avcodec/libsvtav1: send the EOS signal without a one frame delay to allow for the library to operate in a low-delay mode

Co-authored-by: Amir Naghdinezhad <amir.naghdinezhad@intel.com>
Signed-off-by: Cosmin Stejerean <cosmin@cosmin.at>
Signed-off-by: James Almer <jamrial@gmail.com>
(cherry picked from commit 69dd1ce610)

libavcodec/libsvtav1.c

@@ -539,6 +539,14 @@ static int eb_receive_packet(AVCodecContext *avctx, AVPacket *pkt)
     if (svt_ret == EB_NoErrorEmptyQueue)
         return AVERROR(EAGAIN);
 
+#if SVT_AV1_CHECK_VERSION(2, 0, 0)
+    if (headerPtr->flags & EB_BUFFERFLAG_EOS) {
+         svt_enc->eos_flag = EOS_RECEIVED;
+         svt_av1_enc_release_out_buffer(&headerPtr);
+         return AVERROR_EOF;
+    }
+#endif
+
     ref = get_output_ref(avctx, svt_enc, headerPtr->n_filled_len);
     if (!ref) {
         av_log(avctx, AV_LOG_ERROR, "Failed to allocate output packet.\n");
@@ -573,8 +581,10 @@ static int eb_receive_packet(AVCodecContext *avctx, AVPacket *pkt)
     if (headerPtr->pic_type == EB_AV1_NON_REF_PICTURE)
         pkt->flags |= AV_PKT_FLAG_DISPOSABLE;
 
+#if !(SVT_AV1_CHECK_VERSION(2, 0, 0))
     if (headerPtr->flags & EB_BUFFERFLAG_EOS)
         svt_enc->eos_flag = EOS_RECEIVED;
+#endif
 
     ff_side_data_set_encoder_stats(pkt, headerPtr->qp * FF_QP2LAMBDA, NULL, 0, pict_type);