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vdr/remux.c

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/*
* remux.c: Tools for detecting frames and handling PAT/PMT
*
* See the main source file 'vdr.c' for copyright information and
* how to reach the author.
*
* $Id: remux.c 2.45 2010/05/13 14:16:56 kls Exp $
*/
#include "remux.h"
#include "device.h"
#include "libsi/si.h"
#include "libsi/section.h"
#include "libsi/descriptor.h"
#include "shutdown.h"
#include "tools.h"
// Set these to 'true' for debug output:
static bool DebugPatPmt = false;
static bool DebugFrames = false;
#define dbgpatpmt(a...) if (DebugPatPmt) fprintf(stderr, a)
#define dbgframes(a...) if (DebugFrames) fprintf(stderr, a)
ePesHeader AnalyzePesHeader(const uchar *Data, int Count, int &PesPayloadOffset, bool *ContinuationHeader)
{
if (Count < 7)
return phNeedMoreData; // too short
if ((Data[6] & 0xC0) == 0x80) { // MPEG 2
if (Count < 9)
return phNeedMoreData; // too short
PesPayloadOffset = 6 + 3 + Data[8];
if (Count < PesPayloadOffset)
return phNeedMoreData; // too short
if (ContinuationHeader)
*ContinuationHeader = ((Data[6] == 0x80) && !Data[7] && !Data[8]);
return phMPEG2; // MPEG 2
}
// check for MPEG 1 ...
PesPayloadOffset = 6;
// skip up to 16 stuffing bytes
for (int i = 0; i < 16; i++) {
if (Data[PesPayloadOffset] != 0xFF)
break;
if (Count <= ++PesPayloadOffset)
return phNeedMoreData; // too short
}
// skip STD_buffer_scale/size
if ((Data[PesPayloadOffset] & 0xC0) == 0x40) {
PesPayloadOffset += 2;
if (Count <= PesPayloadOffset)
return phNeedMoreData; // too short
}
if (ContinuationHeader)
*ContinuationHeader = false;
if ((Data[PesPayloadOffset] & 0xF0) == 0x20) {
// skip PTS only
PesPayloadOffset += 5;
}
else if ((Data[PesPayloadOffset] & 0xF0) == 0x30) {
// skip PTS and DTS
PesPayloadOffset += 10;
}
else if (Data[PesPayloadOffset] == 0x0F) {
// continuation header
PesPayloadOffset++;
if (ContinuationHeader)
*ContinuationHeader = true;
}
else
return phInvalid; // unknown
if (Count < PesPayloadOffset)
return phNeedMoreData; // too short
return phMPEG1; // MPEG 1
}
#define VIDEO_STREAM_S 0xE0
// --- cRemux ----------------------------------------------------------------
void cRemux::SetBrokenLink(uchar *Data, int Length)
{
int PesPayloadOffset = 0;
if (AnalyzePesHeader(Data, Length, PesPayloadOffset) >= phMPEG1 && (Data[3] & 0xF0) == VIDEO_STREAM_S) {
for (int i = PesPayloadOffset; i < Length - 7; i++) {
if (Data[i] == 0 && Data[i + 1] == 0 && Data[i + 2] == 1 && Data[i + 3] == 0xB8) {
if (!(Data[i + 7] & 0x40)) // set flag only if GOP is not closed
Data[i + 7] |= 0x20;
return;
}
}
dsyslog("SetBrokenLink: no GOP header found in video packet");
}
else
dsyslog("SetBrokenLink: no video packet in frame");
}
// --- Some TS handling tools ------------------------------------------------
int64_t TsGetPts(const uchar *p, int l)
{
// Find the first packet with a PTS and use it:
while (l > 0) {
const uchar *d = p;
if (TsPayloadStart(d) && TsGetPayload(&d) && PesHasPts(d))
return PesGetPts(d);
p += TS_SIZE;
l -= TS_SIZE;
}
return -1;
}
void TsSetTeiOnBrokenPackets(uchar *p, int l)
{
bool Processed[MAXPID] = { false };
while (l >= TS_SIZE) {
if (*p != TS_SYNC_BYTE)
break;
int Pid = TsPid(p);
if (!Processed[Pid]) {
