Audio skips after merging

[borkoborko39]

Hi, so with Premiere i cut 30 second video in half and changed places so the video loops seamless and added cross fade in the middle then i rendered in h264 mp4. The video is fine but when i merge with avidemux i hear the audio stops for milisecond right where the appended video starts then continues. How can i fix that audio jump? After merging the video is 60 seconds and the audio jumps right at 30th second then continues with the appended video. Im trying to make 8 hour video on loop so rendering is not an option for me

[eumagga0x2a]

I suspect that this is related to the presence of B-frames in video stream and the gap between appended videos represents the B-frame delay (i.e. the timestamp of the first frame in video as shown by Avidemux). Please try to export video with the number of B-frames set to zero (I don't know whether Premiere allows to control that).

[borkoborko39]

I tried different settings with premiere and in avidemux timecode now is exactly at 0 but still skips. What video editor or converter i can use to set the correct timing?

[eumagga0x2a]

Using the latest git (in this particular case the last release – 2.7.8 – is recent enough), I cannot reproduce a gap at least when the first frame starts at 0 (no B-frames). However, depending on the particular waveform at the cut point, the latter can be audible as a click, see the magnified waveform of the cut point after appending a MOV file with H.264 video and PCM audio to itself:

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For the cut point to be inaudible, the clip needs to start and to end with silence.