I've recently get a set of medical videos data in DICOM format. The problem is that I know they should be videos but any DICOM program I've used till now, knows each video as a single image!
I've also tried MATLAB dicomreader to convert videos to stream of frames but the same problem occurs.
Does anyone know how can I convert my data to a known video format like avi, mpg, wmv,...?
Can the problem be the system(GEMS echocardiography) which has burnt data on CD? or maybe there must be a setting before writing...
Thank you all for your help and guides.
Imebra has an example called dicom2jpeg that can also convert to video if you have ffmpeg installed on your pc.
The downside is that you have to compile the example yourself using QMake or QtCreator.
In the case that the originator really stored the video as a collection of single images, your best bet is still to use ffmpeg and give the bunch of images (converted to jpeg or png) as input.
Related
I am working on Video steganography using Matlab I have completed my encryption on video successfully but the problem is that I am not able to retrieve my data back in decryption module.
After splitting encoded video into frames i am not able to retrieve the encoded frame from the video.Please give your valuable suggestion.
If you're using a lossy compression codec, it might be messing with your data when it compress the frames. Try using a lossless codec. Wikipedia has a list of such codecs here.
So I have a process that captures images from my webcam, a frame at a time. My process does some adjustment to the image and I want to stream these continuous adjustments. I know I can create an avi file out of these sequences of images, but how do I stream them live?
I haven't done this myself, so not sure how well it will work, but this demo shows how to get a live histogram from your video stream. I guess it could be modified to do what you want.
The techniques here can be used to display other live information too. For example, a live video feed can be placed next to a filtered version of the video.
I have come across some sample codes where set of images are added to make a QTmovie.
I am targeting this for OS X platform without any QT frameworks.
I have ague idea of creating a file with extension and embed it with appropriate metadata and find a way to insert images and audio in required format. So when the file is created it can simply be played.
I am not sure of what format/extension is better.
pointers are much appreciated.
Without QuickTime (or an equivalent multimedia framework), what you describe is quite a lot of work. Ordinarily, you would use a video compression algorithm (such as H.264) to encode your images into video, and an audio compression algorithm (such as AAC) to encode your audio track. Then you would write these streams into a container file, such as an MPEG-4 file, which interleaves the streams for playback, contains metadata and indexes and so on. Then for playback, you parse the file, decode the video and audio data, and schedule them for playback, taking care to keep them in sync.
QuickTime does all this (and more) for you, and it would be an enormous undertaking to write it all yourself. Is there some reason why you are running on OS X but cannot use QuickTime?
Given the question is tagged with iPhone, why can't you just use QTKit?
If you had to do it from scratch, you could adopt a very simple solution whereby you store your image sequence as a set of JPEG files (but then you would require libjpeg; use raw RGB or PPM if you must), the audio track as a raw WAV data, and then have another file (a text file you define) that stored timing information, so you would simply stream out the audio, and have the frame numbers of the images stored with their corresponding timecode/sample offset. That is a very simple solution that could be made to work without too much effort.
If you give us some more idea of what you are trying to achieve, we could offer some more specific suggestions.
If you want to write a program to do this, you could use Xuggler in Java to do it. It will allow you to save your final video in a format playable by almost any media player.
Start out by gaining an understanding of how video files (e.g. MP4, Quicktime) actually represent audio and video with this Overly Simplistic Guide to Internet Video.
Then, play around with the MediaTool tutorials. You can write programs that make raw images into video files (see this sample code). Finally, to write a program that makes audio and video that are in sync, see this tutorial; it generates a set of images, and makes some audio noise that is timed to change when a ball hits the edge of a box.
Hope that helps.
Art
I need to convert image sequences(ie,png) to video file in iPhone. How i can convert the images to video.
Regards,
Just ignore bad advice like "use ffmpeg". That would work on the desktop, but the license issue makes including ffmpeg source code in your iPhone app legally questionable. Apple provides a class named AVAssetWriter that you would use in your app to encode a series of images as h.264 stored in a .m4v quicktime container file. While the apple provided logic does work, it is not so easy to actually use and you will need to read quite a lot of documentation to get the code working. If you want to skip implementing it yourself (and likely save yourself 3 or 4 days of work), please consider using my AVAnimator library for iOS as the h.264 encoding logic is already implemented in the class AVAssetWriterConvertFromMaxvid. Once encoded as h.264, the video can be played with the standard player and it is small enough to upload to a remote server.
You are likely going to need something like FFMPEG
I have come across some sample codes where set of images are added to make a QTmovie.
I am targeting this for OS X platform without any QT frameworks.
I have ague idea of creating a file with extension and embed it with appropriate metadata and find a way to insert images and audio in required format. So when the file is created it can simply be played.
I am not sure of what format/extension is better.
pointers are much appreciated.
Without QuickTime (or an equivalent multimedia framework), what you describe is quite a lot of work. Ordinarily, you would use a video compression algorithm (such as H.264) to encode your images into video, and an audio compression algorithm (such as AAC) to encode your audio track. Then you would write these streams into a container file, such as an MPEG-4 file, which interleaves the streams for playback, contains metadata and indexes and so on. Then for playback, you parse the file, decode the video and audio data, and schedule them for playback, taking care to keep them in sync.
QuickTime does all this (and more) for you, and it would be an enormous undertaking to write it all yourself. Is there some reason why you are running on OS X but cannot use QuickTime?
Given the question is tagged with iPhone, why can't you just use QTKit?
If you had to do it from scratch, you could adopt a very simple solution whereby you store your image sequence as a set of JPEG files (but then you would require libjpeg; use raw RGB or PPM if you must), the audio track as a raw WAV data, and then have another file (a text file you define) that stored timing information, so you would simply stream out the audio, and have the frame numbers of the images stored with their corresponding timecode/sample offset. That is a very simple solution that could be made to work without too much effort.
If you give us some more idea of what you are trying to achieve, we could offer some more specific suggestions.
If you want to write a program to do this, you could use Xuggler in Java to do it. It will allow you to save your final video in a format playable by almost any media player.
Start out by gaining an understanding of how video files (e.g. MP4, Quicktime) actually represent audio and video with this Overly Simplistic Guide to Internet Video.
Then, play around with the MediaTool tutorials. You can write programs that make raw images into video files (see this sample code). Finally, to write a program that makes audio and video that are in sync, see this tutorial; it generates a set of images, and makes some audio noise that is timed to change when a ball hits the edge of a box.
Hope that helps.
Art