ffmpeg patch to fix up muxing HEVC streams with bad version, instead of erroring out

ffmpeg-hevc-version.diff

--- a/libavformat/hevc.c
+++ b/libavformat/hevc.c
@@ -1080,6 +1080,15 @@
         return 0;
     } else if (!(AV_RB24(data) == 1 || AV_RB32(data) == 1)) {
         /* Not a valid Annex B start code prefix */
+        if (*data == 0) {
+            /* The version field is is ignored by the decoder, so any value should be allowed. As this code relies on magic identifiers, we'll be a bit more strict and only accept '0' as a candidate to be fixed */
+            /* (these instances are outputs likely sourced from older/buggy tools) */
+            /* it might be ideal to do extra checks on the subsequent field (profile/tier) but I can't find open documentation on how they work */
+            av_log(pb, AV_LOG_WARNING,  "HEVCDecoderConfigurationRecord.configurationVersion changed from %"PRIu8" to 1\n", *data);
+            avio_w8(pb, 1);
+            avio_write(pb, data + 1, size - 1);
+            return 0;
+        }
         return AVERROR_INVALIDDATA;
     }