avcodec/mediacodecdec: try to receive a frame after signaling EOF to the codec

Avoids returning EAGAIN after signaling EOF to the codec in
ff_mediacodec_dec_send() so we can try to receive a frame before
returning in mediacodec_receive_frame().

This helps avoiding an extra round-trip between avcodec_send_frame() and
avcodec_receive_frame() while draining the remaining frames.

libavcodec/mediacodecdec.c

@@ -461,6 +461,7 @@ static int mediacodec_receive_frame(AVCodecContext *avctx, AVFrame *frame)
             ret = ff_mediacodec_dec_send(avctx, s->ctx, &null_pkt, true);
             if (ret < 0)
                 return ret;
+            return ff_mediacodec_dec_receive(avctx, s->ctx, frame, true);
         } else if (ret == AVERROR(EAGAIN) && s->ctx->current_input_buffer < 0) {
             return ff_mediacodec_dec_receive(avctx, s->ctx, frame, true);
         } else if (ret < 0) {

libavcodec/mediacodecdec_common.c

@@ -631,7 +631,7 @@ int ff_mediacodec_dec_send(AVCodecContext *avctx, MediaCodecDecContext *s,
                    "Queued input buffer %zd size=%zd ts=%"PRIi64"\n", index, size, pts);
 
             s->draining = 1;
-            break;
+            return 0;
         } else {
             size = FFMIN(pkt->size - offset, size);
             memcpy(data, pkt->data + offset, size);