avformat/flvenc: Allow muxing video codecs which are not explicitly supported by the muxer

This allows stream copying video codecs before they are explicitly
supported. The same feature was in the past useful for audio codecs
in flv

This partly reverts the changes from 735ab7c5Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

libavformat/flvenc.c

@@ -336,6 +336,13 @@ static int unsupported_codec(AVFormatContext *s,
     return AVERROR(ENOSYS);
 }
 
+static int check_video_codec_tag(int codec_tag) {
+    if (codec_tag <= 0 || codec_tag > 15) {
+        return AVERROR(ENOSYS);
+    } else
+        return 0;
+}
+
 static int flv_write_header(AVFormatContext *s)
 {
     int i;
@@ -358,7 +365,7 @@ static int flv_write_header(AVFormatContext *s)
                 return AVERROR(EINVAL);
             }
             flv->video_enc = enc;
-            if (!ff_codec_get_tag(flv_video_codec_ids, enc->codec_id))
+            if (check_video_codec_tag(enc->codec_tag) < 0)
                 return unsupported_codec(s, "Video", enc->codec_id);
 
             if (enc->codec_id == AV_CODEC_ID_MPEG4 ||
@@ -542,7 +549,9 @@ static int flv_write_packet(AVFormatContext *s, AVPacket *pkt)
     case AVMEDIA_TYPE_VIDEO:
         avio_w8(pb, FLV_TAG_TYPE_VIDEO);
 
-        flags = ff_codec_get_tag(flv_video_codec_ids, enc->codec_id);
+        flags = enc->codec_tag;
+        if (check_video_codec_tag(flags) < 0)
+            return unsupported_codec(s, "Video", enc->codec_id);
 
         flags |= pkt->flags & AV_PKT_FLAG_KEY ? FLV_FRAME_KEY : FLV_FRAME_INTER;
         break;