user4258: I exported a music video using H.264 for the first time (I would normally just use a simple Apple intermediate codec) and as the 1st shot fades up, for the duration of the fade up, there are ever so slightly visible 'lines' across the white background. It is literally just for the 1st second of the clip, but being the opening shot it's rather important. check it out, it's more obvious at 1080p



By the way, yes it is meant to be out of focus and grainy. 
I set the quality to 10,000KB/s which as far as I'm aware is pretty good for online streaming?? I use Final cut express 4.1
Any help would be greatly appreciated as I have no H.264 knowledge at all 

user2836: Ok, now that I'm home I think I see what you are noticing.  That is just an error with the block transitioning from black to white.  You can either slow down the fade or increase the keyframe frequency.  H.264 works by storing only certain frames and then storing the change in-between.  It breaks the image in to sections to analyse and so you can see if you go frame by frame that it is having a hard time figuring out what the change is around the edge between black and white.
Either decreasing the rate of change or increasing the frequency of keyframes should give it a better idea of what is happening.  You might also try 2 pass VBR if you were only doing one pass or CBR prior as the analysis pass should help clean up artifacts like that by directing more bitrate to harder areas to compress.

4258: <p>I exported a music video using H.264 for the first time (I would normally just use a simple Apple intermediate codec) and as the 1st shot fades up, for the duration of the fade up, there are ever so slightly visible 'lines' across the white background. It is literally just for the 1st second of the clip, but being the opening shot it's rather important. check it out, it's more obvious at 1080p</p>

<p><div class="youtube-embed"><div>
                <iframe width="640px" height="395px" src="https://www.youtube.com/embed/ENBuxqM0pyw?start=0"></iframe>
            </div></div></p>

<p>By the way, yes it is meant to be out of focus and grainy. </p>

<p>I set the quality to 10,000KB/s which as far as I'm aware is pretty good for online streaming?? I use Final cut express 4.1</p>

<p>Any help would be greatly appreciated as I have no H.264 knowledge at all </p>
 2836: <p>Ok, now that I'm home I think I see what you are noticing.  That is just an error with the block transitioning from black to white.  You can either slow down the fade or increase the keyframe frequency.  H.264 works by storing only certain frames and then storing the change in-between.  It breaks the image in to sections to analyse and so you can see if you go frame by frame that it is having a hard time figuring out what the change is around the edge between black and white.</p>

<p>Either decreasing the rate of change or increasing the frequency of keyframes should give it a better idea of what is happening.  You might also try 2 pass VBR if you were only doing one pass or CBR prior as the analysis pass should help clean up artifacts like that by directing more bitrate to harder areas to compress.</p>
