Our last few experiments with playing video+audio on the ESP32-S3 involved converting an MP4 to MJpeg + MP3, where MJpeg is just a bunch of jpegs glued together in a file, and MP3 is what you expect. This works, but we maxed out at 10 or 12 fps on a 480x480 display. You must manage two files, and the FPS must be hardcoded. With this demo https://github.com/moononournation/aviPlayer we are using avi files with Cinepak https://en.wikipedia.org/wiki/Cinepak and MP3 encoding - a big throwback to when we played quicktime clips on our Centris 650. The decoding speed is much better, and 30 FPS is easily handled, so the tearing is not as visible. The decoder keeps up with the SD card file, so you can use long files. This makes the board a good option for props and projects where you want to play ~480p video clips with near-instant startup and want to avoid the complexity of running Linux on a Raspberry Pi + monitor + audio amp. The only downside right now is the ffmpeg cinepak encoder is reaaaaallly slooooow.
"Ancient Roman concretes have survived millennia, but mechanistic insights into their durability remain an enigma. Here, we use a multiscale correlative elemental and chemical mapping approach to investigating relict lime clasts, a ubiquitous and conspicuous mineral component associated with ancient Roman mortars. Together, these analyses provide new insights into mortar preparation methodologies and provide evidence that the Romans employed hot mixing, using quicklime in conjunction with, or instead of, slaked lime, to create an environment where high surface area aggregate-scale lime clasts are retained within the mortar matrix. Inspired by these findings, we propose that these macroscopic inclusions might serve as critical sources of reactive calcium for long-term pore and crack-filling or post-pozzolanic reactivity within the cementitious constructs. The subsequent development and testing of modern lime clast–containing cementitious mixtures demonstrate their self-healing potential, thus paving the way for the development of more durable, resilient, and sustainable concrete formulations."