Constructing pleasant Android digital camera and media experiences

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

Hiya Android Builders!

We’re the Android Developer Relations Digital camera & Media workforce, and we’re excited to carry you one thing a bit of completely different in the present day. Over the previous a number of months, we’ve been onerous at work writing pattern code and constructing demos that showcase how you can make the most of all the nice potential Android gives 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 put up we thought we’d share a number of the learnings we gathered whereas going by means of this train.

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

Future-proof your app with Jetpack

Nevin Mital

Considered one of our focuses for the previous a number of years has been bettering the developer instruments obtainable 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 this moment, I’d wish to give attention to the Composition demo app, a pattern app that showcases a number of the multi-asset modifying experiences that Transformer allows.

I began by including a customized video compositor to show how one can prepare enter video sequences into completely different layouts on your remaining composition, similar to a 2×2 grid or a picture-in-picture overlay. You may customise this by implementing a VideoCompositorSettings and overriding the getOverlaySettings methodology. 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 supplies a presentation time, we will even animate the format, similar to on this picture-in-picture instance:

Subsequent, I spent a while migrating the Composition demo app to make use of Jetpack Compose. With difficult modifying flows, it might probably assist to make the most of as a lot display screen house as is on the market, 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 screen, and export choices are solely proven on the similar time on a bigger show. Beneath, you’ll be able to see how the UI dynamically adapts to the display screen measurement on a foldable system, when switching from the outer display screen to the inside display screen and vice versa.

What’s nice is that through the use of Jetpack Media3 and Jetpack Compose, these options additionally carry over seamlessly to different gadgets and type components, similar 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 House 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 similar 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 through the use of Jetpack Media3 and Jetpack Compose, these options additionally carry over seamlessly to different gadgets and type components, similar 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 House 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 similar 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 coated 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 intention to make the frequent case very accessible and straightforward, 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 vital 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.
// Notice: setting the decision selector is optionally available, 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()

non-public val previewUseCase = Preview.Builder()
  .setResolutionSelector(resolutionSelector)
  .construct()
non-public 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 establishing the fundamental construction for CameraX, you’ll be able to 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(Shade.Black)
    .fillMaxSize(),
  contentAlignment = Alignment.Middle,
) {
  surfaceRequest?.let {
    CameraXViewfinder(
      modifier = Modifier.fillMaxSize(),
      implementationMode = ImplementationMode.EXTERNAL,
      surfaceRequest = surfaceRequest,
     )
  }
  Button(
    onClick = onPhotoCapture,
    form = CircleShape,
    colours = ButtonDefaults.buttonColors(containerColor = Shade.White),
    modifier = Modifier
      .peak(75.dp)
      .width(75.dp),
  )
}

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

You’re already on monitor for a stable digital camera expertise, however what in the event you needed so as to add some additional options on your customers? Including filters and results are simple 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(
  utility,
  PREVIEW or IMAGE_CAPTURE,
  ContextCompat.getMainExecutor(utility),
  {},
)
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. Then you definitely set the checklist of results you wish to apply. Lastly, you add the impact to the useCaseGroupBuilder we outlined earlier.

There are numerous different built-in results you’ll be able to add, too! See the Media3 Impact documentation for extra choices, like brightness, colour lookup tables (LUTs), distinction, blur, and plenty of different results.

To take your results to one more degree, it’s additionally potential to outline your individual results by implementing the GlEffect interface, which acts as a manufacturing facility of GlShaderPrograms. You may implement a BaseGlShaderProgram’s drawFrame() methodology 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 vital person journeys in your app stand out from the remaining, Jetpack has you coated!

Jetpack gives a basis for modern AI Options

Mayuri Khinvasara Khabya

Simply as Donovan demonstrated with CameraX for seize, Jetpack Media3 supplies 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 in the present day’s quickly evolving digital panorama, customers anticipate extra from their media functions. Merely enjoying movies is now not sufficient. Builders are consistently in search of methods to reinforce person experiences and supply deeper engagement. Leveraging the facility of Synthetic Intelligence (AI), significantly when constructed upon strong media frameworks like Media3, gives thrilling alternatives. Let’s check out a number of the methods we will rework the best way 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 investigate video content material and extract significant info. This goes past merely enjoying a video; it is about understanding what’s within the video and making that info readily accessible to the person.
• Actionable Insights: The aim is to remodel uncooked video into summaries, insights, and interactive experiences. This enables customers to rapidly grasp the content material of a video and discover particular info they want or study 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 means 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, similar 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 obtainable quickly on Github.

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

• HDR Thumbnails: AI may also help establish key moments within the video that might make for good thumbnails. With these timestamps, you need to 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 info derived from the video into spoken audio, enhancing accessibility. On Android you can too select to play audio in numerous languages and dialects thus enhancing personalization for a wider viewers.

Utilizing the suitable 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 mechanically.
• 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) {
    attempt {
        val requestContent = content material {
            fileData(videoSource.toString(), "video/mp4")
            textual content(immediate)
        }
        val outputStringBuilder = StringBuilder()

        generativeModel.generateContentStream(requestContent).accumulate { 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 offered video.

After all, you’ll be able to 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 means of Firebase, you’ll be able to 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 functions is huge.

Go above-and-beyond with specialised APIs

Mozart Louis

Android 16 introduces the brand new audio PCM Offload mode which may cut back the facility consumption of audio playback in your app, resulting in longer playback time and elevated person engagement. Eliminating the facility anxiousness tremendously 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 function is being added to the Android NDK and Android 16 referred to 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 important energy saving whereas enjoying again audio and is ideal for functions that play audio within the background or whereas the display screen is off (suppose audiobooks, podcasts, music and many others).

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

Listed below are an important elements!

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 price 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 will confidently set the Oboe audio streams’ efficiency mode to the brand new efficiency mode possibility, 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);
        Outcome consequence = 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 may be extra to this function that will likely be coated in a future weblog put up, absolutely detailing out all the new obtainable APIs that can aid you optimize your audio playback expertise!

What’s subsequent

After all, 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’ll be able to construct on Android. Tune in to our session at Google I/O in a pair weeks to study much more about use-cases supported by options like Jetpack CameraX and Jetpack Media3!