Subtitles out of sync

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1

Hello,

I am using HLS streaming for my VOD content, which is encoded with High profile. It has 3 streams with 700kbps, 1.1mbps and 1.6mbps.

As I have enough bandwidth, I am getting 1.6mbps stream and its duration is 2Hr 40 Mins.

I also have subtitles for this stream in .srt format.

When I try to play the stream without forward/reverse/trick play, the subtitles are in sync with the video. But, if I use trick play and skip for few minutes, there is a delay of few seconds with the subtitles.

If I use trick play few more times, the delay is increasing.

So, what could be the fix for this? Is it due to High profile video or is it a bug?

Thank you for your time!

2

I know this is VERY old, but I have subtitle sync issues as well…HLS streams and sidecar SRT files. I’m hoping perhaps whatever remedy you found may lead to one for my situation.

Anything?

3

Sorry.. I couldn’t figured out the issue and I also stopped working on Roku App long time back.

4

Here is some engineering feedback for a different partner on what might be a similar problem, sanitized for public consumption:

The problem is in the content, the playlist does not match the real video, and the mismatch buildup as we progress in the movie for 24.97fps content. 25fps content should be fine.

proof :

capture from

5

Thanks for this. I presume your mention of 24.97 should be 23.98?

This raises many questions, mainly pertaining to the inner workings of the system, but the end goal is the same - how is this being rectified now? Or, will any file with a fractional frame rate (e.g. 23.98 and 29.97, not to mention DF vs NDF) always drift from CC?

I’m not sure this addresses my specific issue (viewtopic.php?f=34&t=95362 - any input?) but it certainly makes me wonder if I’ll encounter the same issues if I start seeking through the video file…

Thanks!

~Michael