Previously, we had separate MSG_SET_SURFACE and
MSG_SET_VIDEO_DECODER_OUTPUT_BUFFER_RENDERER messages for
setting different types of supported output. Use of these
constants to switch between outputs during use of a player
was confusing because not all video renderers support both
message types.
To switch from VideoDecoderOutputBufferRenderer to a Surface,
it was sufficient just to send MSG_SET_SURFACE, since all
video renderers support this and clear any other output that
might be set. Conversely, to switch in the opposite direction,
just sending a MSG_SET_VIDEO_DECODER_OUTPUT_BUFFER_RENDERER was
not sufficient, because not all video renderers handle this
message to clear any previous output. Hence it was necessary to
explicitly clear a previously set surface using a separate
MSG_SET_SURFACE message. Passing two messages to switch the
output may prevent renderers from implementing the output switch
efficiently.
This change passes all outputs using a single message type, and
requires that all renderers treat unsupported outputs as though
null were passed (i.e., they clear any existing output). There
are some other miscellaneous improvements:
1. Non-surface outputs are now passed to onRenderedFirstFrame.
This fixes a bug in SimpleExoPlayer's onRenderedFirstFrame,
where previously it could not correctly equality check the
output corresponding to the event to its current output in
the VideoDecoderOutputBufferRenderer case.
2. Fix SimpleExoPlayer to report surface size changes for the
VideoDecoderOutputBufferRenderer case. Even though the
surface is rendered to indirectly in this case, we can still
query (and listen to changes to) the surface's size.
PiperOrigin-RevId: 368215850