[AppleTV] CrystalHD + BBC HD rendering issue.
#1
I'm apologise if this and is a known issue. I have spent a couple of months searching and waiting for someone else to post but no luck. xbmc+crystalhd is awesome and even if it can't be fixed I will be happy for some insight as to the cause.

I download the HD TV shows from the BBC and a few months ago they changed the way they encode them. My appleTV+crystalHD now has problems rendering them, they seem stretched (missing the bottom 20-30%) they also have what looks like interlaced lines over the stop 20% of the screen.

If I switch to software they render fine but obviously I get dropped frames with it being HD.

Using deductive reasoning I think the issue could be something to do with the resolution, the BBC seemed to change from 1280x720 to 1280x724 media info is below.

Also here is a photo of the TV screen (they look like scan-lines captured by the camera but they are not) http://imgur.com/dTqnl

[11:26:15] warren@burt:/mnt/raid/media/_tv/BBC/HD $ mediainfo Wonders_of_the_Solar_System_-_5._Aliens_b00rz5ys_default.mp4
General
Complete name : Wonders_of_the_Solar_System_-_5._Aliens_b00rz5ys_default.mp4
Format : MPEG-4
Format profile : Base Media
Codec ID : isom
File size : 1.16 GiB
Duration : 59mn 12s
Overall bit rate : 2 799 Kbps
Writing application : Lavf52.55.0

Video
ID : 1
Format : AVC
Format/Info : Advanced Video Codec
Format profile : [email protected]
Format settings, CABAC : Yes
Format settings, ReFrames : 5 frames
Codec ID : avc1
Codec ID/Info : Advanced Video Coding
Duration : 59mn 12s
Bit rate mode : Variable
Bit rate : 2 699 Kbps
Width : 1 280 pixels
Height : 724 pixels
Original height : 720 pixels
Display aspect ratio : 16:9
Original display aspect ratio : 16:9
Frame rate mode : Variable
Frame rate : 25.000 fps
Minimum frame rate : 12.500 fps
Maximum frame rate : 50.000 fps
Standard : PAL
Resolution : 8 bits
Colorimetry : 4:2:0
Scan type : Progressive
Bits/(Pixel*Frame) : 0.116
Stream size : 1.12 GiB (96%)

Audio
ID : 2
Format : AAC
Format/Info : Advanced Audio Codec
Format version : Version 4
Format profile : LC
Format settings, SBR : Yes
Format settings, PS : No
Codec ID : 40
Duration : 59mn 12s
Bit rate mode : Variable
Bit rate : 96.0 Kbps
Channel(s) : 2 channels
Channel positions : Front: L R
Sampling rate : 48.0 KHz
Stream size : 40.1 MiB (3%)

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#2
Hi,

You say you "downloaded them", off iPlayer HD? I'm guessing becauses of the low bitrate (about 3megabits). Or did you actually capture this off a bSkyB/VM/DVB-T feed?

In effect you shouldn't need to kick in CrystalHD if the stream's only a couple of megabits. Upload an XBMC.log for Davilla - perhaps upload a small sample too (use mkvmerge and split file size after 50Mb)

I think you have problems because the frame rate varies. This is a no go. It's varying from 12.5fps to 50.0 fps. Kind of a wierd encode, probably so Beeb can squish in as much PQ at as little a bitrate as possible

Also add mediainfo output (pastebin it) for a video that works so we can contrast
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#3
Sam.Nazarko Wrote:Hi,

You say you "downloaded them", off iPlayer HD? I'm guessing becauses of the low bitrate (about 3megabits). Or did you actually capture this off a bSkyB/VM/DVB-T feed?

Also add mediainfo output (pastebin it) for a video that works so we can contrast

I downloaded them using a perl script called get_iplayer. It uses flvstreamer + ffmpeg.

Here is the mediainfo from the one that works, same series only a few weeks apart.

http://pastebin.com/hhYu1ADC

Here is a sample of the video snipped using mkvmerge as requested. http://felix.moom.co.uk/sample.mkv

I'm at work now so can't get the XBMC.log but will get it later.

