De-interlacing help for HD file captured from Satellite TV

[nharikrishna]

I have captured 1080i video from Satellite HD Channels using AverMedia Game Capture HD II. I am in PAL region. The captured video is in H.264 format in MP4 container.

MediaInfo says the video has 50 Fps and it is interlaced. Shouldn't it say 50 fields per second and 25 frames per second? Below is the MediaInfo of the original file captured.



When I converted the video to a lower bitrate using AviDemux, MediaInfo says the file is progressive with 25 Fps. Why was the source 50 Fps? I captured Hollywood movies. Below is the MediaInfo of the converted file.



My other question is, the 'converted movie, despite showing as Progressive in MediaInfo, still has a lot of combing in fast moving scenes, on my progressive computer monitor. When I enable De-interlace in VLC, the combing is gone. Does it mean, AviDemux is not doing 'enough' de-interlacing while converting? What is the best strategy for me to edit the captured video (cuting out commercials), may be increase some brightness (I see many movies are low in brightness), and then converting to progressive video with a lower bitrate so that each movie fits in 1.5 GB or something? I want to use Freewares only, I hope it is possible. I am ready to use AviSynth if someone guides me, especialy, for an effective de-interlacing. Would I benefit from converting it to 720p as opposed to 1080p?

Thanks for your help.

[Cauptain]

I have a AGC2 but my captures are 1080i@59.94 at 15k bitrate.

After this I convert using RIPBOT264 with 4.1 profile slow, deinterlaced TFF 50/60 mode with 4096. Good to see.

Avidemux is not good choice for Aver captures.

[jagabo]

Unfortunately, when marketing started calling 25 fps interlaced video "50i" just to make it sound better, and then some developers followed suit, a huge mass of confusion was created. Oviously, 59i is twice as good as 25i, right? No, it's exactly the same thing with a different name. It's all 25 interlaced frames per second, 50 fields per second.

[Cauptain]

Based on your mediainfo log, you have old firmware too.

Get new firmware here: Game Capture HD II firmware 1.1.6

Release Note:
(1) Support HDMI Multi VSDB Monitor
(2) Minor bug fixes and other improvements

Firmware Upgrade Instruction
(1) Extract the downloaded *.zip file and copy the enclosed *.bin file to the root path of your USB Flash drive.
(2) Plug the USB Flash drive on to Game Capture HD II, go to Menu>>Settings>>Firmware Update.
(3) Follow the on-screen instruction to complete the upgrade.

* Game Capture HD II firmware 1.1.6 requires latest GameMate on Apple store (V 1.0.25) and Google play (V 1.0.25).

[manono]

My other question is, the 'converted movie, despite showing as Progressive in MediaInfo, still has a lot of combing in fast moving scenes, on my progressive computer monitor.

Movies, by definition, are not interlaced. It might be phase-shifted, poorly converted from NTSC, or something else. You should make available a short 5-10 second piece from the source, one with steady movement. Just deinterlacing it is almost certainly the wrong thing to do.

[Jerome7573_3]

Unfortunately, when marketing started calling 25 fps interlaced video "50i" just to make it sound better, and then some developers followed suit, a huge mass of confusion was created.

Right

Oviously, 59i is twice as good as 25i, right? No, it's exactly the same thing with a different name. It's all 25 interlaced frames per second, 50 fields per second.

It depends of who is talking. Here, MediaInfo says 50 **frames** per seconds, interlaced, so 100 fields per second (I don't say it is the real content, I say what the metadata is). MediaInfo never mixes fields and frames, there is never a field rate in MediaInfo, fps means frames per second in MediaInfo.

I imagine the file is a bit buggy (I see in the 2nd file that the MP4 header says 25 fps and the H264 VUI still says 50 fps, weird).

