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Add AC-4 decoder capability assessment during track selection #2580

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Merged
copybara-service merged 1 commit into from
Jul 9, 2025
Merged

Add AC-4 decoder capability assessment during track selection #2580

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44 changes: 43 additions & 1 deletion libraries/exoplayer/src/main/java/androidx/media3/exoplayer/mediacodec/MediaCodecInfo.java
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Original file line number Diff line number Diff line change
Expand Up @@ -357,13 +357,22 @@ private boolean isCodecProfileAndLevelSupported(
}
}

if (!isVideo && profile != CodecProfileLevel.AACObjectXHE) {
if (!isVideo &&
!mimeType.equals(MimeTypes.AUDIO_AC4) &&
profile != CodecProfileLevel.AACObjectXHE) {
// AC-4 decoder reports profile levels or audio capabilities that determine whether input
// format is supported or not.
// Some devices/builds underreport audio capabilities, so assume support except for xHE-AAC
// which may not be widely supported. See https://github.com/google/ExoPlayer/issues/5145.
return true;
}

CodecProfileLevel[] profileLevels = getProfileLevels();
if (MimeTypes.AUDIO_AC4.equals(mimeType) && profileLevels.length == 0) {
// Some older devices don't report profile levels for AC-4. Estimate them using other data
// in the codec capabilities.
profileLevels = estimateLegacyAc4ProfileLevels(capabilities);
}
if (SDK_INT <= 23 && MimeTypes.VIDEO_VP9.equals(mimeType) && profileLevels.length == 0) {
// Some older devices don't report profile levels for VP9. Estimate them using other data in
// the codec capabilities.
Expand Down Expand Up @@ -819,6 +828,39 @@ private static int getMaxSupportedInstancesV23(CodecCapabilities capabilities) {
return capabilities.getMaxSupportedInstances();
}

/**
* Called on devices with AC-4 decoders whose {@link CodecCapabilities} do not report profile
* levels. The returned {@link CodecProfileLevel CodecProfileLevels} are estimated based on other
* data in the {@link CodecCapabilities}.
*
* @param capabilities The {@link CodecCapabilities} for an AC-4 decoder, or {@code null} if not
* known.
* @return The estimated {@link CodecProfileLevel CodecProfileLevels} for the decoder.
*/
private static CodecProfileLevel[] estimateLegacyAc4ProfileLevels(
@Nullable CodecCapabilities capabilities) {
int maxInChCount = 2;
if (capabilities != null) {
@Nullable AudioCapabilities audioCapabilities = capabilities.getAudioCapabilities();
if (audioCapabilities != null) {
maxInChCount = audioCapabilities.getMaxInputChannelCount();
}
}

int level = CodecProfileLevel.AC4Level3;
if (maxInChCount > 18) { // AC-4 Level 3 stream is up to 17.1 channel
level = CodecProfileLevel.AC4Level4;
}

return new CodecProfileLevel[] {
createCodecProfileLevel(CodecProfileLevel.AC4Profile00, level),
createCodecProfileLevel(CodecProfileLevel.AC4Profile10, level),
createCodecProfileLevel(CodecProfileLevel.AC4Profile11, level),
createCodecProfileLevel(CodecProfileLevel.AC4Profile21, level),
createCodecProfileLevel(CodecProfileLevel.AC4Profile22, level)
};
}

/**
* Called on devices with {@link Build.VERSION#SDK_INT} 23 and below, for VP9 decoders whose
* {@link CodecCapabilities} do not correctly report profile levels. The returned {@link
Expand Down