if (!TsPayloadStart(p))
p[1] |= TS_ERROR;
else
Processed[Pid] = true;
}
l -= TS_SIZE;
p += TS_SIZE;
}
}
// --- cPatPmtGenerator ------------------------------------------------------
cPatPmtGenerator::cPatPmtGenerator(const cChannel *Channel)
{
numPmtPackets = 0;
patCounter = pmtCounter = 0;
patVersion = pmtVersion = 0;
pmtPid = 0;
esInfoLength = NULL;
SetChannel(Channel);
}
void cPatPmtGenerator::IncCounter(int &Counter, uchar *TsPacket)
{
TsPacket[3] = (TsPacket[3] & 0xF0) | Counter;
if (++Counter > 0x0F)
Counter = 0x00;
}
void cPatPmtGenerator::IncVersion(int &Version)
{
if (++Version > 0x1F)
Version = 0x00;
}
void cPatPmtGenerator::IncEsInfoLength(int Length)
{
if (esInfoLength) {
Length += ((*esInfoLength & 0x0F) << 8) | *(esInfoLength + 1);
*esInfoLength = 0xF0 | (Length >> 8);
*(esInfoLength + 1) = Length;
}
}
int cPatPmtGenerator::MakeStream(uchar *Target, uchar Type, int Pid)
{
int i = 0;
Target[i++] = Type; // stream type
Target[i++] = 0xE0 | (Pid >> 8); // dummy (3), pid hi (5)
Target[i++] = Pid; // pid lo
esInfoLength = &Target[i];
Target[i++] = 0xF0; // dummy (4), ES info length hi
Target[i++] = 0x00; // ES info length lo
return i;
}
int cPatPmtGenerator::MakeAC3Descriptor(uchar *Target)
{
int i = 0;
Target[i++] = SI::AC3DescriptorTag;
Target[i++] = 0x01; // length
Target[i++] = 0x00;
IncEsInfoLength(i);
return i;
}
int cPatPmtGenerator::MakeSubtitlingDescriptor(uchar *Target, const char *Language, uchar SubtitlingType, uint16_t CompositionPageId, uint16_t AncillaryPageId)
{
int i = 0;
Target[i++] = SI::SubtitlingDescriptorTag;
Target[i++] = 0x08; // length
Target[i++] = *Language++;
Target[i++] = *Language++;
Target[i++] = *Language++;
Target[i++] = SubtitlingType;
Target[i++] = CompositionPageId >> 8;
Target[i++] = CompositionPageId & 0xFF;
Target[i++] = AncillaryPageId >> 8;
Target[i++] = AncillaryPageId & 0xFF;
IncEsInfoLength(i);
return i;
}
int cPatPmtGenerator::MakeLanguageDescriptor(uchar *Target, const char *Language)
{
int i = 0;
Target[i++] = SI::ISO639LanguageDescriptorTag;
int Length = i++;
Target[Length] = 0x00; // length
for (const char *End = Language + strlen(Language); Language < End; ) {
Target[i++] = *Language++;
Target[i++] = *Language++;
Target[i++] = *Language++;
Target[i++] = 0x01; // audio type
Target[Length] += 0x04; // length
if (*Language == '+')
Language++;
}
IncEsInfoLength(i);
return i;
}
int cPatPmtGenerator::MakeCRC(uchar *Target, const uchar *Data, int Length)
{
int crc = SI::CRC32::crc32((const char *)Data, Length, 0xFFFFFFFF);
int i = 0;
Target[i++] = crc >> 24;
Target[i++] = crc >> 16;
Target[i++] = crc >> 8;
Target[i++] = crc;
return i;
}
#define P_TSID 0x8008 // pseudo TS ID
#define P_PMT_PID 0x0084 // pseudo PMT pid
#define MAXPID 0x2000 // the maximum possible number of pids
void cPatPmtGenerator::GeneratePmtPid(const cChannel *Channel)
{
bool Used[MAXPID] = { false };
#define SETPID(p) { if ((p) >= 0 && (p) < MAXPID) Used[p] = true; }
#define SETPIDS(l) { const int *p = l; while (*p) { SETPID(*p); p++; } }
SETPID(Channel->Vpid());
SETPID(Channel->Ppid());
SETPID(Channel->Tpid());
SETPIDS(Channel->Apids());
SETPIDS(Channel->Dpids());
SETPIDS(Channel->Spids());
for (pmtPid = P_PMT_PID; Used[pmtPid]; pmtPid++)
;
}
void cPatPmtGenerator::GeneratePat(void)
