mirror of
https://github.com/Abdess/retroarch_system.git
synced 2026-10-10 13:33:24 -05:00
66 lines
3.5 KiB
YAML
66 lines
3.5 KiB
YAML
emulator: video_processor
|
|
type: utility
|
|
core_classification: pure_libretro
|
|
source: "https://github.com/libretro/libretro-video-processor"
|
|
source_mirror: "https://git.libretro.com/libretro/libretro-video-processor"
|
|
upstream: "https://github.com/jaredmcneill/libretro-v4l2"
|
|
author: "Jared McNeill"
|
|
profiled_date: "2026-09-17"
|
|
source_commit: "8fe4751f0039a1b645bf750531fcfc234958a7ac"
|
|
upstream_commit: "c608ced893583e0a8a8153890f99453fd1647d53"
|
|
core_version: "0.0.2"
|
|
display_name: "Video Processor (V4L2)"
|
|
cores:
|
|
- video_processor
|
|
systems: []
|
|
|
|
notes: |
|
|
Capture core for V4L2 devices: a console plugged into a capture card is
|
|
shown through the frontend so its scalers and shaders apply to the signal.
|
|
The core opens the capture device, requests RGB24 and two mmap buffers,
|
|
and converts each dequeued frame to RGB565 for the video callback. Audio
|
|
comes from an ALSA capture PCM opened at 48 kHz, S16_LE, two channels, and
|
|
is read from the frontend audio callback. There is no emulation, no state
|
|
to serialize and no memory map.
|
|
ref: video_processor_v4l2.c:299-419, video_processor_v4l2.c:492-529,
|
|
video_processor_v4l2.c:531-544, video_processor_v4l2.c:554-698
|
|
|
|
Both devices are picked from core options built in retro_set_environment.
|
|
The video list comes from a udev enumeration of the video4linux subsystem
|
|
filtered on the /dev/video prefix, or from a fixed /dev/video0 to
|
|
/dev/video3 list when libudev is not compiled in. The audio list comes from
|
|
the ALSA PCM hints whose IOID is Input and whose name starts with hw: or
|
|
default:. These are device nodes and PCM names, not files: nothing is read
|
|
from the system directory, no path is built and no file is opened. The
|
|
content handed to retro_load_game is not looked at either: valid_extensions
|
|
is NULL, need_fullpath is false and the core never declares no-content
|
|
support, so the frontend still asks for a file whose bytes are ignored.
|
|
ref: video_processor_v4l2.c:140-205, video_processor_v4l2.c:208-242,
|
|
video_processor_v4l2.c:244-268, video_processor_v4l2.c:448-455
|
|
|
|
The frame rate is the frameperiod of the active V4L2 standard and the
|
|
pixel aspect comes from VIDIOC_CROPCAP; retro_get_region reports NTSC when
|
|
the standard carries the NTSC bit and PAL otherwise. A device that does not
|
|
enumerate its active standard makes retro_load_game fail.
|
|
ref: video_processor_v4l2.c:457-480, video_processor_v4l2.c:593-617,
|
|
video_processor_v4l2.c:728-731
|
|
|
|
Linux only, through linux/videodev2.h. libv4l2, ALSA and libudev are each
|
|
autodetected by the Makefile and dropped when their header is missing;
|
|
without libv4l2 the raw ioctl path is used and the format conversion the
|
|
library provides is lost. The GitLab CI installs the three development
|
|
packages, and the buildbot binary for linux x86_64 links libv4l2.so.0,
|
|
libasound.so.2 and libudev.so.1. RetroArch also compiles a diverged copy of
|
|
this core into its own binary under cores/libretro-video-processor when
|
|
HAVE_VIDEOPROCESSOR is set; that copy declares no-content support and adds
|
|
capture and output mode options, and opens the same device nodes only.
|
|
ref: video_processor_v4l2.c:45-57, Makefile:107-124
|
|
|
|
Written by Jared McNeill in July 2016 as libretro-v4l2. The libretro fork
|
|
carries the author's last commits, the audio batch callback and the ALSA
|
|
overrun recovery, then the 2026 CI and dependency autodetection change; the
|
|
original repository stopped at the RGB24 conversion commit.
|
|
|
|
files: []
|
|
source_ref: "video_processor_v4l2.c:27-28, .gitlab-ci.yml:19"
|