C1 Kodi V1.2 (released 1/20/2015) MPEG-2 Problems

by **rober1s** » Wed Jan 21, 2015 4:34 am

Hi,

This latest version released today still has problems playing MPEG Level 2, the video is choppy. This is on a fresh install of
ubuntu-14.04.1lts-lubuntu-odroid-c1-20150120.img, released this morning.

Here's the codec info for the video from VLC, where the file plays properly:

Type: Video
Codec: MPEG-1/2 Video (mpgv)
Resolution: 720x480'
Frame rate: 29.970030
Decoded format: Planar 4:2:0 YUV

Type: Audio
Codec: A52 Audio (aka AC3) (a52 )
Channels: Stereo
Sample rate: 48000 Hz
Bitrate: 224 kb/s

by **mdrjr** » Wed Jan 21, 2015 6:34 am

No useful information here.. sorry..
PM me a test file...

MPEG2 was fine for me... Are you playing that from the network or local?

by **rober1s** » Wed Jan 21, 2015 7:56 am

It is a file on my NFS server, gigabit network. All my media is nsf-mounted on the Kodi C1 server.

You can find a short sample of the file here:

http://www.parrot-farm.net/Odroid/MPEG2-test.mpg

Other formats work fine, even 1080p Matroska, it is just this type of mpeg2 that is giving Kodi problems on the C1.

by **mdrjr** » Wed Jan 21, 2015 8:39 am

Yeah.. Thank you for the file.. i'll see if I can fix it.

by **rober1s** » Wed Jan 21, 2015 8:43 am

Great, much appreciated.

by **rober1s** » Thu Jan 22, 2015 2:06 am

I uploaded another mpeg2 test file that exhibits the same choppy behavior, in case you can use a second one:

http://www.parrot-farm.net/Odroid/MPEG2-test2.mpg

by **danicor** » Thu Jan 22, 2015 6:07 am

I have several problems with mpeg-4 (xvid) too

by **mdrjr** » Thu Jan 22, 2015 6:12 am

Don't off-topic. We are talking about MPEG2 here!
Also post a test file..

by **rober1s** » Thu Jan 22, 2015 6:17 am

Re: mpeg-2, and just fwiw: out of my collection of 2,250 movies, 234 or about 10% are mpeg-2 format.

by **mdrjr** » Thu Jan 22, 2015 6:22 am

I didn't got that issue yet really

I tested several files prior release...

by **rober1s** » Fri Jan 23, 2015 3:30 am

Additional information: I dusted off the old Raspberrry Pi B Raspbbmc box that the new Odroid-C1 replaced and put it back on the network. The Pi version of Kodi is able to play the mpeg2 files flawlessly.

The Pi is running Raspbmc, kernel 3.12.21, and its Kodi version is 14.0 Git: 2014-12-24-e044d5a-dirty

Maybe this will help you chase down whatever the codec problem is on the C1.

by **mdrjr** » Fri Jan 23, 2015 8:49 am

Nope it doesn't help..
VPU on rPi is completely different..

I'm checking if the actual file type/properties is supported or not.

by **rober1s** » Fri Jan 23, 2015 3:07 pm

I don't quite understand: you are going to check if mpeg level 2 is a supported format? Supported by whom?

http://en.wikipedia.org/wiki/MPEG-2

by **memeka** » Fri Jan 23, 2015 3:10 pm

by the hardware decoder; that is, if the video processing unit in the C1 supports decoding MPEG-2; otherwise the CPU will decode it, and it's not as good.

by **rober1s** » Fri Jan 23, 2015 3:22 pm

I see, thanks.

by **rober1s** » Mon Jan 26, 2015 7:08 am

I've written up my experiences in using C1s as replacements for a couple of Raspberry Pis that I've had in service for the past 18 months.

http://things-linux.blogspot.com/2015/01/odroid-c1.html

by **hellonearthis** » Mon Jan 26, 2015 10:12 am

The Pi has a MPEG-2 licence system to help hardware playback.
http://www.raspberrypi.com/mpeg-2-license-key/

by **rober1s** » Mon Jan 26, 2015 10:24 am

That's true, they do. However I don't believe that is the problem here, since there are any number of open source players that do not have the same problem with mpeg level 2 media. VLC, for example.

