Wireshark-dev: [Wireshark-dev] [PATCH] Further improvements to the MPEG decoder
From: "Shaun Jackman" <sjackman@xxxxxxxxx>
Date: Thu, 9 Aug 2007 16:34:55 -0700
This patch adds SCR, PTS, and DTS decoding to the MPEG PES decoder. Cheers, Shaun 2007-08-09 Shaun Jackman <sjackman@xxxxxxxxx> * asn1/mpeg/packet-mpeg-pes-template.c: Improved decoding of PES extension header and Pack header. Decode SCR, PTS, and DTS. * asn1/mpeg/mpeg-pes.asn (Pack): Remove. * epan/dissectors/packet-mpeg-pes.c: Regenerate. * wiretap/mpeg.c (mpeg_read): Decode the SCR using integer arithmetic instead of double float arithmetic to prevent rounding error. * wiretap/wtap-int.h (mpeg_t) <t0>: Use time_t instead of double. Index: asn1/mpeg/packet-mpeg-pes-template.c =================================================================== --- asn1/mpeg/packet-mpeg-pes-template.c (revision 22479) +++ asn1/mpeg/packet-mpeg-pes-template.c (working copy) @@ -43,12 +43,30 @@ static int proto_mpeg = -1; static int proto_mpeg_pes = -1; + +static int ett_mpeg_pes_pack_header = -1; +static int ett_mpeg_pes_header_data = -1; + static int hf_mpeg_pes_pack_header = -1; +static int hf_mpeg_pes_scr = -1; +static int hf_mpeg_pes_program_mux_rate = -1; +static int hf_mpeg_pes_stuffing_length = -1; static int hf_mpeg_pes_stuffing = -1; static int hf_mpeg_pes_extension = -1; static int hf_mpeg_pes_header_data = -1; +static int hf_mpeg_pes_pts = -1; +static int hf_mpeg_pes_dts = -1; +static int hf_mpeg_pes_escr = -1; +static int hf_mpeg_pes_es_rate = -1; +static int hf_mpeg_pes_copy_info = -1; +static int hf_mpeg_pes_crc = -1; +static int hf_mpeg_pes_extension_flags = -1; +static int hf_mpeg_pes_private_data = -1; +static int hf_mpeg_pes_pack_length = -1; +static int hf_mpeg_pes_sequence = -1; +static int hf_mpeg_pes_pstd_buffer = -1; +static int hf_mpeg_pes_extension2 = -1; static int hf_mpeg_pes_padding = -1; - static int hf_mpeg_pes_data = -1; static int hf_mpeg_video_sequence_header = -1; @@ -59,6 +77,7 @@ static int hf_mpeg_video_data = -1; enum { PES_PREFIX = 1 }; + enum { STREAM_PICTURE = 0x00, STREAM_SEQUENCE = 0xb3, @@ -75,6 +94,204 @@ STREAM_VIDEO = 0xe0 }; +enum { + PTS_FLAG = 0x80, + DTS_FLAG = 0x40, + ESCR_FLAG = 0x20, + ES_RATE_FLAG = 0x10, + DSM_TRICK_MODE_FLAG = 0x08, + COPY_INFO_FLAG = 0x04, + CRC_FLAG = 0x02, + EXTENSION_FLAG = 0x01, +}; + +enum { + PRIVATE_DATA_FLAG = 0x80, + PACK_LENGTH_FLAG = 0x40, + SEQUENCE_FLAG = 0x20, + PSTD_BUFFER_FLAG = 0x10, + MUST_BE_ONES = 0x07, + EXTENSION_FLAG2 = 0x01, +}; + +static guint64 tvb_get_ntoh40(tvbuff_t *tvb, unsigned offset) +{ + return (guint64)tvb_get_guint8(tvb, offset) << 32 + | tvb_get_ntohl(tvb, offset + 1); +} + +static guint64 tvb_get_ntoh48(tvbuff_t *tvb, unsigned offset) +{ + return (guint64)tvb_get_ntohs(tvb, offset) << 32 + | tvb_get_ntohl(tvb, offset + 2); +} + +#define TSHZ 90000 + +static guint64 decode_time_stamp(tvbuff_t *tvb, unsigned offset, nstime_t *nst) +{ + guint64 bytes = tvb_get_ntoh40(tvb, offset); + guint64 ts = + (bytes >> 33 & 0x0007) << 30 | + (bytes >> 17 & 0x7fff) << 15 | + (bytes >> 1 & 0x7fff) << 0; + unsigned rem = ts % TSHZ; + nst->secs = ts / TSHZ; + nst->nsecs = 1000000000LL * rem / TSHZ; + return ts; +} + +#define SCRHZ 27000000 + +static guint64 decode_clock_reference(tvbuff_t *tvb, unsigned offset, + nstime_t *nst) +{ + guint64 bytes = tvb_get_ntoh48(tvb, offset); + guint64 ts = + (bytes >> 43 & 0x0007) << 30 | + (bytes >> 27 & 0x7fff) << 15 | + (bytes >> 11 & 0x7fff) << 0; + unsigned ext = bytes >> 1 & 0x1ff; + guint64 cr = 300 * ts + ext; + unsigned rem = cr % SCRHZ; + nst->secs = cr / SCRHZ; + nst->nsecs = 1000000000LL * rem / SCRHZ; + return cr; +} + +static void +dissect_mpeg_pes_header_data(tvbuff_t *tvb, packet_info *pinfo, + proto_tree *root, unsigned flags) +{ + proto_item *item = proto_tree_add_item(root, hf_mpeg_pes_header_data, tvb, + 0, -1, FALSE); + proto_tree *tree = proto_item_add_subtree(item, ett_mpeg_pes_header_data); + + unsigned offset = 0; + if (flags & PTS_FLAG) { + nstime_t nst; + decode_time_stamp(tvb, offset, &nst); + proto_tree_add_time(tree, hf_mpeg_pes_pts, tvb, + offset, 5, &nst); + offset += 5; + + if (check_col(pinfo->cinfo, COL_DEF_DST)) { + SET_ADDRESS(&pinfo->dst, AT_NONE, 0, NULL); + col_add_fstr(pinfo->cinfo, COL_DEF_DST, + "PTS %u.