diff options
| author | Jaap Keuter <jaap.keuter@xs4all.nl> | 2008-02-02 16:41:12 +0000 |
|---|---|---|
| committer | Jaap Keuter <jaap.keuter@xs4all.nl> | 2008-02-02 16:41:12 +0000 |
| commit | 1c2f0439130bef316a92277d97c77fd3d44340d5 (patch) | |
| tree | a071df27378d7cac7dfb5a735fa5b100bca82082 /epan/dissectors/packet-jpeg.c | |
| parent | 1a9aa1ae620ae0b6a9cc8a1f183e1ceaf6bc86d8 (diff) | |
From Peter Kjellerstedt:
I was capturing an RTP stream the other day which contained JPEG images
streamed according to RFC 2435. However, Wireshark reported them as malformed.
After some debugging of the Wireshark code it turned out that the decoding of
JPEG images which contain a quantization table was incorrect. I have attached a
patch to correct the decoding.
svn path=/trunk/; revision=24246
Diffstat (limited to 'epan/dissectors/packet-jpeg.c')
| -rw-r--r-- | epan/dissectors/packet-jpeg.c | 16 |
1 files changed, 9 insertions, 7 deletions
diff --git a/epan/dissectors/packet-jpeg.c b/epan/dissectors/packet-jpeg.c index 4b3f2e4dab..5ac9e263b1 100644 --- a/epan/dissectors/packet-jpeg.c +++ b/epan/dissectors/packet-jpeg.c @@ -77,6 +77,7 @@ dissect_jpeg( tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree ) proto_tree *main_hdr_tree = NULL; proto_tree *restart_hdr_tree = NULL; proto_tree *qtable_hdr_tree = NULL; + guint32 fragment_offset = 0; guint16 len = 0; guint8 type = 0; guint8 q = 0; @@ -103,6 +104,7 @@ dissect_jpeg( tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree ) proto_tree_add_item(main_hdr_tree, hf_rtp_jpeg_main_hdr_ts, tvb, offset, 1, FALSE); offset += 1; proto_tree_add_item(main_hdr_tree, hf_rtp_jpeg_main_hdr_offs, tvb, offset, 3, FALSE); + fragment_offset = tvb_get_ntoh24(tvb, offset); offset += 3; proto_tree_add_item(main_hdr_tree, hf_rtp_jpeg_main_hdr_type, tvb, offset, 1, FALSE); type = tvb_get_guint8(tvb, offset); @@ -128,19 +130,19 @@ dissect_jpeg( tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree ) offset += 2; } - if (q >= 128) { + if (q >= 128 && fragment_offset == 0) { ti = proto_tree_add_item(jpeg_tree, hf_rtp_jpeg_qtable_hdr, tvb, offset, -1, FALSE); qtable_hdr_tree = proto_item_add_subtree(ti, ett_jpeg); - proto_tree_add_item(main_hdr_tree, hf_rtp_jpeg_qtable_hdr_mbz, tvb, offset, 1, FALSE); + proto_tree_add_item(qtable_hdr_tree, hf_rtp_jpeg_qtable_hdr_mbz, tvb, offset, 1, FALSE); offset += 1; - proto_tree_add_item(main_hdr_tree, hf_rtp_jpeg_qtable_hdr_prec, tvb, offset, 1, FALSE); + proto_tree_add_item(qtable_hdr_tree, hf_rtp_jpeg_qtable_hdr_prec, tvb, offset, 1, FALSE); offset += 1; - proto_tree_add_item(main_hdr_tree, hf_rtp_jpeg_qtable_hdr_length, tvb, offset, 2, FALSE); - len = tvb_get_letohs(tvb, offset); + proto_tree_add_item(qtable_hdr_tree, hf_rtp_jpeg_qtable_hdr_length, tvb, offset, 2, FALSE); + len = tvb_get_ntohs(tvb, offset); offset += 2; if (len > 0) { - proto_tree_add_item(main_hdr_tree, hf_rtp_jpeg_qtable_hdr_data, tvb, offset, len, FALSE); - offset += 1; + proto_tree_add_item(qtable_hdr_tree, hf_rtp_jpeg_qtable_hdr_data, tvb, offset, len, FALSE); + offset += len; } proto_item_set_len(ti, len + 4); } |