I suspect that the problem with the C1 is in the Mali 450 GPU driver.

by **memeka** » Mon Jan 26, 2015 11:15 am

Mali is not doing any video decoding. Just 3D.

by **rober1s** » Mon Jan 26, 2015 1:45 pm

So what do you suppose the problem is, then?

by **memeka** » Mon Jan 26, 2015 2:26 pm

the amlogic video decoding unit, see source code https://github.com/mdrjr/c1_aml_libs and the aml codec for kodi, see source code here: https://github.com/mdrjr/xbmc/tree/k_c1 ... decs/Video

by **rober1s** » Mon Jan 26, 2015 2:55 pm

So, you'd like me to conduct a code walkthrough?

by **memeka** » Mon Jan 26, 2015 4:03 pm

rober1s wrote:So, you'd like me to conduct a code walkthrough?

i've shown you where the issues you are having are coming from. you can do whatever you want, why not having a look at the code and identifying the issues?

by **rober1s** » Mon Jan 26, 2015 5:41 pm

That was rather immature of you. If you need to have a complete outsider find and fix code bugs for you, perhaps you have the wrong developers assigned to the project.

by **memeka** » Mon Jan 26, 2015 6:39 pm

rober1s wrote:That was rather immature of you. If you need to have a complete outsider find and fix code bugs for you, perhaps you have the wrong developers assigned to the project.

outsider of what? i am a person just like you, i don't have any developers. in case it's not clear, i am not affiliated with HK and was just trying to help you.

by **rober1s** » Tue Jan 27, 2015 12:14 am

Well, I am a developer, and the last thing I'd do if I had a bug somewhere in a large, complex code base of mine would be to invite a complete outsider to come muck around in it.

The best action here is what has already been done: report the problem, provide an input file that allows the developers to replicate the problem, and then let them fix it. Either they will, or they won't.

by **rober1s** » Tue Jan 27, 2015 1:40 am

PS, memeka: Sorry for sounding cranky. I was feeling cranky, nothing you said was justification for me being a dick towards you. Sorry.

--Doug

by **memeka** » Tue Jan 27, 2015 6:06 am

the code is all open-source, you can have a look at it and try to fix your problems, especially if you are a developer.
e.g. - i want to use C1 for an arcade, but SDL2 is working only in X11 mode on the C1. So i got the sources from SDL2 and made a framebuffer interface for it. SDL2 it's a big project, but it does not mean I can't look for a small bit I am interested in.
For Kodi, you only look at the video codec. That's 4 files in https://github.com/mdrjr/xbmc/tree/k_c1 ... decs/Video : AMLCodec.cpp/h and DVDVideoCodecAmlogic.cpp/h ... these 4 files do use apparently the aml_libs i linked earlier... you can compile your own kodi and try to debug the issue... hw video decoding in kodi for odroid u2/u3 and xu/xu3 for example was developed by forum member @oversun. A lot of rpi code was also done by volunteers / community members. it helps reporting too, but if you can do more, why not?

by **rober1s** » Tue Jan 27, 2015 8:25 am

Indeed, why not. Thanks.

by **rober1s** » Thu Feb 05, 2015 7:13 am

Update on this: I played one of the problematic mpeg-2 files on the C1 using the included Gnome MPlayer tool, and it plays fine without any of the choppyness that Kodi has. The test file is here: http://www.parrot-farm.net/Odroid/MPEG2-test.mpg

Also, after updating the kernel to 3.10.67-55 today, and also updating Kodi, Kodi has no audio.

by **mdrjr** » Thu Feb 05, 2015 8:56 am

Got it.. It was my attempt ot get Psasthrou working on Ubuntu.
A update should be live soon with a fix for it.

by **rober1s** » Thu Feb 05, 2015 9:09 am

Very cool, look forward to the update. Hopefully it will include audio, as well.

by **sweets123** » Fri May 22, 2015 11:09 am

Sorry to resurect an old thread but Ive been searching for an hour and cant find a solution. Is the MPEG2 decoding problem fixed?

