参考：

https://source.android.com/docs/devices/tv/multimedia-tunneling?hl=zh-cn

源码中的media_codecs.xml

./hardware/qcom-caf/sm8250/media/conf_files/lito/media_codecs.xml
./hardware/qcom-caf/sm8250/media/conf_files/bengal/media_codecs.xml
./hardware/qcom-caf/sm8250/media/conf_files/kona/media_codecs.xml
./hardware/qcom-caf/sdm845/media/conf_files/sdm845/media_codecs.xml
./hardware/qcom-caf/sdm845/media/conf_files/sdm710/media_codecs.xml
./hardware/qcom-caf/sm8150/media/conf_files/trinket/media_codecs.xml
./hardware/qcom-caf/sm8150/media/conf_files/atoll/media_codecs.xml
./hardware/qcom-caf/sm8150/media/conf_files/sdmshrike/media_codecs.xml
./hardware/qcom-caf/sm8150/media/conf_files/sm6150/media_codecs.xml
./hardware/qcom-caf/sm8150/media/conf_files/msmnile/media_codecs.xml
./hardware/qcom/sm8150/media/conf_files/sm6150/media_codecs.xml
./hardware/qcom/sm8150/media/conf_files/msmnile/media_codecs.xml
./device/waydroid/waydroid/configs/media_codecs.xml
./device/generic/goldfish/camera/media_codecs.xml
./out/target/product/waydroid_arm/system/apex/com.android.media.swcodec/etc/media_codecs.xml
./out/target/product/waydroid_arm/obj/ETC/com.android.media.swcodec.mediaswcodec.xml_intermediates/media_codecs.xml
./out/target/product/waydroid_arm/vendor/etc/media_codecs.xml
./out/soong/.intermediates/frameworks/av/media/libstagefright/data/mediaswcodec.xml/android_arm_armv7-a-neon_core/media_codecs.xml
 

系统中的media_codecs.xml

./apex/com.android.media.swcodec/etc/media_codecs.xml
./apex/com.android.media.swcodec@290000000/etc/media_codecs.xml
./system/apex/com.android.media.swcodec/etc/media_codecs.xml
./vendor/etc/media_codecs.xml