[jagabo]

MediaInfo says 50 **frames** per seconds, interlaced

Yes. And it's wrong. Some applications are now indicating 50 frames per second in the metadata fields of 25i video. The metadata/mediainfo are obviously wrong, there is no 50 frame per second interlaced video (100 fields per second) in broadcast video. Certainly not over commercial satellite broadcast.

[nharikrishna]

Thank you everyone for the replies.

@Cauptain, I will try and upgrade the firmware. I did that as soon as I purchased the device, but didn't realize one more version has been released. I used AviDemux because it has editing capability and I need to edit out the commercials. Does RipBot have the editing capability?

@manono, @Jerome7573_3, @jagabo, then it is the fault of the 'writing application' for reporting the fps wrongly?? In this case, Aver hardware device is capturing it in the first place, so it must be reporting it as '50i'. And when AviDemux converted it, it is writing it as 25p. What is interesting from the 2nd MediaInfo above, it says 'Frame rate: 25 Fps, Original frame rate: 50 Fps'. I am assuming the Aver device captures the video in the original frame rate that it is receiving the signal. I even tested it with different channels (stations), and all are being captured in 50i only (as per MediaInfo). Should I check it with some other program such as GSpot? My only interest in this is to make my resulting (converted) video as Blue-ray compliant, so that in future, I can burn those movies onto Blueray, playable on a settop blueray player (multiple movies on a single disc).

Another question is, would I benefit from converting it to 720p as opposed to 1080p, in terms of compatibility, combing, file size, still retaining the picture quality reasonably well?



I will try and post a sample of combing that I am seeing.

Regards

[manono]

Another question is, would I benefit from converting it to 720p as opposed to 1080p, in terms of compatibility, combing, file size, still retaining the picture quality reasonably well?

Unless and until you post a short sample one can only guess what you have and how it should be treated.

[Jerome7573_3]

MediaInfo says 50 **frames** per seconds, interlaced

Yes. And it's wrong.

In order to be clear: as I said in my first answer, MediaInfo is fully aware of fields vs frames.

Some applications are now indicating 50 frames per second in the metadata fields of 25i video.

This is not the case of MediaInfo.
MediaInfo reports 50 fps because the file reports 50 **frames** (not fields) per second.

The metadata/mediainfo

The purpose of my first answer was to explain to you that you don't need to write these words. Please stop to insinuate it is the case of MediaInfo.
I don't say that MediaInfo is bug free, but I am 100% sure it is not an issue of misunderstanding from the developer about frame vs field (the developer is fully aware that 50i is 25 frames per second).

there is no 50 frame per second interlaced video (100 fields per second) in broadcast video. Certainly not over commercial satellite broadcast.

Right.

It is the fault of the 'writing application' for reporting the fps wrongly??

MP4 is not the source container format. the "writing application" (the muxer) may be mislead by the H264 header metadata (maybe the muxer does not read the real frame rate which is base on timestamps). The source issue may be the broadcasted content, we can not know until you provide a dump of the Satellite data (i.e. MPEG-TS container, not remuxed).

My only interest in this is to make my resulting (converted) video as Blue-ray compliant, so that in future, I can burn those movies onto Blueray, playable on a settop blueray player (multiple movies on a single disc).

For the moment, I understand the container metadata of your second file is correct (25 fps) and the H264 header still have a problem (50 fps) and you can not know in advance if a player will like it or not (it is not Blu-ray compliant but most players don't care of this issue).
Anyway, without a file difficult to be sure of anything.


If you provide a sample file, I can check and confirm the MediaInfo report (I can provide a trace of the metadata which reports the frame rate and interlace flag). It will not help about how to get a good file, but you'll know the source of the issue.

Jérôme, developer of MediaInfo.

[nharikrishna]

The capturing device (Avermedia Game Capture HD II) captures the stream in .mp4 container. There is no option to change that. The device works in a standalone mode, where we plug in a USB hard drive and it captures to the hard drive. There is no MPEG-TS, neither there is option to connect it to computer for capturing.