I have tried the lastest Android and ubuntu roms and after a tonne of messing around, I cannot find a solution.

Is there compiled software/rom with Kodi presently or is it still waiting to be fixed? Thanks

by **stmicro** » Fri May 22, 2015 11:35 am

The latest Kodi on the Android could play well several MPEG2 video files a couple of weeks ago. But I can't recall the version of Kodi because I'm running the OMV on the C1 now.
Try to install the latest Kodi from Googleplay.

by **sweets123** » Sat May 23, 2015 4:54 pm

Thanks for the tip. I found some files like DVB TV broadcasts played ok but others either locked up kodi or were choppy. Will wait for a fix I guess.

by **rober1s** » Sat Nov 21, 2015 2:01 am

I see that as of 11/20/2015 the latest Kodi still has the same problems playing MPEG-2 video. Are there plans to fix this?

by **meveric** » Sat Nov 21, 2015 8:48 am

It seems to be a hardware limitation, or probably a codec limitation that only AmLogic seem to be able to solve (if it can be solved at all)

by **rober1s** » Sat Nov 21, 2015 10:43 am

Well, it is most definitely not a hardware problem, since as discussed earlier in this thread, MPEG-2 videos play fine when using VLC or other distribution- or Ubuntu-supplied media players. It is only Kodi that seems to have problems with MPEG-2.

by **OverSun** » Sat Nov 21, 2015 6:47 pm

It is most definitely hardware problems then.

by **rober1s** » Sun Nov 22, 2015 2:40 am

Care to explain that?

by **meveric** » Sun Nov 22, 2015 3:19 am

simple..
using other players works, cause they are using "software decoder" which is working just fine, since the CPU is doing all the work.
Kodi is using hardware decoder from AmLogic, which is broken for MPEG2.

by **crashoverride** » Sun Nov 22, 2015 4:00 am

My opinion is that the issue lies in Kodi's use of the MPEG2 codec rather than the hardware being defective.

The reason for this assertion is:
1) MPEG2 is a licensed product. To receive that license, the manufacturer must pass conformance tests.
2) The Amlogic S805 used in C1 was designed for set top boxes. An OTT product that could not decode the ATSC/DVB-* MPEG2 streams would be unsellable.

The key thing that stood out to me about the sample video linked earlier in this thread is that it is 480i (interlaced) not 480p (progressive). This means there are two fields per frame rather than one. Kodi needs to take this into consideration as well as how the other components involved (post processing) deal with converting that to a HDMI display that may be progressing or interlaced (1080p/1080i) and of varying refresh rates (3:2 pulldown).

My recommendation is to start debugging at Kodi and work your way backwards through the pipeline. A good start would be to take the "bad" video posted earlier and remove all the extra streams except for video. A media player uses a different clocking mechanism when there is no audio present.

No matter where the problem lies there is a software solution to it. Everything from Kodi to the kernel drivers to the microcode used on the VPU is modifiable.

by **meveric** » Sun Nov 22, 2015 4:09 am

crashoverride wrote:2) The Amlogic S805 used in C1 was designed for set top boxes. An OTT product that could not decode the ATSC/DVB-* MPEG2 streams would be unsellable.

I think it was @wrxtasy in the OpenELEC forum who said this issues affects ALL AMLogic SoCs not only the one used for the ODROID C1. Most of which are used as set top boxes. I wonder if they use a workaround and simply software decode it or something.

crashoverride wrote:No matter where the problem lies there is a software solution to it. Everything from Kodi to the kernel drivers to the microcode used on the VPU is modifiable.

True, question is if where is the right point of fixing it. Some people say it's the VPU that's causing the issue. I think Kodi is just redirecting everything to the decoder and doesn't do much more than that for AMLogic.
So I'm not sure if Kodi really is the issue here. (Please don't kill me if I understood that wrong

)

by **crashoverride** » Sun Nov 22, 2015 4:25 am

meveric wrote:I think it was @wrxtasy in the OpenELEC forum who said this issues affects ALL AMLogic SoCs

The key point there is it affects Kodi on all AMLogic platforms (all using Kodi's AMLogic interface code)

meveric wrote: I think Kodi is just redirecting everything to the decoder and doesn't do much more than that for AMLogic.

