Count dropped frames

[dkelly701]

Simple and to the point. How do you count dropped frames?

[edDV]

In what context?

[dkelly701]

So much for simple and to the point. Guess I don't know enough to be to the point and I am not sure what I need to clarify, so here goes.

I am capturing with a hardware based device directly to mpg. I would like to take the resulting mpg file and check it for dropped frames, hopefully with some type of software. I have seen where other people are giving very specific counts (17 per hour, etc.) and I would like to know how they are able to arrive at this.

If none of this information is what you meant, let me know.

[canadateck]

What are you using to Capture? Does it not tell you.?

[edDV]

That helps.

Some capture software monitors video frame rate and compares that to #frames captured and reports discrepancies.

Once the file is captured I would think embedded time code (vertical interval aka VITC) could be used to identify lost frames but that would only apply to pro video.

Digital video transfers like DV have camcorder timecode metadata embedded in each frame so it would be possible to detect missing frames.

Experienced video editors can spot dropped frames visually if there is any action. It sort of jumps out at you.

[canadateck]

That helps.

Some capture software monitors video frame rate and compares that to #frames captured and reports discrepancies.

Once the file is captured I would think embedded time code (vertical interval aka VITC) could be used to identify lost frames but that would only apply to pro video.

Digital video transfers like DV have camcorder timecode metadata embedded in each frame so it would be possible to detect missing frames.

I am capturing with a hardware based device directly to mpg.

[edDV]

That helps.

Some capture software monitors video frame rate and compares that to #frames captured and reports discrepancies.

Once the file is captured I would think embedded time code (vertical interval aka VITC) could be used to identify lost frames but that would only apply to pro video.

Digital video transfers like DV have camcorder timecode metadata embedded in each frame so it would be possible to detect missing frames.

I am capturing with a hardware based device directly to mpg.

Then the first paragraph applies.

[dkelly701]

I am using a Hauppauge WinTV PVR 2. It came with WinTV2000 and Ulead DVD MovieFactrory 3. I use the WinTV2000 to capture. I don't see anywhere it tells dropped frame information.

[junkmalle]

It's almost impossible to get the WinTV PVR devices to drop frames. You don't need to worry about it.

[dkelly701]

I was having a capture issue. I have hopefully resolved it by installing a new SATA drive. I was capturing to a RAID 1 array that also contained my OS. I still have experienced the same issue capturing to the new drive when I tried a bitrate of 15000 CBR, but not at 12000 CBR. As long as I can capture at 12000 CBR I will be happy.

I was curious to see if there were dropped frames when I was having the capture issues.

[edDV]

I was having a capture issue. I have hopefully resolved it by installing a new SATA drive. I was capturing to a RAID 1 array that also contained my OS. I still have experienced the same issue capturing to the new drive when I tried a bitrate of 15000 CBR, but not at 12000 CBR. As long as I can capture at 12000 CBR I will be happy.

I was curious to see if there were dropped frames when I was having the capture issues.

Capture drop issues reported here have been closely related to SATA drives and using motherboard drivers, especially RAID zero. Search the forums. RAID 1 in theory will be slow for capture since you are writing multiple drives.

Capture to the OS drive is a No No because the OS is contantly taking control of the drive for background tasks causing interrupt priority over your capture and also taking the heads off the track to seek OS buffers etc.

I suggest you will get much better results capturing to a dedicated video drive and better yet if it is on its own disk controller.

RAID 0 is rarely necessary for single stream captures unless you are doing something unusual. If you are doing high end work, a specialized PCI RAID card designed for synchronized Multistream SDI is probably what you want.

[edDV]

I still have experienced the same issue capturing to the new drive when I tried a bitrate of 15000 CBR, but not at 12000 CBR. As long as I can capture at 12000 CBR I will be happy.

What do you mean by capturing to 12000 or 15000 CBR? Are you encoding on the fly?

The problem is probably on the encoding side rather than disks. 15000Kb/s is a very slow rate for HDD.


Reading your profile:
"Capture Card: (For MCE) Emuzed Angel and Hauppauge WinTV-PVR-USB"

Emuzed Angel - A USB tuner
Are you encoding from that in software?

WinTV-PVR-USB - A realtime TV tuner/MPeg2 encoder
This will encode on the fly in hardware. Are you saying your system won't take 12-15Mb/s off this USB2 device?

