Constructing pleasant Android digital camera and media experiences

Posted by Donovan McMurray, Mayuri Khinvasara Khabya, Mozart Louis, and Nevin Mital – Developer Relations Engineers

Hi there Android Builders!

We’re the Android Developer Relations Digicam & Media staff, and we’re excited to deliver you one thing somewhat completely different at this time. Over the previous a number of months, we’ve been arduous at work writing pattern code and constructing demos that showcase how you can benefit from all the nice potential Android presents for constructing pleasant person experiences.

A few of these efforts can be found so that you can discover now, and a few you’ll see later all year long, however for this weblog submit we thought we’d share among the learnings we gathered whereas going by way of this train.

Seize your favourite Android plush or rubber duck, and browse on to see what we’ve been as much as!

Future-proof your app with Jetpack

Nevin Mital

One among our focuses for the previous a number of years has been bettering the developer instruments accessible for video modifying on Android. This led to the creation of the Jetpack Media3 Transformer APIs, which provide options for each single-asset and multi-asset video modifying preview and export. Right now, I’d wish to give attention to the Composition demo app, a pattern app that showcases among the multi-asset modifying experiences that Transformer allows.

I began by including a customized video compositor to reveal how one can prepare enter video sequences into completely different layouts on your ultimate composition, comparable to a 2×2 grid or a picture-in-picture overlay. You may customise this by implementing a VideoCompositorSettings and overriding the getOverlaySettings technique. This object can then be set when constructing your Composition with setVideoCompositorSettings.

Right here is an instance for the 2×2 grid format:

object : VideoCompositorSettings {
  ...

  override enjoyable getOverlaySettings(inputId: Int, presentationTimeUs: Lengthy): OverlaySettings {
    return when (inputId) {
      0 -> { // First sequence is positioned within the high left
        StaticOverlaySettings.Builder()
          .setScale(0.5f, 0.5f)
          .setOverlayFrameAnchor(0f, 0f) // Center of overlay
          .setBackgroundFrameAnchor(-0.5f, 0.5f) // High-left part of background
          .construct()
      }

      1 -> { // Second sequence is positioned within the high proper
        StaticOverlaySettings.Builder()
          .setScale(0.5f, 0.5f)
          .setOverlayFrameAnchor(0f, 0f) // Center of overlay
          .setBackgroundFrameAnchor(0.5f, 0.5f) // High-right part of background
          .construct()
      }

      2 -> { // Third sequence is positioned within the backside left
        StaticOverlaySettings.Builder()
          .setScale(0.5f, 0.5f)
          .setOverlayFrameAnchor(0f, 0f) // Center of overlay
          .setBackgroundFrameAnchor(-0.5f, -0.5f) // Backside-left part of background
          .construct()
      }

      3 -> { // Fourth sequence is positioned within the backside proper
        StaticOverlaySettings.Builder()
          .setScale(0.5f, 0.5f)
          .setOverlayFrameAnchor(0f, 0f) // Center of overlay
          .setBackgroundFrameAnchor(0.5f, -0.5f) // Backside-right part of background
          .construct()
      }

      else -> {
        StaticOverlaySettings.Builder().construct()
      }
    }
  }
}

Since getOverlaySettings additionally gives a presentation time, we are able to even animate the format, comparable to on this picture-in-picture instance:

Subsequent, I spent a while migrating the Composition demo app to make use of Jetpack Compose. With sophisticated modifying flows, it may possibly assist to benefit from as a lot display house as is accessible, so I made a decision to make use of the supporting pane adaptive format. This fashion, the person can fine-tune their video creation on the preview display, and export choices are solely proven on the identical time on a bigger show. Under, you may see how the UI dynamically adapts to the display measurement on a foldable system, when switching from the outer display to the inside display and vice versa.

What’s nice is that by utilizing Jetpack Media3 and Jetpack Compose, these options additionally carry over seamlessly to different gadgets and kind elements, comparable to the brand new Android XR platform. Proper out-of-the-box, I used to be in a position to run the demo app in Residence Area with the 2D UI I already had. And with some small updates, I used to be even in a position to adapt the UI particularly for XR with options comparable to a number of panels, and to take additional benefit of the additional house, an Orbiter with playback controls for the modifying preview.

What’s nice is that by utilizing Jetpack Media3 and Jetpack Compose, these options additionally carry over seamlessly to different gadgets and kind elements, comparable to the brand new Android XR platform. Proper out-of-the-box, I used to be in a position to run the demo app in Residence Area with the 2D UI I already had. And with some small updates, I used to be even in a position to adapt the UI particularly for XR with options comparable to a number of panels, and to take additional benefit of the additional house, an Orbiter with playback controls for the modifying preview.

