Support variable length sgpd boxes in fMPEG

[dimitry-unified-streaming]

For sgpd boxes with version >= 1, the default_length field is zero if the length of the following sample group entries is variable.

Since the FragmentedMp4Extractor only supports one entry, skip the description_length field if applicable (e.g. when version >= 1 and default_length == 0), instead of throwing an error.

For parsing the following CencSampleEncryptionInformationGroupEntry, this should make no difference.

Issue: #3177

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[microkatz]

@dimitry-unified-streaming

Thank you for creating a PR for this feature! Would you please write some unit tests providing content with variable length sgpd boxes?

[google-oss-bot]

Hey @dimitry-unified-streaming. We need more information to resolve this issue but there hasn't been an update in 14 weekdays. I'm marking the issue as stale and if there are no new updates in the next 7 days I will close it automatically.

If you have more information that will help us get to the bottom of this, just add a comment!

[dimitry-unified-streaming]

I've been trying to add a test, but I'm running into an error that I don't fully understand:

deduplicateConsecutiveFormats=false so TrackOutput must receive at least one sampleMetadata() call between format() calls.
java.lang.IllegalStateException: deduplicateConsecutiveFormats=false so TrackOutput must receive at least one sampleMetadata() call between format() calls.
	at com.google.common.base.Preconditions.checkState(Preconditions.java:513)
	at androidx.media3.test.utils.FakeTrackOutput.format(FakeTrackOutput.java:90)
	at androidx.media3.extractor.mp4.FragmentedMp4Extractor$TrackBundle.updateDrmInitData(FragmentedMp4Extractor.java:2341)
	at androidx.media3.extractor.mp4.FragmentedMp4Extractor.onMoofContainerAtomRead(FragmentedMp4Extractor.java:913)
	at androidx.media3.extractor.mp4.FragmentedMp4Extractor.onContainerAtomRead(FragmentedMp4Extractor.java:784)
	at androidx.media3.extractor.mp4.FragmentedMp4Extractor.processAtomEnded(FragmentedMp4Extractor.java:753)
	at androidx.media3.extractor.mp4.FragmentedMp4Extractor.readAtomPayload(FragmentedMp4Extractor.java:748)
	at androidx.media3.extractor.mp4.FragmentedMp4Extractor.read(FragmentedMp4Extractor.java:581)
	at androidx.media3.test.utils.TestUtil.extractAllSamplesFromByteArray(TestUtil.java:611)
	at androidx.media3.test.utils.TestUtil.extractAllSamplesFromFile(TestUtil.java:574)
	at androidx.media3.extractor.mp4.FragmentedMp4ExtractorNonParameterizedTest.extract_h264WithVariableLengthSgpdBox(FragmentedMp4ExtractorNonParameterizedTest.java:134)
	at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(Unknown Source)
	at java.base/java.lang.reflect.Method.invoke(Unknown Source)
	at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:59)
	at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
	at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:56)
	at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
	at org.junit.runners.ParentRunner$3.evaluate(ParentRunner.java:306)
	at org.robolectric.RobolectricTestRunner$HelperTestRunner$1.evaluate(RobolectricTestRunner.java:524)
	at org.robolectric.internal.SandboxTestRunner.executeInSandbox(SandboxTestRunner.java:494)
	at org.robolectric.internal.SandboxTestRunner.access$900(SandboxTestRunner.java:67)
	at org.robolectric.internal.SandboxTestRunner$7.evaluate(SandboxTestRunner.java:442)
	at org.junit.runners.BlockJUnit4ClassRunner$1.evaluate(BlockJUnit4ClassRunner.java:100)
	at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:366)
	at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:103)
	at org.robolectric.internal.SandboxTestRunner.access$600(SandboxTestRunner.java:67)
	at org.robolectric.internal.SandboxTestRunner$6.evaluate(SandboxTestRunner.java:333)
	at org.robolectric.internal.SandboxTestRunner$3.evaluate(SandboxTestRunner.java:233)
	at org.robolectric.internal.SandboxTestRunner$5.lambda$evaluate$0(SandboxTestRunner.java:317)
	at org.robolectric.internal.bytecode.Sandbox.lambda$runOnMainThread$0(Sandbox.java:101)
	at java.base/java.util.concurrent.FutureTask.run(Unknown Source)
	at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
	at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
	at java.base/java.lang.Thread.run(Unknown Source)

Anybody have an idea what I can do to work around this? The test I'm adding looks like:

  @Test
  public void extract_h264WithVariableLengthSgpdBox() throws Exception {
    FragmentedMp4Extractor extractor =
        new FragmentedMp4Extractor(SubtitleParser.Factory.UNSUPPORTED);
    FakeExtractorOutput output =
        TestUtil.extractAllSamplesFromFile(
            extractor,
            ApplicationProvider.getApplicationContext(),
            "media/mp4/sample_fragmented_variable_length_sgpd.mp4");

    DumpFileAsserts.assertOutput(
        ApplicationProvider.getApplicationContext(),
        output,
        "extractordumps/mp4/fragmented_variable_length_sgpd.mp4");
  }

[dimitry-unified-streaming]

@microkatz let me know if anything else is needed. Do you require the commits to be squashed?

[google-oss-bot]

Since there haven't been any recent updates here, I am going to close this issue.

@dimitry-unified-streaming if you're still experiencing this problem and want to continue the discussion just leave a comment here and we are happy to re-open this.

[dimitry-unified-streaming]

Hum, the bot closed the issue as if there haven't been any updates, but there were? :)

[icbaker]

Please can you re-target this PR against the main branch.

[dimitry-unified-streaming]

Hm, GitHub doesn't seem to have figured out that I rebased against main? Not sure how I can fix this broken PR, maybe I should submit a new fresh one?

[dimitry-unified-streaming]

I can't edit or retarget this pull request, I will open a new one instead.

[dimitry-unified-streaming]

Submitted #3243 as a replacement, @icbaker