I will post a sample of the captured video tonight, as is, unaltered.

regards

[jagabo]

MediaInfo says 50 **frames** per seconds, interlaced

Yes. And it's wrong.

In order to be clear: as I said in my first answer, MediaInfo is fully aware of fields vs frames.

Some applications are now indicating 50 frames per second in the metadata fields of 25i video.

This is not the case of MediaInfo.
MediaInfo reports 50 fps because the file reports 50 **frames** (not fields) per second.

Maybe I could have stated it more clearly but that is what I meant. Some applications have started writing 50 frames per second in the headers of 25i material. MediaInfo is wrong (about the true content of the file) because the headers are wrong.

[jagabo]

Another question is, would I benefit from converting it to 720p as opposed to 1080p

Converting to 720p50 rather than 1080p25 will give you smoother motion with true interlaced sources like live sports and news.

[manono]

Yeah, but he said he caps movies.

[nharikrishna]

Ok. I capture only Hollywood movies.

Here is a sample, unaltered. I extracted this sample using AviDemux with its COPY function.

Thanks for your help.

Regards

[Jerome7573_3]

Here is a sample, unaltered.

Thanks.
Here, MediaInfo does not correctly report frame rate information, and e.g. VLC is also fooled by such file (it also reports 50 fps)
FYI, there is no H264 frame rate header in your file (this is normal, but in such case MediaInfo can not compare metadata) and usually both fields (top and bottom fields) are transported in an unique MP4 packet so the MP4 packet rate is considered as the video frame rate. Here, there is 1 field per packet, and MediaInfo does not catch this difference 1 field per packet (your file) vs 2 fields per packet (the common method).
I patch it ASAP.

I am also interested by the converted video because the "50 fps" information is also not normal (maybe MediaInfo has also a problem with this file, maybe AVIdemux has a problem with such file).

[jagabo]

I am also interested by the converted video because the "50 fps" information is also not normal

ffVideoSource() for example (by default) returns 50 frames per second -- by duplicating each interlaced frame. You can use the fpsnum and fpsden arguments to get it to return 25 fps instead. Or simply decimate the 50 fps yourself with SelectEven(). It also delivers the interlaced frames woven out-of-phase, i.e., the source was 25 fps progressive but the output of ffVideoSource() has fields from different film frames together. They can be repacked into progressive frames with TFM() or SeparateFields().Trim(1,0),Weave().

[manono]

Ok. I capture only Hollywood movies.

Here is a sample, unaltered.

And as I speculated, progressive but phase-shifted. This kind of thing is fairly common in PAL television broadcasts and is also sometimes seen on PAL DVDs.

The last thing you want to do to such a source is deinterlace it. You just have to realign the fields properly (after removing the duplicate frames). Of the two ways jagabo suggested to do that, I'd go with the TFM option.

Always go over your sources carefully to try and understand what you have if it's the least bit out of the ordinary. Or ask here. And when asking here, always provide a short sample.

[nharikrishna]

Thank you all for the investigations and replies. This is too technical for me. Could you please tell me the sequence of steps to be followed after the original video is captured? What I want to do is, remove commercials, and then re-encode at a lower bitrate to fit 1.5 GB (or 2 GB max) per movie, at the same time, making it Blueray-video compliant.

@manono, So, the 1080i that I captured wasn't really interlaced? I am amazed. Thanks for introducing the term 'progressive phase shifted'. I will try and read about it more.

@jagabo, do I do what you suggested in AviSynth?

@Jerome7573_3 , what did you mean by 'I patch it ASAP'?

[newpball]

Ok. I capture only Hollywood movies.

Here is a sample, unaltered.

And as I speculated, progressive but phase-shifted. This kind of thing is fairly common in PAL television broadcasts and is also sometimes seen on PAL DVDs.

The last thing you want to do to such a source is deinterlace it. You just have to realign the fields properly (after removing the duplicate frames). Of the two ways jagabo suggested to do that, I'd go with the TFM option.