Orbiter(
  place = OrbiterEdge.Backside,
  offset = EdgeOffset.inside(offset = MaterialTheme.spacing.commonplace),
  alignment = Alignment.CenterHorizontally,
  form = SpatialRoundedCornerShape(CornerSize(28.dp))
) {
  Row (horizontalArrangement = Association.spacedBy(MaterialTheme.spacing.mini)) {
    // Playback management for rewinding by 10 seconds
    FilledTonalIconButton({ viewModel.seekBack(10_000L) }) {
      Icon(
        painter = painterResource(id = R.drawable.rewind_10),
        contentDescription = "Rewind by 10 seconds"
      )
    }
    // Playback management for play/pause
    FilledTonalIconButton({ viewModel.togglePlay() }) {
      Icon(
        painter = painterResource(id = R.drawable.rounded_play_pause_24),
        contentDescription = 
            if(viewModel.compositionPlayer.isPlaying) {
                "Pause preview playback"
            } else {
                "Resume preview playback"
            }
      )
    }
    // Playback management for forwarding by 10 seconds
    FilledTonalIconButton({ viewModel.seekForward(10_000L) }) {
      Icon(
        painter = painterResource(id = R.drawable.forward_10),
        contentDescription = "Ahead by 10 seconds"
      )
    }
  }
}

Jetpack libraries unlock premium performance incrementally

Donovan McMurray

Not solely do our Jetpack libraries have you ever lined by working persistently throughout current and future gadgets, however in addition they open the doorways to superior performance and customized behaviors to assist all sorts of app experiences. In a nutshell, our Jetpack libraries purpose to make the frequent case very accessible and simple, and it has hooks for including extra customized options later.

We’ve labored with many apps who’ve switched to a Jetpack library, constructed the fundamentals, added their crucial customized options, and really saved developer time over their estimates. Let’s check out CameraX and the way this incremental improvement can supercharge your course of.

// Arrange CameraX app with preview and picture seize.
// Word: setting the decision selector is elective, and if not set,
// then a default 4:3 ratio will likely be used.
val aspectRatioStrategy = AspectRatioStrategy(
  AspectRatio.RATIO_16_9, AspectRatioStrategy.FALLBACK_RULE_NONE)
var resolutionSelector = ResolutionSelector.Builder()
  .setAspectRatioStrategy(aspectRatioStrategy)
  .construct()

personal val previewUseCase = Preview.Builder()
  .setResolutionSelector(resolutionSelector)
  .construct()
personal val imageCaptureUseCase = ImageCapture.Builder()
  .setResolutionSelector(resolutionSelector)
  .setCaptureMode(ImageCapture.CAPTURE_MODE_MINIMIZE_LATENCY)
  .construct()

val useCaseGroupBuilder = UseCaseGroup.Builder()
  .addUseCase(previewUseCase)
  .addUseCase(imageCaptureUseCase)

cameraProvider.unbindAll()

digital camera = cameraProvider.bindToLifecycle(
  this,  // lifecycleOwner
  CameraSelector.DEFAULT_BACK_CAMERA,
  useCaseGroupBuilder.construct(),
)

After organising the fundamental construction for CameraX, you may arrange a easy UI with a digital camera preview and a shutter button. You should utilize the CameraX Viewfinder composable which shows a Preview stream from a CameraX SurfaceRequest.

// Create preview
Field(
  Modifier
    .background(Colour.Black)
    .fillMaxSize(),
  contentAlignment = Alignment.Heart,
) {
  surfaceRequest?.let {
    CameraXViewfinder(
      modifier = Modifier.fillMaxSize(),
      implementationMode = ImplementationMode.EXTERNAL,
      surfaceRequest = surfaceRequest,
     )
  }
  Button(
    onClick = onPhotoCapture,
    form = CircleShape,
    colours = ButtonDefaults.buttonColors(containerColor = Colour.White),
    modifier = Modifier
      .top(75.dp)
      .width(75.dp),
  )
}

enjoyable onPhotoCapture() {
  // Not proven: defining the ImageCapture.OutputFileOptions for
  // your saved photos
  imageCaptureUseCase.takePicture(
    outputOptions,
    ContextCompat.getMainExecutor(context),
    object : ImageCapture.OnImageSavedCallback {
      override enjoyable onError(exc: ImageCaptureException) {
        val msg = "Picture seize failed."
        Toast.makeText(context, msg, Toast.LENGTH_SHORT).present()
      }

      override enjoyable onImageSaved(output: ImageCapture.OutputFileResults) {
        val savedUri = output.savedUri
        if (savedUri != null) {
          // Do one thing with the savedUri if wanted
        } else {
          val msg = "Picture seize failed."
          Toast.makeText(context, msg, Toast.LENGTH_SHORT).present()
        }
      }
    },
  )
}

You’re already on monitor for a strong digital camera expertise, however what should you needed so as to add some additional options on your customers? Including filters and results are straightforward with CameraX’s Media3 impact integration, which is one of many new options launched in CameraX 1.4.0.

