diff --git a/libavcodec/jpeg2000dec.c b/libavcodec/jpeg2000dec.c index f9309be1ef..ac801edba8 100644 --- a/libavcodec/jpeg2000dec.c +++ b/libavcodec/jpeg2000dec.c @@ -635,7 +635,14 @@ static int jpeg2000_decode_packet(Jpeg2000DecoderContext *s, Jpeg2000Cblk *cblk = prec->cblk + cblkno; if (s->buf_end - s->buf < cblk->lengthinc) return AVERROR(EINVAL); - bytestream_get_buffer(&s->buf, cblk->data, cblk->lengthinc); + /* A code-block data can be empty. In that case initialize data + * with 0xffff. */ + if (cblk->lengthinc > 0) + bytestream_get_buffer(&s->buf, cblk->data, cblk->lengthinc); + else { + cblk->data[0] = 0xff; + cblk->data[1] = 0xff; + } cblk->length += cblk->lengthinc; cblk->lengthinc = 0; } @@ -853,12 +860,15 @@ static int decode_cblk(Jpeg2000DecoderContext *s, Jpeg2000CodingStyle *codsty, { int passno = cblk->npasses, pass_t = 2, bpno = cblk->nonzerobits - 1, y; - for (y = 0; y < height + 2; y++) - memset(t1->flags[y], 0, (width + 2) * sizeof(width)); - for (y = 0; y < height; y++) memset(t1->data[y], 0, width * sizeof(width)); + /* If code-block contains no compressed data: nothing to do. */ + if (cblk->length == 0) + return 0; + for (y = 0; y < height + 2; y++) + memset(t1->flags[y], 0, (width + 2) * sizeof(width)); + ff_mqc_initdec(&t1->mqc, cblk->data); cblk->data[cblk->length] = 0xff; cblk->data[cblk->length + 1] = 0xff;