{
memset(pat, 0xFF, sizeof(pat));
uchar *p = pat;
int i = 0;
p[i++] = TS_SYNC_BYTE; // TS indicator
p[i++] = TS_PAYLOAD_START | (PATPID >> 8); // flags (3), pid hi (5)
p[i++] = PATPID & 0xFF; // pid lo
p[i++] = 0x10; // flags (4), continuity counter (4)
p[i++] = 0x00; // pointer field (payload unit start indicator is set)
int PayloadStart = i;
p[i++] = 0x00; // table id
p[i++] = 0xB0; // section syntax indicator (1), dummy (3), section length hi (4)
int SectionLength = i;
p[i++] = 0x00; // section length lo (filled in later)
p[i++] = P_TSID >> 8; // TS id hi
p[i++] = P_TSID & 0xFF; // TS id lo
p[i++] = 0xC1 | (patVersion << 1); // dummy (2), version number (5), current/next indicator (1)
p[i++] = 0x00; // section number
p[i++] = 0x00; // last section number
p[i++] = pmtPid >> 8; // program number hi
p[i++] = pmtPid & 0xFF; // program number lo
p[i++] = 0xE0 | (pmtPid >> 8); // dummy (3), PMT pid hi (5)
p[i++] = pmtPid & 0xFF; // PMT pid lo
pat[SectionLength] = i - SectionLength - 1 + 4; // -2 = SectionLength storage, +4 = length of CRC
MakeCRC(pat + i, pat + PayloadStart, i - PayloadStart);
IncVersion(patVersion);
}
void cPatPmtGenerator::GeneratePmt(const cChannel *Channel)
{
// generate the complete PMT section:
uchar buf[MAX_SECTION_SIZE];
memset(buf, 0xFF, sizeof(buf));
numPmtPackets = 0;
if (Channel) {
int Vpid = Channel->Vpid();
int Ppid = Channel->Ppid();
uchar *p = buf;
int i = 0;
p[i++] = 0x02; // table id
int SectionLength = i;
p[i++] = 0xB0; // section syntax indicator (1), dummy (3), section length hi (4)
p[i++] = 0x00; // section length lo (filled in later)
p[i++] = pmtPid >> 8; // program number hi
p[i++] = pmtPid & 0xFF; // program number lo
p[i++] = 0xC1 | (pmtVersion << 1); // dummy (2), version number (5), current/next indicator (1)
p[i++] = 0x00; // section number
p[i++] = 0x00; // last section number
p[i++] = 0xE0 | (Ppid >> 8); // dummy (3), PCR pid hi (5)
p[i++] = Ppid; // PCR pid lo
p[i++] = 0xF0; // dummy (4), program info length hi (4)
p[i++] = 0x00; // program info length lo
if (Vpid)
i += MakeStream(buf + i, Channel->Vtype(), Vpid);
for (int n = 0; Channel->Apid(n); n++) {
i += MakeStream(buf + i, 0x04, Channel->Apid(n));
const char *Alang = Channel->Alang(n);
i += MakeLanguageDescriptor(buf + i, Alang);
}
for (int n = 0; Channel->Dpid(n); n++) {
i += MakeStream(buf + i, 0x06, Channel->Dpid(n));
i += MakeAC3Descriptor(buf + i);
i += MakeLanguageDescriptor(buf + i, Channel->Dlang(n));
}
for (int n = 0; Channel->Spid(n); n++) {
i += MakeStream(buf + i, 0x06, Channel->Spid(n));
i += MakeSubtitlingDescriptor(buf + i, Channel->Slang(n), Channel->SubtitlingType(n), Channel->CompositionPageId(n), Channel->AncillaryPageId(n));
}
int sl = i - SectionLength - 2 + 4; // -2 = SectionLength storage, +4 = length of CRC
buf[SectionLength] |= (sl >> 8) & 0x0F;
buf[SectionLength + 1] = sl;
MakeCRC(buf + i, buf, i);
// split the PMT section into several TS packets:
uchar *q = buf;
bool pusi = true;
while (i > 0) {
uchar *p = pmt[numPmtPackets++];
int j = 0;
p[j++] = TS_SYNC_BYTE; // TS indicator
p[j++] = (pusi ? TS_PAYLOAD_START : 0x00) | (pmtPid >> 8); // flags (3), pid hi (5)
p[j++] = pmtPid & 0xFF; // pid lo
p[j++] = 0x10; // flags (4), continuity counter (4)
if (pusi) {
