Revert "avformat/demux: Make read_frame_internal() return AVERREOR(EAGAIN) on stuck empty input parser"

Hides the underlying real problem with a demuxer returning 0 sized packets.

This reverts commit 02699490c1.

libavformat/demux.c

@@ -1235,15 +1235,11 @@ static int read_frame_internal(AVFormatContext *s, AVPacket *pkt)
     FFFormatContext *const si = ffformatcontext(s);
     int ret, got_packet = 0;
     AVDictionary *metadata = NULL;
-    int empty = 0;
 
     while (!got_packet && !si->parse_queue.head) {
         AVStream *st;
         FFStream *sti;
 
-        if (empty > 1)
-            return AVERROR(EAGAIN);
-
         /* read next packet */
         ret = ff_read_packet(s, pkt);
         if (ret < 0) {
@@ -1334,8 +1330,6 @@ static int read_frame_internal(AVFormatContext *s, AVPacket *pkt)
             }
             got_packet = 1;
         } else if (st->discard < AVDISCARD_ALL) {
-            if (pkt->size == 0)
-                empty ++;
             if ((ret = parse_packet(s, pkt, pkt->stream_index, 0)) < 0)
                 return ret;
             st->codecpar->sample_rate = sti->avctx->sample_rate;