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refactor goto-functions to draw frame too
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@wong-justin
wong-justin committed Oct 15, 2024
1 parent 9e2d9f4 commit 72a0087
Showing 1 changed file with 62 additions and 74 deletions.
136 changes: 62 additions & 74 deletions src/main.rs
View file
Original file line number Diff line number Diff line change
Expand Up @@ -488,7 +488,7 @@ impl FrameIterator {
return view_string;
}

fn skip_some_frames(&mut self, num_frames: u32) {
fn skip_some_frames(&mut self, num_frames: u32) -> String {
// When you only want to advance a few frames,
// without spawning a new ffmpeg process,
// but also without calling chafa.draw each frame as you would in loop { take_frame() }
Expand All @@ -498,16 +498,17 @@ impl FrameIterator {
for _ in 0..num_frames {
self.stdout.read_exact(&mut self.pixel_buffer);
}
return self.take_frame();
}

fn goto_timestamp(&mut self, timestamp: SecondsFloat) -> Result<(), Box<dyn Error>> {
fn goto_timestamp(&mut self, timestamp: SecondsFloat) -> Result<String, Box<dyn Error>> {
// Start new process at any position in video.
// This should be faster than reading far ahead in the old process,
// and this enables "backward seeking" too.

let new_stdout = FrameIterator::_create_decoding_process(&self.video_path, timestamp)?;
self.stdout = new_stdout;
Ok(())
Ok(self.take_frame())
}
}

Expand Down Expand Up @@ -705,11 +706,9 @@ fn init() -> Result<Model, String> {
// --- UPDATE --- //

fn update(m: &mut Model, terminal_event: Event) -> UpdateResult {

m.needs_to_clear = false;
match terminal_event {
Event::Key(keyevent) => {

if (keyevent.modifiers == KeyModifiers::CONTROL && keyevent.code == KeyCode::Char('c'))
|| keyevent.code == KeyCode::Char('q')
{
Expand Down Expand Up @@ -744,7 +743,53 @@ fn update(m: &mut Model, terminal_event: Event) -> UpdateResult {
return UpdateResult::Continue;
}

// --- find the next frame number to render --- //
let whole_elapsed_frames = frames_since_prev_instant(m);
let is_too_fast = whole_elapsed_frames == 0;
match is_too_fast {
true => {
// slow down by not drawing anything during this tick
m.prev_instant = now;
return UpdateResult::Continue;
},
false => {
// now we know the next frame number to render
m.frame = m.frame_iterator.skip_some_frames(whole_elapsed_frames - 1);
m.frame_number += whole_elapsed_frames as u32;
}
}

// --- update stats --- //

let time_to_update_fps =
m.frame_iterator.num_frames_rendered % NUM_FRAMES_TO_TRACK_FPS as u32 == 0;
if time_to_update_fps {
let recent_time_elapsed: SecondsFloat = (now - m.last_fps_check).as_secs_f64();
m.recent_fps = Some(NUM_FRAMES_TO_TRACK_FPS as f64 / recent_time_elapsed);
m.last_fps_check = now;
} else {
// Either too early and not enough recent data,
// or waiting for next moment to check fps.
// No need to constantly update fps every frame.
}

let time_to_log = m.frame_iterator.num_frames_rendered % 100 == 1;
if time_to_log {
log::info!(
"{:?} {:?} {:?} {:?}",
now - m.start,
m.prev_instant,
m.frame_iterator.num_frames_rendered,
m.frame_number
);
}

m.prev_instant = now;
return UpdateResult::Continue;
}

fn frames_since_prev_instant(m: &mut Model) -> u32 {
// find how many frames elapsed since last tick,
// and modify leftover time

// example converting elapsed ms to elapsed frames:
//
Expand All @@ -758,6 +803,7 @@ fn update(m: &mut Model, terminal_event: Event) -> UpdateResult {
// rounding_err = ---------- * --------- = 0.007 seconds
// 30 frames
//
let now = std::time::Instant::now();
let elapsed_secs = (now - m.prev_instant).as_secs_f64();

// how many frames should have passed since last tick; sometimes 0, usually 1 or more
Expand All @@ -769,6 +815,7 @@ fn update(m: &mut Model, terminal_event: Event) -> UpdateResult {
let rounding_err: SecondsFloat =
elapsed_secs - (whole_elapsed_frames as f64 * m.VIDEO_METADATA.seconds_per_frame);
m.accumulated_time += rounding_err;

let need_leap_frame = m.accumulated_time > m.VIDEO_METADATA.seconds_per_frame;
if need_leap_frame {
whole_elapsed_frames += 1;
Expand All @@ -781,57 +828,7 @@ fn update(m: &mut Model, terminal_event: Event) -> UpdateResult {
// extra_time,
// m.accumulated_time);

