unusedOpenOptions

expect val unusedOpenOptions: List<String>

The pre-open option keys FFmpeg did NOT consume on this open (KD-4). Always empty for the plain open; a non-empty list after an options open is a caller mistake worth reading back, and the S4 diagnostics dump prints it.

actual val unusedOpenOptions: List<String>

The pre-open option keys FFmpeg did NOT consume on this open (KD-4). Always empty for the plain open; a non-empty list after an options open is a caller mistake worth reading back, and the S4 diagnostics dump prints it.

actual val unusedOpenOptions: List<String>

The pre-open option keys FFmpeg did NOT consume on this open (KD-4). Always empty for the plain open; a non-empty list after an options open is a caller mistake worth reading back, and the S4 diagnostics dump prints it.

actual val unusedOpenOptions: List<String>

The pre-open option keys FFmpeg did NOT consume on this open (KD-4). Always empty for the plain open; a non-empty list after an options open is a caller mistake worth reading back, and the S4 diagnostics dump prints it.

actual val unusedOpenOptions: List<String>

The keys FFmpeg did not consume, which is a real answer now.

It answered emptyList() before, while open was also discarding every option unread. That pair is the worst of both: a caller probing for option support reads "none unused" as "all supported". The options are forwarded now and this reports what came back.