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Formating comments and docs strings, fix clang Warnings

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Harshit-Dhanwalkar 2026-06-19 13:05:10 +05:30
parent af6841fcac
commit 7b39cd09c3
5 changed files with 23 additions and 66 deletions
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47
C/src/capture_windows.c
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@ -5,12 +5,6 @@
#include <stdlib.h>
#include <string.h>
// Media Foundation is the modern (post-Vista) successor to DirectShow for
// webcam capture on Windows; DirectShow is still around mainly for legacy
// filter graphs and is on Microsoft's "prefer Media Foundation for new code"
// list, so that's what this backend uses. It needs COM initialized and
// links against mfplat.lib, mf.lib, mfreadwrite.lib, mfuuid.lib, ole32.lib
// (see the Windows section added to the Makefile).
#include <mfapi.h>
#include <mferror.h>
#include <mfidl.h>
@ -21,12 +15,6 @@ struct webcam_impl {
IMFMediaSource *source;
IMFSourceReader *reader;
// The frame fetched by webcam_wait_frame() and consumed by
// webcam_capture_frame(). Media Foundation's ReadSample() call is itself
// blocking/synchronous when no async callback is configured, which maps
// naturally onto this project's wait/capture split: the actual blocking
// read happens in wait_frame, and capture_frame just drains whatever
// wait_frame already fetched.
IMFSample *pending_sample;
int com_initialized;
@ -48,9 +36,6 @@ static void release_pending_sample(struct webcam_impl *im) {
}
}
// Enumerate video capture devices and pick the one whose friendly name
// matches `device` (case-insensitive substring match), or the first device
// found if `device` is NULL. Mirrors capture_macos.c's localizedName match.
static IMFActivate *find_device(const char *device) {
IMFAttributes *attrs = NULL;
IMFActivate **devices = NULL;
@ -102,11 +87,7 @@ static IMFActivate *find_device(const char *device) {
return chosen;
}
// Walk the native media types on stream 0 and pick whichever is closest to
// the requested width/height, same "closest match" approach
// capture_macos.c uses for AVCaptureDeviceFormat. Webcams almost always
// offer NV12 natively; we ask for that explicitly via SetCurrentMediaType so
// the Y-plane copy below can assume it.
// Walk native media types on stream 0 and pick closest to requested width/height
static int negotiate_format(IMFSourceReader *reader, int want_w, int want_h,
int *out_w, int *out_h) {
IMFMediaType *best = NULL;
@ -142,10 +123,7 @@ static int negotiate_format(IMFSourceReader *reader, int want_w, int want_h,
if (!best)
return -1;
// Force NV12 output regardless of the native subtype the camera reports;
// the source reader's built-in video processor (MF_SOURCE_READER_ENABLE_
// VIDEO_PROCESSING) handles the conversion for us if the native format
// is something else (e.g. MJPG).
// Force NV12 output regardless of native subtype camera reports;
IMFMediaType *want_type = NULL;
if (FAILED(MFCreateMediaType(&want_type))) {
SAFE_RELEASE(best);
@ -240,11 +218,6 @@ fail:
int webcam_wait_frame(webcam_t *cam, int timeout_ms) {
struct webcam_impl *im = cam->impl;
// The synchronous reader doesn't take a timeout directly; ReadSample()
// blocks until a sample, error, or end-of-stream arrives. `timeout_ms` is
// accepted for interface parity with the V4L2/select()-based backend but
// isn't enforced here -- in practice a UVC camera that's actively
// streaming delivers samples well within any timeout this app uses.
(void)timeout_ms;
release_pending_sample(im);
@ -281,11 +254,6 @@ int webcam_capture_frame(webcam_t *cam, uint8_t *gray_buffer) {
return -1;
}
// NV12: the Y (luma) plane comes first, tightly packed at cam->width
// stride for the formats this app negotiates -- if a given driver hands
// back a padded stride, IMF2DBuffer::Lock2D below would be the correct
// way to get the real stride, but plain Lock() with width-sized rows
// covers the overwhelming majority of UVC cameras.
size_t plane_size = (size_t)cam->width * (size_t)cam->height;
if ((size_t)cur_len >= plane_size)
memcpy(gray_buffer, data, plane_size);
@ -322,19 +290,8 @@ void webcam_cleanup(webcam_t *cam) {
cam->buffer = NULL;
}
// ---------------------------------------------------------------------------
// Hardware controls: not implemented on Windows yet.
//
// The real equivalents exist (IAMCameraControl for exposure, IAMVideoProcAmp
// for contrast/white-balance, both reachable off the IMFMediaSource via
// IMFGetService::GetService(..., MF_PROXY_PLAYER, IID_IAMCameraControl,...)-
// style queries since these are DirectShow-era COM interfaces that MF
// sources still expose for backward compatibility), but that's a separate
// chunk of COM plumbing from frame capture, so left as a follow-up rather
// than bolted on here speculatively/untested.
// TODO: implement via IAMCameraControl / IAMVideoProcAmp.
// ---------------------------------------------------------------------------
int webcam_set_auto_exposure(webcam_t *cam, int enable) {
(void)cam;
(void)enable;