%09u", nst.secs, nst.nsecs); + } + } + if (flags & DTS_FLAG) { + nstime_t nst; + decode_time_stamp(tvb, offset, &nst); + proto_tree_add_time(tree, hf_mpeg_pes_dts, tvb, + offset, 5, &nst); + offset += 5; + + if (check_col(pinfo->cinfo, COL_DEF_SRC)) { + SET_ADDRESS(&pinfo->src, AT_NONE, 0, NULL); + col_add_fstr(pinfo->cinfo, COL_DEF_SRC, + "DTS %u.%09u", nst.secs, nst.nsecs); + } + } + if (flags & ESCR_FLAG) { + nstime_t nst; + decode_clock_reference(tvb, offset, &nst); + proto_tree_add_time(tree, hf_mpeg_pes_escr, tvb, + offset, 6, &nst); + offset += 6; + } + if (flags & ES_RATE_FLAG) { + unsigned es_rate = (tvb_get_ntohs(tvb, offset) >> 1 & 0x3fff) * 50; + proto_tree_add_uint(tree, hf_mpeg_pes_es_rate, tvb, + offset, 3, es_rate); + offset += 3; + } + if (flags & COPY_INFO_FLAG) { + proto_tree_add_item(tree, hf_mpeg_pes_copy_info, tvb, + offset, 1, FALSE); + offset++; + } + if (flags & CRC_FLAG) { + proto_tree_add_item(tree, hf_mpeg_pes_crc, tvb, + offset, 2, FALSE); + offset += 2; + } + + if (flags & EXTENSION_FLAG) { + int flags2 = tvb_get_guint8(tvb, offset); + proto_tree_add_item(tree, hf_mpeg_pes_extension_flags, tvb, + offset, 1, FALSE); + offset++; + + if (flags2 & PRIVATE_DATA_FLAG) { + proto_tree_add_item(tree, hf_mpeg_pes_private_data, tvb, + offset, 2, FALSE); + offset += 2; + } + if (flags2 & PACK_LENGTH_FLAG) { + proto_tree_add_item(tree, hf_mpeg_pes_pack_length, tvb, + offset, 1, FALSE); + offset++; + } + if (flags2 & SEQUENCE_FLAG) { + proto_tree_add_item(tree, hf_mpeg_pes_sequence, tvb, + offset, 2, FALSE); + offset += 2; + } + if (flags2 & PSTD_BUFFER_FLAG) { + unsigned pstd = tvb_get_ntohs(tvb, offset); + proto_tree_add_uint(tree, hf_mpeg_pes_pstd_buffer, tvb, + offset, 2, (pstd & 0x2000 ? 1024 : 128) * (pstd & 0x1ff)); + offset += 2; + } + if (flags2 & EXTENSION_FLAG2) { + proto_tree_add_item(tree, hf_mpeg_pes_extension2, tvb, + offset, 2, FALSE); + offset += 2; + } + } +} + +static unsigned +dissect_mpeg_pes_pack_header(tvbuff_t *tvb, unsigned offset, + packet_info *pinfo, proto_tree *root) +{ + unsigned program_mux_rate, stuffing_length; + + proto_item *item = proto_tree_add_item(root, hf_mpeg_pes_pack_header, tvb, + offset / 8, 10, FALSE); + proto_tree *tree = proto_item_add_subtree(item, ett_mpeg_pes_pack_header); + + nstime_t nst; + decode_clock_reference(tvb, offset / 8, &nst); + proto_tree_add_time(tree, hf_mpeg_pes_scr, tvb, offset / 8, 6, &nst); + offset += 6 * 8; + + program_mux_rate = (tvb_get_ntoh24(tvb, offset / 8) >> 2) * 50; + proto_tree_add_uint(tree, hf_mpeg_pes_program_mux_rate, tvb, offset / 8, 3, + program_mux_rate); + offset += 3 * 8; + + if (check_col(pinfo->cinfo, COL_DEF_SRC)) { + SET_ADDRESS(&pinfo->src, AT_NONE, 0, NULL); + col_add_fstr(pinfo->cinfo, COL_DEF_SRC, "%u B/s", program_mux_rate); + } + + stuffing_length = tvb_get_guint8(tvb, offset / 8) & 0x07; + proto_tree_add_item(tree, hf_mpeg_pes_stuffing_length, tvb, + offset / 8, 1, FALSE); + offset += 1 * 8; + + if (stuffing_length > 0) { + proto_tree_add_item(tree, hf_mpeg_pes_stuffing, tvb, + offset / 8, stuffing_length, FALSE); + offset += stuffing_length * 8; + } + + return offset; +} + void dissect_mpeg(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree); @@ -84,7 +301,7 @@ int prefix; int stream; asn1_ctx_t asn1_ctx; - int offset = 0; + unsigned offset = 0; if (!tvb_bytes_exist(tvb, 0, 3)) return FALSE; /* not enough bytes for a PES prefix */ @@ -156,31 +373,23 @@ es = tvb_new_subset(tvb, offset / 8, -1, -1); dissect_mpeg_pes(es, pinfo, tree); } else if (stream == STREAM_PACK) { - int length; - switch (tvb_get_guint8(tvb, 4) >> 6) { - case 1: - length = tvb_get_guint8(tvb, 13) & 0x07; - offset = dissect_mpeg_pes_Pack(tvb, offset, &asn1_ctx, - tree, hf_mpeg_pes_pack_header); - if (length > 0) - proto_tree_add_item(tree, hf_mpeg_pes_stuffing, tvb, - offset / 8, length, FALSE); - break; - default: - length = 8; - proto_tree_add_item(tree, hf_mpeg_pes_data, tvb, - offset / 8, length, FALSE); + if (tvb_get_guint8(tvb, offset / 8) >> 6 == 1) { + offset = dissect_mpeg_pes_pack_header(tvb, offset, pinfo, tree); + } else { + proto_tree_add_item(tree, hf_mpeg_pes_data, tvb, + offset / 8, 8, FALSE); + offset += 8 * 8; } - offset += length * 8; - } else if (stream == STREAM_SYSTEM) { - offset = dissect_mpeg_pes_Stream(tvb, offset, &asn1_ctx, - tree, hf_mpeg_pes_extension); + } else if (stream == STREAM_SYSTEM || stream == STREAM_PRIVATE2) { + unsigned data_length = tvb_get_ntohs(tvb, offset / 8); + proto_tree_add_item(tree, hf_mpeg_pes_length, tvb, + offset / 8, 2, FALSE); + offset += 2 * 8; + proto_tree_add_item(tree, hf_mpeg_pes_data, tvb, - offset / 8, -1, FALSE); + offset / 8, data_length, FALSE); } else if (stream == STREAM_PADDING) { - int padding_length; - - padding_length = tvb_get_ntohs(tvb, 4); + unsigned padding_length = tvb_get_ntohs(tvb, offset / 8); proto_tree_add_item(tree, hf_mpeg_pes_length, tvb, offset / 8, 2, FALSE); offset += 2 * 8; @@ -189,32 +398,43 @@ offset / 8, padding_length, FALSE); } else if (stream == STREAM_PRIVATE1 || stream >= STREAM_AUDIO) { - int length; - int header_length; - tvbuff_t *es; + int length = tvb_get_ntohs(tvb, 4); - length = tvb_get_ntohs(tvb, 4); + if ((tvb_get_guint8(tvb, 6) & 0xc0) == 0x80) { + int header_length; + tvbuff_t *es; - offset = dissect_mpeg_pes_Stream(tvb, offset, &asn1_ctx, - tree, hf_mpeg_pes_extension); - length -= 5 * 8; + offset = dissect_mpeg_pes_Stream(tvb, offset, &asn1_ctx, + tree, hf_mpeg_pes_extension); + length -= 5 * 8; - header_length = tvb_get_guint8(tvb, 8); - if (header_length > 0) { - proto_tree_add_item(tree, hf_mpeg_pes_header_data, tvb, - offset / 8, header_length, FALSE); - offset += header_length * 8; - length -= header_length * 8; + header_length = tvb_get_guint8(tvb, 8); + if (header_length > 0) { + int flags = tvb_get_guint8(tvb, 7); + tvbuff_t *header_data = tvb_new_subset(tvb, offset / 8, + header_length, header_length); + dissect_mpeg_pes_header_data(header_data, pinfo, tree, flags); + offset += header_length * 8; + length -= header_length * 8; + } + + es = tvb_new_subset(tvb, offset / 8, -1, length / 8); + if (tvb_get_ntoh24(es, 0) == PES_PREFIX) + dissect_mpeg_pes(es, pinfo, tree); + else if (tvb_get_guint8(es, 0) == 0xff) + dissect_mpeg(es, pinfo, tree); + else + proto_tree_add_item(tree, hf_mpeg_pes_data, es, + 0, -1, FALSE); + } else { + unsigned data_length = tvb_get_ntohs(tvb, offset / 8); + proto_tree_add_item(tree, hf_mpeg_pes_length, tvb, + offset / 8, 2, FALSE); + offset += 2 * 8; + + proto_tree_add_item(tree, hf_mpeg_pes_data, tvb, + offset / 8, data_length, FALSE); } - - es = tvb_new_subset(tvb, offset / 8, -1, length / 8); - if (tvb_get_ntoh24(es, 0) == PES_PREFIX) - dissect_mpeg_pes(es, pinfo, tree); - else if (tvb_get_guint8(es, 0) == 0xff) - dissect_mpeg(es, pinfo, tree); - else - proto_tree_add_item(tree, hf_mpeg_pes_data, es, - 0, -1, FALSE); } else { proto_tree_add_item(tree, hf_mpeg_pes_data, tvb, offset / 8, -1, FALSE); @@ -245,6 +465,15 @@ { &hf_mpeg_pes_pack_header, { "Pack header", "mpeg-pes.pack", FT_NONE, BASE_NONE, NULL, 0, NULL, HFILL }}, + { &hf_mpeg_pes_scr, + { "system clock reference (SCR)", "mpeg-pes.scr", + FT_RELATIVE_TIME, BASE_NONE, NULL, 0, NULL, HFILL }}, + { &hf_mpeg_pes_program_mux_rate, + { "PES program mux rate", "mpeg-pes.program-mux-rate", + FT_UINT24, BASE_DEC, NULL, 0, NULL, HFILL }}, + { &hf_mpeg_pes_stuffing_length, + { "PES stuffing length", "mpeg-pes.stuffing-length", + FT_UINT8, BASE_DEC, NULL, 0x07, NULL, HFILL }}, { &hf_mpeg_pes_stuffing, { "PES stuffing bytes", "mpeg-pes.stuffing", FT_BYTES, BASE_NONE, NULL, 0, NULL, HFILL }}, @@ -254,6 +483,42 @@ { &hf_mpeg_pes_header_data, { "PES header data", "mpeg-pes.header-data", FT_BYTES, BASE_NONE, NULL, 0, NULL, HFILL }}, + { &hf_mpeg_pes_pts, + { "presentation time stamp (PTS)", "mpeg-pes.pts", + FT_RELATIVE_TIME, BASE_NONE, NULL, 0, NULL, HFILL }}, + { &hf_mpeg_pes_dts, + { "decode time stamp (DTS)", "mpeg-pes.dts", + FT_RELATIVE_TIME, BASE_NONE, NULL, 0, NULL, HFILL }}, + { &hf_mpeg_pes_escr, + { "elementary stream clock reference (ESCR)", "mpeg-pes.escr", + FT_RELATIVE_TIME, BASE_NONE, NULL, 0, NULL, HFILL }}, + { &hf_mpeg_pes_es_rate, + { "elementary stream rate", "mpeg-pes.es-rate", + FT_UINT24, BASE_DEC, NULL, 0x7ffe, NULL, HFILL }}, + { &hf_mpeg_pes_copy_info, + { "copy info", "mpeg-pes.copy-info", + FT_UINT8, BASE_DEC, NULL, 0x7f, NULL, HFILL }}, + { &hf_mpeg_pes_crc, + { "CRC", "mpeg-pes.crc", + FT_UINT16, BASE_DEC, NULL, 0, NULL, HFILL }}, + { &hf_mpeg_pes_extension_flags, + { "extension flags", "mpeg-pes.extension-flags", + FT_UINT8, BASE_HEX, NULL, 0, NULL, HFILL }}, + { &hf_mpeg_pes_private_data, + { "private data", "mpeg-pes.private-data", + FT_UINT16, BASE_HEX, NULL, 0, NULL, HFILL }}, + { &hf_mpeg_pes_pack_length, + { "pack length", "mpeg-pes.pack-length", + FT_UINT8, BASE_DEC, NULL, 0, NULL, HFILL }}, + { &hf_mpeg_pes_sequence, + { "sequence", "mpeg-pes.sequence", + FT_UINT16, BASE_HEX, NULL, 0, NULL, HFILL }}, + { &hf_mpeg_pes_pstd_buffer, + { "P-STD buffer size", "mpeg-pes.pstd-buffer", + FT_UINT16, BASE_DEC, NULL, 0, NULL, HFILL }}, + { &hf_mpeg_pes_extension2, + { "extension2", "mpeg-pes.extension2", + FT_UINT16, BASE_HEX, NULL, 0, NULL, HFILL }}, { &hf_mpeg_pes_padding, { "PES padding", "mpeg-pes.padding", FT_BYTES, BASE_NONE, NULL, 0, NULL, HFILL }}, @@ -282,6 +547,8 @@ static gint *ett[] = { #include "packet-mpeg-pes-ettarr.c" + &ett_mpeg_pes_pack_header, + &ett_mpeg_pes_header_data, }; proto_mpeg = proto_register_protocol( Index: asn1/mpeg/mpeg-pes.asn =================================================================== --- asn1/mpeg/mpeg-pes.asn (revision 22479) +++ asn1/mpeg/mpeg-pes.asn (working copy) @@ -26,24 +26,6 @@ } (0..255) } -Pack ::= SEQUENCE { - must-be-zero BOOLEAN, - must-be-one0 BOOLEAN, - scr30 BIT STRING (SIZE (3)), - must-be-one1 BOOLEAN, - scr15 BIT STRING (SIZE (15)), - must-be-one2 BOOLEAN, - scr0 BIT STRING (SIZE (15)), - must-be-one3 BOOLEAN, - scr-ext BIT STRING (SIZE (9)), - must-be-one4 BOOLEAN, - program-mux-rate BIT STRING (SIZE (22)), - must-be-one5 BOOLEAN, - must-be-one6 BOOLEAN, - reserved BIT STRING (SIZE (5)), - stuffing-length INTEGER (0..7) -} - Stream ::= SEQUENCE { length INTEGER (0..65535), must-be-one BOOLEAN, Index: wiretap/wtap-int.h =================================================================== --- wiretap/wtap-int.h (revision 22479) +++ wiretap/wtap-int.h (working copy) @@ -151,7 +151,7 @@ typedef struct { struct wtap_nstime now; - double t0; + time_t t0; } mpeg_t; typedef gboolean (*subtype_read_func)(struct wtap*, int*, char**, gint64*); Index: wiretap/mpeg.c =================================================================== --- wiretap/mpeg.c (revision 22479) +++ wiretap/mpeg.c (working copy) @@ -41,7 +41,6 @@ #include "buffer.h" #include "file_wrappers.h" #include <errno.h> -#include <math.h> #include <stdlib.h> #include <string.h> #include <time.h> @@ -106,6 +105,8 @@ return TRUE; } +#define SCRHZ 27000000 + static gboolean mpeg_read(wtap *wth, int *err, gchar **err_info _U_, gint64 *data_offset) @@ -138,10 +139,6 @@ guint32 pack0; guint64 pack; guint8 stuffing; - guint32 scr; - guint16 scr_ext; - double t; - double secs; bytes_read = file_read(&pack1, 1, sizeof pack1, wth->fh); if (bytes_read != sizeof pack1) { @@ -172,15 +169,20 @@ stuffing &= 0x07; packet_size = 14 + stuffing; - scr = (guint32) - ((pack >> 59 & 0x0007) << 30 | - (pack >> 43 & 0x7fff) << 15 | - (pack >> 27 & 0x7fff) << 0); - scr_ext = (guint16)(pack >> 17 & 0x1ff); - t = wth->capture.mpeg->t0 + scr / 90e3 + scr_ext / 27e6; - - wth->capture.mpeg->now.nsecs = (int)(modf(t, &secs) * 1e9); - wth->capture.mpeg->now.secs = (time_t)secs; + { + guint64 bytes = pack >> 16; + guint64 ts = + (bytes >> 43 & 0x0007) << 30 | + (bytes >> 27 & 0x7fff) << 15 | + (bytes >> 11 & 0x7fff) << 0; + unsigned ext = bytes >> 1 & 0x1ff; + guint64 cr = 300 * ts + ext; + unsigned rem = cr % SCRHZ; + wth->capture.mpeg->now.secs + = wth->capture.mpeg->t0 + cr / SCRHZ; + wth->capture.mpeg->now.nsecs + = 1000000000LL * rem / SCRHZ; + } ts = wth->capture.mpeg->now; break; default: @@ -297,7 +299,7 @@ wth->capture.mpeg = g_malloc(sizeof(mpeg_t)); wth->capture.mpeg->now.secs = time(NULL); wth->capture.mpeg->now.nsecs = 0; - wth->capture.mpeg->t0 = (double) wth->capture.mpeg->now.secs; + wth->capture.mpeg->t0 = wth->capture.mpeg->now.secs; return 1; }