Always go over your sources carefully to try and understand what you have if it's the least bit out of the ordinary. Or ask here. And when asking here, always provide a short sample.

I must be missing something, I open this in Premiere Pro, I get 25fps progressive and it looks just fine. How did you see the duplicate frames and phase shifting?

[Jerome7573_3]

@Jerome7573_3 , what did you mean by 'I patch it ASAP'?

Showing "50 fps" is a bug in MediaInfo due to how the 2 fields of a frame are packetized, this is a bug (it should be "25 fps", and I'll add another line saying if there are 1 or 2 fields per packet because other software may be impacted by this difference) and I'll fix this bug as soon as I can.

PS : still interested in the converted video.

[nharikrishna]

Ok. I will upload the 'converted' video tonight when I am home (in another 8 hours). The converted video is simply a reduced bit rate video with AviDemux with all default settings untouched except for CRF.

[manono]

How did you see the duplicate frames and phase shifting?

jagabo already explained in his post #17.

[jagabo]

@jagabo, do I do what you suggested in AviSynth?

I did this:

 ffVideoSource("Sample.mp4")
SelectEven() # get rid of duplicate frames, 50 fps -> 25 fps
AssumeTFF() # frames are TFF
TFM() # field match
LanczosResize(1280,720)

You don't have to downsize but if you're looking to encode entire movies to less than 2GB you'll get better quality with the smaller frame.

x264 video only clip attached.

[LMotlow]

Well.....it does work going to 1280x720, and thanks to jagabo for the tip on how to get it there. I'd have a bit of a problem with it. 25fps progressive isn't valid for that frame format in standard BluRay/AVCHD or broadcast video. Yep, it does play. I've recorded movies that come off the BBC at 1080i, but they're interlaced because interlaced is valid for HD formats at that frame size unless the source is playing at film speed (23.976, but progressive only). For NTSC I get some weird looking frames coming through that I've cleaned up pretty well using similar means to make a 720x480 DVD from that stuff.

So, for broadcast I suppose the original had to be interlaced 25fps frames per second but 50fps fields per second. In my case, the BBC videos are at NTSC frame speed, but the broadcaster is still sending interlaced video in the manner described here. I can see how MediaInfo might screw up on that.

Whatever. The mkv does OK on my PC. Got no idea what my BluRay players would do with it on TV.

[jagabo]

Well.....it does work going to 1280x720, and thanks to jagabo for the tip on how to get it there. I'd have a bit of a problem with it. 25fps progressive isn't valid for that frame format in standard BluRay/AVCHD or broadcast video.

All you have to do is slow it to 24 fps with AssumeFPS(24). You'll also need to adjust the audio, of course.

I haven't burned DVD or BD in years. I have no use for discs any more.

[ndjamena]

You need to encode 25p as FAKE interlaced for BD:

http://www.x264bluray.com/home/1080i-p

[newpball]

How did you see the duplicate frames and phase shifting?

jagabo already explained in his post #17.

I simply like to see this myself, how did you see the phase shifting, what viewer?
As I wrote before in Premiere Pro it simply reports as 25p and it looks fine.

[newpball]

Well.....it does work going to 1280x720, and thanks to jagabo for the tip on how to get it there. I'd have a bit of a problem with it. 25fps progressive isn't valid for that frame format in standard BluRay/AVCHD or broadcast video.

All you have to do is slow it to 24 fps with AssumeFPS(24). You'll also need to adjust the audio, of course.

Then what about this woven out of phase you are talking about?

How can I see that with my own eyes?

[jagabo]

Then what about this woven out of phase you are talking about?

How can I see that with my own eyes?

Use the same script without the TFM() and resize. You'll see the comb artifacts. Then apply a simple bob() instead of TFM(). You'll see every pair of frames (previously fields) is the same (except for bob artifacts).