Right here’s how easy it’s so as to add a black and white filter from Media3’s built-in results.

val media3Effect = Media3Effect(
  software,
  PREVIEW or IMAGE_CAPTURE,
  ContextCompat.getMainExecutor(software),
  {},
)
media3Effect.setEffects(listOf(RgbFilter.createGrayscaleFilter()))
useCaseGroupBuilder.addEffect(media3Effect)

The Media3Effect object takes a Context, a bitwise illustration of the use case constants for focused UseCases, an Executor, and an error listener. You then set the record of results you wish to apply. Lastly, you add the impact to the useCaseGroupBuilder we outlined earlier.

There are lots of different built-in results you may add, too! See the Media3 Impact documentation for extra choices, like brightness, colour lookup tables (LUTs), distinction, blur, and lots of different results.

To take your results to yet one more degree, it’s additionally attainable to outline your individual results by implementing the GlEffect interface, which acts as a manufacturing unit of GlShaderPrograms. You may implement a BaseGlShaderProgram’s drawFrame() technique to implement a customized impact of your individual. A minimal implementation ought to inform your graphics library to make use of its shader program, bind the shader program’s vertex attributes and uniforms, and subject a drawing command.

Jetpack libraries meet you the place you might be and your app’s wants. Whether or not that be a easy, fast-to-implement, and dependable implementation, or customized performance that helps the crucial person journeys in your app stand out from the remainder, Jetpack has you lined!

Jetpack presents a basis for modern AI Options

Mayuri Khinvasara Khabya

Simply as Donovan demonstrated with CameraX for seize, Jetpack Media3 gives a dependable, customizable, and feature-rich resolution for playback with ExoPlayer. The AI Samples app builds on this basis to please customers with useful and enriching AI-driven additions.

In at this time’s quickly evolving digital panorama, customers count on extra from their media purposes. Merely enjoying movies is not sufficient. Builders are always in search of methods to reinforce person experiences and supply deeper engagement. Leveraging the facility of Synthetic Intelligence (AI), notably when constructed upon sturdy media frameworks like Media3, presents thrilling alternatives. Let’s check out among the methods we are able to remodel the way in which customers work together with video content material:

• Empowering Video Understanding: The core concept is to make use of AI, particularly multimodal fashions just like the Gemini Flash and Professional fashions, to research video content material and extract significant data. This goes past merely enjoying a video; it is about understanding what’s within the video and making that data readily accessible to the person.
• Actionable Insights: The purpose is to rework uncooked video into summaries, insights, and interactive experiences. This enables customers to rapidly grasp the content material of a video and discover particular data they want or be taught one thing new!
• Accessibility and Engagement: AI helps make movies extra accessible by offering options like summaries, translations, and descriptions. It additionally goals to extend person engagement by way of interactive options.

A Glimpse into AI-Powered Video Journeys

The next instance demonstrates potential video journies enhanced by synthetic intelligence. This pattern integrates a number of elements, comparable to ExoPlayer and Transformer from Media3; the Firebase SDK (leveraging Vertex AI on Android); and Jetpack Compose, ViewModel, and StateFlow. The code will likely be accessible quickly on Github.

There are two experiences particularly that I’d like to spotlight:

• HDR Thumbnails: AI can assist establish key moments within the video that would make for good thumbnails. With these timestamps, you should use the brand new ExperimentalFrameExtractor API from Media3 to extract HDR thumbnails from movies, offering richer visible previews.
• Textual content-to-Speech: AI can be utilized to transform textual data derived from the video into spoken audio, enhancing accessibility. On Android you too can select to play audio in several languages and dialects thus enhancing personalization for a wider viewers.

Utilizing the correct AI resolution

Presently, solely cloud fashions assist video inputs, so we went forward with a cloud-based resolution.Iintegrating Firebase in our pattern empowers the app to:

• Generate real-time, concise video summaries robotically.
• Produce complete content material metadata, together with chapter markers and related hashtags.
• Facilitate seamless multilingual content material translation.

So how do you truly work together with a video and work with Gemini to course of it? First, ship your video as an enter parameter to your immediate:

val promptData =
"Summarize this video within the type of high 3-4 takeaways solely. Write within the type of bullet factors. Do not assume if you do not know"

val generativeModel = Firebase.vertexAI.generativeModel("gemini-2.0-flash")
_outputText.worth = OutputTextState.Loading

viewModelScope.launch(Dispatchers.IO) {
    strive {
        val requestContent = content material {
            fileData(videoSource.toString(), "video/mp4")
            textual content(immediate)
        }
        val outputStringBuilder = StringBuilder()

        generativeModel.generateContentStream(requestContent).acquire { response ->
            outputStringBuilder.append(response.textual content)
            _outputText.worth = OutputTextState.Success(outputStringBuilder.toString())
        }

        _outputText.worth = OutputTextState.Success(outputStringBuilder.toString())

    } catch (error: Exception) {
        _outputText.worth = error.localizedMessage?.let { OutputTextState.Error(it) }
    }
}

Discover there are two key elements right here:

• FileData: This element integrates a video into the question.
• Immediate: This asks the person what particular help they want from AI in relation to the supplied video.

