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Video Capture Details - DV Terms and Concepts Explained
DV
DV is an acronym for Digital Video. DV is a well defined standard which enables DV compatible devices to transmit and receive movies.
Resolution
The resolution of DV movies are fixed to the following sizes:
Format | Resolution |
PAL | 720 x 576 |
NTSC | 720 x 480 |
Frame Rate
DV uses the following frame rates:
Format | Frames Per Second |
PAL | 25 |
NTSC | 29.97 |
Video Compression
DV uses a lossy form of compression for reducing the size of the video stored in the file. The video is compressed to around a fifth of its original size (5:1 compression). The compression algorithm is similar to MJPEG, with each frame being compressed individually.
Audio Settings
DV audio can have 1 or 2 audio channels and the sample rate is either 32 KHz or 48 KHz. The relationship is shown in the table below:
Number of Channels | Sample Rate |
1 | 48 KHz stereo |
2 | 32 KHz stereo |
These combinations are fixed (ie. it is not possible to have 2 channel 48 KHz or 1 channel 32 KHz). The audio remains uncompressed.
When you capture 32 KHz audio from a DV source, Capture only captures the audio from the first channel. Capture does not support capturing audio from the second channel.
Data Rate
DV is transferred at a constant 3.6 MB per second, for both PAL and NTSC formats. The audio settings do not change the data rate.