On Tue, 20 Dec 2011 23:10:05 -0500 Jeremy Huntwork <[email protected]> wrote:
> Nathan's email reminded me that there's also a dubious statement on the > current ffmpeg page. The page references using qt-faststart to 'flatten' > files by moving the index to the front of the file. > > Indeed, qt-faststart does move the moov atom (which contains metadata about > the video) to the front - the purpose being that video players can begin > playing the video before it has even fully downloaded. But I don't believe > that the correct term for this procedure is 'flattening'. > > The term 'flattening a video' originates from the need to export a mac > formatted file so it could be played in Windows, by moving all the movie data > into the data fork instead of leaving necessary components in the resource > fork (elements which were part of how the Mac OS stored its files). One of > the best descriptions I found is here: > http://www.macwindows.com/tutfiles.html#Flattening > > Also, here's a link to the qt-faststart source which has a good description > about what it does in comments at the top: > http://git.videolan.org/?p=ffmpeg.git;a=blob;f=tools/qt-faststart.c;h=ace4c113c88850613aff2f9158a08a6164fc6bac;hb=HEAD > > I suppose it is possible that many traditional tools when performing the > 'flatten' task also moved the moov atom to the front (I haven't verified > that) and perhaps that's why YouTube used that term in its error messages, > but doing that alone (which is all qt-faststart does) is not flattening. So what should we have on the page? At the moment it says: If you upload certain formats (quicktime, mov or mp4) to youtube, you need to "flatten" them (move the index to the front of the file) before uploading. FFmpeg contains a tool called qt-faststart that can do this. If need qt-faststart, you can compile it with gcc: Suggestions for improved wording are welcomed. Andy -- http://linuxfromscratch.org/mailman/listinfo/blfs-dev FAQ: http://www.linuxfromscratch.org/blfs/faq.html Unsubscribe: See the above information page