// TODO:
// cap fps if we're rendering too quickly.
// i think we should choose to save CPU by capping at decent framerate
// than to be faithful to high fps and use extra CPU
// aka
// if < 15 ms elapsed, that means we're getting +60 fps
// so probably better skip rendering at this moment and save some CPU cycles
// and still get smooth 30fps,
// than overuse CPU to get more than is necessary
// aka
// let is_too_fast = immediate_fps > min(m.VIDEO_METADATA.fps, 30fps) || elapsed_frames == 0

let is_too_fast = whole_elapsed_frames == 0;
if is_too_fast {
// slow down by not drawing anything during this tick
m.prev_instant = now;
return UpdateResult::Continue;
}

// now we know the next frame number to render
m.frame_iterator.skip_some_frames(whole_elapsed_frames - 1);
m.frame = m.frame_iterator.take_frame();
m.frame_number += whole_elapsed_frames as u32;

// --- update stats --- //

let time_to_update_fps =
m.frame_iterator.num_frames_rendered % NUM_FRAMES_TO_TRACK_FPS as u32 == 0;
if time_to_update_fps {
let recent_time_elapsed: SecondsFloat = (now - m.last_fps_check).as_secs_f64();
m.recent_fps = Some(NUM_FRAMES_TO_TRACK_FPS as f64 / recent_time_elapsed);
m.last_fps_check = now;
} else {
// Either too early and not enough recent data,
// or waiting for next moment to check fps.
// No need to constantly update fps every frame.
}

let time_to_log = m.frame_iterator.num_frames_rendered % 100 == 1;
if time_to_log {
log::info!(
"{:?} {:?} {:?} {:?}",
now - m.start,
m.prev_instant,
m.frame_iterator.num_frames_rendered,
m.frame_number
);
}

m.prev_instant = now;
return UpdateResult::Continue;
return whole_elapsed_frames;
}

fn toggle_paused(m: &mut Model) {
Expand All @@ -847,12 +844,14 @@ fn toggle_controls_visibility(m: &mut Model) {
m.needs_to_clear = true; // controls will still show at bottom unless cleared/drawn over
}

// note: any function that modifies playerhead position aka m.frame_number in Segment mode
// must check if segment number has changed

fn seek_backwards_15s(m: &mut Model) {
let frames_to_backtrack = (m.VIDEO_METADATA.fps * 15.0) as u32;
m.frame_number = std::cmp::max(m.frame_number as i32 - frames_to_backtrack as i32, 0) as u32;
let timestamp = m.frame_number as SecondsFloat / m.VIDEO_METADATA.fps;
m.frame_iterator.goto_timestamp(timestamp).unwrap();
m.frame = m.frame_iterator.take_frame();
m.frame = m.frame_iterator.goto_timestamp(timestamp).unwrap();

// TODO: update current segment
// let old_position = m.hovering.position;
Expand All @@ -864,8 +863,7 @@ fn seek_forwards_15s(m: &mut Model) {
let frames_to_skip = (m.VIDEO_METADATA.fps * 15.0) as u32;
m.frame_number += frames_to_skip;
let timestamp = m.frame_number as SecondsFloat / m.VIDEO_METADATA.fps;
m.frame_iterator.goto_timestamp(timestamp).unwrap();
m.frame = m.frame_iterator.take_frame();
m.frame = m.frame_iterator.goto_timestamp(timestamp).unwrap();

// TODO: update current segment
// let upcoming_markers =
Expand All @@ -889,8 +887,7 @@ fn goto_prev_marker(m: &mut Model) {
};
let timestamp: SecondsFloat = m.markers[new_position as usize];
m.frame_number = (timestamp * m.VIDEO_METADATA.fps) as u32;
m.frame_iterator.goto_timestamp(timestamp).unwrap();
m.frame = m.frame_iterator.take_frame();
m.frame = m.frame_iterator.goto_timestamp(timestamp).unwrap();
m.paused = true;
}
}
Expand All @@ -917,16 +914,14 @@ fn goto_next_marker(m: &mut Model) {
};
let timestamp: SecondsFloat = m.markers[new_position];
m.frame_number = (timestamp * m.VIDEO_METADATA.fps) as u32;
m.frame_iterator.goto_timestamp(timestamp).unwrap();
m.frame = m.frame_iterator.take_frame();
m.frame = m.frame_iterator.goto_timestamp(timestamp).unwrap();
m.paused = true;
}
};
}

fn create_marker(m: &mut Model) {
// create new marker at current timestamp
//
match m.hovering.mode {
HoverMode::Markers => (),
HoverMode::Segments => {
Expand All @@ -939,7 +934,6 @@ fn create_marker(m: &mut Model) {

fn delete_marker(m: &mut Model) {
// delete current marker and enter segments mode
//
match m.hovering.mode {
HoverMode::Segments => (),
HoverMode::Markers => {
Expand All @@ -953,18 +947,12 @@ fn advance_one_frame(m: &mut Model) {
match m.paused {
false => (),
true => {
m.frame = m.frame_iterator.take_frame();
m.frame = m.frame_iterator.skip_some_frames(1);
m.frame_number += 1;
}
}
}







// --- VIEW --- //

fn format_secs_to_mm_ss(seconds: SecondsFloat) -> String {
Expand Down

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