p[j++] = 0x00; // pointer field (payload unit start indicator is set)
pusi = false;
}
int l = TS_SIZE - j;
memcpy(p + j, q, l);
q += l;
i -= l;
}
IncVersion(pmtVersion);
}
}
void cPatPmtGenerator::SetVersions(int PatVersion, int PmtVersion)
{
patVersion = PatVersion & 0x1F;
pmtVersion = PmtVersion & 0x1F;
}
void cPatPmtGenerator::SetChannel(const cChannel *Channel)
{
if (Channel) {
GeneratePmtPid(Channel);
GeneratePat();
GeneratePmt(Channel);
}
}
uchar *cPatPmtGenerator::GetPat(void)
{
IncCounter(patCounter, pat);
return pat;
}
uchar *cPatPmtGenerator::GetPmt(int &Index)
{
if (Index < numPmtPackets) {
IncCounter(pmtCounter, pmt[Index]);
return pmt[Index++];
}
return NULL;
}
// --- cPatPmtParser ---------------------------------------------------------
cPatPmtParser::cPatPmtParser(bool UpdatePrimaryDevice)
{
updatePrimaryDevice = UpdatePrimaryDevice;
Reset();
}
void cPatPmtParser::Reset(void)
{
pmtSize = 0;
patVersion = pmtVersion = -1;
pmtPid = -1;
vpid = vtype = 0;
ppid = 0;
}
void cPatPmtParser::ParsePat(const uchar *Data, int Length)
{
// Unpack the TS packet:
int PayloadOffset = TsPayloadOffset(Data);
Data += PayloadOffset;
Length -= PayloadOffset;
// The PAT is always assumed to fit into a single TS packet
if ((Length -= Data[0] + 1) <= 0)
return;
Data += Data[0] + 1; // process pointer_field
SI::PAT Pat(Data, false);
if (Pat.CheckCRCAndParse()) {
dbgpatpmt("PAT: TSid = %d, c/n = %d, v = %d, s = %d, ls = %d\n", Pat.getTransportStreamId(), Pat.getCurrentNextIndicator(), Pat.getVersionNumber(), Pat.getSectionNumber(), Pat.getLastSectionNumber());
if (patVersion == Pat.getVersionNumber())
return;
SI::PAT::Association assoc;
for (SI::Loop::Iterator it; Pat.associationLoop.getNext(assoc, it); ) {
dbgpatpmt(" isNITPid = %d\n", assoc.isNITPid());
if (!assoc.isNITPid()) {
pmtPid = assoc.getPid();
dbgpatpmt(" service id = %d, pid = %d\n", assoc.getServiceId(), assoc.getPid());
}
}
patVersion = Pat.getVersionNumber();
}
else
esyslog("ERROR: can't parse PAT");
}
void cPatPmtParser::ParsePmt(const uchar *Data, int Length)
{
// Unpack the TS packet:
bool PayloadStart = TsPayloadStart(Data);
int PayloadOffset = TsPayloadOffset(Data);
Data += PayloadOffset;
Length -= PayloadOffset;
// The PMT may extend over several TS packets, so we need to assemble them
if (PayloadStart) {
pmtSize = 0;
if ((Length -= Data[0] + 1) <= 0)
return;
Data += Data[0] + 1; // this is the first packet
if (SectionLength(Data, Length) > Length) {
if (Length <= int(sizeof(pmt))) {
memcpy(pmt, Data, Length);
pmtSize = Length;
}
else
esyslog("ERROR: PMT packet length too big (%d byte)!", Length);
return;
}
// the packet contains the entire PMT section, so we run into the actual parsing
}
else if (pmtSize > 0) {
// this is a following packet, so we add it to the pmt storage
if (Length <= int(sizeof(pmt)) - pmtSize) {
memcpy(pmt + pmtSize, Data, Length);
pmtSize += Length;
}
else {
esyslog("ERROR: PMT section length too big (%d byte)!", pmtSize + Length);
pmtSize = 0;
}
if (SectionLength(pmt, pmtSize) > pmtSize)
return; // more packets to come
// the PMT section is now complete, so we run into the actual parsing
Data = pmt;
}
else
return; // fragment of broken packet - ignore
SI::PMT Pmt(Data, false);
if (Pmt.CheckCRCAndParse()) {
