I am puzzled about the actual operation of digital video cameras. It is clear that some consumer models can now record HD at 720p and 1080p resolutions, and I have used a small camcorder (Zoom Q2HD) to record at high resolution.
Calculating the pixel processing rates suggests very high internal data rates and very significant storage would be required even for video lasting only one minute - storage in the range of several Gbytes. We know that the output file formats are typically compressed, which gets the storage and data rate requirements down, but I think some cameras may have an internal format which is intermediate between the raw pixel rate and any possible output format. Maybe I'm wrong!
For still cameras, many now record, or are capable of recording, in RAW formats, and the RAW formats take up considerably more storage than compressed formats such as MPEG.
Doing web searches to find out what really goes on in video cameras is, perhaps not too surprisingly, unhelpful, as mostly the results are far too simple. Even if cameras can and do go quickly from pixel scanning to a compressed storage format, there must surely be some very fast proessing to make that possible. I suspect that at least one intermediate data form is used as otherwise I don't see how the cameras could operate at the resolutions and scan rates which they clearly do.
Does anyone here know? Are there any useful references?
Calculating the pixel processing rates suggests very high internal data rates and very significant storage would be required even for video lasting only one minute - storage in the range of several Gbytes. We know that the output file formats are typically compressed, which gets the storage and data rate requirements down, but I think some cameras may have an internal format which is intermediate between the raw pixel rate and any possible output format. Maybe I'm wrong!
For still cameras, many now record, or are capable of recording, in RAW formats, and the RAW formats take up considerably more storage than compressed formats such as MPEG.
Doing web searches to find out what really goes on in video cameras is, perhaps not too surprisingly, unhelpful, as mostly the results are far too simple. Even if cameras can and do go quickly from pixel scanning to a compressed storage format, there must surely be some very fast proessing to make that possible. I suspect that at least one intermediate data form is used as otherwise I don't see how the cameras could operate at the resolutions and scan rates which they clearly do.
Does anyone here know? Are there any useful references?