diff options
| -rw-r--r-- | wiretap/mpeg.c | 17 | ||||
| -rw-r--r-- | wsutil/mpeg-audio.c | 27 | ||||
| -rw-r--r-- | wsutil/mpeg-audio.h | 3 |
3 files changed, 46 insertions, 1 deletions
diff --git a/wiretap/mpeg.c b/wiretap/mpeg.c index fc60e66419..ea81f8ffba 100644 --- a/wiretap/mpeg.c +++ b/wiretap/mpeg.c @@ -163,7 +163,22 @@ mpeg_read_packet(wtap *wth, FILE_T fh, wtap_rec *rec, Buffer *buf, } } } else { - packet_size = mpeg_resync(fh, err); + if ((n & 0xffffff00) == 0x49443300) { + /* We have an ID3v2 header; read the size */ + if (file_seek(fh, 6, SEEK_CUR, err) == -1) + return FALSE; + if (!wtap_read_bytes_or_eof(fh, &n, sizeof n, err, err_info)) + return FALSE; + if (file_seek(fh, -(gint64)(6+sizeof(n)), SEEK_CUR, err) == -1) + return FALSE; + n = g_ntohl(n); + + /* ID3v2 size does not include the 10-byte header */ + packet_size = decode_synchsafe_int(n) + 10; + } else { + packet_size = mpeg_resync(fh, err); + } + if (packet_size == 0) return FALSE; } diff --git a/wsutil/mpeg-audio.c b/wsutil/mpeg-audio.c index 00ac78d8bd..e22bef38c8 100644 --- a/wsutil/mpeg-audio.c +++ b/wsutil/mpeg-audio.c @@ -81,6 +81,33 @@ mpa_padding(const struct mpa *mpa) return(mpa->padding ? mpa_padding_data[mpa_layers[mpa->layer]] : 0); } +/* Decode an ID3v2 synchsafe integer. + * See https://id3.org/id3v2.4.0-structure section 6.2. + */ +guint32 +decode_synchsafe_int(guint32 input) +{ + guint32 value; + + /* High-order byte */ + value = (input >> 24) & 0x7f; + /* Shift the result left to make room for the next 7 bits */ + value <<= 7; + + /* Now OR in the 2nd byte */ + value |= (input >> 16) & 0x7f; + value <<= 7; + + /* ... and the 3rd */ + value |= (input >> 8) & 0x7f; + value <<= 7; + + /* For the 4th byte don't do the shift */ + value |= input & 0x7f; + + return value; +} + /* * Editor modelines - https://www.wireshark.org/tools/modelines.html * diff --git a/wsutil/mpeg-audio.h b/wsutil/mpeg-audio.h index ced51ff745..e496a9b10d 100644 --- a/wsutil/mpeg-audio.h +++ b/wsutil/mpeg-audio.h @@ -11,6 +11,7 @@ #ifndef MPA_H #define MPA_H 1 +#include <glib.h> #include "ws_symbol_export.h" struct mpa { @@ -71,6 +72,8 @@ WS_DLL_PUBLIC unsigned int mpa_frequency(const struct mpa *); WS_DLL_PUBLIC unsigned int mpa_padding(const struct mpa *); +WS_DLL_PUBLIC +guint32 decode_synchsafe_int(guint32); #define MPA_DATA_BYTES(mpa) (mpa_bitrate(mpa) * mpa_samples(mpa) \ / mpa_frequency(mpa) / 8) |