kdenlive

English Multimedia
#1

Hello,

I have recorded a short 1min video of my desktop using qt-recordMyDesktop.
The video is 672x640 25fps (I recorded a small region of my desktop).

I am trying to use kdenlive to polish the video with a title and closing
graphic. I have manage to get everything into place, but I have having some
troubles:

  1. Exporting the timeline never seems to finish. It stays at 99% and I have
    to abort it. The video does play though. This happens with any export type
    I pick.

  2. I can’t seem to find any information on the settings to pass to
    libavformat in the custom encoding box. I have finally got it to encode to
    the same size as the input .ogv. But the quality is too low…much lower
    than the original ogv created by recordMyDesktop

  3. How can I remove the audio track from encoded file? This relates to #2
    since I cannot find any information on the options to pass to libavformat.

Can anyone help me with the 3 items above?

Thanks,

–
Alvin

#2

This has been a bug as long as I’ve been using kdenlive. But it still works. So it doesn’t bother me.

Best ask this in the kdenlive forum: kdenlive forum

Or do what I do, which is to encode with kdenlive to a high quality avi file, and then use other software to produce a high quality video in the format of my choice.

… Why remove it? Simply mute the audio in the production. Or use other software, such as avidemux to remove the audio if you wish.

#3

oldcpu wrote:

>
> Alvin;1831960 Wrote:
>> 1. Exporting the timeline never seems to finish. It stays at 99% and I
>> have to abort it. The video does play though. This happens with any
>> export type I pick.This has been a bug as long as I’ve been using
>> kdenlive. But it still
> works. So it doesn’t bother me.

> Alvin;1831960 Wrote:
>> 2. I can’t seem to find any information on the settings to pass to
>> libavformat in the custom encoding box. I have finally got it to encode
>> to the same size as the input .ogv. But the quality is too low…much
>> lower than the original ogv created by recordMyDesktopBest ask this in
>> the kdenlive forum: ‘kdenlive forum’
> (http://www.kdenlive.org/bbforum/)
>
> Or do what I do, which is to encode with kdenlive to a high quality avi
> file, and then use other software to produce a high quality video in the
> format of my choice.
>
>
> Alvin;1831960 Wrote:
>> 3. How can I remove the audio track from encoded file? This relates to
>> #2 since I cannot find any information on the options to pass to
>> libavformat. … Why remove it? Simply mute the audio in the
>> production. Or use
> other software, such as avidemux to remove the audio if you wish.
>
>

I tried searching kdenlive’s forum but couldn’t find anything on the
exporting not finishing. AFAICT, the kdenlive_render program doesn’t
terminate. I’m not sure why though.

When I create a mp4 video the quality is very good. I think I will need to
experiment with ffmpeg and mencoder to see which can produce the better
looking OGG video.

I figure that since I don’t have any audio in the tracks, it would be best
to remove them. I used ffmpeg to strip the audio track and the size of the
OGG video only decreased by 200K. So, it’s probably not worth the hassle I
guess. Perhaps when I convert the mp4 -> ogg I can strip the audio at that
point.

Thanks,

Alvin

#4

Alvin wrote:
> When I create a mp4 video the quality is very good. I think I will need to
> experiment with ffmpeg and mencoder to see which can produce the better
> looking OGG video.

I’m answering my own reply, but I think I found a solution that works well.
Hopefully others will to:

  1. With kdenlive, I create a mp4 using the following custom encoding:

Name: MP4
Extension: mp4

Parameters (libavformat):
format=mp4 video_rc_min_rate=0 video_bit_rate=18000000 vcodec=xvid mbd=2
trell=1 v4mv=1 progressive=1 profile=custom_alvin

The profile is a MLT profile I made with the correct settings of the video I
recored using recordMyDesktop. For completeness, here is the file:

$> cat /usr/share/mlt/profiles/custom_alvin
description=Custom (Alvin)
frame_rate_num=25
frame_rate_den=1
width=672
height=640
progressive=1
sample_aspect_num=1
sample_aspect_den=1
display_aspect_num=21
display_aspect_den=20

  1. I installed ffmpeg2theora cause I got frustrated with the raw ffmpeg
    settings :). I use the following command to produce the final ogg video:

ffmpeg2theora --nosound -v 10 -V 2048 --optimize -o untitled.mp4.ogg
untitled.mp4

The original untitled.mp4, created by kdenlive, is 32.3 MB. The OGG video,
produced by ffmpeg2theora, untitled.mp4.ogg is 13.4 MB.

Hope this helps someone else.

–
Alvin