2007-08-09 Shaun Jackman <sjackman@xxxxxxxxx> * asn1/mpeg/packet-mpeg-pes-template.c: Improved decoding of PES extension header and Pack header. Decode SCR, PTS, and DTS. * asn1/mpeg/mpeg-pes.asn (Pack): Remove. * epan/dissectors/packet-mpeg-pes.c: Regenerate. * wiretap/mpeg.c (mpeg_read): Decode the SCR using integer arithmetic instead of double float arithmetic to prevent rounding error. * wiretap/wtap-int.h (mpeg_t) <t0>: Use time_t instead of double. Index: asn1/mpeg/packet-mpeg-pes-template.c =================================================================== --- asn1/mpeg/packet-mpeg-pes-template.c (revision 22479) +++ asn1/mpeg/packet-mpeg-pes-template.c (working copy) @@ -43,12 +43,30 @@ static int proto_mpeg = -1; static int proto_mpeg_pes = -1; + +static int ett_mpeg_pes_pack_header = -1; +static int ett_mpeg_pes_header_data = -1; + static int hf_mpeg_pes_pack_header = -1; +static int hf_mpeg_pes_scr = -1; +static int hf_mpeg_pes_program_mux_rate = -1; +static int hf_mpeg_pes_stuffing_length = -1; static int hf_mpeg_pes_stuffing = -1; static int hf_mpeg_pes_extension = -1; static int hf_mpeg_pes_header_data = -1; +static int hf_mpeg_pes_pts = -1; +static int hf_mpeg_pes_dts = -1; +static int hf_mpeg_pes_escr = -1; +static int hf_mpeg_pes_es_rate = -1; +static int hf_mpeg_pes_copy_info = -1; +static int hf_mpeg_pes_crc = -1; +static int hf_mpeg_pes_extension_flags = -1; +static int hf_mpeg_pes_private_data = -1; +static int hf_mpeg_pes_pack_length = -1; +static int hf_mpeg_pes_sequence = -1; +static int hf_mpeg_pes_pstd_buffer = -1; +static int hf_mpeg_pes_extension2 = -1; static int hf_mpeg_pes_padding = -1; - static int hf_mpeg_pes_data = -1; static int hf_mpeg_video_sequence_header = -1; @@ -59,6 +77,7 @@ static int hf_mpeg_video_data = -1; enum { PES_PREFIX = 1 }; + enum { STREAM_PICTURE = 0x00, STREAM_SEQUENCE = 0xb3, @@ -75,6 +94,204 @@ STREAM_VIDEO = 0xe0 }; +enum { + PTS_FLAG = 0x80, + DTS_FLAG = 0x40, + ESCR_FLAG = 0x20, + ES_RATE_FLAG = 0x10, + DSM_TRICK_MODE_FLAG = 0x08, + COPY_INFO_FLAG = 0x04, + CRC_FLAG = 0x02, + EXTENSION_FLAG = 0x01, +}; + +enum { + PRIVATE_DATA_FLAG = 0x80, + PACK_LENGTH_FLAG = 0x40, + SEQUENCE_FLAG = 0x20, + PSTD_BUFFER_FLAG = 0x10, + MUST_BE_ONES = 0x07, + EXTENSION_FLAG2 = 0x01, +}; + +static guint64 tvb_get_ntoh40(tvbuff_t *tvb, unsigned offset) +{ + return (guint64)tvb_get_guint8(tvb, offset) << 32 + | tvb_get_ntohl(tvb, offset + 1); +} + +static guint64 tvb_get_ntoh48(tvbuff_t *tvb, unsigned offset) +{ + return (guint64)tvb_get_ntohs(tvb, offset) << 32 + | tvb_get_ntohl(tvb, offset + 2); +} + +#define TSHZ 90000 + +static guint64 decode_time_stamp(tvbuff_t *tvb, unsigned offset, nstime_t *nst) +{ + guint64 bytes = tvb_get_ntoh40(tvb, offset); + guint64 ts = + (bytes >> 33 & 0x0007) << 30 | + (bytes >> 17 & 0x7fff) << 15 | + (bytes >> 1 & 0x7fff) << 0; + unsigned rem = ts % TSHZ; + nst->secs = ts / TSHZ; + nst->nsecs = 1000000000LL * rem / TSHZ; + return ts; +} + +#define SCRHZ 27000000 + +static guint64 decode_clock_reference(tvbuff_t *tvb, unsigned offset, + nstime_t *nst) +{ + guint64 bytes = tvb_get_ntoh48(tvb, offset); + guint64 ts = + (bytes >> 43 & 0x0007) << 30 | + (bytes >> 27 & 0x7fff) << 15 | + (bytes >> 11 & 0x7fff) << 0; + unsigned ext = bytes >> 1 & 0x1ff; + guint64 cr = 300 * ts + ext; + unsigned rem = cr % SCRHZ; + nst->secs = cr / SCRHZ; + nst->nsecs = 1000000000LL * rem / SCRHZ; + return cr; +} + +static void +dissect_mpeg_pes_header_data(tvbuff_t *tvb, packet_info *pinfo, + proto_tree *root, unsigned flags) +{ + proto_item *item = proto_tree_add_item(root, hf_mpeg_pes_header_data, tvb, + 0, -1, FALSE); + proto_tree *tree = proto_item_add_subtree(item, ett_mpeg_pes_header_data); + + unsigned offset = 0; + if (flags & PTS_FLAG) { + nstime_t nst; + decode_time_stamp(tvb, offset, &nst); + proto_tree_add_time(tree, hf_mpeg_pes_pts, tvb, + offset, 5, &nst); + offset += 5; + + if (check_col(pinfo->cinfo, COL_DEF_DST)) { + SET_ADDRESS(&pinfo->dst, AT_NONE, 0, NULL); + col_add_fstr(pinfo->cinfo, COL_DEF_DST, + "PTS %u.