Frame-accurate seek in both directions about mdk-sdk HOT 5 CLOSED

Do you mean step to the next/previous 1 frame? It's still developing. But for timeline preview, accurate seeking to a given time is enough, via seek(msec, SeekFlag::FromStart) see example https://github.com/wang-bin/mdk-examples/blob/master/Qt/qmdkplay.cpp#L23

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Do you mean step to the next/previous 1 frame?

Yes exactly, next 1 frame works fine, but previous doesn't and it will be useful too. Also seek to arbitrary exact frame will be useful, so for example I can call

seek(1234, SeekFlag::FromStart | SeekFlag::Frame)
and then for example
seek(976, SeekFlag::FromStart | SeekFlag::Frame)

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Do you mean step to the next/previous 1 frame?

Yes exactly, next 1 frame works fine, but previous doesn't and it will be useful too. Also seek to arbitrary exact frame will be useful, so for example I can call

seek(1234, SeekFlag::FromStart | SeekFlag::Frame)
and then for example
seek(976, SeekFlag::FromStart | SeekFlag::Frame)

If frame rate is known, seek forward a large number of frames and seek to by time are equivalent. If frame rate is unknown, it's impossible to fast seek by frame, you must decode frames 1 by 1(it's supported now) and which will be slow. So seeking to arbitrary exact frame is not useful.

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If frame rate is known, seek forward a large number of frames and seek to by time are equivalent.

You're right, this seems to work correctly if I calculate the timestamp from frame and frame rate and seek to timestamp.

I'll close this issue, but still it would be nice for the user of the SDK if that happens internally when passing SeekFlag::Frame.
Maybe something like this could be implemented in the SDK for SeekFlag::FromStart | SeekFlag::Frame case, if frame rate is known

auto delta = targetFrame - currentFrame;
if (delta > 0 && delta < 5) {
    seek(delta, SeekFlag::FromNow | SeekFlag::Frame);
} else {
    double timestampMs = (targetFrame / codec.frame_rate) * 1000.0;
    seek(timestampMs, SeekFlag::FromStart);
}

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Try the latest build. Backward seeking works. the first parameter pos can be -1, -2, -3 etc. frame rate must be known.

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