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View Full Version : [Solved] Strange "waves" over image on x264 encoded video


Lyris
8th April 2011, 23:11
Just recently I was using x264 to convert some DigiBeta material to Blu-ray Disc (not for a commercial release, but for a one-off festival screening).

The disc plays fine in set top players and most Windows playback programs, but, using Arcsoft TotalMedia Theatre, you can observe a weird sort of diagonal 'wave' like pattern over the image. This behaviour has been confirmed on two different machines and doesn't happen with any store-bought BDs I've tried to play. The problem also disappears when I choose to enable Hardware Acceleration in the player.

It's quite hard to see in a still frame, but this is a pretty good example, with the 4 slices making up the image being apparent: http://img64.imageshack.us/img64/5669/avcissue.jpg

Sample clip: http://landofwhimsy.com/upload/femmetest.avc (72mb)

Encode settings:

x264 --bitrate 28500 --preset faster --tune film --fps 24000/1001 --force-cfr
--weightp 1 --bframes 3 --nal-hrd vbr --vbv-maxrate 38000 --vbv-bufsize 30000
--level 4.1 --keyint 24 --b-pyramid strict --slices 4 --aud --colorprim "bt709"
--transfer "bt709" --colormatrix "bt709" --sar 1:1 -o G:\avc\test.avc D:\Digibeta\in.avs

Encoded with x264 core 114 r1924 08d04a4

Can anyone else replicate this? Should we be concerned or is the issue on the player side? I have seen the same issue (albeit in a much more mild manifestation) with VLC Media Player when its hardware acceleration is turned off.

sneaker_ger
8th April 2011, 23:37
I can also see the slices when using ffdshow (both libavcodec and ffmpeg-mt) 3785 generic. But only when seeking, not when viewing the sample from start to end. (Muxed with mkvmerge)

Dark Shikari
9th April 2011, 00:41
That's almost certainly a bug in the deblocking filter in the program's software decoder. Most likely the bug only occurs if disable_deblock_filter_idc == 0 (deblocking enabled between slices) and multislice is on.

Lyris
9th April 2011, 01:18
Right you are, DS - I encoded a new test with --no-deblock in the line and the playback is clean. I guess most Hollywood BD movies are encoded with the deblocking filter off so the issue wasn't appearing with those. Thanks!

Dark Shikari
9th April 2011, 01:19
No, most movies have the deblocking filter on. Most likely they have deblocking disabled between slices (disable_deblock_idc == 2).