Re: [playogg-discuss] Re: Re: Which tool to encode web video or audio? (Jaime Alberto Silva)

[George Chriss]

Hi,

Thank you for this report---I ran into the same issue, which seems to
originate in ffmpeg conversion rather than the Theora codec, per se.  I
think the problem is that WMV videos can have variable frame rates,
whereas most other video codecs use a fixed frame rate.  This is not easy
to fix.

Also, I suggest checking that the working version has correct a/v sync at
random points through the video.


Sincerely,
George


On Sat, August 29, 2009 11:54, Jeff Shippen wrote:
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> Here is my experience from first attempts at transcoding the WMV file to
> ogv on Mac OS X.  I am using VLC 1.0.1 for playback.
>
>
> Application: * Firefogg 0.9.9.6 * (the latest version to date)
>
> I used the three different presets (high quality, low quality, and web).
>
> _Results_ :
>
> In all three results, it looked like the video cycled through all the
> frames within the first couple seconds.  The video then displays the
> last frame for the remainder of the 2 minute video.
>
> The Audio was fine in all three results.
>
>
>
> Application: * VLC 1.0.1 * (latest version to date).
>
> As a previous poster mentioned. VLC has the capability to transcode
> files.  In mac, click on File > Streaming/Exporting Wizard.  Choose the
> appropriate settings (theora for video, ogg for audio).  My first couple
> attempts, using low quality settings, failed.  The product was similar
> to that of firefogg product, the audio played fine, but the video cycled
> through too quickly.
>
> After failed attempts, I upped the quality for both video and audio, and
> then WHALA!  It worked!  NOTE: VLC requires the output file to be in
> ".ogg" extension.  Once the ogg file is generated, I manually changed
> the extension to ".ogv".
>
> The following are the successful BITRATE settings I used:
> Theora: 192
> Vorbis: 64
>
> These settings were a few steps up from those that did not work, and
> chosen somewhat at random.
>
>
> Jeff Shippen
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