VideoHelp Forum

Try DVDFab and download streaming video, copy, convert or make Blu-rays,DVDs! Download free trial !
+ Reply to Thread
Results 1 to 20 of 20
Thread
  1. Member
    Join Date
    Feb 2015
    Location
    England
    Search Comp PM
    Hi All,
    I've been asked to try and get some footage from a security camera working. Now, this is not my normal area of expertise, so, while I've had an interesting day off tinkering, I thought I'd ask for advice from people who deal with this kind of thing more often.

    I have a file of 14,671,754 bytes size, hotspot.mp4
    After some basic investigation I found that there were none of the expected headers of an mp4 file, so, as the file looked to be opening on data, I spliced in a header from another mp4 file using a hex editor and saved the result back to hotspot_fudge.mp4 and went looking for mp4 fix utilities. Now, I've only tried a couple, for example File Repair 2.1.0.2 and Video Repair Software from Grau GmbH, but they have have been completely unsuccessful; not surprising really, as I don't even know if the header details I hacked in are compatible.
    However.
    The spliced file provides a thumbnail of its content as an icon which matches the expectation of the view from a security camera and opening the it in Windows Movie Maker shows thumbnails as well. If the clip is played, all that displays is a green strip covering about the bottom 1/12th of the screen. There is the odd crackle on the audio at the start of the clip; to be honest, I don't know if there's an audio channel available, although I doubt it as this is security-cam material.
    The slight crackle and the blown picture suggests to me I'm reading the 'wrong' data, but the thumbnails give me hope.

    Now.
    Do I have a hope in hell of getting this thing running by this method?
    Can anybody suggest something easier and better and, naturally, at no cost (other than time, of course)?

    If it is feasible to get the file moving, can anybody suggest which header parameters I should be modifying and what sort of values I should be aiming for?
    And is there a way of working out how long the file should play for, based on its byte-size? I have a basic value of 4m 18s in at the moment, which is simply the length of the mp4 video I borrowed the substitute header off in the first place?

    I hope I haven't just caused a forumful of folk to start laughing at naive ambitiousness of this...

    All the best
    QuinB
    Last edited by QuinB; 28th Feb 2015 at 14:49.
    Quote Quote  
  2. Usually there is a conversion software and/or viewing software +/- a software decoder included with the equipment - have you tried that?

    Patching in a header or modifying with a hex editor usually won't work for these, and it does play it will usually be damaged
    Quote Quote  
  3. Member
    Join Date
    Feb 2015
    Location
    England
    Search Comp PM
    Sorry to say, all I have is a file, all I've tried I've told.
    I have been offered no access to the hardware, I don't know what it is, I don't know what software might be available. That's the problem with being a techie - mates want free support.
    I might be able to get a site visit sorted out, but that's a 'might'. Can you give any more detail of the sort of thing I should be looking for? I can wing these things, but it's nice to have a bit of background.
    Damaged footage would be bad as this stuff might have to be used as evidence. Not necessarily at a court level, but enough to establish an identity.
    However, it's a real education and there's nothing like getting your hands dirty to learn the real ins and outs of a new area.
    Quote Quote  
  4. If you have the model#, or the company name that makes the device - you can do a better search for the proper software . Some security devices have encrypted recordings on top of the header issues. So do all you can to find out more information

    If you want to upload the clip ,since it's fairly small, there might be someone able to hack it or get it working here
    Quote Quote  
  5. Member
    Join Date
    Feb 2015
    Location
    England
    Search Comp PM
    Well, here y'go.

    One headerless file, one fudged; with thanks to anybody stepping up and taking a swing at the problem - that's how I got into this one, after all!


    Say.
    How is it that you can see thumbnails of the content in the of the fudged file?
    I still have catchup reading on the MP4 standard to get through; it's not exactly fast-fix friendly, is it?
    Image Attached Files
    Quote Quote  
  6. Member
    Join Date
    Aug 2010
    Location
    San Francisco, California
    Search PM
    If you really have a raw H.264 file, you may be able to containerize it with FFmpeg:

    ffmpeg.exe -f h264 -i <RawInputFile> -vcodec copy -r <DesiredFrameRate> <OutPutFilename>.mp4
    Quote Quote  
  7. You should upload the unpatched original
    Quote Quote  
  8. Member
    Join Date
    Feb 2015
    Location
    England
    Search Comp PM
    "Anything for a weird life!"