[dkelly701]

Sorry, I updated my profile. I got rid of the Emuzed card and only capture with the Hauppauge.

I was having an issue with the Hauppauge when capturing to my RAID 1 array. At approximately the 1 hour mark of capturing, the picture would begin to slow down and sometimes even completely freeze. The resulting file would sometimes be alright and sometimes corrupt. I called Hauppauge Technical Support several times and together we tried several things with no resolution. See this thread.

https://www.videohelp.com/forum/viewtopic.php?t=276001

I have just installed a new Seagate 160 GB SATA drive to capture to and so far it seems to have helped. I have done 6 or 8 captures at 12000 Kbs CBR successfully and 2 captures at 15000 Kbs CBR, 1 successful and 1 not. As long as I can capture at 12000 Kbs CBR I will be happy.

I was curious to see if I had any dropped frames on the unsuccessful captures.

[edDV]

Sorry, I updated my profile. I got rid of the Emuzed card and only capture with the Hauppauge.

I was having an issue with the Hauppauge when capturing to my RAID 1 array. At approximately the 1 hour mark of capturing, the picture would begin to slow down and sometimes even completely freeze. The resulting file would sometimes be alright and sometimes corrupt. I called Hauppauge Technical Support several times and together we tried several things with no resolution. See this thread.

https://www.videohelp.com/forum/viewtopic.php?t=276001

I have just installed a new Seagate 160 GB SATA drive to capture to and so far it seems to have helped. I have done 6 or 8 captures at 12000CBR successfully and 2 captures at 15000 CBR, 1 successful and 1 not. As long as I can capture at 12000 CBR I will be happy.

I was curious to see if I had any dropped frames on the unsuccessful captures.

Do you see this problem after 45min of just watching the USB stream of does it only happen while recording?

If only when recording, try recording to a disk that is not part of the RAID1 and not containing the OS. An EIDE drive should work fine.

The idea is to isolate OS interrupts and the RAID and see if it then works. Next test whether the problem is SATA drive related by using EIDE.

PS: Are you sure you have adequate disk space? 15Mb/s takes ~ 6GB at 45min and the RAID 1 is doing continuous backups to double that to 12 GB at 45Min.

[dkelly701]

Do you see this problem after 45min of just watching the USB stream of does it only happen while recording?

Only while recording. If I stop recording, the problem immediately stops.

If only when recording, try recording to a disk that is not part of the RAID1 and not containing the OS. An EIDE drive should work fine.

See above. I just installed a new 160 GB SATA Seagate Barracuda drive that is not part of the array. I am now capturing to it. I have only had 1 capture with a problem since this new drive was installed. This was at 15000 Kbs CBR. As long as I can capture at 12000 Kbs CBR with no problems I will be satisfied.

[edDV]

[quote]

If only when recording, try recording to a disk that is not part of the RAID1 and not containing the OS. An EIDE drive should work fine.[/qoute]
See above. I just installed a new 160 GB SATA Seagate Barracuda drive that is not part of the array. I am now capturing to it. I have only had 1 capture with a problem since this new drive was installed. This was at 15000 Kbs CBR. As long as I can capture at 12000 Kbs CBR with no problems I will be satisfied.

An EIDE Barracuda on its own controller should be able to sustain 40-60 MegaBytes/sec with no errors. 15Mb/s or ~2MB/sec is using 2% of the disks sustained rate so that probably isn't the problem.

I can't think of anything that would cause a USB2 transfer to slow down after 45min. I would open up the Windows Task Manager and watch active processes and CPU performance for clues.

I'm running out of ideas. I have a 300MHz PII that handles 30Mb/s DV transfers for hours at a time to ATA 66/100 HDDs.

[dkelly701]

If I continue to have this trouble I an going to contact Hauppauge and try to get a replacement and see if that helps.

Thanks for your replies.

[junkmalle]

I've seen lots of people having problems capturing to RAID arrays. This is exactly the opposite of what you would expect but there appears to be something about some RAID drivers that screws up real time processes. They all solved the problem by capturing to a non RAID drive.

I use a Hauppauge WinTV PVR-250 (PCI card) and can defrag the hard drive while capturing at 15 Mb/s CBR and not drop frames (as far as I can tell). I haven't done it for an hour though!