A5 (#171): fire the muxer guard that repairs "MP4 for everything", which had never fired #183

Merged
JMR-dev merged 2 commits from test/media3-muxer-guard into main 2026-09-02 04:02:04 +00:00
2 changed files with 325 additions and 0 deletions
@@ -0,0 +1,99 @@
package org.libremediaconverter.convert
import android.net.Uri
import androidx.media3.common.util.UnstableApi
import kotlinx.coroutines.runBlocking
import kotlinx.coroutines.withTimeout
import org.junit.Assert.assertEquals
import org.junit.Assert.assertFalse
import org.junit.Assert.assertNotEquals
import org.junit.Assert.assertNull
import org.junit.Assert.assertTrue
import org.junit.Test
import org.junit.runner.RunWith
import org.libremediaconverter.model.AudioCodec
import org.libremediaconverter.model.AudioPlan
import org.libremediaconverter.model.Container
import org.libremediaconverter.model.ConversionRequest
import org.libremediaconverter.model.CopyPlanner
import org.libremediaconverter.model.InputProbe
import org.libremediaconverter.model.OutputSpec
import org.libremediaconverter.model.VideoCodec
import org.libremediaconverter.model.VideoPlan
import org.robolectric.RobolectricTestRunner
import org.robolectric.RuntimeEnvironment
import java.io.File
import java.util.concurrent.CancellationException
/**
* A job that reached Media3 with a container Media3 cannot mux.
*
* [Media3Muxers]' own KDoc names the defect this guards: *"the router claimed five containers while
* the engine silently wrote MP4 for all of them."* `factoryFor` answers null for fourteen of the
* app's containers, and `buildTransformer` turns that null into a failed job rather than letting
* `Transformer` fall back to its default muxer.
*
* The guard had never fired. `Media3Engine$buildTransformer$3` -- the `requireNotNull` message
* lambda -- was four lines and four branches at 0%, which is to say the entire repair for a defect
* the codebase went to the trouble of writing down was untested. Weakening it would restore that
* bug silently, because the wrong output is a *playable file with the wrong container*, not a crash.
*
* Same harness and same two disciplines as [Media3EngineEmptyCompositionTest]: assert the plan
* really is the one the test needs before driving the engine, and rule out
* `CancellationException` so an unresumed continuation cannot read as a pass.
*/
@UnstableApi
@RunWith(RobolectricTestRunner::class)
class Media3MuxerGuardTest {
@Test
fun `a container Media3 cannot mux fails the job rather than silently writing MP4`() {
val context = RuntimeEnvironment.getApplication()
val engine = Media3Engine(context)
val request = ConversionRequest(
spec = OutputSpec(Container.WEBM, VideoCodec.VP9, AudioCodec.OPUS),
probe = InputProbe(videoCodec = "h264", audioCodec = "aac", container = Container.MP4),
)
// The premise, asserted rather than assumed -- three separate ways this test could pass
// over a path it never entered.
val plan = CopyPlanner.plan(request.spec, request.probe)
assertEquals("the plan has to still be WebM by the time the engine sees it", Container.WEBM, plan.container)
assertNull("...and Media3 really has no muxer for it", Media3Muxers.factoryFor(plan.container))
// Not the empty-composition refusal, which fires earlier and is a different test's subject.
assertNotEquals(VideoPlan.Drop, plan.video)
assertNotEquals(AudioPlan.Drop, plan.audio)
val failure = try {
runCatching {
runBlocking {
withTimeout(TIMEOUT_MS) {
engine.transcode(Uri.parse("file:///dev/null"), File(context.cacheDir, "guard.webm"), request) {
}
}
}
}.exceptionOrNull()
} finally {
engine.close()
}
assertFalse(
"the continuation was never resumed -- the refusal escaped instead of failing the job: $failure",
failure is CancellationException,
)
// Type *and* message, and the message half is the load-bearing one. Replacing the
// requireNotNull with a fallback factory does not make the export succeed here: it lets it
// run on and fail some other way, which a bare type assertion would happily accept.
