theora - Jun 2009 - Strange results encoding with latest ffmpeg2theora-0.24 and playback on Directshow through Winamp

Hi Folks,

First, I would like to thank the eople in development who are doing so much to
develope these great video and audio tools.
I use Ogg Vorbis to store most of my music projects in studio and the results
are stunning.  Quite frankly, in the audio file reduction game, nothing beats
Ogg Vorbis and I can personally say this from my own experience.  So a huge
thank you to the team.

I've tried for the first time to encode an AVI file from my digital camera
to .ogv using ffmpeg2theora.
I came across a few potential bugs.
First, if changing the speedlevel parameter to 0 or using the Optimize
parameter, and an output file is not specified, the encoder does not
automatically assume the same input Filename.avi to output Filename.ogv.

Also, in order to playback using Winamp, I installed the Ogg Codec from the
download page, and added the .ogv extension to Winamp's Directshow input
plugin's extension list.
The playback of the files, whether or not I play them in Mediaplayer, Winamp or
another player, produces a very distorted audio playback, which sounds more like
audio distortion of chipmunks through an overdrive guitar filter, (for lack of a
better description).
The video is upsidedown in Winamp but looks correct in Mediaplayer.

Back to the audio, I'm not sure if the audio problem exists because my
digital camera produces audio at 11025 Hz, 8 bps, Mono (that's according to
Winamp's info reported by the Directshow stream).

To keep things simple, I encoded with ffmpeg2theora without using any -switches
or parameters. It was a .avi video of my 3-month old son being bathed and
splashing in the water.
Here's the very basic syntax I've used:
ffmpeg2theora Baby.avi

Does anyone have any solutions to identifying why I am getting these strange
results?  How much of it could have to do with the ffmpeg2theora encoder and how
much to do with the Directshow decoder    ?

I'm more than ready to send the .AVI file to someone for testing, though it
may be quite large, around 160 Mb.

One last question: What do I do if I want to create a straight .ogv file out of
a DVD video, wherein there is the Audio_ts and Video_ts folders?  You know, from
regular DVD Videos.

Thanks for any advice in advance.
Kind regards,

Yogan
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On Jun 15, 2009, at 4:37 AM, Yamuna Jivana dasa wrote:
> First, if changing the speedlevel parameter to 0 or using the  
> Optimize parameter, and an output file is not specified, the encoder  
> does not automatically assume the same input Filename.avi to output  
> Filename.ogv.
I use the --optimize option without specifying an output file and it  
does behave correctly for me (i.e., saving the same filename .ogv in  
the same directory as the input file.) Perhaps you could share some  
more specific details about what you're experiencing?

> The playback of the files, whether or not I play them in  
> Mediaplayer, Winamp or another player, produces a very distorted  
> audio playback, which sounds more like audio distortion of chipmunks  
> through an overdrive guitar filter, (for lack of a better  
> description).
> The video is upsidedown in Winamp but looks correct in Mediaplayer.
Do they play correctly in VLC (http://videolan.org/vlc.) This may help  
to point things in the correct direction of the problem.

> What do I do if I want to create a straight .ogv file out of a DVD  
> video, wherein there is the Audio_ts and Video_ts folders?  You  
> know, from regular DVD Videos.
ffmpeg2theora really isn't the best programing for use with DVDs. You  
can feed .vob files to ffmpeg2theora, but you may find that things are  
not arranged in the way you'd expect: It's normal for multiple DVD  
titles to be muxed across multiple VOB files, so you need to find a  
way to demux the desired title out  of the various VOB files first or  
find a program (such as HandBrake or Thoggen) that does everything for  
you.
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> Also, in order to playback using Winamp, I installed the Ogg Codec from the
> download page, and added the .ogv extension to Winamp's Directshow
input
> plugin's extension list.
> The playback of the files, whether or not I play them in Mediaplayer,
Winamp
> or another player, produces a very distorted audio playback, which sounds
> more like audio distortion of chipmunks through an overdrive guitar filter,
> (for lack of a better description).
> The video is upsidedown in Winamp but looks correct in Mediaplayer.
The upsidedown video in Winamp is a know problem
(https://trac.xiph.org/ticket/1497)
which I will address in the next version of the codecs (no estimated
time of arrival
though)
>
> Back to the audio, I'm not sure if the audio problem exists because my
> digital camera produces audio at 11025 Hz,?8 bps, Mono (that's
according to
> Winamp's info reported by the Directshow stream).
>
>
> Does anyone have any solutions to identifying why I am getting these
strange
> results?? How much of it could have to do with the ffmpeg2theora encoder
and
> how much to do with the Directshow decoder??? ?
You can test the video with other decoders to see if it plays better
(VLC, SMplayer)
>
> I'm more than ready to send the .AVI file to someone for testing,
though it
> may be quite large, around 160 Mb.
You can send me the video in private (using for example rapidshare which has a
200mb file limit and 10 downloads for free users) for testing.

Cheers,
Cristian.