Fedora 21 Kdenvlive 0.9.10. When rendering to file I see no log files for two pass rendering. It writes directly to the final file. I tried both "H.264/AAC High Profile" and "H.264/AAC (CBR)":





What is really happening?

does this help ?
https://userbase.kde.org/Kdenlive/Manua ... Parameters

ttguy wrote:does this help ?
https://userbase.kde.org/Kdenlive/Manua ... Parameters

Both the H264 profiles use this preset:

Code: Select all

$ cat /usr/share/mlt/presets/consumer/avformat/x264-medium
f=mp4
acodec=aac
ab=256k
vcodec=libx264
threads=0
vpre=medium
preset=medium
movflags=+faststart
meta.preset.extension=mp4
meta.preset.name=H.264 High Profile


Now how does that relate to ffmpeg parameters? How can I make it 2 pass VBR?

It should send the number of passes through to the render in the main parameters. And from your screen shot it is doing that.

How do you know it is not doing two passes ? Do you know for sure you need to see a log file for there to be two passes being done ?

ttguy wrote:How do you know it is not doing two passes ?

I don't.

ttguy wrote:Do you know for sure you need to see a log file for there to be two passes being done ?

In previous versions I could see the log file being populated and it was not deleted at the end. Now unless its path is different (why would it be?) it is not generated.

Where can I see the real command sent to ffmepeg?

I was just looking at this and on my system the number of passes is greyed out when you select a VBR render option. I guess the number of passes is not relevant on a VBR option. You are specifying a quality and ffmpeg decides what to do after that. I might suspect it does a multipass encode so it can figure out what bit rate to do which parts.
But who cares about any of this? Do you get a good quality render and a good file size? Just play with the quality setting until you get acceptable quality for an acceptable file size.

If you want to see some internals then you can choose the render to script option.
it will write a file_name.sh and file_name.mlt file. But I don't know how you see an ffmpeg command.