Sony HDCAM-SR format is the high end of High Definition television. Models include SRW-5000, SRW-5500, and the SRW-5800. This VTR also allows recording and playback of the well-proven HDCAM format. Applications range from HDTV to digital cinematography. Key features include high-quality 1080i, 1080PsF, or 720P recording and playback, a wide array of internal format conversions, including 4:4:4 to 4:2:2, legacy playback of Digital Beta cam tape formats.
Cross conversion in HD High Definition is also possible using HDCAM-SR ability to convert 1080 to 720. This is useful in transferring HDCAM, HDCAM-SR to other HD formats like Panasonic D5, Panasonic DVCproHD, and Sony HDV. 3:2 pull down can also be managed in cross conversions.
The SRW-5800 HDCAM-SR Studio Recorder is equipped with the same key features as SRW-5500 and SRW-5000 recorders in the series. This deck records 1920 x 1080 resolution 10bit HD signals using MPEG-4 Studio Profile with visually loss-less compression. Video data rate is 440Mbps and 880Mbps is also possible with HKSR-5803HQ option. 12 channels of 24-bit discrete uncompressed audio can be recorded. Multiple frame rates are supported i.e. 1080 23.98/24/25/29.97/30PsF, 50/59.94/60i and 720 50/59.94P. 1080 50P and 59.94P are also supported with HKSR-5803HQ by using double speed recording mode. RGB4:4:4 signals can be recorded and played back with option cards. The HKSR-5803SQ supports 4:4:4 SQ mode only and the HKSR-5803HQ supports both 4:4:4 SQ and HQ mode. By using HKSR-5802 option, it can playback HDCAM and Digital Beta cam tapes. Up-conversion output is possible when playback Digital Beta cam tapes. HKSR-5001 format converter option for SRW-5000 and SRW-5500 can be used for SRW-5800, too. This versatile format converter allows 2-3 pull down and 1080i or 1080PsF to 720P conversion or vice versa. Color space conversion between 4:4:4 and 4:2:2 is possible as well. HKSR-5803HQ option enables X2 transfer of Video, Audio and Timecode to specified server in 1080 50i (25PsF), 60i (30PsF), 24PsF and 720 50/59.94P over HD-SDI dual link by using 880Mbps mode.
Here are some of the features:
1080 recording and playback at multiple frame rates: 23.98PsF, 24PsF, 25PsF, 29.97PsF, 50i, 59.94i in HDCAM and HDCAM-SR formats.
720P recording and playback (HDCAM-SR only)
Switchable 4:4:4/4:2:2 recording
High quality MPEG-4 studio profile compression
High quality audio recording: 12 channels, 24-bit audio at 48kHz in the HDCAM-SR format
Internal format conversion including up and down conversion, 4:4:4 to 4:2:2 conversion. 10 bit 4:2:2 and 4:4:4 recording. 12 x 24 bit audio channels. Down conversion and cross conversion to 4:2:2 and SDI.
Playback of Digital Beta cam format tapes
Long recording time on a single cassette of up to 155 minutes at 1080/24PsF
Frame accurate insert and assemble editing
Dynamic tracking playback
Dynamic Motion Control (DMC) playback
Selectable picture modes including squeeze, letter box and edge crop
Audio output channel routing: can route audio to any HD-SDI or SDI output
Off-speed playback capability
Built-in tele-file read/write capability
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.