dbgpatpmt("PMT: sid = %d, c/n = %d, v = %d, s = %d, ls = %d\n", Pmt.getServiceId(), Pmt.getCurrentNextIndicator(), Pmt.getVersionNumber(), Pmt.getSectionNumber(), Pmt.getLastSectionNumber());
dbgpatpmt(" pcr = %d\n", Pmt.getPCRPid());
if (pmtVersion == Pmt.getVersionNumber())
return;
if (updatePrimaryDevice)
cDevice::PrimaryDevice()->ClrAvailableTracks(false, true);
int NumApids = 0;
int NumDpids = 0;
int NumSpids = 0;
vpid = vtype = 0;
ppid = 0;
apids[0] = 0;
dpids[0] = 0;
spids[0] = 0;
atypes[0] = 0;
dtypes[0] = 0;
SI::PMT::Stream stream;
for (SI::Loop::Iterator it; Pmt.streamLoop.getNext(stream, it); ) {
dbgpatpmt(" stream type = %02X, pid = %d", stream.getStreamType(), stream.getPid());
switch (stream.getStreamType()) {
case 0x01: // STREAMTYPE_11172_VIDEO
case 0x02: // STREAMTYPE_13818_VIDEO
case 0x1B: // MPEG4
vpid = stream.getPid();
vtype = stream.getStreamType();
ppid = Pmt.getPCRPid();
break;
case 0x03: // STREAMTYPE_11172_AUDIO
case 0x04: // STREAMTYPE_13818_AUDIO
{
if (NumApids < MAXAPIDS) {
apids[NumApids] = stream.getPid();
atypes[NumApids] = stream.getStreamType();
*alangs[NumApids] = 0;
SI::Descriptor *d;
for (SI::Loop::Iterator it; (d = stream.streamDescriptors.getNext(it)); ) {
switch (d->getDescriptorTag()) {
case SI::ISO639LanguageDescriptorTag: {
SI::ISO639LanguageDescriptor *ld = (SI::ISO639LanguageDescriptor *)d;
SI::ISO639LanguageDescriptor::Language l;
char *s = alangs[NumApids];
int n = 0;
for (SI::Loop::Iterator it; ld->languageLoop.getNext(l, it); ) {
if (*ld->languageCode != '-') { // some use "---" to indicate "none"
dbgpatpmt(" '%s'", l.languageCode);
if (n > 0)
*s++ = '+';
strn0cpy(s, I18nNormalizeLanguageCode(l.languageCode), MAXLANGCODE1);
s += strlen(s);
if (n++ > 1)
break;
}
}
}
break;
default: ;
}
delete d;
}
if (updatePrimaryDevice)
cDevice::PrimaryDevice()->SetAvailableTrack(ttAudio, NumApids, apids[NumApids], alangs[NumApids]);
NumApids++;
apids[NumApids]= 0;
}
}
break;
case 0x06: // STREAMTYPE_13818_PES_PRIVATE
{
int dpid = 0;
char lang[MAXLANGCODE1] = "";
SI::Descriptor *d;
for (SI::Loop::Iterator it; (d = stream.streamDescriptors.getNext(it)); ) {
switch (d->getDescriptorTag()) {
case SI::AC3DescriptorTag:
dbgpatpmt(" AC3");
dpid = stream.getPid();
break;
case SI::SubtitlingDescriptorTag:
dbgpatpmt(" subtitling");
if (NumSpids < MAXSPIDS) {
spids[NumSpids] = stream.getPid();
*slangs[NumSpids] = 0;
subtitlingTypes[NumSpids] = 0;
compositionPageIds[NumSpids] = 0;
ancillaryPageIds[NumSpids] = 0;
SI::SubtitlingDescriptor *sd = (SI::SubtitlingDescriptor *)d;
SI::SubtitlingDescriptor::Subtitling sub;
char *s = slangs[NumSpids];
int n = 0;
for (SI::Loop::Iterator it; sd->subtitlingLoop.getNext(sub, it); ) {
if (sub.languageCode[0]) {
dbgpatpmt(" '%s'", sub.languageCode);
subtitlingTypes[NumSpids] = sub.getSubtitlingType();
compositionPageIds[NumSpids] = sub.getCompositionPageId();
ancillaryPageIds[NumSpids] = sub.getAncillaryPageId();
if (n > 0)
*s++ = '+';
strn0cpy(s, I18nNormalizeLanguageCode(sub.languageCode), MAXLANGCODE1);
s += strlen(s);
if (n++ > 1)
break;
}
}
if (updatePrimaryDevice)
cDevice::PrimaryDevice()->SetAvailableTrack(ttSubtitle, NumSpids, spids[NumSpids], slangs[NumSpids]);
NumSpids++;
spids[NumSpids]= 0;
}
break;
case SI::ISO639LanguageDescriptorTag: {
