Unsupported GMC

[NicL]

Unsupported GMC message received when I tried to play XVID MPEG-4 file - read the Wikipedia page on Global Motion Compensation but do not quite understand why I got this massage.  Have played this file on PC and similar devices and have not received this message before.

[Insomniac]

Please supply MediaInfo text output of the file for analysis.

[NicL]

General
Complete name                    : ****.avi
Format                           : AVI
Format/Info                      : Audio Video Interleave
File size                        : 350 MiB
Duration                         : 42mn 7s
Overall bit rate                 : 1 163 Kbps
Writing application              : Nandub v1.0rc2
Writing library                  : Nandub build 1853/release

Video
ID                               : 0
Format                           : MPEG-4 Visual
Format profile                   : AdvancedSimple@L5
Format settings, BVOP            : Yes
Format settings, QPel            : No
Format settings, GMC             : No warppoints
Format settings, Matrix          : Default (H.263)
Muxing mode                      : Packed bitstream
Codec ID                         : XVID
Codec ID/Hint                    : XviD
Duration                         : 42mn 7s
Bit rate                         : 1 019 Kbps
Width                            : 640 pixels
Height                           : 352 pixels
Display aspect ratio             : 16:9
Frame rate                       : 25.000 fps
Resolution                       : 24 bits
Colorimetry                      : 4:2:0
Scan type                        : Progressive
Bits/(Pixel*Frame)               : 0.181
Stream size                      : 307 MiB (88%)
Writing library                  : XviD 1.0.2 (UTC 2004-08-29)

Audio
ID                               : 1
Format                           : MPEG Audio
Format version                   : Version 1
Format profile                   : Layer 3
Codec ID                         : 55
Codec ID/Hint                    : MP3
Duration                         : 42mn 7s
Bit rate mode                    : Variable
Bit rate                         : 131 Kbps
Channel(s)                       : 2 channels
Sampling rate                    : 48.0 KHz
Resolution                       : 16 bits
Stream size                      : 39.6 MiB (11%)
Alignment                        : Aligned on interleaves
Interleave, duration             : 24 ms (0.60 video frame)
Interleave, preload duration     : 453 ms

[NicL]

Please supply MediaInfo text output of the file for analysis

Did I supply the correct Mediainfo?  If not, please le me know what exactly you need to enable you to investigate this matter.

[Mede8er1]

Pls get we get a copy of this file in order to investigate this issue. 

[NicL]

Sure, provide me with your FTP server details and I will gladly upload the file in question.

[Maudrid]

Hi, I'm getting a similar problem with some of my videos. (Xvid)
I read a post on the PlayOn! forum that said that DivX supports only one level of GMC and that Xvid supports 3.
Most players support the 1 level that DivX uses and not the other 2 that Xvid supports.
Is this a hardware support issue or can the other 2 levels of GMC eventually be supported on the media player with a software update? The post stated that the first level is support for panning motion and that the other 2 levels are more CPU intensive.

[tjun]

I got the same message for some video.
The video can be played, but it displays scramble blocks every few seconds.

[lazy_67]

I have the player since a week ago and I'm very happy with it, but today I found a file that gave me the "Unsupported GMC" error.

This is the MediaInfo text details:

General
Complete name                    : xxx.avi
Format                           : AVI
Format/Info                      : Audio Video Interleave
File size                        : 1.16 GiB
Duration                         : 1h 34mn
Overall bit rate                 : 1 768 Kbps
Writing application              : VirtualDubMod 1.5.10.2 (build 2540/release)
Writing library                  : VirtualDubMod build 2540/release

Video
ID                               : 0
Format                           : MPEG-4 Visual
Format profile                   : Advanced Simple@L5
Format settings, BVOP            : Yes
Format settings, QPel            : Yes
Format settings, GMC             : 3 warppoints
Format settings, Matrix          : Default (MPEG)
Muxing mode                      : Packed bitstream
Codec ID                         : XVID
Codec ID/Hint                    :
Duration                         : 1h 34mn
Bit rate                         : 1 606 Kbps
Width                            : 704 pixels
Height                           : 384 pixels
Display aspect ratio             : 16:9
Frame rate                       : 25.000 fps
Resolution                       : 8 bits
Colorimetry                      : 4:2:0
Scan type                        : Progressive
Bits/(Pixel*Frame)               : 0.238
Stream size                      : 1.06 GiB (91%)
Writing library                  : XviD 1.1.0 (UTC 2005-11-22)

