 x 1080 resolution.
Features Down Conversion at PAL or NTSC Frame rates with letterbox, anamorphic or edge cropped formatting via serial digital output. Dolby E 5.1 Compatible.
Panasonic HD1200 Features Up Conversion, Down Conversion and Cross Conversion as well as
Multi-format, PAL or NTSC, playback of Mini DV, DVCAM, DVCPRO 25, DVCPRO 50, DVCPRO HD. Capable of up converting standard definition Mini DV, DVCAM, DVCPRO 25, DVCPRO 50 tapes to HD in real time as well as DVCPRO HD down conversion to standard definition. Supports 24, 25 and 30 frame rates at 720p or 1080i. Compatible with varicam cameras for seamless 24p integration with Final Cut Pro HD via Firewire 400.
GENERAL THINGS TO KNOW ABOUT HD
The 720 formats, used with DVCPro HD and D5, are all progressive. The 1080 formats, which include HDCAM, D5, and DVCPro HD, are capable of both progressive and interlaced frame types, depending on the frame rate and format you choose.?
Unlike NTSC, or PAL Standard definition formats, HD outputs it's image in square pixels instead of rectangular pixels. Some HD formats sample internally using rectangular pixels but resample on output to square pixels. This is done to effectively compress the signal in order to save space.
Another method of space saving is luminance and chrominance sub-sampling. For instance, DV uses a 4:1:1? color sampling scheme. The first digit represents a full sampling of luminance, i.e. the 4 means that luminance is sampled once for every pixel in the image. The second and third digit represent a %25 sub-sampling of chrominance, Cr and Cb respectively, meaning color components are sampled with every 4th luminance sample on each horizontal line. With HDCAM, for instance, 3:1:1 means that luma is sampled horizontally at three quarters of the full luminance sampling rate and chrominance is sampled at 1/4 of the full chrominance sampling rate on the Cr and Cb channels.
Quantization, as it refers to pixel sampling, is another way in which space is saved on recorded tape formats. HDCAM uses 8bits per pixel to store on tape but upsamples on output in order to accommodate full 10bit streams. D5 and HDCAM SR are capable of recording 10bit streams to tape.
Sony HDCAM is capable of 1080 resolution at frame rates of 23.98, 24p, 25p, 29.97, 50i, 59.94i and 60i. The codec stores video at 1440 x 1080(non-square pixels) and is unsampled to 1920 x 1080 using an 8bit DCT compressed 3:1:1 recording, which breaks down to a compression value of 4.4:1. Though it stores in 8bit, it handles 10bit input and output with a recorded video bitrate of 144Mbits. It uses 4 channels of AES/EBU 20-bit/48khz audio and supports Dolby E surround sound using using existing audio channels.
HDCAM SR uses a higher particle density tape stock and records with an increased bitrate of 440Mbit/s. It produces a 4:4:4: RGB recording with 10bit input and output. HDCAMSR uses a MPEG-4 compression scheme and expands the audio capability to 12 channels at 48khz/24bit.
Unlike formats such as DVC Pro, HDCAM and HDCAM SR do not share tape stock compatibility. Sony differentiates the stock by using an orange lid for HDCAM and a Cyan lid for HDCAM SR.
DVCPro HD(A.K.A. D7-HD) is a Panasonic HD format that uses the same tape stock as DVCPro running at a faster transport speed. It does 720/60p and 1080/60i, and will soon support 1080/24p.
A derivative format called Varicam uses the DVCPro HD codec to create a varible framerate, from 4 to 60fps, to create rapid or slow motion effects used in film. It can also be used to shoot in 24p, thus approximating the "look" of film. An important thing to remember is that the transport speed of the tape does not change but instead still runs at 60fps and creates duplicated frames and flags them for identification on output. Programs like Final Cut Pro can identify these flags and remove them, hence creating a true varible frame rate clip. In the case of a 24fps tape, it is essentially like a reverse telecine. Varicam is only available in 720p.
DVC Pro HD uses 6.7:1 compression and encodes using 4:2:2 color sampling. DVCProHD streams at a native bitrate of 100Mbits, and supports 10-bit input and output with up to 8 channels of audio. Like HDCAM, DVCPro HD uses a prefiltering process that takes a 720p source and stores it at 960 x 720 and a 1080 source and stores it at 1280 x 1080(1440 x 1080 for 50i) and unsamples the video to full resolution on playback. DVCPro HD can also be recorded to cameras supporting the P2 card(PCMCIA), which can then be imported into systems such as Final Cut for editing, all without the use of tape.
A common source of confusion is with tape stock. Since DVCPro tape can be used with DVCPro, DVCPro50 and DVCPro HD, the running times printed on the tape apply differently. Panasonic has three different color codings for tape stock to help with figuring out tape run times. Yellow is for DVCPro. If you have a yellow tape and it says 66/33, then you'll get 66 minutes with the DVCPro format and 33 minutes with the DVCPro50 format. You can also use this tape for DVCProHD, however, keep in mind DVCProHD uses 4x the amount of space as DVCPro thus you will only have 16.5 minutes of run time. A blue lid signifies DVCPro50 and the run time printed on the tape will be for DVCPro 50. This time you will get twice as much run time if you record DVCPro and half as much run time with DVCPro HD. The red lid identifies? the the run time printed on the tape as a DVCProHD run time and, of course, the math works in reverse when recording DVC Pro and DVC Pro 50.
HDV is a prosumer format which records highly compressed MPEG-2 on a mini DV tape. The interframe-compressed MPEG-2 streams at 19Mbits per second for 720p and 25 Mbps for 1080i. 384 Kbps MPEG-1 Layer 2 stereo audio is used for during encoding. The interframe encoding is good for storing high quality video at a lower bitrate but makes it more difficult to edit.
The method of compression uses a GOP, or group of pictures. This means a series of I-frames(intra-frames) and B and P(bi-directional predictive and predictive) frames encode as much as 12 to 15 video frames into 1 GOP. Since predictive frames cannot be decoded individually, the entire GOP must be decoded in order to edit those frames. Editing on GOP boundaries is possible without decoding, but limits editing accuracy. Complex transitions are prone to artifacting and fair better if the Mpeg-2 is decoded first, posing an additional inconvenience. Just to belabor the point, HDV footage also tends to cause editing systems to work harder as independent cells have to be continually rebuilt by the NLE when cuts are made.
The interframe compression method also increases the impact of dropouts or errors in the bit stream. This is because of the error or dropout will effect all frames in the GOP. Unfortunately, this is just an accepted drawback of the format.
All this said, programs such as Final Cut 5 have developed their software to edit HDV with only a few hang-ups. Apple's Intermediate Codec, though requiring much more drive space, transcodes the HDV format to an intermediate format. It helps maintain quality and system efficiency while editing in Final Cut.
Understanding HDV's response to light and motion is important to producing good results with minimal artifacts. Recent films and TV shows have established work-flows when handling and shooting HDV to minimize incident. It should be noted, however, that many broadcasters only accept HDV in a limited capacity and likely only with prior consent.
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