HEVC-TS transmuxing display window

[avelad]

What version of Hls.js are you using?

1.6.7

What browser (including version) are you using?

Safari 18.5

What OS (including version) are you using?

macOS

Test stream

Rob has it, but it's private

Configuration

{}

Additional player setup steps

No response

Checklist

• The issue observed is not already reported by searching on Github under https://github.com/video-dev/hls.js/issues
• The issue occurs in the stable client (latest release) on https://hlsjs.video-dev.org/demo and not just on my page
• The issue occurs in the latest client (main branch) on https://hlsjs-dev.video-dev.org/demo and not just on my page
• The stream has correct Access-Control-Allow-Origin headers (CORS)
• There are no network errors such as 404s in the browser console when trying to play the stream

Steps to reproduce

1. Load the stream

Expected behaviour

The stream is rendered correctly

What actually happened?

The stream displays correctly in Chrome/Edge/Opera, but in Safari the stream is cut off:
Chrome:

Safari:

By changing the hls.js code, it seems to render correctly, but I'm no expert on this...

diff --git a/src/demux/video/hevc-video-parser.ts b/src/demux/video/hevc-video-parser.ts
index 485ee85c6..c078afd79 100644
--- a/src/demux/video/hevc-video-parser.ts
+++ b/src/demux/video/hevc-video-parser.ts
@@ -516,10 +516,10 @@ class HevcVideoParser extends BaseVideoParser {
       eg.readBoolean(); // frame_field_info_present_flag
       default_display_window_flag = eg.readBoolean();
       if (default_display_window_flag) {
-        pic_left_offset += eg.readUEG();
-        pic_right_offset += eg.readUEG();
-        pic_top_offset += eg.readUEG();
-        pic_bottom_offset += eg.readUEG();
+        eg.readUEG();
+        eg.readUEG();
+        eg.readUEG();
+        eg.readUEG();
       }
       const vui_timing_info_present_flag = eg.readBoolean();
       if (vui_timing_info_present_flag) {

Console output

-

Chrome media internals output

-

[avelad]

FYI @robwalch @devoldemar

[robwalch]

@devoldemar contributed the hevc-video-parser and default_display_window_flag and pic offset handling.

[robwalch]

Not a Contribution

Related changes in common libraries
https://github.com/xqq/mpegts.js/pull/95/files
https://github.com/shaka-project/shaka-player/pull/8868/files

[devoldemar]

I also found that, e.g. in gpac, default_display_window_flag is not somehow used to compute video dimensions from SPS.
Only offsets of display window.

The stream displays correctly in Chrome/Edge/Opera, but in Safari the stream is cut off

That's strange

[robwalch]

Thanks @devoldemar,

Will you submit a PR that updates the video parser?