avcodec/av1_parser: don't set AVCodecContext pixel format

This is a property a decoder must set, not a parser.

Signed-off-by: James Almer <jamrial@gmail.com>

libavcodec/av1_parser.c

@@ -155,8 +155,6 @@ static int av1_parser_parse(AVCodecParserContext *ctx,
         color->transfer_characteristics  == AVCOL_TRC_IEC61966_2_1)
         ctx->format = pix_fmts_rgb[color->high_bitdepth + color->twelve_bit];
 
-    avctx->pix_fmt = ctx->format;
-
     avctx->profile = seq->seq_profile;
     avctx->level   = seq->seq_level_idx[0];