feature/video-frame-rate #98

Merged
cameron merged 3 commits from feature/video-frame-rate into master 2026-05-18 00:09:36 +00:00
2 changed files with 74 additions and 14 deletions
Showing only changes of commit bd61e10158 - Show all commits

9
.gitattributes vendored Normal file
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@@ -0,0 +1,9 @@
# Normalize line endings in the repo to LF. Windows checkouts can still
# present working-copy files as CRLF; this just keeps the committed history
# stable so contributors on any OS don't see whitespace-only diffs every
# time someone touches a file.
* text=auto eol=lf
# Migrations and SQL must be LF — SQLite parsers don't care, but diffing
# is much cleaner with stable endings.
*.sql text eol=lf

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@@ -133,6 +133,21 @@ pub struct VideoStreamMeta {
pub frame_rate: Option<f32>,
}
/// Parse ffprobe's rational frame-rate strings (`"30000/1001"`,
/// `"60/1"`, `"0/0"`). Rejects 0/0 (ffprobe's "unknown" sentinel),
/// non-positive results, and anything wildly out of range so a malformed
/// probe can't poison the scrubber's step size.
fn parse_ffprobe_rational(s: &str) -> Option<f32> {
let (num, den) = s.split_once('/')?;
let num: f32 = num.parse().ok()?;
let den: f32 = den.parse().ok()?;
if den.abs() < f32::EPSILON {
return None;
}
let v = num / den;
(v.is_finite() && v > 0.0 && v < 1000.0).then_some(v)
}
/// Probe video stream metadata in one ffprobe call. Returns default (codec
/// unknown, rotation 0, fps None) on any failure — callers fall back to
/// transcoding / a default framerate.
@@ -198,27 +213,15 @@ pub async fn probe_video_stream_meta(video_path: &str) -> VideoStreamMeta {
// ffprobe reports frame rates as rational strings like "30000/1001".
// Prefer avg_frame_rate (handles VFR) and fall back to r_frame_rate.
// Reject 0/0 (unknown), negative numbers, and anything wildly out of
// range so a malformed probe can't poison the scrubber's step size.
let parse_rational = |s: &str| -> Option<f32> {
let (num, den) = s.split_once('/')?;
let num: f32 = num.parse().ok()?;
let den: f32 = den.parse().ok()?;
if den.abs() < f32::EPSILON {
return None;
}
let v = num / den;
(v.is_finite() && v > 0.0 && v < 1000.0).then_some(v)
};
let frame_rate = stream
.get("avg_frame_rate")
.and_then(|v| v.as_str())
.and_then(parse_rational)
.and_then(parse_ffprobe_rational)
.or_else(|| {
stream
.get("r_frame_rate")
.and_then(|v| v.as_str())
.and_then(parse_rational)
.and_then(parse_ffprobe_rational)
});
debug!(
@@ -820,3 +823,51 @@ impl Handler<GeneratePreviewClipMessage> for PreviewClipGenerator {
})
}
}
#[cfg(test)]
mod tests {
use super::parse_ffprobe_rational;
#[test]
fn parses_common_rational_framerates() {
// NTSC 29.97 fps
assert!((parse_ffprobe_rational("30000/1001").unwrap() - 29.970_03).abs() < 1e-3);
// Plain integer fps
assert!((parse_ffprobe_rational("30/1").unwrap() - 30.0).abs() < 1e-6);
assert!((parse_ffprobe_rational("60/1").unwrap() - 60.0).abs() < 1e-6);
// iPhone slow-mo
assert!((parse_ffprobe_rational("240/1").unwrap() - 240.0).abs() < 1e-6);
}
#[test]
fn rejects_ffprobe_unknown_sentinel() {
// 0/0 is ffprobe's way of saying "I don't know" — must not be
// interpreted as 0 fps.
assert_eq!(parse_ffprobe_rational("0/0"), None);
}
#[test]
fn rejects_malformed_input() {
assert_eq!(parse_ffprobe_rational(""), None);
assert_eq!(parse_ffprobe_rational("30"), None);
assert_eq!(parse_ffprobe_rational("/1"), None);
assert_eq!(parse_ffprobe_rational("30/"), None);
assert_eq!(parse_ffprobe_rational("abc/def"), None);
}
#[test]
fn rejects_non_positive_results() {
// Negative numerator -> negative fps; meaningless.
assert_eq!(parse_ffprobe_rational("-30/1"), None);
// Zero numerator -> zero fps; also meaningless for frame stepping.
assert_eq!(parse_ffprobe_rational("0/1"), None);
}
#[test]
fn rejects_out_of_range() {
// Anything > 1000 fps is almost certainly garbage probe output,
// not a real source. (Real high-speed capture maxes near 1 kHz.)
assert_eq!(parse_ffprobe_rational("999999/1"), None);
}
}