%09u", nst.secs, nst.nsecs); + } + } + if (flags & DTS_FLAG) { + nstime_t nst; + decode_time_stamp(tvb, offset, &nst); + proto_tree_add_time(tree, hf_mpeg_pes_dts, tvb, + offset, 5, &nst); + offset += 5; + + if (check_col(pinfo->cinfo, COL_DEF_SRC)) { + SET_ADDRESS(&pinfo->src, AT_NONE, 0, NULL); + col_add_fstr(pinfo->cinfo, COL_DEF_SRC, + "DTS %u.%09u", nst.secs, nst.nsecs); + } + } + if (flags & ESCR_FLAG) { + nstime_t nst; + decode_clock_reference(tvb, offset, &nst); + proto_tree_add_time(tree, hf_mpeg_pes_escr, tvb, + offset, 6, &nst); + offset += 6; + } + if (flags & ES_RATE_FLAG) { + unsigned es_rate = (tvb_get_ntohs(tvb, offset) >> 1 & 0x3fff) * 50; + proto_tree_add_uint(tree, hf_mpeg_pes_es_rate, tvb, + offset, 3, es_rate); + offset += 3; + } + if (flags & COPY_INFO_FLAG) { + proto_tree_add_item(tree, hf_mpeg_pes_copy_info, tvb, + offset, 1, FALSE); + offset++; + } + if (flags & CRC_FLAG) { + proto_tree_add_item(tree, hf_mpeg_pes_crc, tvb, + offset, 2, FALSE); + offset += 2; + } + + if (flags & EXTENSION_FLAG) { + int flags2 = tvb_get_guint8(tvb, offset); + proto_tree_add_item(tree, hf_mpeg_pes_extension_flags, tvb, + offset, 1, FALSE); + offset++; + + if (flags2 & PRIVATE_DATA_FLAG) { + proto_tree_add_item(tree, hf_mpeg_pes_private_data, tvb, + offset, 2, FALSE); + offset += 2; + } + if (flags2 & PACK_LENGTH_FLAG) { + proto_tree_add_item(tree, hf_mpeg_pes_pack_length, tvb, + offset, 1, FALSE); + offset++; + } + if (flags2 & SEQUENCE_FLAG) { + proto_tree_add_item(tree, hf_mpeg_pes_sequence, tvb, + offset, 2, FALSE); + offset += 2; + } + if (flags2 & PSTD_BUFFER_FLAG) { + unsigned pstd = tvb_get_ntohs(tvb, offset); + proto_tree_add_uint(tree, hf_mpeg_pes_pstd_buffer, tvb, + offset, 2, (pstd & 0x2000 ? 1024 : 128) * (pstd & 0x1ff)); + offset += 2; + } + if (flags2 & EXTENSION_FLAG2) { + proto_tree_add_item(tree, hf_mpeg_pes_extension2, tvb, + offset, 2, FALSE); + offset += 2; + } + } +} + +static unsigned +dissect_mpeg_pes_pack_header(tvbuff_t *tvb, unsigned offset, + packet_info *pinfo, proto_tree *root) +{ + unsigned program_mux_rate, stuffing_length; + + proto_item *item = proto_tree_add_item(root, hf_mpeg_pes_pack_header, tvb, + offset / 8, 10, FALSE); + proto_tree *tree = proto_item_add_subtree(item, ett_mpeg_pes_pack_header); + + nstime_t nst; + decode_clock_reference(tvb, offset / 8, &nst); + proto_tree_add_time(tree, hf_mpeg_pes_scr, tvb, offset / 8, 6, &nst); + offset += 6 * 8; + + program_mux_rate = (tvb_get_ntoh24(tvb, offset / 8) >> 2) * 50; + proto_tree_add_uint(tree, hf_mpeg_pes_program_mux_rate, tvb, offset / 8, 3, + program_mux_rate); + offset += 3 * 8; + + if (check_col(pinfo->cinfo, COL_DEF_SRC)) { + SET_ADDRESS(&pinfo->src, AT_NONE, 0, NULL); + col_add_fstr(pinfo->cinfo, COL_DEF_SRC, "%u B/s", program_mux_rate); + } + + stuffing_length = tvb_get_guint8(tvb, offset / 8) & 0x07; + proto_tree_add_item(tree, hf_mpeg_pes_stuffing_length, tvb, + offset / 8, 1, FALSE); + offset += 1 * 8; + + if (stuffing_length > 0) { + proto_tree_add_item(tree, hf_mpeg_pes_stuffing, tvb, + offset / 8, stuffing_length, FALSE); + offset += stuffing_length * 8; + } + + return offset; +} + void dissect_mpeg(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree); @@ -84,7 +301,7 @@ int prefix; int stream; asn1_ctx_t asn1_ctx; - int offset = 0; + unsigned offset = 0; if (!tvb_bytes_exist(tvb, 0, 3)) return FALSE; /* not enough bytes for a PES prefix */ @@ -156,31 +373,23 @@ es = tvb_new_subset(tvb, offset / 8, -1, -1); dissect_mpeg_pes(es, pinfo, tree); } else if (stream == STREAM_PACK) { - int length; - switch (tvb_get_guint8(tvb, 4) >> 6) { - case 1: - length = tvb_get_guint8(tvb, 13) & 0x07; - offset = dissect_mpeg_pes_Pack(tvb, offset, &asn1_ctx, - tree, hf_mpeg_pes_pack_header); - if (length > 0) - proto_tree_add_item(tree, hf_mpeg_pes_stuffing, tvb, - offset / 8, length, FALSE); - break; - default: - length = 8; - proto_tree_add_item(tree, hf_mpeg_pes_data, tvb, - offset / 8, length, FALSE); + if (tvb_get_guint8(tvb, offset / 8) >> 6 == 1) { + offset = dissect_mpeg_pes_pack_header(tvb, offset, pinfo, tree); + } else { + proto_tree_add_item(tree, hf_mpeg_pes_data, tvb, + offset / 8, 8, FALSE); + offset += 8 * 8; } - offset += length * 8; - } else if (stream == STREAM_SYSTEM) { - offset = dissect_mpeg_pes_Stream(tvb, offset, &asn1_ctx, - tree, hf_mpeg_pes_extension); + } else if (stream == STREAM_SYSTEM || stream == STREAM_PRIVATE2) { + unsigned data_length = tvb_get_ntohs(tvb, offset / 8); + proto_tree_add_item(tree, hf_mpeg_pes_length, tvb, + offset / 8, 2, FALSE); + offset += 2 * 8; + proto_tree_add_item(tree, hf_mpeg_pes_data, tvb, - offset / 8, -1, FALSE); + offset / 8, data_length, FALSE); } else if (stream == STREAM_PADDING) { - int padding_length; - - padding_length = tvb_get_ntohs(tvb, 4); + unsigned padding_length = tvb_get_ntohs(tvb, offset / 8); proto_tree_add_item(tree, hf_mpeg_pes_length, tvb, offset / 8, 2, FALSE); offset += 2 * 8; @@ -189,32 +398,43 @@ offset / 8, padding_length, FALSE); } else if (stream == STREAM_PRIVATE1 || stream >= STREAM_AUDIO) { - int length; - int header_length; - tvbuff_t *es; + int length = tvb_get_ntohs(tvb, 4); - length = tvb_get_ntohs(tvb, 4); + if ((tvb_get_guint8(tvb, 6) & 0xc0) == 0x80) { + int header_length; + tvbuff_t *es; - offset = dissect_mpeg_pes_Stream(tvb, offset, &asn1_ctx, - tree, hf_mpeg_pes_extension); - length -= 5 * 8; + offset = dissect_mpeg_pes_Stream(tvb, offset, &asn1_ctx, + tree, hf_mpeg_pes_extension); + length -= 5 * 8; - header_length = tvb_get_guint8(tvb, 8); - if (header_length > 0) { - proto_tree_add_item(tree, hf_mpeg_pes_header_data, tvb, - offset / 8, header_length, FALSE); - offset += header_length * 8; - length -= header_length * 8; + header_length = tvb_get_guint8(tvb, 8); + if (header_length > 0) { + int flags = tvb_get_guint8(tvb, 7); + tvbuff_t *header_data = tvb_new_subset(tvb, offset / 8, + header_length, header_length); + dissect_mpeg_pes_header_data(header_data, pinfo, tree, flags); + offset += header_length * 8; + length -= header_length * 8; + } + + es = tvb_new_subset(tvb, offset / 8, -1, length / 8); + if (tvb_get_ntoh24(es, 0) == PES_PREFIX) + dissect_mpeg_pes(es, pinfo, tree); + else if (tvb_get_guint8(es, 0) == 0xff) + dissect_mpeg(es, pinfo, tree); + else + proto_tree_add_item(tree, hf_mpeg_pes_data, es, + 0, -1, FALSE); + } else { + unsigned data_length = tvb_get_ntohs(tvb, offset / 8); + proto_tree_add_item(tree, hf_mpeg_pes_length, tvb, + offset / 8, 2, FALSE); + offset += 2 * 8; + + proto_tree_add_item(tree, hf_mpeg_pes_data, tvb, + offset / 8, data_length, FALSE); } - - es = tvb_new_subset(tvb, offset / 8, -1, length / 8); - if (tvb_get_ntoh24(es, 0) == PES_PREFIX) - dissect_mpeg_pes(es, pinfo, tree); - else if (tvb_get_guint8(es, 0) == 0xff) - dissect_mpeg(es, pinfo, tree); - else - proto_tree_add_item(tree, hf_mpeg_pes_data, es, - 0, -1, FALSE); } else { proto_tree_add_item(tree, hf_mpeg_pes_data, tvb, offset / 8, -1, FALSE); @@ -245,6 +465,15 @@ { &hf_mpeg_pes_pack_header, { "Pack header", "mpeg-pes.pack", FT_NONE, BASE_NONE, NULL, 0, NULL, HFILL }}, + { &hf_mpeg_pes_scr, + { "system clock reference (SCR)", "mpeg-pes.scr", + FT_RELATIVE_TIME, BASE_NONE, NULL, 0, NULL, HFILL }}, + { &hf_mpeg_pes_program_mux_rate, + { "PES program mux rate", "mpeg-pes.program-mux-rate", + FT_UINT24, BASE_DEC, NULL, 0, NULL, HFILL }}, + { &hf_mpeg_pes_stuffing_length, + { "PES stuffing length", "mpeg-pes.stuffing-length", + FT_UINT8, BASE_DEC, NULL, 0x07, NULL, HFILL }}, { &hf_mpeg_pes_stuffing, { "PES stuffing bytes", "mpeg-pes.stuffing", FT_BYTES, BASE_NONE, NULL, 0, NULL, HFILL }}, @@ -254,6 +483,42 @@ { &hf_mpeg_pes_header_data, { "PES header data", "mpeg-pes.header-data", FT_BYTES, BASE_NONE, NULL, 0, NULL, HFILL }}, + { &hf_mpeg_pes_pts, + { "presentation time stamp (PTS)", "mpeg-pes.pts", + FT_RELATIVE_TIME, BASE_NONE, NULL, 0, NULL, HFILL }}, + { &hf_mpeg_pes_dts, + { "decode time stamp (DTS)", "mpeg-pes.dts", + FT_RELATIVE_TIME, BASE_NONE, NULL, 0, NULL, HFILL }}, + { &hf_mpeg_pes_escr, + { "elementary stream clock reference (ESCR)", "mpeg-pes.escr", + FT_RELATIVE_TIME, BASE_NONE, NULL, 0, NULL, HFILL }}, + { &hf_mpeg_pes_es_rate, + { "elementary stream rate", "mpeg-pes.es-rate", + FT_UINT24, BASE_DEC, NULL, 0x7ffe, NULL, HFILL }}, + { &hf_mpeg_pes_copy_info, + { "copy info", "mpeg-pes.copy-info", + FT_UINT8, BASE_DEC, NULL, 0x7f, NULL, HFILL }}, + { &hf_mpeg_pes_crc, + { "CRC", "mpeg-pes.crc", + FT_UINT16, BASE_DEC, NULL, 0, NULL, HFILL }}, + { &hf_mpeg_pes_extension_flags, + { "extension flags", "mpeg-pes.extension-flags", + FT_UINT8, BASE_HEX, NULL, 0, NULL, HFILL }}, + { &hf_mpeg_pes_private_data, + { "private data", "mpeg-pes.private-data", + FT_UINT16, BASE_HEX, NULL, 0, NULL, HFILL }}, + { &hf_mpeg_pes_pack_length, + { "pack length", "mpeg-pes.pack-length", + FT_UINT8, BASE_DEC, NULL, 0, NULL, HFILL }}, + { &hf_mpeg_pes_sequence, + { "sequence", "mpeg-pes.sequence", + FT_UINT16, BASE_HEX, NULL, 0, NULL, HFILL }}, + { &hf_mpeg_pes_pstd_buffer, + { "P-STD buffer size", "mpeg-pes.pstd-buffer", + FT_UINT16, BASE_DEC, NULL, 0, NULL, HFILL }}, + { &hf_mpeg_pes_extension2, + { "extension2", "mpeg-pes.extension2", + FT_UINT16, BASE_HEX, NULL, 0, NULL, HFILL }}, { &hf_mpeg_pes_padding, { "PES padding", "mpeg-pes.padding", FT_BYTES, BASE_NONE, NULL, 0, NULL, HFILL }}, @@ -282,6 +547,8 @@ static gint *ett[] = { #include "packet-mpeg-pes-ettarr.c" + &ett_mpeg_pes_pack_header, + &ett_mpeg_pes_header_data, }; proto_mpeg = proto_register_protocol( Index: asn1/mpeg/mpeg-pes.asn =================================================================== --- asn1/mpeg/mpeg-pes.asn (revision 22479) +++ asn1/mpeg/mpeg-pes.asn (working copy) @@ -26,24 +26,6 @@ } (0..255) } -Pack ::= SEQUENCE { - must-be-zero BOOLEAN, - must-be-one0 BOOLEAN, - scr30 BIT STRING (SIZE (3)), - must-be-one1 BOOLEAN, - scr15 BIT STRING (SIZE (15)), - must-be-one2 BOOLEAN, - scr0 BIT STRING (SIZE (15)), - must-be-one3 BOOLEAN, - scr-ext BIT STRING (SIZE (9)), - must-be-one4 BOOLEAN, - program-mux-rate BIT STRING (SIZE (22)), - must-be-one5 BOOLEAN, - must-be-one6 BOOLEAN, - reserved BIT STRING (SIZE (5)), - stuffing-length INTEGER (0..7) -} - Stream ::= SEQUENCE { length INTEGER (0..65535), must-be-one BOOLEAN, Index: wiretap/wtap-int.h =================================================================== --- wiretap/wtap-int.h (revision 22479) +++ wiretap/wtap-int.h (working copy) @@ -151,7 +151,7 @@ typedef struct { struct wtap_nstime now; - double t0; + time_t t0; } mpeg_t; typedef gboolean (*subtype_read_func)(struct wtap*, int*, char**, gint64*); Index: wiretap/mpeg.c =================================================================== --- wiretap/mpeg.c (revision 22479) +++ wiretap/mpeg.c (working copy) @@ -41,7 +41,6 @@ #include "buffer.h" #include "file_wrappers.h" #include <errno.h> -#include <math.h> #include <stdlib.h> #include <string.h> #include <time.h> @@ -106,6 +105,8 @@ return TRUE; } +#define SCRHZ 27000000 + static gboolean mpeg_read(wtap *wth, int *err, gchar **err_info _U_, gint64 *data_offset) @@ -138,10 +139,6 @@ guint32 pack0; guint64 pack; guint8 stuffing; - guint32 scr; - guint16 scr_ext; - double t; - double secs; bytes_read = file_read(&pack1, 1, sizeof pack1, wth->fh); if (bytes_read != sizeof pack1) { @@ -172,15 +169,20 @@ stuffing &= 0x07; packet_size = 14 + stuffing; - scr = (guint32) - ((pack >> 59 & 0x0007) << 30 | - (pack >> 43 & 0x7fff) << 15 | - (pack >> 27 & 0x7fff) << 0); - scr_ext = (guint16)(pack >> 17 & 0x1ff); - t = wth->capture.mpeg->t0 + scr / 90e3 + scr_ext / 27e6; - - wth->capture.mpeg->now.nsecs = (int)(modf(t, &secs) * 1e9); - wth->capture.mpeg->now.secs = (time_t)secs; + { + guint64 bytes = pack >> 16; + guint64 ts = + (bytes >> 43 & 0x0007) << 30 | + (bytes >> 27 & 0x7fff) << 15 | + (bytes >> 11 & 0x7fff) << 0; + unsigned ext = bytes >> 1 & 0x1ff; + guint64 cr = 300 * ts + ext; + unsigned rem = cr % SCRHZ; + wth->capture.mpeg->now.secs + = wth->capture.mpeg->t0 + cr / SCRHZ; + wth->capture.mpeg->now.nsecs + = 1000000000LL * rem / SCRHZ; + } ts = wth->capture.mpeg->now; break; default: @@ -297,7 +299,7 @@ wth->capture.mpeg = g_malloc(sizeof(mpeg_t)); wth->capture.mpeg->now.secs = time(NULL); wth->capture.mpeg->now.nsecs = 0; - wth->capture.mpeg->t0 = (double) wth->capture.mpeg->now.secs; + wth->capture.mpeg->t0 = wth->capture.mpeg->now.secs; return 1; }
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