VideoHelp Forum
+ Reply to Thread
Results 1 to 17 of 17
Thread
  1. Member
    Join Date: Aug 2003
    Location: Sydney OZ
    Search Comp PM
    Hi,

    I have been given a live show videod on a Pro HDV camera. It is two 60 minute shows.

    He copied them from his camera Flash cards to the PC and they came out as 3 m2t files each show.

    I have tried to join them on the time-line however there are a few blank frames at the begininnig of the 2 joins so when it runs, I get this quick black so the audio is in sync.

    If I close the gap between the files, the audio gets out of sync a little.

    What can I do to join them in sync please?

    They have not been changed just straight out of the cam into flash drive which I copied onto my PC.

    Any help please

    oz
    Quote Quote  
  2. Member
    Join Date: Jun 2012
    Location: USA
    Search Comp PM
    Truly Pro HDV is recorded to cards within a specific folder structure, different manufacturers handle this slightly differently but the principle is consistent. The proper way to read these files is to ingest the entire structure into a pro NLE which will properly interpret and display the spanned clips. Camera manufacturers often supply software to mange the clips for those who are not using them in pro settings.

    If you are using only the clips, you may have to re-synch and trim them by hand in your NLE.

    Since we do not know the camera, or your NLE, this information is necessarily generic.
    Quote Quote  
  3. Member
    Join Date: Aug 2003
    Location: Sydney OZ
    Search Comp PM
    Hi,

    Firstly sorry about the double post. I know the camera was a Sony about 3 years old.

    The files were transferred in their folders.

    VIDEO/HVR
    00_0001_2014-03-23_123318.IDX
    00_0001_2014-03-23_123318.M2T
    00_0001_2014-03-23_125502.M2T
    00_0001_2014-03-23_131647.M2T
    3 m2t files.m2t
    tracks.dat

    I have tried inserting the m2t's into Magix Video Pro X 4 and Power Director 12 but get the black frames.

    Thanks

    oz
    Quote Quote  
  4. Member
    Join Date: Sep 2012
    Location: Australia
    Search Comp PM
    If the blank frames are part of a larger GOP you may need to lose some actual frames as well, or else re-encode without them. What is the end result supposed to be? Are you trying to re-encode or do you want to keep the video/audio streams intact?
    Quote Quote  
  5. Member
    Join Date: Jun 2012
    Location: USA
    Search Comp PM
    Originally Posted by ozstar100 View Post
    I have tried inserting the m2t's into Magix Video Pro X 4 and Power Director 12 but get the black frames.
    Sounds like you imported them correctly.

    Without knowing the exact model of the camera, you may require a utility like Sony Picture Motion Browser. Magix and Powerdirector are not pro apps. You may want to see if Vegas Movie Studio (a sony product, free trial) can open the files correctly. If not -- you're into Vegas Pro or Premiere Pro or Avid Media Composer, or doing it by hand.
    Last edited by smrpix; 25th Apr 2014 at 12:30.
    Quote Quote  
  6. Member
    Join Date: Sep 2012
    Location: Australia
    Search Comp PM
    Is there a negative audio delay that's being filled in or does the audio extend beyond the end of the video? Are the blank frames in the original files? Unless someone on the forum happens to have specific knowledge of exactly what you're doing, you're going to have to give us more information. What camera is it? You might be able to download a software package for it. What does MediaInfo say about the files?
    Quote Quote  
  7. Member
    Join Date: Aug 2003
    Location: Sydney OZ
    Search Comp PM
    Firstly many thanks for your time, I really do appreciate it.

    Since my post I have ..

    Dragged into the time line of Video-Pro X4 all files in the HDR folder above together. Asked whether 1440 or 720 which was the project.. chose 1440.

    Looked very closely at the joins and seen this..

    the 1st clip is
    video goes to 21:44:21
    audio seems to drop out 1/2 way thru 21:44:15

    2nd clip
    video again at 21:45:03
    audio starts at 21.44.22


    15.16.17.18.19.20.21.22.23.24.00.01.02.03.04.05.06
    V V V V V V V B B B B B B V V V V 6 frames blank video
    A M M M M M M A A A A A A A A A A 6 frames mute
    I will try the Sony Movie trial now.

    oz
    Last edited by ozstar100; 25th Apr 2014 at 19:05. Reason: V - B etc out of sync
    Quote Quote  
  8. Member
    Join Date: Sep 2007
    Location: Canada
    Search Comp PM
    Was that observation made only in VideoProX4 or both programs ? I ask because some programs might decode or handle the files differently

    Did you check the beginning and middle of the file? Is it in sync?

    If I'm understanding the graphic and your description in the 1st post correctly, if you shift the audio the equivalent of 6 frames forward, it will match but not sync up. (the 6 blank frames will match up with 6 mute frames) - Is that correct ? ie. the misalignment is what keeps everything in sync?

    I'm not familiar with that editor, but what were the project settings? What were the file interpretation settings? e.g. Does the program "think" the clips are 25.0 FPS, and the project is set to 25.0 FPS ?

    What does mediainfo (view=>text) say about the files?
    Last edited by poisondeathray; 25th Apr 2014 at 19:36.
    Quote Quote  
  9. Member
    Join Date: Aug 2003
    Location: Sydney OZ
    Search Comp PM
    Again thank you for your time.

