spawn_empty_frame  564 libavcodec/opusenc.c             AVFrame *empty = spawn_empty_frame(s);
spawn_empty_frame  673 libavcodec/opusenc.c     ff_bufqueue_add(avctx, &s->bufqueue, spawn_empty_frame(s));
spawn_empty_frame 1119 libavcodec/vorbisenc.c                AVFrame *empty = spawn_empty_frame(avctx, venc->channels);