+ H264RawPPS *pps;
+ int err;
+
+ // The changes we are about to perform affect the parsing process,
+ // so we must make sure that the PPS is writable, otherwise the
+ // parsing of future slices will be incorrect and even raise errors.
+ err = ff_cbs_make_unit_writable(ctx->input, unit);
+ if (err < 0)
+ return err;
+ pps = unit->content;
+