fix(player): pick a decodable track in the no-audio fallback (DR-146)

When ExoPlayer selected no audio track, the recovery forced group 0 /
track 0 unconditionally. But the most likely reason nothing was selected
is that this very track cannot be decoded on this device, so the override
reinstated the silence it was meant to fix.

Scan the groups for the first isTrackSupported track and override to
that. Also clear setTrackTypeDisabled(TRACK_TYPE_AUDIO), since audio may
equally have been off at the type level, which an override alone does not
undo. When no group holds a supported track, log it as an error — the
server was expected to transcode — instead of leaving a silent video with
no explanation in the log.

Verified by compiling :app:compileArm64DebugKotlin. Not unit-tested: this
tree has no Kotlin test source set, as noted in the previous commit.
This commit is contained in:
2026-08-09 15:07:18 +02:00
parent 19bc265a8d
commit 7b531a40be
2 changed files with 49 additions and 16 deletions
@@ -383,29 +383,61 @@ class JellyTauPlayer(private val appContext: Context) {
android.util.Log.d("JellyTauPlayer", " Video group: ${group.length} tracks, selected=${group.isSelected}")
}
// CRITICAL FIX: Auto-select first audio track if none is selected
// This fixes the issue where some videos play without audio
// TRACES: UR-004 | DR-146
// Auto-select an audio track if none is selected — some videos
// otherwise play with no sound. Pick a track the renderer says it
// *supports*: when nothing was selected because track 0 failed to
// initialize, forcing track 0 again just reinstates the silence.
if (!hasSelectedAudio && audioTracks.isNotEmpty() && currentMediaType == MediaType.VIDEO) {
android.util.Log.w("JellyTauPlayer", "⚠️ NO AUDIO TRACK SELECTED! Auto-selecting first audio track...")
android.util.Log.w("JellyTauPlayer", "⚠️ NO AUDIO TRACK SELECTED! Looking for a supported audio track...")
val trackSelector = exoPlayer.trackSelector
if (trackSelector != null) {
try {
// Select the first audio track group
val firstAudioGroup = audioTracks[0]
val override = androidx.media3.common.TrackSelectionOverride(
firstAudioGroup.mediaTrackGroup,
0 // Select the first track in this group
)
var chosenGroup: androidx.media3.common.Tracks.Group? = null
var chosenIndex = -1
outer@ for (group in audioTracks) {
for (i in 0 until group.length) {
if (group.isTrackSupported(i)) {
chosenGroup = group
chosenIndex = i
break@outer
}
}
}
val parameters = trackSelector.parameters
.buildUpon()
.clearOverridesOfType(C.TRACK_TYPE_AUDIO)
.addOverride(override)
.build()
if (chosenGroup == null) {
// Every track is undecodable on this device. The
// server should have transcoded; say so loudly
// rather than leaving a silent video unexplained.
android.util.Log.e(
"JellyTauPlayer",
"✗ No supported audio track in ${audioTracks.size} group(s) - " +
"device cannot decode any of them, expected a transcode"
)
} else {
val format = chosenGroup.getTrackFormat(chosenIndex)
val override = androidx.media3.common.TrackSelectionOverride(
chosenGroup.mediaTrackGroup,
chosenIndex
)
trackSelector.setParameters(parameters)
android.util.Log.d("JellyTauPlayer", "✓ Auto-selected first audio track")
val parameters = trackSelector.parameters
.buildUpon()
// Audio may also be off because the track type
// was disabled; an override alone would not
// bring it back.
.setTrackTypeDisabled(C.TRACK_TYPE_AUDIO, false)
.clearOverridesOfType(C.TRACK_TYPE_AUDIO)
.addOverride(override)
.build()
trackSelector.setParameters(parameters)
android.util.Log.d(
"JellyTauPlayer",
"✓ Auto-selected supported audio track $chosenIndex (${format.sampleMimeType}, ${format.channelCount}ch)"
)
}
} catch (e: Exception) {
android.util.Log.e("JellyTauPlayer", "Failed to auto-select audio track", e)
}