I have a video that currently in Android uses the hardware accelerated decoder. Is there any way that I can customize it to use the android software decoder at the app layer? If so, how do I go about it? Is there another way to do this?
Try taking a look at ffmpeg for software video decoding. Also, see this article relating to ffmpeg and Android.
Also, this post contains further information regarding this topic of encoding for Android.
Related
I have gone through this links and few other links also,
khronos
OpenMax_Development_Guide
bellagio_openmax_il_open_source_implementation_enables_developers_to_create
but all of them just explains how the calling sequence is, picture of block diagram etc but don't explain how to write and build openmax component and plug it in android. Even the link for android building and porting is complicated it doesn't explain, that you will need whole source code to write and build openmax plugin or part of android source code or without android source code you can create it.
I am having firefly K3288 board with android OS Kitkat 4.4 which is supporting hevc hardware decoder but I want to add hevc software decoder.
If anyone know how to write and build openmax hevc video decoder component and plug it in android please give some directions.
For the 1st question of how to develop an OMX component, you will have to write a new component either out of scratch or using a template of existing functions. Please do refer to the OMXIL specification, specifically chapter 2.
I would recommend you to write a component based on Bellagio implementation which can be found here. Please refer to omx_base_video_port.c as this is essential for your decoder development.
An alternative could be to refer the implementation from one of the vendors. In AOSP tree, please refer to the qcom implementation as here which could provide you a good reference for starting with your development.
Note: Please note that OMX wrapper is more aligned towards state management, context management and buffer management. The interaction with your decoder whether HW or SW is dependent on your driver architecture which you should decide on. Once this driver architecture is finalized, integrating into OMX should be fairly easy.
For the 2nd question on how to integrate the hevc decoder, please refer to this question which has relevant details.
I to allow users in my app to record video and then post process it. Basically all I need is to video to be square (low res, something about 400x400) and when recording is done then allow user to modify brightness/contrast.
I did some research on that and found ffmpeg library which can do that. But I'm not sure if I am ok with its licensing. When I use ffmpeg do I have to release my app sources as well? My app will be free to download and use but I am not comfortable with its releasing sources.
Also about that square recording - as I am supporting API 14, android doesn't let me adjust resolution directly. There are 2 ways I think of:
Record video file in 640x480, then resize/crop and after that allow user to do post processing. - totally need ffmpeg for that
Capture CameraPreviewFrames - crop them as they go and render them into mp4 video, and after video is rendered then allow user to post process it further - need ffmpeg for that as well.
My question is then - may I use ffmpeg without any worries about licensing etc?
Or is there any other library which allows me to do above and is open to use?
Thanks very much
I am not a lawyer, and this is not legal advice. You should consult your lawyer for real legal advice.
FFmpeg is LGPL. You should read the license; it's somewhat more readable than most legalese.
The LGPL differs from the GPL in that you are not required to distribute your source code so long as you do not incorporate FFmpeg source code into your project. To achieve this, you must use FFmpeg as a so-called dynamic link library (e.g., .so, .dylib, .framework, .dll, etc). This is the default configuration.
If you modify the FFmpeg source, you must make it available.
You must also comply with the copyright license/patent license restrictions of all codecs you compile with FFmpeg. These are possible to distinguish by the FFmpeg configure options, e.g. --enable-gpl. If you use this configure option, for example, you are agreeing to distribute your source code as well as the FFmpeg source code, subject to the requirements of that codec's license(s). (In the case of x264, I believe there is a commercial license as well as the GPL.)
Straight from the horse's mouth: http://www.ffmpeg.org/legal.html
Especially check the checklist.
For API 11+, you can use the stagefright framework to encode your video to mp4, you don't need ffmpeg for this.
OTOH, there are quite a few ports of ffmpeg to Android, some even install a separate service whose sole purpose is to provide ffmpeg support for any app on the device. Using such approach you definitely do not violate any SW licenses.
I am thinking about making app on videos in android. I came to know that there are 2 famous libraries, FFMPEG and Vitamio.
I just want to know that can i do simple video functions like playing the video, grabbing a frame, converting video to mp3 with both the libraries? What are their pros and cons?
Thanks in advance.
Vitamio is much easier to use. It is just like the default MediaPlayer in Android but with some fancy capabilities. At the same time it can't do everything you want. As I understand it just plays video.
FFmpeg is not as simple. It is quite a powerful library that requires some thoughtful native coding in C. I'm sure you can do whatever you need with it, but it will cost you lots of efforts.
So I can recommend you to use either default Android's or Vitamio's MediaPlayer for playing video. And implement some specific features with the help of FFmpeg.
Old question, but since I'm working on this very problem and I found a lot of outdated information, I think it might be worth an answer anyway.