In fact, you may finetune your immediate as per your necessities and get the responses accordingly.

In conclusion, by harnessing the capabilities of Jetpack Media3 and integrating AI options like Gemini by way of Firebase, you may considerably elevate video experiences on Android. This mixture allows superior options like video summaries, enriched metadata, and seamless multilingual translations, finally enhancing accessibility and engagement for customers. As these applied sciences proceed to evolve, the potential for creating much more dynamic and clever video purposes is huge.

Go above-and-beyond with specialised APIs

Mozart Louis

Android 16 introduces the brand new audio PCM Offload mode which may scale back the facility consumption of audio playback in your app, resulting in longer playback time and elevated person engagement. Eliminating the facility anxiousness significantly enhances the person expertise.

Oboe is Android’s premiere audio api that builders are ready to make use of to create excessive efficiency, low latency audio apps. A brand new characteristic is being added to the Android NDK and Android 16 known as Native PCM Offload playback.

Offload playback helps save battery life when enjoying audio. It really works by sending a big chunk of audio to a particular a part of the system’s {hardware} (a DSP). This enables the CPU of the system to enter a low-power state whereas the DSP handles enjoying the sound. This works with uncompressed audio (like PCM) and compressed audio (like MP3 or AAC), the place the DSP additionally takes care of decoding.

This may end up in vital energy saving whereas enjoying again audio and is ideal for purposes that play audio within the background or whereas the display is off (suppose audiobooks, podcasts, music and so forth).

We created the pattern app PowerPlay to reveal how you can implement these options utilizing the newest NDK model, C++ and Jetpack Compose.

Listed below are crucial components!

First order of enterprise is to guarantee the system helps audio offload of the file attributes you want. Within the instance under, we’re checking if the system assist audio offload of stereo, float PCM file with a pattern fee of 48000Hz.

       val format = AudioFormat.Builder()
            .setEncoding(AudioFormat.ENCODING_PCM_FLOAT)
            .setSampleRate(48000)
            .setChannelMask(AudioFormat.CHANNEL_OUT_STEREO)
            .construct()

        val attributes =
            AudioAttributes.Builder()
                .setContentType(AudioAttributes.CONTENT_TYPE_MUSIC)
                .setUsage(AudioAttributes.USAGE_MEDIA)
                .construct()
       
        val isOffloadSupported = 
            if (Construct.VERSION.SDK_INT >= Construct.VERSION_CODES.Q) {
                AudioManager.isOffloadedPlaybackSupported(format, attributes)
            } else {
                false
            }

        if (isOffloadSupported) {
            participant.initializeAudio(PerformanceMode::POWER_SAVING_OFFLOADED)
        }

As soon as we all know the system helps audio offload, we are able to confidently set the Oboe audio streams’ efficiency mode to the brand new efficiency mode choice, PerformanceMode::POWER_SAVING_OFFLOADED.

// Create an audio stream
        AudioStreamBuilder builder;
        builder.setChannelCount(mChannelCount);
        builder.setDataCallback(mDataCallback);
        builder.setFormat(AudioFormat::Float);
        builder.setSampleRate(48000);

        builder.setErrorCallback(mErrorCallback);
        builder.setPresentationCallback(mPresentationCallback);
        builder.setPerformanceMode(PerformanceMode::POWER_SAVING_OFFLOADED);
        builder.setFramesPerDataCallback(128);
        builder.setSharingMode(SharingMode::Unique);
           builder.setSampleRateConversionQuality(SampleRateConversionQuality::Medium);
        Consequence outcome = builder.openStream(mAudioStream);

Now when audio is performed again, it is going to be offloading audio to the DSP, serving to save energy when enjoying again audio.

There’s extra to this characteristic that will likely be lined in a future weblog submit, totally detailing out all the new accessible APIs that can make it easier to optimize your audio playback expertise!

What’s subsequent

In fact, we had been solely in a position to share the tip of the iceberg with you right here, so to dive deeper into the samples, try the next hyperlinks:

Hopefully these examples have impressed you to discover what new and engaging experiences you may construct on Android. Tune in to our session at Google I/O in a pair weeks to be taught much more about use-cases supported by options like Jetpack CameraX and Jetpack Media3!