WebM, ffmpeg and Avisynth

[paulom]

I am trying to encode video clips from my cameras as WebM files, using ffmpeg.
I have clips in three different formats: mpg/mpeg1 files from a Sony camera, mov/mjpeg files and mts/avchd files from a Panasonic.

Inputting the files themselves (ffmpeg -i file.ext file.webm) works perfectly for all the three formats.

I use Avisynth to edit my clips. The mpg files are opened with DirectShowSource. The mov files are opened with QTInput(audio = 2). The mts files can be opened with DirectShowSource(fps = 29.97, convertfps = true) and Haali splitter installed.

Inputting avs script files (only one line with the opening function call) results in the following:
The mpg file causes the error:

[webm @ 02F03860] Application provided invalid, non monotonically increasing dts
 to muxer in stream 0: 33 >= 33
av_interleaved_write_frame(): Invalid argument

The mts files cause the error:

[webm @ 0E0D3940] Application provided invalid, non monotonically increasing dts
 to muxer in stream 0: 33 >= 33
av_interleaved_write_frame(): Invalid argument

The mov file is encoded without problems.

Can someone help me, please?

[paulom]

I can see this is the only post in this forum with 0 answers. Maybe:

1 - It's not the place for this question.

2 - It's such a silly question that deserves no answer.

Please let me know if this is the case. Just say 1 or 2...