Vitamio is acually based on ffmpeg which makes the "Vitamio vs ffmpeg" question moot:
What's Vitamio, on the Vitamio website
The Media Formats paragraph cites:
Vitamio used FFmpeg as the demuxers and main decoders, many audio and video codecs are packed into Vitamio beside the default media format built in Android platform, some of them are listed below.
the "used" instead of "uses" looks like a typo (the site is choke full of them...).
Therefore the tip of the scale would point toward Vitaminio, it seems, as it's very easy to use. However...
Vitamio is a derivative work of ffmpeg for android, with an unspecified license (it's spelled quite clearly on the site that individuals can use the library for their own apps freely, though. That part was probably added after the answer by Marcus Wolschon)
ffmpeg for android is a derivative work of ffmpeg (more than that, actually: it's a port) and it's released under the LGPL v3 to abide it's contractual terms with ffmpeg (it actually does), relaying the same obligations to the user in a viral way (attribution, making the source of the library used for the compilation available, etc etc)
ffmpeg (the original work) is released under a dual license: a very liberal GPL (of no consequence in this discussion) and LGPL (the one picked by ffmpeg for android)
What follows is strictly my biased personal opinion, not a statement about the facts
This leads me to think that unless the company selling Vitamio has some agreement with both the author of ffmpeg android and ffmpeg, that we know nothing about, Vitamio is violating the copyright of ffmpeg for android (and therefore ffmpeg) hard.
The fact that the Vitamio's website has a lot of broken links, a grammatically challenged documentation, and not all legal information required for an educated choice, doesn't exactly plays in its favor, if I had to make my mind between considering them a high profile company or some individual trying to live off the back of the ffmpeg team's work...
This leads me to the following considerations:
from a practical standpoint, Vitamio might or might not be the best choice as it should be easy to integrate in your project (I say it should, as I didn't manage to do it yet, and I have quite some experience as an android developer under my belt...). The conditional is due, as the software is based on ffmpeg for android, which already makes an effort for easy Android integration.
from a legal standpoint, the situation is even more shadier, the options are:
turn a blind eye. The company behind Vitamio says that the product is fine and it's free to use (more than that actually: it sells the library), so if there is a licensing issue, it's their issue: as developers we have a semi-legitimate reason to bother to a point, as we would be as cheated as the people behind ffmpeg (I'm not very convinced about this whole argument myself...).
golf for honesty and shun Vitamio, adopting ffmpeg for android instead, which might mean more homework during the integration, both to replicate MediaPlayer and to abide to the LGPL terms, but guarantees a clear conscience
I didn't my mind yet, but I'll probably opt for "2"
Hope this helps
UPDATE It looks like that Vitamio is (at least partially) complying with the terms of the LGPL license, as they are publishing the source code required to build their product:
ffmpeg for Vitamio on GitHub
I don't have the time to find out if this is all that's required for complying with the original ffmpeg license (I'm skeptic), and how that influences the previous considerations (sorry).
You can't use Vitamio in any project because it has no license.
Without a LICENSE file or any other mention what rights you are granted you are granted to rights to use it at all.
See here: http://vitamio.org/topics/93?locale=en
I am writting an app which needs to decode H.264(AVC) bitstream. I find there are AVC codec sources exist in /frameworks/base/media/libstagefright/codecs/avc, does anyone know how can one get access to those codecs in an Android app? I guess it's through JNI, but not clear about how this can be done.
After some investigation I think one approach is to create my own classes and JNI interfaces in the Android source to enable using the CODECS in an Android App.
Another way which does not require any changes in Android source is to include CODECS as shared library in my application, use NDK. Any thoughts on these? Which way is better(if feasible)?
I didn't find much information about Stagefright, it would be great if anyone can point out some? I am developing on Android 2.3.3.
Any comments are highly appreciated.Thanks!
Stagefright does not support elementary H.264 decoding. However it does have H.264 decoder component. In theory, this library could be used. But in reality, it will be tough to use it as a standalone library due to its dependencies.
Best approach would be use to JNI wrapped independent h.264 decoder(like the one available with ffmpeg).
I'm looking for a way to decode AAC natively to PCM on Android. The decoder source code is at https://android.googlesource.com/platform/external/opencore/+/master/codecs_v2/audio/aac/dec, but I'm not familiar with NDK at all.
1) There's no way of doing this directly using the Android SDK, but can this be done via the NDK?
2) I would especially be interested in a simple way of accessing the decoder from SDK, with a short "bridge" through the NDK. Is this feasible?
3) Would such a solution work all Android versions (1.5-2.2)?
4) I guess I could use http://code.google.com/p/aacplayer-android/ instead, but it looks like this implementation is fairly CPU intensive. Does anyone have experiences with this?
Not sure what the policy is here for answering really old questions but what is working well for me is using OpenSL with the NDK; it comes built in and in fact the NDK comes with an example "native-audio" that demonstrates what you need.
One thing you may look into is the FFMpeg stuff, it is GPL and TuneIn radio posted their mods here: http://radiotime.com/mobile/android#/support/open-source