    Correct, even though I try and match up the blank vid/aud files there is still an audio glitch.

    I tried to join them on the same timeline and move them on top of each other until the 1st video continued to the 2nd video with no blank frame.
    I still got a quick black frame on play

    Then put video 2 on track 2 and matched up the frames but still the same.
    I then placed video 2 on track 1 and video 1 on track 2 and the video worked.

    I still am left with a very tiny audio glitch which I guess is the 1/2 frame of audio that is missing from the 1st clip. It
    s not that bad now actually

    I have uploaded to My Files a video of each side of the join and the MediaInfo files for each of the 3 videos

    http://files.videohelp.com/u/54883/02-m2t.txt
    http://files.videohelp.com/u/54883/18-m2t.txt
    http://files.videohelp.com/u/54883/47-m2t.txt
    http://files.videohelp.com/u/54883/2014%20Mounties%201440x%20m2t%20test.mp4

    oz
    Last edited by ozstar100; 25th Apr 2014 at 21:00. Reason: added links
    Quote Quote  
  10. Member
    Join Date: Sep 2007
    Location: Canada
    Search Comp PM
    It might be that your software is the source of the problem, perhaps with the negative delay in the audio as reported by mediainfo

    Did you try vegas yet ?

    Some other things things you can try:

    1) You can try joining them with tsmuxer

    2) Join them with dgindex (push the "add" button to append, then file=>save project and demux video) . There will be elementary video & audio which you can multiplex with tsmuxer, or if you editor can handle elementary streams, then import them separately
    Quote Quote  
  11. Member
    Join Date: Sep 2012
    Location: Australia
    Search Comp PM
    MakeMKV would be perfect for this, if you could figure out how get it to see them as a single file... Maybe convert them to a BD structure, make a single title to encompasses them all, then point MakeMKV at it.
    Quote Quote  
  12. Member
    Join Date: Aug 2003
    Location: Sydney OZ
    Search Comp PM
    Once again many thanks for all the input. Yes I tried Sony Movie and Vegas but still had much the same problem, slight as it really is.

    I decided to copy 6 frames from the end of clip 1, delete the blank clips on Clip 2 and paste the other clips there. Unless one really watches you do not see the very slight 'glitch' when played.

    I replaced the camera audio with a mixed audio multi track of the show and added that so now it sounds half bad and looks ..well ....

    You guys are great. I am afraid I cannot reciprocate, as my knowledge is very limited to a 'lay guy' although been at it for years at this level through a multitude of programs, originally starting with the first version of Premiere and even the very early Final Cut.

    I have found Magix Video Pro X4 to be the easiest and most intuitive for me even for multi cam.

    I can however see why Vegas is pretty much the pro choice for PCs. Lots of bells and whistles!

    Anyway enough of this frivolity..so thanks again. Good chance we'll meet again I feel...

    oz
    Last edited by ozstar100; 26th Apr 2014 at 20:29. Reason: Added text
    Quote Quote  
  13. Member
    Join Date: Sep 2012
    Location: Australia
    Search Comp PM
    The video is 25 fps PAL, so each frame should last for exactly 40ms, the audio is 48000 MP2 so I'm pretty sure each frame should last for 24ms. The negative audio delay was 216ms. 216/24 is exactly 9 audio frames. 216/40=5.4 Video Frames. That accounts for most of the 6 added frames. I have no idea what's at the end of the files though. You probably could have just cut the 9 leading audio frames off.
    Quote Quote  
  14. Member
    Join Date: Aug 2003
    Location: Sydney OZ
    Search Comp PM
    Wow ndj ! Yes you are probably right.... Still, for my needs at the mo' what I did is okay.
    In fact, I just played it again and had to replay to see it.
    If I get the time, I might do that with the 9 frames, just to see if it does work in case I get the same thing happen again, heaven forbid!

    Thanks again.
    Quote Quote  
  15. Member 2Bdecided's Avatar
    Join Date: Nov 2007
    Location: United Kingdom
    Search Comp PM
    With a tiny bit of luck, if you do a simple binary concatenation (joining) of the raw mt2 files, you'll get a single file that plays fine.

    If you still know how to launch and use the command line, it's just
    copy /b file1.m2t + file2.m2t + file3.m2t result.m2t

    Cheers,
    David.
    Quote Quote  
  16. Member
    Join Date: Sep 2012
    Location: Australia
    Search Comp PM
    Originally Posted by ozstar100 View Post
    If I close the gap between the files, the audio gets out of sync a little.
    I'm still trying to make sense of his little diagram, because it does indicate 6 blank video frames to 6 mute audio frames, which means a simple stream append should work, but apparently it doesn't. Maybe it removes the negative audio delay at the beginning as a consequence? Maybe it's just the software, I guess he should have tried TSMuxer as PDR suggested.

    copy /b file1.m2t + file2.m2t + file3.m2t result.m2t
    Wow, I didn't realise m2t files could be manipulated like that... almost like elementary streams. Would that work on M2TS files as well, 'cause apparently they're the same thing...?
    Quote Quote  
  17. Member 2Bdecided's Avatar
    Join Date: Nov 2007
    Location: United Kingdom
    Search Comp PM
    Transport streams are sequences of 188-byte packets. As long as no one added an additional header to mess things up, or removed one or more packets, you're fine.
    Quote Quote