snapsy wrote: Daran wrote: snapsy wrote: docusync wrote: dclark wrote: docusync wrote:
I'm wondering why no camera manufacturer offers RAID0-like card access? Of course not on the sector level but on the file level. I.e. odd files go on the card 1 and even files go on the card 2. Even if you lose a card - you'd still have half of your files. That would reduce the image dump time in half.
That would help image write time only if it is limited by card bandwidth, not camera electronic processing. It appears to be limited by camera electronics ability to process files not the card's bandwidth..
I'm not sure, but I thought the files are already processed (in the manufacturer-specific raw format) when they get into the buffer, no? If we're dealing with a slow system bus, then switching to the CFeA 4.0 cards won't make any difference
There is a long image pipeline the raw sensor data has to undergo before it becomes a fully-formed image read for writing. This includes the various flavors of noise reduction (spatial filtering, impulse noise removal), WB scaling, PDAF pixel interpolation, pixel remapping interpolation, etc... and that's just the raw bayered data. Even raws then undergo the full debayered pipeline since they all included embedded jpgs. For a general idea of what this pipeline entails here's the documentation of RawTherapee's pipeline:
Think about how long it takes for a computer-based raw processor to render a single raw image and then multiply that by a camera's continuous frame rate and you'll get a sense for how computationally and data intensive the specialized imaging ASICs in cameras are, and why they are often the bottleneck in buffer clearing performance.
Be that as it may, it seems to me that for lossy compressed images the A1 is pretty much done processing after pushing the image into the buffer. So buffer clearing speed should benefit. And like docusync suggested it would provide some level of data loss protection for weirdos like me who shoot practically everything in bursts, without requiring extra hardware nor consuming extra space.
Can you describe what observation can be made to establish that the A1 is done processing after pushing the sensor data into the buffer? For reference the A1 reads out at 1/256, so fully processing an image in 3.9ms with all the image processing steps that requires doesn't seem plausible.
A1 readout is the time required to digitize all the sensor pixels and get the data into memory that is in the stacked electronics, it is not the time required to move the data to the buffer which is much longer. If it could move the data to the buffer in 1/256 sec it could run at 256 fps until the buffer was full. We have pretty strong evidence that the A1 stores the frame data in the buffer after it has been compressed since the buffer capacity in greater in the lossy compressed mode than it is for uncompressed frames (see the linked thread page 1, #1). That does not mean all the other stuff that needs to be done has been completed by the time the frame is in the buffer but the lossy compression has been completed.
snapsy wrote: Daran wrote: snapsy wrote: docusync wrote: dclark wrote: docusync wrote:
I'm wondering why no camera manufacturer offers RAID0-like card access? Of course not on the sector level but on the file level. I.e. odd files go on the card 1 and even files go on the card 2. Even if you lose a card - you'd still have half of your files. That would reduce the image dump time in half.
That would help image write time only if it is limited by card bandwidth, not camera electronic processing. It appears to be limited by camera electronics ability to process files not the card's bandwidth..
I'm not sure, but I thought the files are already processed (in the manufacturer-specific raw format) when they get into the buffer, no? If we're dealing with a slow system bus, then switching to the CFeA 4.0 cards won't make any difference
There is a long image pipeline the raw sensor data has to undergo before it becomes a fully-formed image read for writing. This includes the various flavors of noise reduction (spatial filtering, impulse noise removal), WB scaling, PDAF pixel interpolation, pixel remapping interpolation, etc... and that's just the raw bayered data. Even raws then undergo the full debayered pipeline since they all included embedded jpgs. For a general idea of what this pipeline entails here's the documentation of RawTherapee's pipeline:
Think about how long it takes for a computer-based raw processor to render a single raw image and then multiply that by a camera's continuous frame rate and you'll get a sense for how computationally and data intensive the specialized imaging ASICs in cameras are, and why they are often the bottleneck in buffer clearing performance.
Be that as it may, it seems to me that for lossy compressed images the A1 is pretty much done processing after pushing the image into the buffer. So buffer clearing speed should benefit. And like docusync suggested it would provide some level of data loss protection for weirdos like me who shoot practically everything in bursts, without requiring extra hardware nor consuming extra space.
Can you describe what observation can be made to establish that the A1 is done processing after pushing the sensor data into the buffer? For reference the A1 reads out at 1/256, so fully processing an image in 3.9ms with all the image processing steps that requires doesn't seem plausible.
A1 readout is the time required to digitize all the sensor pixels and get the data into a memory that is in the stacked electronics, it is not the time required to move the data to the buffer which is much longer. If it could move the data to the buffer in 1/256 sec it could run at 256 fps until the buffer was full. We have pretty strong evidence that the A1 stores the frame data in the buffer after it has been compressed since the buffer capacity in greater in the lossy compressed mode than it is for uncompressed frames (see the linked thread page 1, #1). That does not mean all the other stuff that needs to be done has been completed by the time the frame is in the buffer but the lossy compression has been completed.
May 16, 2024 at 01:56 PM
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