是否有可能让新的 ImageDecoder 类手动返回位图，一帧一帧? [英] Is it possible to get the new ImageDecoder class to return Bitmaps, one frame after another, manually?
问题描述
我正在尝试手动(逐帧)查看动画 GIF 和 WEBP 文件的位图，以便它不仅适用于视图，还适用于其他情况(例如动态壁纸).
I'm trying to go over bitmaps of animated GIF&WEBP files manually (frame by frame), so that it would work not just for Views, but on other cases too (such as a live wallpaper).
动画 GIF/WEBP 文件仅受 Android P 支持，使用 ImageDecoder API(例如 此处).
Animated GIF/WEBP files are supported only from Android P, using ImageDecoder API (example here) .
对于 GIF，我想尝试 Glide 来完成任务，但我失败了，所以我尝试通过使用允许加载它们的库(这里，解决方案在这里).我认为它工作得很好.
For GIF, I wanted to try Glide for the task, but I've failed, so I've tried overcoming this, by using a library that allows to load them (here, solution here). I think it works fine.
对于 WebP，我想我找到了另一个可以在旧版 Android 上运行的库(此处，在此处)，但它似乎在某些情况下不能很好地处理 WebP 文件(报告 这里).我试图弄清楚是什么问题以及如何解决它，但我没有成功.
For WebP, I thought I've found another library that could work on older Android versions (here, made fork here), but it seems that it can't handle WebP files well in some cases (reported here). I tried to figure out what's the issue and how to solve it, but I didn't succeed.
因此，假设有一天 Google 将通过支持库支持旧版 Android 的 GIF 和 WEBP 动画(他们写了 这里)，我决定尝试使用 ImageDecoder 来完成这项任务.
So, assuming that some day Google will support GIF&WEBP animation for older Android versions via the support library (they wrote it here), I've decided to try to use ImageDecoder for the task.
事实是，纵观 ImageDecoder 的整个 API，我们应该如何使用它是非常受限的.我不知道如何克服它的局限性.
Thing is, looking in the entire API of ImageDecoder , it's quite restricted in how we should use it. I don't see how I can overcome its limitations.
这是如何使用 ImageDecoder 在 ImageView 上显示动画 WebP(当然只是一个示例，可用 这里) :
This is how ImageDecoder can be used to show an animated WebP on an ImageView (just a sample, of course, available here) :
class MainActivity : AppCompatActivity() {
@SuppressLint("StaticFieldLeak")
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
val source = ImageDecoder.createSource(resources, R.raw.test)
object : AsyncTask<Void, Void, Drawable?>() {
override fun doInBackground(vararg params: Void?): Drawable? {
return try {
ImageDecoder.decodeDrawable(source)
} catch (e: Exception) {
null
}
}
override fun onPostExecute(result: Drawable?) {
super.onPostExecute(result)
imageView.setImageDrawable(result)
if (result is AnimatedImageDrawable) {
result.start()
}
}
}.execute()
}
}
我已尝试阅读 ImageDecoder 和 AnimatedImageDrawable，并查看它的代码，但我不明白如何手动遍历每一帧，并在它们之间有需要等待的时间.
I've tried to read all of the documentations of ImageDecoder and AnimatedImageDrawable, and also look at its code, but I don't see how it's possible to manually go over each frame, and have the time that needs to be waited between them.
有没有办法使用 ImageDecoder API 手动遍历每一帧，获取要绘制的位图并知道在帧之间等待多长时间?任何可用的解决方法?也许甚至使用 AnimatedImageDrawable ?
Is there a way to use ImageDecoder API to go over each frame manually, getting a Bitmap to draw and knowing how much time it's needed to wait between frames? Any workaround available? Maybe even using AnimatedImageDrawable ?
我想在旧的 Android 版本上做同样的事情.是否可以?如果是这样怎么办?也许在不同的 API/库上?谷歌写的它可以在旧的 Android 版本上使用 ImageDecoder，但我没有看到任何地方提到它(除了我提供的链接).可能还没准备好……Android P 甚至还没有达到 0.1% 的用户……也许 壁画能做到吗?我也尝试在那里检查它，但我也没有看到它有能力做这样的事情，而且它是一个巨大的库，仅用于此任务，所以我更愿意使用不同的库.. 我也知道 libwebp 是可用的，但它是用 C/C++ 编写的，不确定它是否适合 Android，以及在 Java/Kotlin for Android 上是否有它的端口.
