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Project Eideticker: Difference between revisions
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→Initial prototype
(→Initial prototype: Link to primer on DeckLink cards) |
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Code (and installation/usage docs): https://github.com/markrcote/eideticker | Code (and installation/usage docs): https://github.com/markrcote/eideticker | ||
See the [[Project_Eideticker/DeckLink_Primer|primer]] on Blackmagic DeckLink cards for information on their capabilities and notes on installation, use, and application development. | |||
=== | === Status === | ||
* | * Captures 1080p60 output from the LG phone at 8-bit YUV 4:2:2 to a raw video file. | ||
* | * Transforms raw video into a compressed AVI and a zipped archive of PNG images, one per frame. | ||
* | * Controlled by a web interface, which can also serve the capture files. | ||
* Unable to use the DeckLink with the Transformer since the latter does not output at a broadcast standard. I believe it outputs at its screen resolution (1280x800). | |||
=== The Phone === | |||
* | * Its screen is 480x800, but there is no option to output at this resolution on the HDMI port. A variety of standard formats are available. | ||
* | * It must be scaling (and potentially converting) the output at some level below the application layer. | ||
=== Issues and Concerns === | |||
* Full RGB capture appears to be impossible. As noted in the [[Project_Eideticker/DeckLink_Primer|primer]], the DeckLink card ''cannot'' capture 8-bit nor 10-bit RGB at 1080p60, nor can it capture 8-bit RGB at 720p60. It ''can'' supposedly capture 10-bit RGB at 720p60; however, when in this mode the card cannot find an input source when the phone is connected and outputting at 720p. Perhaps the card itself is outputting at YUV 4:2:2, if that's possible. | |||
* Full screen resolution also appears to be impossible. The phone's screen is 800 pixels high, but the HDMI output is restricted to HDMI standards (1080, 720, etc.). Furthermore the card can only capture broadcast standards, even if the phone could output at 800 pixels (as the Transformer appears to). | |||
* | * Thus an exact 1:1 mapping of the pixels of the captured output to the pixels calculated and displayed to the phone's screen is not possible with the current hardware configuration. I am uncertain of the exact ramifications of this on the project's goals, but there are probably some tasks that can be accomplished even with this inexact capture of screen output. | ||
** Theoretically an HDMI-capable device with a screen exactly 720 or 1080 pixels high (or wide) should output a pixel-by-pixel match. Alternatively, there may exist capture cards that can capture at any resolution, which would have to be paired with a device that can output at exactly its screen's resolution (e.g. potentially the Transformer but not the LG). | ** Theoretically an HDMI-capable device with a screen exactly 720 or 1080 pixels high (or wide) should output a pixel-by-pixel match. Alternatively, there may exist capture cards that can capture at any resolution, which would have to be paired with a device that can output at exactly its screen's resolution (e.g. potentially the Transformer but not the LG). | ||
** Alternatively, perhaps it would be possible to hack a device to treat its HDMI output as primary. | ** Alternatively, perhaps it would be possible to hack a device to treat its HDMI output as primary. | ||
* | * At 1080p YUV 4:2:2, there is no frame skipping. However disk speed could become an issue if we somehow manage to capture full RGB output. | ||
** This shouldn't be an issue with a sufficiently fast disk. | ** This shouldn't be an issue with a sufficiently fast disk. | ||
** Also, perhaps a custom app could record only the pixels of interest, since most of each frame is black. There would probably be a CPU-disk speed tradeoff here. | ** Also, perhaps a custom app could record only the pixels of interest, since most of each frame is black. There would probably be a CPU-disk speed tradeoff here. | ||