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Question: HLS stream in Compressor: Key frames don't fit

Hello 🙂


I'm trying to convert a H.264 MP4 file into a segmented HLS (HTTP Live) stream using Compressor 4.4.


Compressor creates the files, but the problem is that the key frames are not at all where they should be.


The frame rate of the original file is 25fps. And I would like to have segments of 6 seconds each (as recommended by Apple). So I set the segment duration to this value and the key frame interval to 150 (as 6 seconds are equal to 150 frames).


So according to my logic, a key frame should be at the first position of every segment (as is required).


But this is not the case. Playing the .ts files in VLC Play (for example) reveals that only after some seconds of each segment the player "sees" a key frame and starts playing. Also the "iframe_index.m3u8" file shows that the number of key frames per .ts file is inconsistent and they are not at the very beginning.


What am I doing wrong?


I bought Compressor explicitly for this task. Thanks for any input.


PS: I checked with ffprobe to see where the key frames are. And comparing them with the key frames of the .mp4 file generated by Compressor, I see that there are no "new" keyframe positions. All of the Compressor-keyframes are also present in the original file, in general there are just less key-frames. So apparently Compressor did not encode new keyframe positions, it just chose "old" keyframes which are probably close to the key frame interval I specified.


So how can I force the set key frame interval?

Compressor, macOS High Sierra (10.13.2), null

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Question: HLS stream in Compressor: Key frames don't fit