On Wed, Aug 4, 2010 at 11:06 AM, Simon Eugster <[email protected]> wrote: > 2010/8/4 Dan Dennedy <[email protected]>: >> On Wed, Aug 4, 2010 at 3:22 AM, Simon Eugster <[email protected]> wrote: >>> Dear *, >>> >>> It seems we've really got a big A/V sync issue. >>> http://kdenlive.org/forum/dnxhd-av-out-sync >>> http://kdenlive.org/forum/there-any-way-keep-audio-sync >>> http://kdenlive.org/forum/audiovideo-out-sync-after-rending-uploading-youtube >>> http://kdenlive.org/forum/cannot-render-mpeg4xvid4h264flash >>> etc. >>> >>> Seems like something is wrong? >> >> You must be new to audio/video and reviewing problem reports of a >> modestly popular software package. :-) IOW, a/v sync is *always* a >> problem due to proliferation of standards, formats, and tools. It is >> easy to feel like chicken little while reviewing a bunch of reports. >> So, ignore those reports for a moment, and based on your experience >> what do you think? > > As you said: Everyone wants his own format? Frame rates of 29.97? Tons > of funny ideas ffmpeg would have to consider to decode/sync it > «correctly»? Kind of OOXML?
What is interesting about the reports above is that one is about the ffmpeg-based Transcode feature and another occurs just with the YouTube conversion. I do know that variable framerate clips are a problem, and it is not typically obvious when a clip has variable rate. I also know that for some classes of input (e.g. MPEG-2 program stream, DV) that FFmpeg with MLT maintains good sync in the decoding, processing, and SDI output stages because I have clients who have payed me to ensure that. However, that is only critically verified at certain points in time. Then, there may be major changes that create a problem, but these become prominent and repaired due to the high exposure afforded by the open source projects like Kdenlive and OpenShot. I suppose there could be some things wrong in the encoded output, but much of that code is based on ffmpeg, the utility, and it seems to work fine most of the times I use it. With that said, it is important to qualify problem reports in this area and look for patterns that pinpoint a specific area to look. -- +-DRD-+ ------------------------------------------------------------------------------ The Palm PDK Hot Apps Program offers developers who use the Plug-In Development Kit to bring their C/C++ apps to Palm for a share of $1 Million in cash or HP Products. Visit us here for more details: http://p.sf.net/sfu/dev2dev-palm _______________________________________________ Kdenlive-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/kdenlive-devel
