The parser depends on the codec and thus must not be used with a different one.
If it is, the 'avctx->codec_id == s->parser->codec_ids[0] ...' assert in
av_parser_parse2 gets triggered.
Reviewed-by: Michael Niedermayer <michael@niedermayer.cc>
Signed-off-by: Andreas Cadhalpun <Andreas.Cadhalpun@googlemail.com>