I'd like to do the same on older Android versions. Is it possible? If so how? Maybe on a different API/library? Google wrote it works on a way to use ImageDecoder on older Android versions, but I don't see it being mentioned anywhere (except for the link I've provided). Probably not ready yet... Android P didn't even reach 0.1% of users yet... Maybe Fresco can do it? I've tried to check it there too, but I don't see that it's capable of such a thing either, and it's a huge library to use just for this task, so I'd prefer to use a different library instead... I also know that libwebp is available, but it's in C/C++ and not sure if it's suited for Android, and whether there is a port for it on Java/Kotlin for Android.
<小时>
因为我认为我得到了我想要的东西，对于第三方库和 ImageDecoder，能够从动画 WebP 中获取位图，我仍然想知道如何使用ImageDecoder，如果可能的话.我尝试使用 ImageDecoder.decodeDrawable(source, object : ImageDecoder.OnHeaderDecodedListener... ，但它不提供帧计数信息，并且在 API 中我无法看到我可以转到特定的帧索引并从那里开始，或者知道特定帧需要多长时间才能进入下一帧.所以我对那些 此处.
Since I think I got what I wanted, for both a third party library and for ImageDecoder, to be able to get bitmaps out of animated WebP, I'd still want to know how to get the frame count and current frame using ImageDecoder, if that's possible. I tried using ImageDecoder.decodeDrawable(source, object : ImageDecoder.OnHeaderDecodedListener... , but it doesn't provide frame count information, and there is no way in the API that I can see that I can go to a specific frame index and start from there, or to know for a specific frame how long it needs to go to the next frame. So I made a reuqest about those here.
遗憾的是，我也找不到 Google 提供适用于旧 Android 版本的 ImageDecoder.
Sadly I also could not find that Google has ImageDecoder available for older Android versions, either.
如果有什么方法可以像我对HEIC这个相对较新的动画文件做的一样，也很有趣.目前仅在 Android P 上支持.
It's also interesting if there is some kind of way to do the same as I did for the relatively new animation file of HEIC. Currently it's supported only on Android P.
推荐答案
好的，我得到了一个可能的解决方案，使用 Glide 库，连同 GlideWebpDecoder 库 .
OK, I got a possible solution, using Glide library, together with GlideWebpDecoder library .
我不确定这是否是最好的方法，但我认为它应该可以正常工作.下一个代码展示了如何为动画需要显示的每一帧将 drawable 绘制到我创建的 Bitmap 实例中.这不完全是我问的问题，但它可能会帮助其他人.
I'm not sure if that's the best way to do it, but I think it should work fine. The next code shows how it's possible to make the drawable draw into the Bitmap instance that I create, for each frame that the animation needs to show. It's not exactly what I asked, but it might help others.
这是代码(项目可用这里):
Here's the code (project available here) :
CallbackEx.kt
abstract class CallbackEx : Drawable.Callback {
override fun unscheduleDrawable(who: Drawable, what: Runnable) {}
override fun invalidateDrawable(who: Drawable) {}
override fun scheduleDrawable(who: Drawable, what: Runnable, `when`: Long) {}
}
MyAppGlideModule.kt
@GlideModule
class MyAppGlideModule : AppGlideModule()
MainActivity.kt
class MainActivity : AppCompatActivity() {
var webpDrawable: WebpDrawable? = null
var gifDrawable: GifDrawable? = null
var callback: Drawable.Callback? = null
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
useFrameByFrameDecoding()
// useNormalDecoding()
}
fun useNormalDecoding() {
//webp url : https://res.cloudinary.com/demo/image/upload/fl_awebp/bored_animation.webp
Glide.with(this)
// .load(R.raw.test)
// .load(R.raw.fast)
.load(R.raw.example2)
// .load("https://res.cloudinary.com/demo/image/upload/fl_awebp/bored_animation.webp")
.into(object : SimpleTarget<Drawable>() {
override fun onResourceReady(drawable: Drawable, transition: Transition<in Drawable>?) {
imageView.setImageDrawable(drawable)
when (drawable) {
is GifDrawable -> {
drawable.start()
}
is WebpDrawable -> {
drawable.start()
}
}
}
})
}
fun useFrameByFrameDecoding() {
