Full details on my issue are described here: GPUOpen-LibrariesAndSDKs/AMF#447
As well as discussion with AMF developer on this topic.

Video sample [cut to 1 minute, 1:03 due to "key-frames"]: https://drive.google.com/file/d/1bBhxS3vGQOQVn-mzR2cLFMFdCcfOZUHX/view?usp=drive_link

System spec:

• OS: Windows 11, 23H2, build 22631.3085
• Driver Version: 24.1.1
• GPU: RX 7800XT

Description: I have video, that was encoded by using only 1 IDR I-frame at beginning, and then every other keyframe was done via SEI (recovery_point) + non-IDR I-frame combination [with exact_match flag]. When i seek through it [mostly by using arrow keys in MPC-HC or other players to skip few seconds], i can encounter several situations. When video is simply being played - no issues, meaning problem is exclusively for seek functionality.

1. Video plays back normally as if nothing happen. (it does sometimes happen)
2. Video freezes frame and starts flicker to different frame
3. Video corrupts frame by either green, blue or rainbowy artifacts
4. Video corrupts as if is corruption artifacts or square-blocky corrupted frame data
   Every issue can happen both instantly after seek, or within few seconds
   Corruption effects can overlap with frame freeze effect.
   When issue triggers it can last from second or two up to 10 seconds (until it hits new key frame?) but no more.

In MPC-HC issue only appears on D3D11 HW acceleration, DXVA2 (both native and copy-back) looks to be safe. It also doesn't happen on Nvidia GPU's based on few tests, which i managed to get from other people (while they streamed that to me).

But! In other players this issue is persistent, including Windows default ones. In every single one. Severity often not AS bad in MPC-HC or VLC though (frequency is less and frame freezes are mush less frequent occurence compared to artifacting, with small seek skip length it can potentially be affected if seeking backwards, but with large one, it will corrupt more if i move forwards.
In D3D11 MPC-HC [tried MPC-VR, MadVR and custom EVR], and VLC it will corrupt easily both ways even on small sample as seek skip time is not tied to video duration, i assume). And in VLC, for example, even DXVA2 mode is affected, compated to MPC-HC.

With FFmpeg i can cut fragments from video without problems, and it will be cut according to SEI marked non-IDR I-frames as keyframes, meaning it will playback fine. But seek functionality will still be in same exact state.

In MPC-HC i noted that skips despite being generally spaced as 0-10-12-17-27-37-49(50)-59-63 seconds, sometimes instead of 37 it skips to 39. If you pause and skip, it will be 27-->37, but 49-->39 instead. VLC doesn't follow this trend, as it always skips 10 seconds.

Originally i thought that it was AMF related problem, but after long discussion and some research on my side i came to conclusion that it was not, as from discussion i understood that HW decoder only passes filled with data structures, and processing of data is being done by recieving side.

Currently i am interested in reason why could that happen, why behaviour is different between DXVA2 and D3D11 in MPC-HC, is it even fixable (it should be based on how other people play it), and where/how should it be fixed so i could at least attempt to ask for resolve (even if it will depend on wish of developers).

Sorry for asking too many questions.