Audio
ID                               : 1
Format                           : MPEG Audio
Format version                   : Version 1
Format profile                   : Layer 3
Mode                             : Joint stereo
Format_Settings_ModeExtension    : MS Stereo
Codec ID                         : 55
Codec ID/Hint                    : MP3
Duration                         : 1h 34mn
Bit rate mode                    : Variable
Bit rate                         : 149 Kbps
Channel(s)                       : 2 channels
Sampling rate                    : 48.0 KHz
Stream size                      : 100 MiB (8%)
Alignment                        : Aligned on interleaves
Interleave, duration             : 24 ms (0.60 video frame)
Interleave, preload duration     : 130 ms
Writing library                  : LAME3.90.
Encoding settings                : -m j -V 2 -q 2 -lowpass 19 --vbr-old



I also uploaded a short clip from this file on the ftp site: the file name is Unsupported GMC.avi.zip

Thank you for any help on this matter, I have an entire TV serie with the same encoding and I wouldn't like to re-encode it...

Regards

[Insomniac]

Here is a bit of Wikipedia info on 'Global Motion Compensation', or 'GMC' (click to follow the link)

Furthermore, a little Google research reveals this:

• All Realtek 1073,1283 have this problem - Xvid 1280x720 will show "GMC not supported"
• Realtek 1073,1283 do not support more than one GMC warppoint.
• When converting Xvid's "3-warp-point GMC" encoding option and an "MPEG" matrix (using an outdated AVI-Mux GUI) will cause this.

Common fields with these "Unsupported GMC" files:
  Writing library                  : XviD 1.1.0 (UTC 2005-11-22)
or
  Writing library                  : XviD 1.0.2 (UTC 2004-08-29)
- these libraries are old.

And obviously you'll see this field in your MediaInfo 'TEXT' output:
  Format settings, GMC             : 3 warppoints


Similar topic in Mede8er Forums are here:
  http://www.mede8erforum.com/index.php?topic=1060.0
and here:
  http://www.mede8erforum.com/index.php?topic=992.0
(perhaps I will merge these topics to keep the subject together)


Note that no respectable scene release-group is using warppoints any more - even Divx-playing DVD players can not support these due to the CPU-intensive requirement.
It would appear this is not going to be resolved with a simple firmware update - best solution would be to 're-aquire' a supported file or re-encode in a supported format without GMC.

[tachita]

Unsupported GMC message received when I tried to play XVID MPEG-4 file - read the Wikipedia page on Global Motion Compensation but do not quite understand why I got this massage.  Have played this file on PC and similar devices and have not received this message before.

NicL, from mediainfo log i dont see why your video give that message: no warp points, no qpel and good quantization.

lazy_67, your file seems like a true "Unsupported GMC", your file have 3 warp points, active QPEL and mpeg quantization.

this kind of videos will not play on  standalone players (hdd players or optical disc players - if exist one will be very expensive), chipset doesnt provide enough capabilities to implement aplications to support suck kind of scene &  frames prediction.
i believe there are some players that support  LIMITED QPEL or GMC, in fact all of these are a encoding problems, for good quality at small file size (low bitrates).
some variations of LIMITED QPEL or GMC might work but only with h263 quantization, not mpeg.
mpeg quantization is used for small file size and only with smooth filters (require more time & procesing capabilities), otherwise you'll get a harsher video with too many artefacts.
for short time, will not exist a support for GMC , who have files like that should try to remuxe them or try to rewrite header and index, if not work just reencode those files with same bitrates or a little higher.

[tachita]

insomniac, didnt see your post and in fact i repeated you, but i leave it so, 'cause is much helpful.

All Realtek 1073,1283 have this problem - Xvid 1280x720 will show "GMC not supported"

never try that, xvid at this resolution    dont have any, i'll do a test.
 if so might be a bug and not a chipset limitation.
is good to know that.

[Insomniac]

insomniac, didnt see your post and in fact i repeated you, but i leave it so, 'cause is much helpful.

Thanks for your input - your in-depth knowledge is clearly demonstrated and your contribution is always appreciated.

never try that, xvid at this resolution    dont have any, i'll do a test.
 if so might be a bug and not a chipset limitation.
is good to know that.

I don't have any of these either - this comment I found after a bit of research - your confirmation would be appreciated.

This still leaves me clueless as to NicL's reason for 'Unsupported GMC', if that was the error encountered for this specific file.

[lazy_67]

Thanks Insomniac and tachita, now I know a bit more about video encoding and I understand that I will never be able to see these files on my 42"   

Well, maybe I'll use some CPU time to convert them, hoping not to loose too much in the operation.

Regards

[Maudrid]

Just re-encode it with a supported codec and you will be fine.