//webp url : https://res.cloudinary.com/demo/image/upload/fl_awebp/bored_animation.webp
Glide.with(this)
.load(R.raw.test)
// .load(R.raw.fast)
// .load(R.raw.example2)
// .load("https://res.cloudinary.com/demo/image/upload/fl_awebp/bored_animation.webp")
.into(object : SimpleTarget<Drawable>() {
override fun onResourceReady(drawable: Drawable, transition: Transition<in Drawable>?) {
// val callback
when (drawable) {
is GifDrawable -> {
gifDrawable = drawable
val bitmap = Bitmap.createBitmap(drawable.intrinsicWidth, drawable.intrinsicHeight, Bitmap.Config.ARGB_8888)
val canvas = Canvas(bitmap)
drawable.setBounds(0, 0, bitmap.width, bitmap.height)
drawable.setLoopCount(GifDrawable.LOOP_FOREVER)
callback = object : CallbackEx() {
override fun invalidateDrawable(who: Drawable) {
who.draw(canvas)
imageView.setImageBitmap(bitmap)
Log.d("AppLog", "invalidateDrawable ${drawable.toString().substringAfter('@')} ${drawable.frameIndex}/${drawable.frameCount}")
}
}
drawable.callback = callback
drawable.start()
}
is WebpDrawable -> {
webpDrawable = drawable
val bitmap = Bitmap.createBitmap(drawable.intrinsicWidth, drawable.intrinsicHeight, Bitmap.Config.ARGB_8888)
val canvas = Canvas(bitmap)
drawable.setBounds(0, 0, bitmap.width, bitmap.height)
drawable.setLoopCount(WebpDrawable.LOOP_FOREVER)
callback = object : CallbackEx() {
override fun invalidateDrawable(who: Drawable) {
who.draw(canvas)
imageView.setImageBitmap(bitmap)
Log.d("AppLog", "invalidateDrawable ${drawable.toString().substringAfter('@')} ${drawable.frameIndex}/${drawable.frameCount}")
}
}
drawable.callback = callback
drawable.start()
}
}
}
})
}
override fun onStart() {
super.onStart()
gifDrawable?.start()
gifDrawable?.start()
}
override fun onStop() {
super.onStop()
Log.d("AppLog", "onStop")
webpDrawable?.stop()
gifDrawable?.stop()
}
}
不知道为什么 SimpleTarget 被标记为已弃用，但我应该改用什么.
Not sure why SimpleTarget is marked as deprecated, and what I should use instead, though.
使用类似的技术，我还发现了如何使用 ImageDecoder 进行操作，但由于某种原因没有使用相同的功能.此处提供了一个示例项目.
Using a similar technique, I've also found out how to do it using ImageDecoder, but not with the same functionality for some reason. A sample project available here.
代码如下:
MainActivity.kt
class MainActivity : AppCompatActivity() {
var webpDrawable: AnimatedImageDrawable? = null
@SuppressLint("StaticFieldLeak")
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
val source = ImageDecoder.createSource(resources, R.raw.test)
object : AsyncTask<Void, Void, Drawable?>() {
override fun doInBackground(vararg params: Void?): Drawable? {
return try {
ImageDecoder.decodeDrawable(source)
} catch (e: Exception) {
null
}
}
override fun onPostExecute(drawable: Drawable?) {
super.onPostExecute(drawable)
// imageView.setImageDrawable(result)
if (drawable is AnimatedImageDrawable) {
webpDrawable = drawable
val bitmap =
Bitmap.createBitmap(drawable.intrinsicWidth, drawable.intrinsicHeight, Bitmap.Config.ARGB_8888)
val canvas = Canvas(bitmap)
drawable.setBounds(0, 0, bitmap.width, bitmap.height)
drawable.repeatCount = AnimatedImageDrawable.REPEAT_INFINITE
drawable.callback = object : Drawable.Callback {
val handler = Handler()
override fun unscheduleDrawable(who: Drawable, what: Runnable) {
Log.d("AppLog", "unscheduleDrawable")
}
override fun invalidateDrawable(who: Drawable) {
who.draw(canvas)
imageView.setImageBitmap(bitmap)
Log.d("AppLog", "invalidateDrawable")
}
override fun scheduleDrawable(who: Drawable, what: Runnable, `when`: Long) {
Log.d("AppLog", "scheduleDrawable next frame in ${`when` - SystemClock.uptimeMillis()} ms")
handler.postAtTime(what, `when`)
}
}
drawable.start()
}
}
}.execute()
}
override fun onStart() {
super.onStart()
webpDrawable?.start()
}
override fun onStop() {
super.onStop()
webpDrawable?.stop()
}
}
这篇关于是否有可能让新的 ImageDecoder 类手动返回位图，一帧一帧?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
