Download-Tools/mkvtoolnix
1
0
Fork 0
mirror of https://gitlab.com/mbunkus/mkvtoolnix.git synced 2025-01-04 09:15:05 +00:00
Code Issues Actions Packages Projects Releases Wiki Activity

If a packet header cannot be parsed then try skipping this packet. Additionally try to resync to the next start code in the case of errors.

Browse Source
This commit is contained in:
Moritz Bunkus 2007-03-05 12:45:06 +00:00
parent 989ac0aad8
commit 4a6674e730
3 changed files with 45 additions and 15 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
ChangeLog
View File

@ -1,5 +1,9 @@
2007-03-05 Moritz Bunkus <moritz@bunkus.org>
* mkvmerge: enhancement: Fixed the MPEG PS reader so that it will
just skip blocks whose headers it cannot parse instead of
aborting.
* mkvmerge: new feature: Added support for handling AVC/h.264
tracks in MPEG program streams.

52
src/input/r_mpeg.cpp
View File

@ -506,10 +506,12 @@ bool
mpeg_ps_reader_c::parse_packet(int id,
int64_t &timestamp,
int &length,
int &full_length,
int &aid) {
uint8_t c;
length = io->read_uint16_be();
full_length = length;
if ((id < 0xbc) || (id >= 0xf0) ||
(id == 0xbe) || // padding stream
(id == 0xbf)) { // private 2 stream
@ -623,7 +625,7 @@ mpeg_ps_reader_c::new_stream_v_mpeg_1_2(int id,
int length,
mpeg_ps_track_ptr &track) {
int64_t timecode;
int state, aid;
int state, aid, full_length;
auto_ptr<M2VParser> m2v_parser(new M2VParser);
MPEG2SequenceHeader seq_hdr;
MPEGChunk *raw_seq_hdr;
@ -636,7 +638,7 @@ mpeg_ps_reader_c::new_stream_v_mpeg_1_2(int id,
if (!find_next_packet_for_id(id, PS_PROBE_SIZE))
break;
if (!parse_packet(id, timecode, length, aid))
if (!parse_packet(id, timecode, length, full_length, aid))
break;
memory_c new_buf((unsigned char *)safemalloc(length), 0, true);
if (io->read(new_buf.get(), length) != length)
@ -684,7 +686,7 @@ mpeg_ps_reader_c::new_stream_v_avc(int id,
int length,
mpeg_ps_track_ptr &track) {
mpeg4::p10::avc_es_parser_c parser;
int aid;
int aid, full_length;
int64_t timecode;
parser.ignore_nalu_size_length_errors();
@ -700,7 +702,7 @@ mpeg_ps_reader_c::new_stream_v_avc(int id,
if (!find_next_packet_for_id(id, PS_PROBE_SIZE))
break;
if (!parse_packet(id, timecode, length, aid))
if (!parse_packet(id, timecode, length, full_length, aid))
break;
memory_c new_buf((unsigned char *)safemalloc(length), 0, true);
if (io->read(new_buf.get(), length) != length)
@ -834,10 +836,10 @@ mpeg_ps_reader_c::found_new_stream(int id) {
try {
int64_t timecode;
int length, aid;
int length, aid, full_length;
unsigned char *buf;
if (!parse_packet(id, timecode, length, aid))
if (!parse_packet(id, timecode, length, full_length, aid))
throw false;
if ((id == 0xbd) && (aid == -1))
@ -989,7 +991,7 @@ mpeg_ps_reader_c::find_next_packet(int &id,
break;
default:
if (!mpeg_is_start_code(header))
if (!mpeg_is_start_code(header) && !resync_stream(header))
return false;
id = header & 0xff;
@ -1019,6 +1021,29 @@ mpeg_ps_reader_c::find_next_packet_for_id(int id,
return false;
}
bool
mpeg_ps_reader_c::resync_stream(uint32_t &header) {
mxverb(2, "MPEG PS: synchronisation lost at " LLD
"; looking for start code\n", io->getFilePointer());
try {
while (1) {
header <<= 8;
header |= io->read_uint8();
if (mpeg_is_start_code(header))
break;
}
mxverb(2, "resync succeeded at " LLD ", header 0x%08x\n",
io->getFilePointer() - 4, header);
return true;
} catch (...) {
mxverb(2, "resync failed: exception caught\n");
return false;
}
}
void
mpeg_ps_reader_c::create_packetizer(int64_t id) {
if ((id < 0) || (id >= tracks.size()))
@ -1117,7 +1142,7 @@ file_status_e
mpeg_ps_reader_c::read(generic_packetizer_c *,
bool) {
int64_t timecode, packet_pos;
int new_id, length, aid, skip_bytes;
int new_id, length, aid, skip_bytes, full_length;
unsigned char *buf;
if (file_done)
@ -1133,12 +1158,11 @@ mpeg_ps_reader_c::read(generic_packetizer_c *,
}
packet_pos = io->getFilePointer() - 4;
if (!parse_packet(new_id, timecode, length, aid)) {
file_done = true;
flush_packetizers();
mxverb(2, "mpeg_ps: file_done: !parse_packet @ " LLD "\n",
packet_pos);
return FILE_STATUS_DONE;
if (!parse_packet(new_id, timecode, length, full_length, aid)) {
mxverb(2, "mpeg_ps: packet_parse failed @ " LLD ", skipping %d\n",
packet_pos, full_length);
io->setFilePointer(packet_pos + 4 + 2 + full_length);
continue;
}
if (new_id == 0xbd)

4
src/input/r_mpeg.h
View File

@ -116,7 +116,8 @@ public:
virtual void found_new_stream(int id);
virtual bool read_timestamp(int c, int64_t &timestamp);
virtual bool parse_packet(int id, int64_t &timestamp, int &size, int &aid);
virtual bool parse_packet(int id, int64_t &timestamp, int &length,
int &full_size, int &aid);
virtual bool find_next_packet(int &id, int64_t max_file_pos = -1);
virtual bool find_next_packet_for_id(int id, int64_t max_file_pos = -1);
@ -135,6 +136,7 @@ private:
int length, mpeg_ps_track_ptr &track);
virtual void new_stream_a_dts(int id, unsigned char *buf,
int length, mpeg_ps_track_ptr &track);
virtual bool resync_stream(uint32_t &header);
};
#endif // __R_MPEG_H