"Fuzzy" .264's

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odellkevin
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"Fuzzy" .264's

Post by odellkevin »

Anytime I stream a .264 file to my XBOX, either from my local drive, or from online via a plugin, the image will appear "relatively" sharp, and then deteriorate into a somewhat blocky/fuzzy image over the course of about 8 - 10 seconds, and then re-sharpen itself, and repeat. This doesn't happen with xvids, (although there aren't many sites streaming xvids), only 264 files. Anyone else have this problem? Anyone have a solution?
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BuZz
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Re: "Fuzzy" .264's

Post by BuZz »

without a debug log ? not really.

you should know this already as you have been asked to provide one previously.

read this post again.

http://www.xbmc4xbox.org.uk/forum/viewt ... p?f=6&t=65
poshea
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Re: "Fuzzy" .264's

Post by poshea »

I've experienced this with files encoded with 264 codec (regardless of container MKV or mp4). For me, it only occurred when using this setting:

SETTINGS | VIDEOS | PLAYBACK | H.264 Skip Loop Filter ....... "Skip Everything" or "Skip Non Key Frames"

If I use any other preset for the h264 skip loop filter setting, (default or skip bidirectional frames or skip non referenced frames) this does not happen, the image stays relatively clear - but uses extra CPU power to process the h264 and in my case resulted in dropped frames instead of the fuzz.

My solution was to use ffmpeg to encode the files using an MKV container but the MPEG 4 encoder. This resulted in no fuzz an no dropped frames an excellent payback on xbmc4xbox.

The code is all over the forums, and credit to buzz... but in case you missed it...

Code: Select all

BuZz wrote:
i use (commandline ffmpeg)

ffmpeg -i some_1080p_infile.mkv -scodec copy -acodec copy -vcodec mpeg4 -b:v 3000k -maxrate 5000k -bufsize 4096k -s 1280x720 -f matroska -y outfile.mkv


single pass (as I transcode in realtime using mediatomb), but results look decent.
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Re: "Fuzzy" .264's

Post by poshea »

Oh. I should note that not ALL H264 files I have display this build up fuzz over 8-12 secs then clear. Not sure, but I think it may be more noticeable on video files with a lower data rate. I have a whole collection of files encoded with quicktime that use the h264 codec and a video data rate of about 3000kb... they play fine - even with loop filter set to skip everything.

The problem files I had were encoded with handbrake using the H264 codec and video data rate of 2200kb.

What's the specs of the problem video files?

A log file would be good so the developers could have a look.
odellkevin
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Re: "Fuzzy" .264's

Post by odellkevin »

It's mainly files that are streamed from the internet via plugins, so it's hard to give the "specs" on them as they are so random. But I think it's safe to assume, that they are all fairly "low data rate" as they are designed for web streaming. After observing different files over the last few days, some "go fuzzy" after 5-6 seconds, some after 10 - 12 seconds, some stay relatively clear/stable for the entire movie, except for sometimes in really complex scenes, which would farther seem to suggest it's a data rate issue. I'll play around with the Skip Loop Filter and see if it helps.
Also, when I said it happens with locally streamed 264's as well...a while back I was attempting to try encoding some of my stuff to 264, because, according to common consensus, when comparing xvid and 264, 264 will give "better quality at the same bit rate or equal quality at a lower bit rate". So, over the course of a week, I tried hundreds of 264 test encodes, using dozens of different softwares and scores of settings, and I could never get "better quality at the same bit rate or equal quality at a lower bite rate" (at least when played back through the xbox, and in my opinion of "better quality"). The 264's would either fuzz out, or the xbox would choke, so I went back to xvid. Now, I was using data rates in the 800 - 1200 kb range, yeah I know that's pretty low, but I just can't encode my library using the 3000 - 5000 kb data rate that a lot of people use, yeah the quality is excellent, but I would need ~20 TB of space to hold my library.
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Dan Dar3
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Re: "Fuzzy" .264's

Post by Dan Dar3 »

That is a very good point - one could take the streaming URL and put it in VLC and watch the actual bitrate at runtime (Tools > Codec Information > Statistics).

Here's an article on how different profiles affect quality:
http://www.adobe.com/devnet/adobe-media ... oding.html
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