Blockiness in Flash videos

What causes blockiness in Flash videos being converted from a high quality wmv file? It gets blocky and messy on fast jacking scenes and such.

Jimmy

Re: Blockiness in Flash videos

It has to do with how the program you’re using is compressing the videos. That is one of the biggest problems with doing Flash Videos. What program are you using to do your conversion? Are there settings you can change?

Re: Blockiness in Flash videos

I’m using Sorenson 4.5. I’m not sure what setting to change, and I’ve guessed a million times already. Grrrrr

Jimmy

Re: Blockiness in Flash videos

I’ve also come across blockiness when I’ve encoded a large dimension (eg 640x480) video with MP4 (h.264 codec) and displayed it embedded in a page and viewed with Flash Player 9. I think this may be due to lack of CPU power, as the blockiness isn’t there when viewed in a standard player.

Re: Blockiness in Flash videos

Up your bit rate and it will go away. FLV does not have the best compression these days and that’s as good as it gets for that bitrate.

OR have your swf call a H.264 encoded mpeg file which has much better compression and can render more detail. This is the future of flash video, but the problem is you need at least Flash version 9,0,115 to have it work (versions below that only support FLV).

Re: Blockiness in Flash videos

Flash is certainly not the future for large dimension embedded videos for some time to come. A 384x288 Flash video uses 40-50% of my CPU. Which is about double the amount a same size embedded WMV uses. This is why YouTube blows up a 320x240 video to a larger size in the HTML code.

Re: Blockiness in Flash videos

The vast majority of Flash video out there is FLV. I’m talking about SWFs that call H.264 MPEGs. They will be processor intensive though - that’s just the nature of efficient compression…

If you want to see Flash using H.264 MPEGs - choose the “watch in high quality” option on YouTube.

Re: Blockiness in Flash videos

Even standard FLV is CPU intensive compared to Windows Media. Check it yourself by hitting Control Alt Delete and looking at Processes as you play videos.

Re: Blockiness in Flash videos

I agree with all of the above. We encode Flash at 1Mbit using the On2 codec (which is included in Sorenson.) It seems to work better than the Sorenson Spark codec.

H.264 in Flash looks much better, but it requires the Flash 9 player, which has only been available since December. We haven’t switched to that yet because a lot of people haven’t yet upgraded. I don’t know what % of people have the newest Flash player, but we will probably wait at least 2-3 more months before we switch over to encoding in H.264 for Flash.

Re: Blockiness in Flash videos

I’m on a Mac. WMVs are the problem files for me - Flip for Mac works, but isn’t exactly elegant…

But yes, watching an FLV-based YouTube videos takes about 70+% of processor speed. Watching “high quality” ones (that are presumably H.264-based) takes about 80+% of processor speed.

Re: Blockiness in Flash videos

It does look amazing at 384x288 at 750k. Here’s one we made about ‘cycling’:

http://www.viduk.com/

I think the bitrate on that one is 650k-700k and that’s with stereo audio.

What I really like is the way it keeps the contrast.

Re: Blockiness in Flash videos

Thanks everyone for your comments. It helped some working today trying to figure out what the f to do. But I still need that magic wand to make all these videos in the perfect flash format.

Jimmy