Previously that was implicit, it was the passthrough dance:
- MimeTypes.getEncoding(inputFormat) did not
implement RAW MIME, so it was returning INVALID_ENCODING for PCM
- and allowPassthrough was returning
MimeTypes.getEncoding() != INVALID_ENCODING
- which was setting codecInfo.passthrough, and passthroughEnabled.
Thus Util.isEncodingPcm(encoding) is the opposite of
(MimeTypes.getEncoding(inputFormat) != C.ENCODING_INVALID)
This was rather implicit and brittle as anyone
could add support for audio/RAW in
MimeTypes.getEncoding and break PCM playback.
As a result make it explicit that allowPassthrough
must always return false in PCM.
PiperOrigin-RevId: 295144013
