Intro buffer

[gatorshoes]

Is there an easy way to add a short silent bit of blank video to the start of ie a music video where the audio is too close to the start (which causes my player to hiccup the start). On one i was able to copy a silent bit from the ending and append it at the front which worked. But the other videos don't have any silence to use. And what would be the ideal length of time - 120ms worked on one.

[sark]

Duplicate first frame for chosen duration with Transform/Still Image filter.

120ms suggests PAL video. At 25fps that's just three frames.... You will hardly notice the static start.

[eumagga0x2a]

gatorshoes, you need to use an external application (e.g. Audacity) to create a WAV audio file containing silence with the number of channels, sampling frequency and bit depth (Avidemux supports only signed integer 16 and 24 format, maybe 8 as well, but unsure) matching the audio track of the music video, then add this file as external audio track to the brief still video you created the way sark suggested. You then need to encode it with exactly the same audio codec and encoder parameters the audio track in the music video had been created.

After these steps, you can append the silent pre-roll to the music video and cut/paste it to the start (or append the music video to the pre-roll) and re-encode the video track of the merged video leaving audio in copy mode.

Getting audio encoder parameters perfectly matching may be the trickiest part of the task. You can avoid this only by extracting the audio track of the music video as PCM (WAV), editing it (I would add silence to the end rather than prepending it with silence), then adding it back as an external audio track in Avidemux after having added a still video without an audio track to the end, find a proper A/V sync, cut the silent part at the end and paste it at the start, then re-encode either the audio track alone (video stays in copy mode) or both audio and video in Avidemux.