assertTrue("expected the muxer guard to refuse the job, got $failure", failure is IllegalArgumentException)
assertTrue(
"the refusal has to name the container it could not mux, got: ${failure?.message}",
failure?.message.orEmpty().contains("cannot mux") &&
failure?.message.orEmpty().contains(Container.WEBM.name),
)
}
private companion object {
/** Nothing is decoded or muxed on this path -- the guard refuses before any of that. */
const val TIMEOUT_MS = 10_000L
}
}
@@ -0,0 +1,226 @@
package org.libremediaconverter.work
import android.app.Application
import android.net.Uri
import androidx.media3.common.util.UnstableApi
import androidx.work.Data
import androidx.work.ListenableWorker
import androidx.work.testing.TestListenableWorkerBuilder
import kotlinx.coroutines.CancellationException
import kotlinx.coroutines.runBlocking
import org.junit.After
import org.junit.Assert.assertEquals
import org.junit.Assert.assertFalse
import org.junit.Assert.assertThrows
import org.junit.Assert.assertTrue
import org.junit.Before
import org.junit.Test
import org.junit.runner.RunWith
import org.libremediaconverter.convert.ConversionDependencies
import org.libremediaconverter.convert.HardwareTranscoder
import org.libremediaconverter.convert.SoftwareTranscoder
import org.libremediaconverter.convert.installTestWorkManager
import org.libremediaconverter.model.Container
import org.libremediaconverter.model.ConversionRequest
import org.libremediaconverter.model.DeviceCodecs
import org.libremediaconverter.model.EnginePreference
import org.libremediaconverter.model.InputProbe
import org.libremediaconverter.model.OutputFormat
import org.robolectric.RobolectricTestRunner
import org.robolectric.RuntimeEnvironment
import java.io.File
import java.util.UUID
/**
* What happens when the hardware engine does not finish the job.
*
* `runMedia3OrFallBack` was eleven lines at 0% on the JVM and `isCancellation` had never been
* called by any unit test at all. Its own KDoc calls the fallback the protection against vendor
* hardware encoders that "cannot be tested for correctness", so it is the branch most likely to
* matter on a device nobody here owns — and it was reachable the whole time through
* `ConversionDependencies.hardware`, which no unit test had ever used.
*
* The sharp one is cancellation. `runMedia3OrFallBack` catches `Throwable`, so without the
* `isCancellation` re-throw a user cancelling a hardware transcode would have the app quietly
* start a *second* conversion in software — the one thing cancelling is supposed to prevent.
*
* `ForcedFailureTest` covers the failure half on a device. It does not cover the cancellation half,
* and this host cannot run it either way.
*/
@UnstableApi
@RunWith(RobolectricTestRunner::class)
class HardwareFallbackTest {
private lateinit var app: Application
private lateinit var hardware: RecordingHardwareTranscoder
private lateinit var software: RecordingSoftwareTranscoder
@Before
fun setUp() {
app = RuntimeEnvironment.getApplication()
hardware = RecordingHardwareTranscoder()
software = RecordingSoftwareTranscoder()
ConversionDependencies.publisher = { AlwaysRoomPublisher(app) }
ConversionDependencies.hardware = { hardware }
ConversionDependencies.software = { software }
// A probe with real codecs, not the default: `InputProbe()` reports UNPARSEABLE, which
// PERMISSIVE.canDecode refuses, and the router would send every job here straight to
// FFmpeg without any of these tests mentioning why.
ConversionDependencies.probe = { _, _ -> H264_SOURCE }
ConversionDependencies.deviceCodecs = { DeviceCodecs.PERMISSIVE }
installTestWorkManager(app, Data.EMPTY)
}
@After
fun tearDown() {
ConversionDependencies.reset()
}
@Test
fun `a hardware failure runs the job again in software, on a clean staging file`() {
hardware.failWith = { error("the vendor encoder produced nothing usable") }
val result = runBlocking { worker().doWork() }
assertTrue("the job should still succeed, got $result", result is ListenableWorker.Result.Success)
assertEquals("the hardware engine gets exactly one attempt", 1, hardware.attempts)
assertEquals("and the job then goes to software", 1, software.attempts)
// The `staged.delete()` between the two, asserted where it is observable: FFmpeg must not
// find a half-written hardware output sitting at the path it is about to write.