    I''ll see what I can do. Thanks for the suggestion.
    Image Attached Files
    Quote Quote  
  9. Member
    Join Date
    Feb 2015
    Location
    England
    Search Comp PM
    @poisondeathray - it's attached on the next post. Had a minor issue and the upload canned without me noticing before posting.
    Quote Quote  
  10. It's just an unencrpyted elementary AVC stream

    You can rename it "hotspot.h264" then use mkvmerge to import and wrap into a mkv container. Something like VLC, ffplay etc... will play it
    Image Attached Files
    Quote Quote  
  11. Member
    Join Date
    Aug 2010
    Location
    San Francisco, California
    Search PM
    Yup, FFmpeg had no trouble with it. Are you looking to bust the man whose dog left a calling card?
    Image Attached Files
    Last edited by JVRaines; 28th Feb 2015 at 16:42.
    Quote Quote  
  12. Member
    Join Date
    Feb 2015
    Location
    England
    Search Comp PM
    Originally Posted by JVRaines View Post
    If you really have a raw H.264 file, you may be able to containerize it with FFmpeg:

    ffmpeg.exe -f h264 -i <RawInputFile> -vcodec copy -r <DesiredFrameRate> <OutPutFilename>.mp4

    SCORE!

    Perfect.
    Very easy. Not as satisfying as finding out what everything does, but at this time of night, I'm not quibbling.

    Many thanks.
    Quote Quote  
  13. HAHA . I saw the "crime"

    There was a doggie taking a poop, and the owner didn't scoop it up .
    Quote Quote  
  14. Member
    Join Date
    Aug 2010
    Location
    San Francisco, California
    Search PM
    Originally Posted by QuinB View Post
    SCORE!

    Perfect.
    Very easy. Not as satisfying as finding out what everything does, but at this time of night, I'm not quibbling.

    Many thanks.
    You're welcome. The -f option tells FFmpeg to treat the input file as H.264 material. The -codec option says no transcoding; just copy the stream to output. FFmpeg guesses the container format from the extension of the output filename. Now, let's hope catching the perp will be so easy!
    Quote Quote  
  15. Member
    Join Date
    Feb 2015
    Location
    England
    Search Comp PM
    Originally Posted by JVRaines View Post
    Originally Posted by QuinB View Post
    SCORE!

    Perfect.
    Very easy. Not as satisfying as finding out what everything does, but at this time of night, I'm not quibbling.

    Many thanks.
    You're welcome. The -f option tells FFmpeg to treat the input file as H.264 material. The -codec option says no transcoding; just copy the stream to output. FFmpeg guesses the container format from the extension of the output filename. Now, let's hope catching the perp will be so easy!
    Small town; he's known for 'aiming' the dog at doorsteps. Round here there's a 1000 fine for not scooping but there's trouble getting the evidence of not clearing up, unlike the evidence of misdemeanour, to stick
    Not a civil court problem, but the dog wardens will be interested and the town councillor who begged the favour will be over the moon.
    Quote Quote  
  16. Member
    Join Date
    Feb 2015
    Location
    England
    Search Comp PM
    Originally Posted by poisondeathray View Post
    HAHA . I saw the "crime"

    There was a doggie taking a poop, and the owner didn't scoop it up .

    First World Problems
    Quote Quote  
  17. Member
    Join Date
    Feb 2015
    Location
    England
    Search Comp PM
    Originally Posted by poisondeathray View Post
    It's just an unencrpyted elementary AVC stream

    You can rename it "hotspot.h264" then use mkvmerge to import and wrap into a mkv container. Something like VLC, ffplay etc... will play it
    Sharp work - thanks for the effort.
    Quote Quote  
  18. 1000 fine ?! wow steep. It varies in Canada, but most places are only $50-200. Not a huge deterrent

    The problem with that shot is there is no direct view of the actual poop . You can only infer that something was left there, but the view is obscured. It wouldn't hold up to any legal scrutiny. Well placed, and "aimed" indeed
    Quote Quote  
  19. Member
    Join Date
    Feb 2015
    Location
    England
    Search Comp PM
    Originally Posted by poisondeathray View Post
    1000 fine ?! wow steep. It varies in Canada, but most places are only $50-200. Not a huge deterrent

    The problem with that shot is there is no direct view of the actual poop . You can only infer that something was left there, but the view is obscured. It wouldn't hold up to any legal scrutiny
    True. I think it's dodgy from that perspective; you wouldn't get a decent picture of the owner from the local paper for ID, but I reckon this is in the realm of parking tickets. There's a fight going on here over four residents who pay for their parking but weren't issued with new certificates. Out of date permit? Parking ticket! Which nobody can now cancel, even though it's not the fault of the ticketed drivers. With that mentality, they'll be handing out the fine to the owner and he'll have to fight it in the small claims court, the same as it looks like the poor folk whose parking permits walked. If it's the guy they think it is, he has it coming - although that's not any reason to send him up the river on poor evidence - and 1000 is pretty steep; I don't reckon he's got the money anyway, but I don't believe he looks like the kind of lad who'd meekly stump up the cash in the first place. At least it'll make the papers and maybe we'll be doing less squelching and more walking as people get the idea that this is something that's going to be dealt with.
    Quote Quote  
  20. Your town councillor has probably already done this, but he should approach other shops in the area who might have other recordings or views.

    Just a rant now: if someone is going to invest in an actual security camera system etc... not a prop for deterrent - they are better off getting a decent one that has some resolution to it . Even if the perp walked right in and put his face to the camera , you could barely make out any details. Even the ancient old analog recording tape systems would be better than this setup
    Quote Quote