Autor: Redaktion

AVC Intra (P2HD)

The P2 card system (P2 HD) was introduced by Panasonic in 2004.

It features in a wide range of cameras, recorders and accessories. The memory cards are a RAID of four SD cards housed in a PCMCIA enclosure. The capacity of the cards is usually between 32 and 64GB, but for recording AVC Ultra and 4K there is also a 256GB card available.

The P2 system offers multiple memory slots in all P2-enabled cameras, this allows the camera to continuously record, using a number of P2 cards. Once one card is full the camera starts recording on the next, rather than halting the recording. This makes it possible to change memory cards during operation. Mixing recording formats on the same card is also possible.

The P2 cards do not need any proprietary drives to backup P2 media. A computer with a PCMCIA interface (and freely available Panasonic P2 drivers) will recognise a P2 card as a removable drive, allowing rushes to be copied or backed up or for immediate editing, working directly from the card. These characteristics make the format used primarily for news gathering applications.

The P2 name actually describes the storage medium. In theory, there are no restrictions on the format or image quality of the video. The P2 card stores data from a P2-compatible camera in the codec(s) available on that camera. The video, audio and associated metadata are then wrapped in an industry-standard MXF OP1a container.

Panasonic uses several different codecs in its range of P2 cameras. The specific codecs available will differ depending on the camera model. Typically the DVCPRO family, which are a legacy SD format, and the newer AVC-Intra (50/100) codecs are used. The Panasonic-specific codec is based on MPEG-4 / Part 10 for the recording of HD material with a 10 bit signal and colour sub-sampling of 4:2:2. The "Intra" indicates that this codec generates individually encoded I-frames in contrast to the GOP (Group of Pictures) generated by inter-frame codecs such as XDCAM HD .

The latest generation of the Panasonic AVC video codec is AVC Ultra. This is an extension of the  large family of codecs based on MPEG-4 / Part 10. These include the variants AVC 444, AVC Intra 50/100/200, AVC LongG 50, AVC LongG 25 and AVC proxy. It is worth noting that the prosumer AVCHD format is not part of the Ultra family. The colour sub-sampling of 4:2:0 found in in AVC-Intra 50 in not recommended for professional use due to the loss of delivery quality in mainstream platforms.

AVC-Intra 100 and 200 codecs are well suited for professional usage. The image quality is equivalent to that of the Sony XDCAM HD422 format, with the AVC-Intra 200 codec offeing an almost doubled data rate and is designed for use with frame rates higher than 25p (eg 1080p / 50). The Long-GOP and proxy format are provided for lower-cost workflows and web applications. The AVC-Intra format can be imported into all major editing and post production systems and can be processed natively. 

AVC Intra (P2HD) Summary

Mastering AVC Intra UT

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