MPEG4 (XVID) playback issues.

[Pihkal]

Hi,

i'm breaking my head about this xvid-playback issue so i finally started a thread about it.
Here's the problem (sorry about the bad picture quality):





This however doesn't happen all the time,it plays ok but then for a second or two i get the garbage images above and this repeats multiple times over the entire episode.

MediaInfo data:

Code:

General
Complete name                            : Z:\Torrent\family guy season3\Episode 302 - Brian Does Hollywood.avi
Format                                   : AVI
Format/Info                              : Audio Video Interleave
File size                                : 136 MiB
Duration                                 : 22mn 33s
Overall bit rate                         : 844 Kbps
Writing application                      : VirtualDubMod 1.5.1.1a (build 1639/release)
Writing library                          : VirtualDubMod build 1639/release

Video
ID                                       : 0
Format                                   : MPEG-4 Visual
Format profile                           : Advanced Simple@L3
Format settings, BVOP                    : No
Format settings, QPel                    : No
Format settings, GMC                     : 2 warppoints
Format settings, Matrix                  : Default (H.263)
Codec ID                                 : XVID
Codec ID/Hint                            : XviD
Duration                                 : 22mn 33s
Bit rate                                 : 643 Kbps
Width                                    : 640 pixels
Height                                   : 480 pixels
Display aspect ratio                     : 4:3
Frame rate                               : 23.976 fps
Color space                              : YUV
Chroma subsampling                       : 4:2:0
Bit depth                                : 8 bits
Scan type                                : Progressive
Compression mode                         : Lossy
Bits/(Pixel*Frame)                       : 0.087
Stream size                              : 104 MiB (76%)
Writing library                          : XviD 0.0.09 (UTC 2003-03-25)

Audio
ID                                       : 1
Format                                   : MPEG Audio
Format version                           : Version 1
Format profile                           : Layer 3
Mode                                     : Joint stereo
Mode extension                           : MS Stereo
Codec ID                                 : 55
Codec ID/Hint                            : MP3
Duration                                 : 22mn 33s
Bit rate mode                            : Constant
Bit rate                                 : 192 Kbps
Channel(s)                               : 2 channels
Sampling rate                            : 48.0 KHz
Compression mode                         : Lossy
Stream size                              : 31.0 MiB (23%)
Alignment                                : Split accross interleaves
Interleave, duration                     : 42 ms (1.00 video frame)
Interleave, preload duration             : 464 ms

The problem always occurs,upnp-,samba-,usb-source...it doesn't make any difference.
I'm on the latest xbian-build (RC2 compiled yesterday) but the previous version also had this problem.
I'm using a 128MB/128MB memorysplit.

Any ideas?

Greetz

[Koenkk]

Can you share a sample?

[Pihkal]

I would if i knew how to?
Since i have 0 experience with video editing i'm finding it pretty hard to cut a few seconds out of an episode and saving it to the excact same format...
I could upload the entire episode but this would probaly be illegal...

Edit:

i've sort of managed to cut a short piece and keep the codec.
There are a few repeat/skips in the sample,please ignore this.
The decoding issues are clearly visible.

sample.avi (7 MB)

[rikardo1979]

Ive sent you a PM, so please response

[stelford]

MPEG-4 updates the picture by chunks/blocks. It detects changes and tries to only update those. When your processor can't keep up with the updates, you tend to get what you displayed in your pictures.

If you can, try turning off the subtitles. In anime (especially) I have noticed that soft-coded subs (such as those in mpeg4/h264) cause all sorts of juddering and slow playback. Libass is not as "performant" as it could be, I guess.

My solution, until libass is sorted, is to convert the mpeg4's into divx's. The reason for this is, that the subtitle stream is then 'hard coded' into place, rather than inside another stream in the mkv/mp4/whatever.

The command I used on my linux machine to batch convert was; for files in *.mkv; do mencoder -o "${files%.mkv}.avi" -oac mp3lame -ovc xvid -ass -xvidencopts pass=1 "$files" &> "${files%.mkv}.translog"; done

Hopefully, I am wrong, but.. there is definitely something 'funky' with soft subtitles and the pi

[Pihkal]

Well,it does happen mostly when the full screen has to get updated.
First i also thought it was caused by the lack of cpu-power,since mpeg4 isn't hardware accelerated,however when i ssh into the pi and run htop it shows around 50% cpu usage so there's plenty cpu power available.
My Soc is oc'd,the arm is doing 1050 Mhz,the core is running at 525 Mhz,the oc is stable,tested playing quake 3 in raspbian so this should also be ok.
I never use subtitles,and i've disabled them in the audio settings,no change..

[rikardo1979]

thanks for the file to test it
but I haven't find any way how to fix this issue, and it is really happening no matter what I've tried
Looks the RPi doesn't like this type of media file, for some reason.
And it is really easy file, so the RPi shouldn't have a prob to play it.
So I have no clue here. sorry m8

[Pihkal]

Thanks for looking into it any way.
I don't consider it as a big issue since 95% of my media plays fine.