How to join audio?

Hi! Can someone please tell me what's the best way to join audio and video?

I have separate audio and video files, and I want to cut the video together with the audio. I can add both to the timeline and group them. That works fine if I just want to drag the clips around: both are moved together. But if I use "Resize item start" or "Resize item end", only one of the clips is resized, not the group.

That makes editing very tediuos, bacause I have to do all the work twice: once for the audio, once for the video. Why isn't there a "Join audio", that does the opposite of "Split audio"? Wouldn't it be very useful? Am I missing something?

Until now I have been merging both clips using ffmpeg, something like:
ffmpeg -i 120518-000.wav -itsoffset 30.93 -i out_0002.mkv -shortest -vcodec copy -acodec copy new_out_0002.mkv
but for some reason, since a few days ago, the merged video plays fine on VLC, but if I try importing it into Kdenlive, I get:
[swscaler @ 0xaa2ddca0] Unknown format is not supported as input pixel format
and it fails to import.

Any suggestions about how to edit and audio and a video clip as they were one?

Thanks,

aBe

Ok, I got my ffmpeg merging fixed, but still, having an audio join feature in Kdenlive would avoid this step on the command line.

It seems Kdenlive does not like when a video file starts only with audio and no video. There is an offset in the video because I have an audio recorder which I activate first, and then I start the video recording.

What I did this time was to first remove a few seconds out of the audio file:
ffmpeg -i 120518-000.wav -acodec copy -ss 30.93 short.wav

And then merge audio and video:
ffmpeg -i short.wav -i out_0002.mkv -vcodec copy -acodec copy new_out_0002.mkv

This imports succesfully into Kdenlive

Let me put it in another way.

If you apply Timeline > Current Clip > Cut Clip on a group, this is performed on all group items. So far so good.

But if you use Resize Item Start or Resize Item End, the group is ignored and the trimming only happens on the current track.

Is that a bug? Shouldn't the resizing happen on all group items?

The reason I have to use the command line to merge audio and video files is because groups are ignored when resizing.

>> Is that a bug? Shouldn't the resizing happen on all group items?
You will only know if you file a bug report.

I thought it was a good idea to know if something is a bug before posting a bug report. Maybe I just didn't understand what's the right way of working with groups. But I did what you suggested.

http://www.kdenlive.org/mantis/view.php?id=2631