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Date: Sat, 21 Mar 2026 20:31:33 +0900
To: cygwin@cygwin.com
Subject: Re: [ffmpeg hevc] Build require amd gpu
Message-Id: <20260321203133.76a5f92411148188585d682a@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 Fri, 20 Mar 2026 23:23:33 -0400
jeremie bergeron wrote:
> With ffmpeg 8.0.1-4, if I run the command: ffprobe hdr10tags-stream.mp4, I
> get this error:
> [AMF @ 0xa00056680] DLL amfrt64.dll failed to open
> [hevc_amf @ 0xa00053800] Failed to create  hardware device context (AMF) :
> Unknown error occurred
> [mov,mp4,m4a,3gp,3g2,mj2 @ 0xa0004ca40] Failed to open codec in
> avformat_find_stream_info
> [AMF @ 0xa00056a40] DLL amfrt64.dll failed to open
> [hevc_amf @ 0xa00053800] Failed to create  hardware device context (AMF) :
> Unknown error occurred
> 
> It is pretty normal that it fails since I don't have an amd gpu, so I
> don't have the amfrt64 dll.
> 
> Note that any hevc file will produce this error. hdr10tags-stream.mp4 is
> available here:
> https://storage.googleapis.com/ffms2tests/hdr10tags-stream.mp4
> 
> Would it be possible to disable this hardware decoder?

AFAIK, there is no options for ffprobe that disable hardware decoding.
Usually, ffmpeg uses software decoder for hevc, however it is not
included in cygwin ffmpeg package due to patent issue.
So, ffmpeg attempts to use
hevc_amf
hevc_cuvid
hevc_qsv
If you have none of AMD/NVIDIA/INTEL GPU, you cannnot use HEVC codec
at all unfortunately.

In addition, when using NVIDIA GPU, but you do not specify "-c:v hevc_cuvid",
ffmpeg attempts to use hevc_amf first, then after some errors, automatically
uses hevc_cuvid as you observed.

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

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