From fde5c7dc79eb017790ba232442ad2a4eecea4bf1 Mon Sep 17 00:00:00 2001 From: Mark Wachsler Date: Thu, 7 Sep 2017 09:42:07 -0400 Subject: [PATCH] libavcodec/h264_parse: don't use uninitialized value when chroma_format_idc==0 When parsing a monochrome file, chroma_log2_weight_denom was used without being initialized, which could lead to a bogus error message being printed, e.g. [h264 @ 0x61a000026480] chroma_log2_weight_denom 24576 is out of range It also could led to warnings using AddressSanitizer. Signed-off-by: Michael Niedermayer --- libavcodec/h264_parse.c | 27 +++++++++++++++------------ 1 file changed, 15 insertions(+), 12 deletions(-) diff --git a/libavcodec/h264_parse.c b/libavcodec/h264_parse.c index 3d20075f6a..a7c71d9bbb 100644 --- a/libavcodec/h264_parse.c +++ b/libavcodec/h264_parse.c @@ -34,21 +34,22 @@ int ff_h264_pred_weight_table(GetBitContext *gb, const SPS *sps, pwt->use_weight = 0; pwt->use_weight_chroma = 0; - pwt->luma_log2_weight_denom = get_ue_golomb(gb); - if (sps->chroma_format_idc) - pwt->chroma_log2_weight_denom = get_ue_golomb(gb); + pwt->luma_log2_weight_denom = get_ue_golomb(gb); if (pwt->luma_log2_weight_denom > 7U) { av_log(logctx, AV_LOG_ERROR, "luma_log2_weight_denom %d is out of range\n", pwt->luma_log2_weight_denom); pwt->luma_log2_weight_denom = 0; } - if (pwt->chroma_log2_weight_denom > 7U) { - av_log(logctx, AV_LOG_ERROR, "chroma_log2_weight_denom %d is out of range\n", pwt->chroma_log2_weight_denom); - pwt->chroma_log2_weight_denom = 0; - } + luma_def = 1 << pwt->luma_log2_weight_denom; - luma_def = 1 << pwt->luma_log2_weight_denom; - chroma_def = 1 << pwt->chroma_log2_weight_denom; + if (sps->chroma_format_idc) { + pwt->chroma_log2_weight_denom = get_ue_golomb(gb); + if (pwt->chroma_log2_weight_denom > 7U) { + av_log(logctx, AV_LOG_ERROR, "chroma_log2_weight_denom %d is out of range\n", pwt->chroma_log2_weight_denom); + pwt->chroma_log2_weight_denom = 0; + } + chroma_def = 1 << pwt->chroma_log2_weight_denom; + } for (list = 0; list < 2; list++) { pwt->luma_weight_flag[list] = 0; @@ -102,9 +103,11 @@ int ff_h264_pred_weight_table(GetBitContext *gb, const SPS *sps, if (picture_structure == PICT_FRAME) { pwt->luma_weight[16 + 2 * i][list][0] = pwt->luma_weight[16 + 2 * i + 1][list][0] = pwt->luma_weight[i][list][0]; pwt->luma_weight[16 + 2 * i][list][1] = pwt->luma_weight[16 + 2 * i + 1][list][1] = pwt->luma_weight[i][list][1]; - for (j = 0; j < 2; j++) { - pwt->chroma_weight[16 + 2 * i][list][j][0] = pwt->chroma_weight[16 + 2 * i + 1][list][j][0] = pwt->chroma_weight[i][list][j][0]; - pwt->chroma_weight[16 + 2 * i][list][j][1] = pwt->chroma_weight[16 + 2 * i + 1][list][j][1] = pwt->chroma_weight[i][list][j][1]; + if (sps->chroma_format_idc) { + for (j = 0; j < 2; j++) { + pwt->chroma_weight[16 + 2 * i][list][j][0] = pwt->chroma_weight[16 + 2 * i + 1][list][j][0] = pwt->chroma_weight[i][list][j][0]; + pwt->chroma_weight[16 + 2 * i][list][j][1] = pwt->chroma_weight[16 + 2 * i + 1][list][j][1] = pwt->chroma_weight[i][list][j][1]; + } } } }