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| Pete Fraser 2006-04-08, 6:55 pm |
| I have a file that has a sequence of concatenated JPEG images
(all with the same resolution). What's the easiest way for me to
make this file recognizable by some commonly available video player.
I'm hoping I can just give it the appropriate extension, and slap some
sort of header on it.
Thanks
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| cr88192 2006-04-08, 9:55 pm |
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"Pete Fraser" <pfraser@covad.net> wrote in message
news:123gk8r811853ea@news.supernews.com...
>I have a file that has a sequence of concatenated JPEG images
> (all with the same resolution). What's the easiest way for me to
> make this file recognizable by some commonly available video player.
>
odd, you make the file or it came from somewhere else?...
> I'm hoping I can just give it the appropriate extension, and slap some
> sort of header on it.
>
doubtful.
most video formats are a little more "involved" than this, eg, each encoded
frame is wrapped in some manner of container, and the whole mass is prefixed
by any requisite headers (telling what codecs are used for the audio and
video frames, ...).
afaik, one could encode each image as a seperate frame in, say, an avi file,
and use a motion-jpeg codec, along with having the correct fourcc and
similar in the avi headers. then again, I don't know, somehow I suspect that
many motion jpeg codecs would tweak out the encoded jpegs somehow to try to
save space (only encoding huffman and quantizer tables or such in some
frames, ...).
maybe giving the basic idea:
http://en.wikipedia.org/wiki/AVI
http://msdn.microsoft.com/library/d...lereference.asp
then again, someone who knows more about this could probably offer better
answers.
> Thanks
>
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| Pete Fraser 2006-04-08, 9:55 pm |
| "cr88192" <cr88192@NOSPAM.hotmail.com> wrote in message
news:8a7e6$443862be$ca83b3d3$10673@saipa
n.com...
>
> "Pete Fraser" <pfraser@covad.net> wrote in message
> news:123gk8r811853ea@news.supernews.com...
> odd, you make the file or it came from somewhere else?...
It was streaming TCP from a camera. I used Ethereal to extract the data.
>
> doubtful.
>
> most video formats are a little more "involved" than this, eg, each
> encoded frame is wrapped in some manner of container, and the whole mass
> is prefixed by any requisite headers (telling what codecs are used for the
> audio and video frames, ...).
Motion JPEG files I've examined before seem fairly simple, but I was only
interested in the codestreams, so I didn't pay attention to the file format.
I tried calling it a .mov, and quicktime happily plays the first frame.
There's some info between each frame, so I tried removing that, and no
diffference. I didn't expect it to work, because I've seen data between
JPEG frames before and it has played fine. I should look at a file I know
works,
an see if there's some stco type mechanism.
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| Pete Fraser 2006-04-08, 9:55 pm |
| "Pete Fraser" <pfraser@covad.net> wrote in message
news:123gqfgr0hnr46c@news.supernews.com...
>
> Motion JPEG files I've examined before seem fairly simple, but I was only
> interested in the codestreams, so I didn't pay attention to the file
> format.
> I tried calling it a .mov, and quicktime happily plays the first frame.
Replying to my own post, I just looked at a couple of motion JPEG files,
and they seem to have a full-on mj2/mp4 box/atom structure, with stbl
and stco, etc. I had hoped I could do something simpler, but I've got some
old mj2 code, so perhaps I'll modify that.
However,
http://bmrc.berkeley.edu/research/c..._chunkfile.html
seems to discuss a simpler approach, so I'll try that first.
Pete
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| cr88192 2006-04-09, 3:55 am |
|
"Pete Fraser" <pfraser@covad.net> wrote in message
news:123grg05fftas89@news.supernews.com...
> "Pete Fraser" <pfraser@covad.net> wrote in message
> news:123gqfgr0hnr46c@news.supernews.com...
>
>
> Replying to my own post, I just looked at a couple of motion JPEG files,
> and they seem to have a full-on mj2/mp4 box/atom structure, with stbl
> and stco, etc. I had hoped I could do something simpler, but I've got some
> old mj2 code, so perhaps I'll modify that.
>
> However,
> http://bmrc.berkeley.edu/research/c..._chunkfile.html
> seems to discuss a simpler approach, so I'll try that first.
>
dunno...
> Pete
>
>
>
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| Jasen Betts 2006-04-09, 3:55 am |
| On 2006-04-09, Pete Fraser <pfraser@covad.net> wrote:
> I have a file that has a sequence of concatenated JPEG images
> (all with the same resolution). What's the easiest way for me to
> make this file recognizable by some commonly available video player.
mjpegtools and an mpeg encoder worked for me.
> I'm hoping I can just give it the appropriate extension, and slap some
> sort of header on it.
nope, you need to convert to something the player recognises.
--
Bye.
Jasen
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