That is also how I understand it to be. On other platforms, the codec runs as-fast-as-it-can. Then Kodi presents a frame to the framebuffer via GLES. On C1, its different. The codec runs real-time: it handles frame sync and vsync in an interrupt and presents the video independently from what Kodi and the framebuffer are doing.

https://github.com/hardkernel/linux/blob/odroidc-3.10.y/drivers/amlogic/amports/vmpeg12.c#L248
You can see in the code that a correct PTS is much more important there in addition to 3:2 pulldown taking place (line 336).

So there is much more that Kodi needs to worry about when using the codec than just throwing data at it.

by **meveric** » Sun Nov 22, 2015 4:32 am

But issn't the amcodec used by Kodi coming from the AMLogic guys?
As far as I know this codec is even upstream in Kodi ever since Kodi 14.

by **crashoverride** » Sun Nov 22, 2015 4:41 am

meveric wrote:But issn't the amcodec used by Kodi coming from the AMLogic guys?

Someone else will have to answer that one. I do not know.

[Edit]
The point I hoped to make was that display timing is important. Additionally, the state of the post-processor (de-interlacer) should be verified correct for the display mode.

by **wrxtasy** » Sun Nov 22, 2015 6:18 pm

From what I have found with Kodi on all AMLogic Android / OpenELEC / Linux platforms:

- Interlaced 25/50Hz mpeg2 in .ts and .mkv containers plays back just fine. I watch broadcast TV with this all the time.

- Interlaced mpeg2 content found in .vob containers which originate from ISO DVD Rips plays back with stuttering problems when using amcodec (libamcodec) Hardware decoding.
This is what I am talking about:
https://mega.nz/#!utliWBia!fSA0DburGv0z ... TPWRtCt9lk

I do not know if this is a Kodi demuxer problem, and deinterlace issue or a decoder or even a Kernel / VPU problem.

What we really need is a another Hardware decoded video player to see if Kodi is the problem. I've tried a few in Android but they software decode. I will keep hunting.

The same playback issue occurs in the older AMLogic SoC in the WeTek Play as well. The new WeTek Core has the same problem.

Questions for the HardKernel Devs

a) Are AMLogic aware of this issue ?
b) If they are not, I kindly ask that you send them some samples please.
c) If AMLogic are aware of this problem can you at the very least give Users here on the Forum some feedback that AMLogic may or may not be looking at the issue ?

This looks like a very long standing playback problem. End users have been kept in the dark long enough. I ask the HardKernel devs to ask AMLogic if they are at least doing anything. Some feedback within the week would be appreciated.

by **crashoverride** » Sun Nov 22, 2015 6:54 pm

wrxtasy wrote:I ask the HardKernel devs to ask AMLogic if they are at least doing anything.

Again, its just my opinion, but I don't believe either HK or AMLogic "owns" this problem. It occurs with Kodi on other S805 boards, so WeTek could just as easily raise the issue.

Looking at the source code:
https://github.com/mdrjr/xbmc/commit/73fae08231724b1d883a5678b78d73cb630186a6

Copyright (C) 2005-2011 Team XBMC
http://www.xbmc.org

The issue should probably be raised with the Kodi (XBMC) Team or the author that made the commit: https://github.com/davilla. Its more likely that a Kodi developer could work with AMLogic to resolve the issue than 3rd parties (reproducible test cases, etc that would demonstrate an actual issue for AMLogic to resolve rather than just a bug in Kodi).

by **rober1s** » Wed Nov 25, 2015 2:00 am

wrxtasy wrote:
This looks like a very long standing playback problem. End users have been kept in the dark long enough. I ask the HardKernel devs to ask AMLogic if they are at least doing anything. Some feedback within the week would be appreciated.

So far as I can tell, nothing has been done on this issue since I first reported in on Wed Jan 14, 2015 10:28 am.