Centralize H.265 settings-string comparisons on VideoDecoder.CodecType

settings.videoCodec comparisons against the literal "H.265" were
duplicated across AapVideo.kt, AapControl.kt, ServiceDiscoveryResponse.kt,
and HeadUnitScreenConfig.kt. Added CodecType.settingsValue as the single
source of truth for the settings-string form ("H.264"/"H.265"), distinct
from the existing mimeType ("video/avc"/"video/hevc") and displayName
("H.264/AVC"/"H.265/HEVC") fields, and switched all four call sites to
reference it instead of a bare string literal.

The Auto/H.265 `when` branch in ServiceDiscoveryResponse.kt and the
SettingsFragment.kt codec picker array are left as-is, since "Auto" has
no CodecType counterpart to centralize against.

Author: o-jcardenass

app/src/main/java/com/andrerinas/openheadunit/aap/AapControl.kt

@@ -14,6 +14,7 @@ import com.andrerinas.openheadunit.aap.protocol.proto.Input
 import com.andrerinas.openheadunit.aap.protocol.proto.Media
 import com.andrerinas.openheadunit.aap.protocol.proto.Sensors
 import com.andrerinas.openheadunit.decoder.MicRecorder
+import com.andrerinas.openheadunit.decoder.VideoDecoder
 import com.andrerinas.openheadunit.utils.AppLog
 import com.andrerinas.openheadunit.utils.Settings
 
@@ -109,7 +110,7 @@ internal class AapControlMedia(
     private fun maxUnackedFor(channel: Int): Int {
         if (channel == Channel.ID_VID) {
             val softwareHevc =
-                aapTransport.settings.videoCodec == "H.265" &&
+                aapTransport.settings.videoCodec == VideoDecoder.CodecType.H265.settingsValue &&
                         aapTransport.settings.forceSoftwareDecoding &&
                         aapTransport.settings.softwareVideoDecoder == Settings.SoftwareVideoDecoder.BUNDLED_FFMPEG
             if (softwareHevc) {

app/src/main/java/com/andrerinas/openheadunit/aap/AapVideo.kt

@@ -9,7 +9,7 @@ import java.nio.ByteBuffer
 internal class AapVideo(private val videoDecoder: VideoDecoder, private val settings: Settings, private val onFrameCorrupted: () -> Unit) {
 
     private val messageBuffer = ByteBuffer.allocate(
-        if (settings.videoCodec == "H.265") {
+        if (settings.videoCodec == VideoDecoder.CodecType.H265.settingsValue) {
             Messages.DEF_BUFFER_LENGTH * 64 // ~8MB for H.265 support
         } else {
             Messages.DEF_BUFFER_LENGTH * 16 // ~2MB for H.264 legacy support
@@ -59,14 +59,14 @@ internal class AapVideo(private val videoDecoder: VideoDecoder, private val sett
         if (scLen <= 0 || scOffset + scLen >= len)
             return true
 
-        val nalType = if (settings.videoCodec == "H.265") {
+        val nalType = if (settings.videoCodec == VideoDecoder.CodecType.H265.settingsValue) {
             (buf[scOffset + scLen].toInt() and 0x7E) shr 1 // H.265 NAL
         } else {
             buf[scOffset + scLen].toInt() and 0x1F // H.264 NAL
         }
 
         // Check if it's an I-Frame or VPS/SPS/PPS (types that can start a clean stream)
-        val isKeyframe = if (settings.videoCodec == "H.265") {
+        val isKeyframe = if (settings.videoCodec == VideoDecoder.CodecType.H265.settingsValue) {
             nalType in 16..21 || nalType in 32..34
         } else {
             nalType == 5 || nalType == 7 || nalType == 8

app/src/main/java/com/andrerinas/openheadunit/aap/protocol/messages/ServiceDiscoveryResponse.kt

@@ -10,6 +10,7 @@ import com.andrerinas.openheadunit.aap.protocol.Channel
 import com.andrerinas.openheadunit.aap.protocol.proto.Control
 import com.andrerinas.openheadunit.aap.protocol.proto.Media
 import com.andrerinas.openheadunit.aap.protocol.proto.Sensors
+import com.andrerinas.openheadunit.decoder.VideoDecoder
 import com.andrerinas.openheadunit.utils.AppLog
 import com.andrerinas.openheadunit.utils.HeadUnitScreenConfig
 import com.google.protobuf.Message
@@ -46,7 +47,7 @@ class ServiceDiscoveryResponse(private val context: Context)
                 service.id = Channel.ID_VID
                 service.mediaSinkService = Control.Service.MediaSinkService.newBuilder().also { mediaSinkServiceBuilder ->
                     val explicitSoftwareHevc =
-                        settings.videoCodec == "H.265" &&
+                        settings.videoCodec == VideoDecoder.CodecType.H265.settingsValue &&
                                 settings.forceSoftwareDecoding &&
                                 when (settings.softwareVideoDecoder) {
                                     com.andrerinas.openheadunit.utils.Settings.SoftwareVideoDecoder.BUNDLED_FFMPEG ->

app/src/main/java/com/andrerinas/openheadunit/decoder/VideoDecoder.kt

@@ -159,9 +159,9 @@ class VideoDecoder(private val settings: Settings) {
     val videoWidth: Int get() = mWidth
     val videoHeight: Int get() = mHeight
 
-    enum class CodecType(val mimeType: String, val displayName: String) {
-        H264("video/avc", "H.264/AVC"),
-        H265("video/hevc", "H.265/HEVC")
+    enum class CodecType(val mimeType: String, val displayName: String, val settingsValue: String) {
+        H264("video/avc", "H.264/AVC", "H.264"),
+        H265("video/hevc", "H.265/HEVC", "H.265")
     }
 
     /**

app/src/main/java/com/andrerinas/openheadunit/utils/HeadUnitScreenConfig.kt

@@ -351,7 +351,7 @@ object HeadUnitScreenConfig {
 
     private fun canNegotiateHevcHighResolution(): Boolean {
         if (VideoDecoder.isHevcSupported()) return true
-        if (currentSettings.videoCodec != "H.265" || !currentSettings.forceSoftwareDecoding) return false
+        if (currentSettings.videoCodec != VideoDecoder.CodecType.H265.settingsValue || !currentSettings.forceSoftwareDecoding) return false
         return when (currentSettings.softwareVideoDecoder) {
             Settings.SoftwareVideoDecoder.BUNDLED_FFMPEG -> VideoDecoder.isBundledHevcDecoderAvailable()
             Settings.SoftwareVideoDecoder.DEVICE_MEDIACODEC -> VideoDecoder.isHevcDecoderAvailable(includeSoftware = true)