ffmpeg | branch: master | Frank Plowman <p...@frankplowman.com> | Sun Jun 9 12:17:26 2024 +0100| [d72a5fe719c01da07af30e4402a7c3cd994b4cfc] | committer: Nuo Mi
lavc/vvc: Prevent overflow in chroma QP derivation On the top of p. 112 in VVC (09/2023): It is a requirement of bitstream conformance that the values of qpInVal[ i ][ j ] and qpOutVal[ i ][ j ] shall be in the range of −QpBdOffset to 63, inclusive for i in the range of 0 to numQpTables − 1, inclusive, and j in the range of 0 to sps_num_points_in_qp_table_minus1[ i ] + 1, inclusive. Additionally, don't discard the return code from sps_chroma_qp_table. Signed-off-by: Frank Plowman <p...@frankplowman.com> > http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=d72a5fe719c01da07af30e4402a7c3cd994b4cfc --- libavcodec/vvc/ps.c | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-) diff --git a/libavcodec/vvc/ps.c b/libavcodec/vvc/ps.c index 1b23675c98..92368eafc2 100644 --- a/libavcodec/vvc/ps.c +++ b/libavcodec/vvc/ps.c @@ -101,9 +101,14 @@ static int sps_chroma_qp_table(VVCSPS *sps) qp_out[0] = qp_in[0] = r->sps_qp_table_start_minus26[i] + 26; for (int j = 0; j < num_points_in_qp_table; j++ ) { + const uint8_t delta_qp_out = (r->sps_delta_qp_in_val_minus1[i][j] ^ r->sps_delta_qp_diff_val[i][j]); delta_qp_in[j] = r->sps_delta_qp_in_val_minus1[i][j] + 1; + // Note: we cannot check qp_{in,out}[j+1] here as qp_*[j] + delta_qp_* + // may not fit in an 8-bit signed integer. + if (qp_in[j] + delta_qp_in[j] > 63 || qp_out[j] + delta_qp_out > 63) + return AVERROR(EINVAL); qp_in[j+1] = qp_in[j] + delta_qp_in[j]; - qp_out[j+1] = qp_out[j] + (r->sps_delta_qp_in_val_minus1[i][j] ^ r->sps_delta_qp_diff_val[i][j]); + qp_out[j+1] = qp_out[j] + delta_qp_out; } sps->chroma_qp_table[i][qp_in[0] + off] = qp_out[0]; for (int k = qp_in[0] - 1 + off; k >= 0; k--) @@ -186,8 +191,11 @@ static int sps_derive(VVCSPS *sps, void *log_ctx) sps_inter(sps); sps_partition_constraints(sps); sps_ladf(sps); - if (r->sps_chroma_format_idc != 0) - sps_chroma_qp_table(sps); + if (r->sps_chroma_format_idc != 0) { + ret = sps_chroma_qp_table(sps); + if (ret < 0) + return ret; + } return 0; } _______________________________________________ ffmpeg-cvslog mailing list ffmpeg-cvslog@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-cvslog To unsubscribe, visit link above, or email ffmpeg-cvslog-requ...@ffmpeg.org with subject "unsubscribe".
