Viewing MJPEG Video Streams - android

I know Android doesn't support MJPEG natively but are there any jar files/drivers available that can be added to a project to make it possible?

There is a View available to display MJPEG streams:
Android and MJPEG Topic

Hardly, unless it's your Android platform (i.e. you are the integrator of special-purpose devices running Android).
A good place to start looking on how the Android framework handles video streams is here:
http://opencore.net/files/opencore_framework_capabilities.pdf
If you want to cook up something entirely incompatible, I guess you could do that with the NDK, jam ffmpeg into there, and with a bit of luck (and a nightmare supporting different Android devices) you can have it working.
What is the root problem you are trying to solve, perhaps we could work something out.

You can of course write or port software to handle any documented video format, the problem is that you won't have the same degree of hardware optimized code as the built in video codecs, and won't have as efficient low-level access to the framebuffer. So your code is likely to not be able to play back at full speed. Sometimes that might be okay, if you just want to get a sense of something. Also mjpeg compresses frames individually, so it should be trivial to write something that just skips a lot of frames and only decodes whatever fraction of them it can keep up with.
I think that some people have managed to build ffmpeg or mplayer using the optional features of the cpus in some phones and get to full frame rate for some videos, but it's tricky and device-specific.

I'm probably stating the obvious here, but MJPEG consists simply of multiple JPEGs. If you can grab the frames by cutting out data, you can probably get that data to be displayed as any other image.

I couldn't find any information on when exactly this was implemented, but as of now (testing on Android 8) you can view MJPEG stream just fine using a WebView.

Related

Android and FFmpeg. Video is very slow

I have built ffmpeg library for my Android device from here: https://github.com/appunite/AndroidFFmpeg. But some video files playing very very slow (i find out that very slow are playing videos which my Android device can play by itself). Here is build.sh script
https://github.com/appunite/AndroidFFmpeg/blob/master/FFmpegLibrary/jni/build_android.sh
May be this is because of these lines:
--enable-hwaccel=h264_vaapi \
--enable-hwaccel=h264_vaapi \
--enable-hwaccel=h264_dxva2 \
--enable-hwaccel=mpeg4_vaapi \
As I have understood these lines are enabling hw acceleration (the author of that code says that this can raise some bugs). The basic idea of the player is to decode video and audio streams in native code, then render video frame into AndroidBitmap and render Audio into Android MediaPlayer.
Does anyone know how to solve problem of slow video decoding (maybe decrease video frame resolution or something else?) I will be pleased for any help and ideas.
Strange that --enable-hwaccel=h264_vaapi is specified twice in a row, but I see that it's in the original build script that you linked to.
DXVA2 refers to DirectX Video Acceleration, available on Windows desktop computers. So that won't help here. VAAPI refers to Video Acceleration API. I was about to say that it targets only Unix desktops, but the Wikipedia page states that it can also target Android.
The likely reason that the decode is slow is that a software decode path is being taken. What type of video data are you decoding, and at what profile and resolution? Generally, it's best to leverage the Android media facilities, such as MediaPlayer for playback, unless you're doing something special. You have probably already researched this option and perhaps you found that you can't obtain raw AndroidBitmaps (I am not too familiar with Android development).
I'm looking at the source for both FFmpeg's VAAPI interface and the VAAPI->Android code. If you have FFmpeg compiled for Android, how is it accessing VAAPI? Do you have VAAPI compiled for Android as well? I have a feeling that VAAPI is not a stock component of Android (but again, I'm not sure), so you may need to ensure that VAAPI is in place. Then, are you correctly asking FFmpeg to use VAAPI? I don't think FFmpeg will autodetect this.

