oggenc: fix condition when not to flush due to keyframe granule.

The previous condition of 0 page size was wrong,
that would disable the mechanism for all frames at
a start of a page, thus some keyframes still would not
get their own granule.
The real problem is that header packets must not be flushed,
but they have (and must have) 0 granule and thus would
be detected as keyframes.
Add a separate parameter to mark header packets.
Signed-off-by: Reimar Döffinger <Reimar.Doeffinger@gmx.de>
Signed-off-by: Justin Ruggles <justin.ruggles@gmail.com>

libavformat/oggenc.c

@@ -192,7 +192,8 @@ static int ogg_buffer_page(AVFormatContext *s, OGGStreamContext *oggstream)
 }
 
 static int ogg_buffer_data(AVFormatContext *s, AVStream *st,
-                           uint8_t *data, unsigned size, int64_t granule)
+                           uint8_t *data, unsigned size, int64_t granule,
+                           int header)
 {
     OGGStreamContext *oggstream = st->priv_data;
     OGGContext *ogg = s->priv_data;
@@ -201,7 +202,7 @@ static int ogg_buffer_data(AVFormatContext *s, AVStream *st,
     int i, segments, len, flush = 0;
 
     // Handles VFR by flushing page because this frame needs to have a timestamp
-    if (st->codec->codec_id == CODEC_ID_THEORA &&
+    if (st->codec->codec_id == CODEC_ID_THEORA && !header &&
         ogg_granule_to_timestamp(oggstream, granule) >
         ogg_granule_to_timestamp(oggstream, oggstream->last_granule) + 1) {
         if (oggstream->page.granule != -1)
@@ -231,8 +232,8 @@ static int ogg_buffer_data(AVFormatContext *s, AVStream *st,
         if (i == total_segments)
             page->granule = granule;
 
-        if (page->segments_count == 255 ||
-            (ogg->pref_size > 0 && page->size >= ogg->pref_size)) {
+        if (!header && (page->segments_count == 255 ||
+            (ogg->pref_size > 0 && page->size >= ogg->pref_size))) {
            ogg_buffer_page(s, oggstream);
         }
     }
@@ -431,7 +432,7 @@ static int ogg_write_header(AVFormatContext *s)
     for (j = 0; j < s->nb_streams; j++) {
         OGGStreamContext *oggstream = s->streams[j]->priv_data;
         ogg_buffer_data(s, s->streams[j], oggstream->header[0],
-                        oggstream->header_len[0], 0);
+                        oggstream->header_len[0], 0, 1);
         oggstream->page.flags |= 2; // bos
         ogg_buffer_page(s, oggstream);
     }
@@ -441,7 +442,7 @@ static int ogg_write_header(AVFormatContext *s)
         for (i = 1; i < 3; i++) {
             if (oggstream && oggstream->header_len[i])
                 ogg_buffer_data(s, st, oggstream->header[i],
-                                oggstream->header_len[i], 0);
+                                oggstream->header_len[i], 0, 1);
         }
         ogg_buffer_page(s, oggstream);
     }
@@ -492,7 +493,7 @@ static int ogg_write_packet(AVFormatContext *s, AVPacket *pkt)
     } else
         granule = pkt->pts + pkt->duration;
 
-    ret = ogg_buffer_data(s, st, pkt->data, pkt->size, granule);
+    ret = ogg_buffer_data(s, st, pkt->data, pkt->size, granule, 0);
     if (ret < 0)
         return ret;