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avcodec/midivid: improve decoding of widths not multiple of 32

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This commit is contained in:
Paul B Mahol 2020-02-13 10:11:20 +01:00
parent 018a42790c
commit 388a221a8b
1 changed files with 8 additions and 6 deletions
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14
libavcodec/midivid.c
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@ -59,16 +59,17 @@ static int decode_mvdv(MidiVidContext *s, AVCodecContext *avctx, AVFrame *frame)
uint32_t nb_blocks;
nb_vectors = bytestream2_get_le16(gb);
intra_flag = bytestream2_get_le16(gb);
intra_flag = !!bytestream2_get_le16(gb);
if (intra_flag) {
nb_blocks = (avctx->width / 2) * (avctx->height / 2);
} else {
int ret, skip_linesize;
int ret, skip_linesize, padding;
nb_blocks = bytestream2_get_le32(gb);
skip_linesize = avctx->width >> 1;
mask_start = gb->buffer_start + bytestream2_tell(gb);
mask_size = (avctx->width >> 5) * (avctx->height >> 2);
mask_size = (FFALIGN(avctx->width, 32) >> 2) * (avctx->height >> 2) >> 3;
padding = (FFALIGN(avctx->width, 32) - avctx->width) >> 2;
if (bytestream2_get_bytes_left(gb) < mask_size)
return AVERROR_INVALIDDATA;
@ -88,6 +89,7 @@ static int decode_mvdv(MidiVidContext *s, AVCodecContext *avctx, AVFrame *frame)
skip[(y*2+1)*skip_linesize + x*2 ] = flag;
skip[(y*2+1)*skip_linesize + x*2+1] = flag;
}
skip_bits_long(&mask, padding);
}
}
@ -96,10 +98,10 @@ static int decode_mvdv(MidiVidContext *s, AVCodecContext *avctx, AVFrame *frame)
return AVERROR_INVALIDDATA;
bytestream2_skip(gb, nb_vectors * 12);
if (nb_vectors > 256) {
if (bytestream2_get_bytes_left(gb) < (nb_blocks + 7) / 8)
if (bytestream2_get_bytes_left(gb) < (nb_blocks + 7 * !intra_flag) / 8)
return AVERROR_INVALIDDATA;
bytestream2_init(&idx9, gb->buffer_start + bytestream2_tell(gb), (nb_blocks + 7) / 8);
bytestream2_skip(gb, (nb_blocks + 7) / 8);
bytestream2_init(&idx9, gb->buffer_start + bytestream2_tell(gb), (nb_blocks + 7 * !intra_flag) / 8);
bytestream2_skip(gb, (nb_blocks + 7 * !intra_flag) / 8);
}
skip = s->skip;