assertFalse(
"the partial hardware output must be gone before FFmpeg starts",
software.outputExistedOnEntry,
)
assertEquals("the hardware engine is closed either way", 1, hardware.closes)
}
@Test
fun `a cancelled hardware transcode is not quietly retried in software`() {
hardware.failWith = { throw CancellationException("the user pressed Cancel") }
assertThrows(CancellationException::class.java) { runBlocking { worker().doWork() } }
assertEquals("the hardware engine ran", 1, hardware.attempts)
assertEquals(
"cancelling must not start a second conversion -- that is the whole point of cancelling",
0,
software.attempts,
)
assertEquals("and the engine is still closed on the way out", 1, hardware.closes)
}
@Test
fun `a hardware transcode that works never reaches the software engine`() {
val result = runBlocking { worker().doWork() }
assertTrue("got $result", result is ListenableWorker.Result.Success)
assertEquals(1, hardware.attempts)
assertEquals("the fallback is a fallback, not a second pass", 0, software.attempts)
assertEquals(1, hardware.closes)
}
/**
* #169: the display-name fallback, which reaches further than the notification title.
*
* `inputData.getString(KEY_DISPLAY_NAME) ?: "input"` had never taken its right-hand side. The
* value is not only the foreground notification's title: it feeds `outputNameFor`, so it is
* also the filename offered in the user's save dialog. A job enqueued by an older build, or
* built by hand, carries no such key.
*/
@Test
fun `a job that names no input file still suggests an output name`() {
val result = runBlocking { worker(displayName = null).doWork() }
assertTrue("got $result", result is ListenableWorker.Result.Success)
val suggested = (result as ListenableWorker.Result.Success)
.outputData.getString(ConversionWorker.KEY_SUGGESTED_NAME)
assertTrue(
"expected a name built from the fallback, got $suggested",
suggested.orEmpty().startsWith("input"),
)
}
private fun worker(displayName: String? = DISPLAY_NAME): ConversionWorker {
val spec = OutputFormat.MP4_H265.spec
val entries = buildMap<String, Any> {
put(ConversionWorker.KEY_INPUT_URI, INPUT.toString())
displayName?.let { put(ConversionWorker.KEY_DISPLAY_NAME, it) }
put(ConversionWorker.KEY_SIZE_BYTES, INPUT_BYTES)
put(ConversionWorker.KEY_CONTAINER, spec.container.name)
put(ConversionWorker.KEY_VIDEO_CODEC, spec.videoCodec.name)
put(ConversionWorker.KEY_AUDIO_CODEC, spec.audioCodec.name)
// AUTO rather than FORCE_SOFTWARE, which is what every other worker test uses and is
// exactly why this path had no coverage: forcing software never enters the function.
put(ConversionWorker.KEY_ENGINE_PREFERENCE, EnginePreference.AUTO.name)
}
return TestListenableWorkerBuilder<ConversionWorker>(
context = app,
inputData = Data.Builder().putAll(entries).build(),
runAttemptCount = 0,
).setId(JOB_ID).build()
}
private companion object {
val INPUT: Uri = Uri.parse("file:///tmp/holiday.mp4")
const val DISPLAY_NAME = "holiday.mp4"
const val INPUT_BYTES = 1024L
val JOB_ID: UUID = UUID.fromString("00000000-0000-4000-8000-000000000009")
val H264_SOURCE = InputProbe(
videoCodec = "h264",
audioCodec = "aac",
container = Container.MP4,
durationMs = 1_000,
)
}
}
/**
* A hardware engine that writes something before it fails, and remembers being closed.
*
* Writing first is the point, exactly as it is for `PartialThenFailingTranscoder`: an engine that
* only threw would let a missing `staged.delete()` pass unnoticed.
*/
@UnstableApi
private class RecordingHardwareTranscoder : HardwareTranscoder {
var attempts = 0
var closes = 0
var failWith: (() -> Unit)? = null
override suspend fun transcode(input: Uri, output: File, request: ConversionRequest, onProgress: (Int) -> Unit) {
attempts++
output.writeBytes(ByteArray(PARTIAL_BYTES))
failWith?.invoke()
}
override fun close() {
closes++
}
private companion object {
const val PARTIAL_BYTES = 2048
}
}
/** The software engine, recording whether the hardware attempt's leftovers were cleared first. */
private class RecordingSoftwareTranscoder : SoftwareTranscoder {
var attempts = 0
var outputExistedOnEntry = false
override suspend fun run(
request: ConversionRequest,
inputPath: String,
output: File,
durationMs: Long,
onProgress: (Int) -> Unit,
) {
attempts++
outputExistedOnEntry = output.exists()
output.writeBytes(ByteArray(OUTPUT_BYTES))
}
private companion object {
const val OUTPUT_BYTES = 512
}
}