Thanks for your help.
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#4
3 significant changes between your original recordings and your new ones:

1. Original video is L3.2, other is profile 4.1 - shouldn't make a difference.
2. Resolution is different as you noted shouldn't make a difference.
3. Here's the problem though. The one that works has a constant frame rate, 25FPS, the one that doesn't has a variable frame rate. This is what I suspected earlier.

Sorry but clearly the Beebs change in encoding techniques has messed you over. Have you considered downloading your content in 720p/1080i from BBC HD or recording it? You're a license payer (atleast I hope Wink, and your already circumventing DRM of iPlayer so really there's no moral issues for you as you would be doing what you're doing now. Alternatively, you could transcode (but lose quality, and it takes time) But truth be told - the video looks quite low bitrate, around 3megabits. I think the aTV could handle this without Crystal HD, try turning off the CrystalHD render temporairily and see if it plays alright (not ideal but if it does it for now)

Think CrystalHD can't handle a variable frame rate at this point of time, maybe Davilla will chime in and tell us. XBMC.log will be appreciated by him, so definately put that up

Hope this helps

Oh and just realised this was your first thread. Welcome Smile
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#5
This probably wont work but have you changed the 'interlaced handling' method setting? I had a similar problem with certain 4:3 DVD ISOs and that fixed it up... worth a try.
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#6
Content is progressive but has variable frame rate, wierd.

Interlaced is not supported by Crystal anyway - deinterlacing has no effect
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#7
I'm away from my CrystalHD boxes for the next few days, no help from me till then.
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#8
Sam.Nazarko Wrote:Hi,

Upload an XBMC.log for Davilla

Below is a link to an xbmc.log from a different video with the same problem.
http://pastebin.com/m56C92vu

thanks for looking into it.
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#9
Ok some more info:

I have having the same issue with video's which don't have a variable framerate.

Here is the mediainfo for one:

http://pastebin.com/031QCFqY

and here is the xbmc.log for it:

http://pastebin.com/6LS6PuUk

I'm using the svn from today.

30MB Sample
http://dc.moom.co.uk/sample.mkv
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#10
Hasn't downloading iPlayer come to an end now? I heard getiplayer had stopped gettingiplayer.
Check out my stationery blog- http://www.tailormadeinvites.co.uk
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#11
Shoesy Wrote:Hasn't downloading iPlayer come to an end now? I heard getiplayer had stopped gettingiplayer.

Someone took over development http://git.infradead.org/get_iplayer.git
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#12
Sweet! (clicks update button on getiplayer automator) Damn Sad

Oh well - looks like there is hope Smile
Check out my stationery blog- http://www.tailormadeinvites.co.uk
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#13
I am now almost certain that my issue stems from the video resolution.

These are two video's both are almost identical (see image below) the one on the left plays fine the one on the right I get a strange stretched picture. The only thing which seems to differ is the height and "Original Height".

I found (on another forum) this quote:

Quote:Difference between "Height" and "Original height" is that the camera records in 1088 pixels (original height) but the container has been modified by the muxer in the camera to read 1080 pixels for compatibility reasons, because else the HDMI output of the camera will not synch with HDTV screens - this require the standard resolution of 1080p

Any help or information is appreciated, thanks!

Image
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#14
Just found this thread... you'll just have been notified of my reply, and come leaping over in the vain hope that I have a solution... but, alas, no - sorry. I do have a similar problem, though, although mine is related to VDPAU on ION on Ubuntu (mostly a thread of me talking to myself while trying to find the problem).

I can confirm that it's a resolution issue... the 724 lines should be cropped, but it seems that not all players understand what to do, and behaviour varies as to how they thus respond. VLC works fine; Quicktime chokes; mplayer works; XBMC seems to struggle.

What I haven't nailed down yet is *where* it goes wrong. I don't know if it's an ffmpeg issue or an XBMC issue. It was introduced into XBMC along with an ffmpeg update, so I suspect that's where the problem lies for me.

Not sure that's at all relevant to you, but it might be - the worst you can do is ignore me. But if it's relevant, keep an eye on my thread/diary on the off chance I get somewhere useful.
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[AppleTV] CrystalHD + BBC HD rendering issue.0