VideoEncoderConfigDefaultResolver.java
/*
* Copyright 2021 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package androidx.camera.video.internal.config;
import android.util.Range;
import android.util.Size;
import androidx.annotation.NonNull;
import androidx.annotation.RequiresApi;
import androidx.camera.core.Logger;
import androidx.camera.video.VideoSpec;
import androidx.camera.video.internal.encoder.VideoEncoderConfig;
import androidx.core.util.Supplier;
/**
* A {@link VideoEncoderConfig} supplier that resolves requested encoder settings from a
* {@link VideoSpec} for the given surface {@link Size} using pre-defined default values.
*/
@RequiresApi(21) // TODO(b/200306659): Remove and replace with annotation on package-info.java
public class VideoEncoderConfigDefaultResolver implements Supplier<VideoEncoderConfig> {
private static final String TAG = "VidEncCfgDefaultRslvr";
// Base config based on generic 720p H264 quality will be scaled by actual source settings.
// TODO: These should vary based on quality/codec and be derived from actual devices
private static final int VIDEO_BITRATE_BASE = 14000000;
private static final Size VIDEO_SIZE_BASE = new Size(1280, 720);
private static final int VIDEO_FRAME_RATE_BASE = 30;
private final String mMimeType;
private final VideoSpec mVideoSpec;
private final Size mSurfaceSize;
/**
* Constructor for a VideoEncoderConfigDefaultResolver.
*
* @param mimeType The mime type for the video encoder
* @param videoSpec The {@link VideoSpec} which defines the settings that should be used with
* the video encoder.
* @param surfaceSize The size of the surface required by the camera for the video encoder.
*/
public VideoEncoderConfigDefaultResolver(@NonNull String mimeType,
@NonNull VideoSpec videoSpec, @NonNull Size surfaceSize) {
mMimeType = mimeType;
mVideoSpec = videoSpec;
mSurfaceSize = surfaceSize;
}
@Override
@NonNull
public VideoEncoderConfig get() {
int resolvedFrameRate = VideoConfigUtil.resolveFrameRate(mVideoSpec);
Range<Integer> videoSpecBitrateRange = mVideoSpec.getBitrate();
Logger.d(TAG, "Using fallback VIDEO bitrate");
// We have no other information to go off of. Scale based on fallback defaults.
int resolvedBitrate = VideoConfigUtil.scaleAndClampBitrate(
VIDEO_BITRATE_BASE,
resolvedFrameRate, VIDEO_FRAME_RATE_BASE,
mSurfaceSize.getWidth(), VIDEO_SIZE_BASE.getWidth(),
mSurfaceSize.getHeight(), VIDEO_SIZE_BASE.getHeight(),
videoSpecBitrateRange);
return VideoEncoderConfig.builder()
.setMimeType(mMimeType)
.setResolution(mSurfaceSize)
.setBitrate(resolvedBitrate)
.setFrameRate(resolvedFrameRate)
.build();
}
}