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Date: Wed, 27 May 2026 14:24:24 +0900
To: "cygwin@cygwin.com" <cygwin@cygwin.com>
Subject: Re: "Invalid DTS" warnings only in Cygwin version of ffmpeg
Message-Id: <20260527142424.e92ff4bd432c3cf04fccc611@nifty.ne.jp>
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From: Takashi Yano via Cygwin <cygwin@cygwin.com>
Reply-To: Takashi Yano <takashi.yano@nifty.ne.jp>
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On Wed, 27 May 2026 04:26:40 +0000
destal takul wrote:
> Hi. Thank you for looking into this. I had a quick look at the source code change you did to fix the issue.
> Should I assume that every file that has been remuxed using the previous versions of ffmpeg in Cygwin with those warnings is now permanently damaged?

Unfortunately, yes.

> I had noticed minor jerkiness/choppiness while playing such remuxed files, as though frames were being played out of order, which led me to believe those warnings might not have been cosmetic, and ended up digging deeper and realizing other builds of ffmpeg are not affected.

Your observation is correct.

> Also, will you be reporting this to the Fedora ffmpeg package maintainers?

It's under consideration for now.

> I am not quite sure how/why their source code has diverged so far from the official ffmpeg source code that it is introducing issues which do not exist in the official source.

This is because ffmpeg itself contains numerous codecs that are not
patent-royalty-free. For example, royalties of the H.264 codec is
managed by Via Licensing Alliance (Via LA) and MPEG LA.

> At this point I would be more inclined to use the official ffmpeg Windows builds in Cygwin.

I’d be happy if you use the Cygwin ffmpeg package, but of course
it’s your choice.

-- 
Takashi Yano <takashi.yano@nifty.ne.jp>

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