Pivid development notes and links

Raspberry Pi specifics

All about accelerated video on the Raspberry Pi - my notes
kernel.org: V3D Graphics Driver - RPi 4 GPU kernel driver docs
rpi kernel source: drivers/gpu/drm/vc4 - RPi 2D GPU kernel driver
rpi kernel source: drivers/gpu/drm/v3d - RPi 4 3D GPU kernel driver
rpi kernel source: include/uapi/v3d_drm.h - ioctls for RPi 3D driver
Blog post: Exploring Hardware Compositing With the Raspberry Pi - nice hardware video scaler walkthrough

Wikipedia: Direct Rendering Manager - a decent overview
Blog post: "From pre-history to beyond the global thermonuclear war" - Linux graphics history
LWN article: Atomic mode setting design overview - the current KMS API
Man page: Direct Rendering Manager - Kernel Mode-Setting - incomplete but helpful
Man page: Direct Rendering Manager - Memory Management - incomplete but helpful
kernel.org: Linux GPU Driver Userland Interfaces - basic notes on the kernel/user interface
kernel.org: KMS Properties - exhaustive object property list
kernel source: include/uapi/drm/drm.h and drm_mode.h - kernel/user headers
kernel source: include/drm/drm_print.h - debugging definitions
ST Micro: DRM/KMS Overview - decent general docs from a chip vendor
ST Micro: How to trace and debug the framework - an especially useful section
libdrm - library wrapper; see xf86drm.h and xf86drmMode.h (not X-specific despite "xf86")
libgbm - GPU allocation helper library; see gbm.h
modetest - command line tool (in the libdrm-tests Debian package)
kmscube - oft-referenced KMS/GL example program
kms++ - C++ KMS wrapper & utilities

kernel.org: Buffer Sharing and Synchronization - kernel buffer management (and user interface)
kernel.org: Linux GPU Memory Management - PRIME buffer sharing - exporting GPU buffers as "dma-bufs"
kernel.org: Video for Linux - Streaming I/O (DMA buffer importing) - using "dma-buf" objects in V4L2
hello_drmprime - nice example of hardware H.264/H.265 sending to DRM/KMS with zero copy

libav - video processing libraries ffmpeg, including encoding and decoding
rpi-ffmpeg - branch of ffmpeg and libav with Raspberry Pi hardware support (via V4L2)
kernel.org: Video for Linux API - kernel/user interface
github issue: Keeping buffers allocated by h264_v4l2m2m - issues with "buffer stealing" from libav decoders