Decoding h264 raw stream on Android 2.3.3

I'm trying to decode a raw h264 stream on "older" Android versions.
I've tried MediaPlayer class and does not seem to support the stream format.
I can see the stream on other Cam Viewer apps from the market, so I figure there must be a way to do it, probably using the NDK.
I've read about OpenMAX and Stagefright, but couldn't find a working example about streaming.
Could someone please point me in the right direction?
Also, I'm reading in several places about "frameworks/av/include/media/stagefright/MediaSource.h" and other sources, but they don't seem to be either in the regular SDK or the NDK.
Where is this source located? is there another sdk?
Thanks in advance.
Update: I'm receiving a rtsp connection.
If you wish to perform only a simple experiment to verify certain functionality, you can consider employing the command line stagefright utility. Please do consider this condition where your streaming input may not be supported.
If you wish to build a more comprehensive player pipeline, you can consider the handling for rtsp as in here or http as in here. Please note that NuCachedSource2 implementation is essential for streaming input as this provides a page cache implementation which acts as a jitter for the streaming data.
Please do note one critical point: Command line stagefright utility doesn't render to the screen. Hence, if you wish to render, you will to implement the complete playback pipeline with rendering.
On a related note, if your input is streaming input, the standard player implementation does have support for streaming inputs as can be observed here. Did you face any issues with the same?
As fadden has already pointed out, your work is made far more simpler with the introduction of MediaCodec in Android 4.x.
You should use third-party libs like android-h264-decoder which uses JNI for increasing the performance! Also look at this lib Intel
Update: Media codec wasn't exposed until API 16 (Android 4.1), so that won't work for a 2.3.3 device.
Stagefright and OpenMAX IL were (and still are) internal components of Android. You can find the code (including MediaSource.h) at https://android.googlesource.com/platform/frameworks/av/+/master Note that the media framework has moved to a separate "tree" frameworks/av only recently. Before it was part of 'frameworks/base', e.g. https://android.googlesource.com/platform/frameworks/base/+/gingerbread/media/

How to record the http live streaming from an IP Cam

I have created the application in which the client can view the ip camera which is giving
an http live stream of MJPEG using this link
Android ICS and MJPEG using AsyncTask
Now i want the user to record the video into its memory card .
I have googled for a while and the only two approaches which came in my mind :-
Either i keep storing the jpeg images and when user clicks stop recording then i
somehow clip all the images as to provide a 3GP video or some other file format.
But i don't know how to create the video from all the images and will this be an efficient
approach or not.
Or i do ffmpeg and in this case i will have to deal with NDK and it seems to be a longer
path which may lead to nowhere :P
So is FFMPEG a better option? If yes please share some links or is the first option better.
Thanks in advance
FFmpeg is the better option, but you'll probably get stuck with a pretty poor encoding resolution/compression. Maybe some low quality MPEG-4 like xvid will work, but even that might require too high of performance from the CPU.
Android doesn't have an API to access the video encoder logic in the SoC, so a native implementation is pretty much your only choice. If so, FFmpeg through NDK is probably the easiest.

Replacing the standard Android H264 software encoder with an ffmpeg based one

In Android ICS and later, a new OpenMax IL API version is in use, making old binary blobs useless/unused. This leads to older devices that otherwise run ICS just fine and dandy to have broken video playback (YouTube HQ and IMBD, for example) because Androids fallback software decoder sucks when compared to what ffmpeg can do on the same device (I tested MXPlayer+arm6vfp ffmpeg and a 720p movie played back great).
I am trying to dig through the Android source code to see where and what exactly I could add/replace code to allow the ffmpeg library's awesomeness to be used. The problem is I don't know exactly what code is being used in for example the YouTube app to decode video, or how that's decided.
So I have two options as far as I can tell:
Figure out the current software decoder being used, and try to wrap its external interface around ffmpeg, effectively replacing the slow software decoder currently used. The end result would be a single .so I could push to the device.
Figure out how to trick Android into thinking an OMX library based on ffmpeg (I have built one succesfully for Android: limoa) and add this somewhere to the list of considered libraries (or better: replace the unusable hardware codec).
As an extension, I'd like to also make camcorder video encoding work through this, so a true integrated solution would be very much wanted. The question is: how, and where, and what? Searching the Android source tree gives numerous counts of "H264" and related stuff in many different places. I need the lowest and simplest possible, so I can simply wrap the hypothetical decode(buffer) function call to use ffmpeg (libavcodec).
It seems to me that this presentation ("Integrating a Hardware Video Codec into Android Stagefright using OpenMAX IL") is exactly what you'd like to do. Good luck with your project!

Transcode/Convert Video to Mp4 on Android

I've a requirement where I need to transcode small video clips shot from Native camera app to lower bitrate/resolution Mp4 which is shreable via email etc.
What is the best way to transcode/convert the video on device itself. FFMPEG or any other library?
p.s. I know this is an overkill for the device but client leaves me with no option. He doesn't care about battery or time it takes. I'm targeting this for quad-cores, where CPU is not a problem.
Your best bet would be to use something like ffmpeg which has been ported to Android (see this SO post: ffmpeg for a android (using tutorial: "ffmpeg and Android.mk") and the ffmpeg port for android which is here: http://bambuser.com/opensource). You'll have to use JNI etc, but that will save you the hassle of dealing with the byte stream yourself.
Haven't tried it on Android myself, so YMMV:
Is there a Java API for mp4 files?
http://code.google.com/p/mp4parser/
If you're recording on-device, why not set the expected format from your code? It appears the api lets you set video size, framerate etc. in the MediaRecorder class.

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