SI::ISO639LanguageDescriptor *ld = (SI::ISO639LanguageDescriptor *)d;
dbgpatpmt(" '%s'", ld->languageCode);
strn0cpy(lang, I18nNormalizeLanguageCode(ld->languageCode), MAXLANGCODE1);
}
break;
default: ;
}
delete d;
}
if (dpid) {
if (NumDpids < MAXDPIDS) {
dpids[NumDpids] = dpid;
dtypes[NumDpids] = stream.getStreamType();
strn0cpy(dlangs[NumDpids], lang, sizeof(dlangs[NumDpids]));
if (updatePrimaryDevice && Setup.UseDolbyDigital)
cDevice::PrimaryDevice()->SetAvailableTrack(ttDolby, NumDpids, dpid, lang);
NumDpids++;
dpids[NumDpids]= 0;
}
}
}
break;
default: ;
}
dbgpatpmt("\n");
if (updatePrimaryDevice) {
cDevice::PrimaryDevice()->EnsureAudioTrack(true);
cDevice::PrimaryDevice()->EnsureSubtitleTrack();
}
}
pmtVersion = Pmt.getVersionNumber();
}
else
esyslog("ERROR: can't parse PMT");
pmtSize = 0;
}
bool cPatPmtParser::GetVersions(int &PatVersion, int &PmtVersion) const
{
PatVersion = patVersion;
PmtVersion = pmtVersion;
return patVersion >= 0 && pmtVersion >= 0;
}
// --- cTsToPes --------------------------------------------------------------
cTsToPes::cTsToPes(void)
{
data = NULL;
size = 0;
Reset();
}
cTsToPes::~cTsToPes()
{
free(data);
}
void cTsToPes::PutTs(const uchar *Data, int Length)
{
if (TsError(Data)) {
Reset();
return; // ignore packets with TEI set, and drop any PES data collected so far
}
if (TsPayloadStart(Data))
Reset();
else if (!size)
return; // skip everything before the first payload start
Length = TsGetPayload(&Data);
if (length + Length > size) {
size = max(KILOBYTE(2), length + Length);
data = (uchar *)realloc(data, size);
if (!data) {
Reset();
return;
}
}
memcpy(data + length, Data, Length);
length += Length;
}
#define MAXPESLENGTH 0xFFF0
const uchar *cTsToPes::GetPes(int &Length)
{
if (repeatLast) {
repeatLast = false;
Length = lastLength;
return lastData;
}
if (offset < length && PesLongEnough(length)) {
if (!PesHasLength(data)) // this is a video PES packet with undefined length
offset = 6; // trigger setting PES length for initial slice
if (offset) {
uchar *p = data + offset - 6;
if (p != data) {
p -= 3;
memmove(p, data, 4);
}
int l = min(length - offset, MAXPESLENGTH);
offset += l;
if (p != data) {
l += 3;
p[6] = 0x80;
p[7] = 0x00;
p[8] = 0x00;
}
p[4] = l / 256;
p[5] = l & 0xFF;
Length = l + 6;
lastLength = Length;
lastData = p;
return p;
}
else {
Length = PesLength(data);
if (Length <= length) {
offset = Length; // to make sure we break out in case of garbage data
lastLength = Length;
lastData = data;
return data;
}
}
}
return NULL;
}
void cTsToPes::SetRepeatLast(void)
{
repeatLast = true;
}
void cTsToPes::Reset(void)
{
length = offset = 0;
lastData = NULL;
lastLength = 0;
repeatLast = false;
}
// --- Some helper functions for debugging -----------------------------------
void BlockDump(const char *Name, const u_char *Data, int Length)
{
printf("--- %s\n", Name);
for (int i = 0; i < Length; i++) {
if (i && (i % 16) == 0)
printf("\n");
printf(" %02X", Data[i]);
}
printf("\n");
}
void TsDump(const char *Name, const u_char *Data, int Length)
{
printf("%s: %04X", Name, Length);
int n = min(Length, 20);
for (int i = 0; i < n; i++)
printf(" %02X", Data[i]);
if (n < Length) {
printf(" ...");
n = max(n, Length - 10);
for (n = max(n, Length - 10); n < Length; n++)
printf(" %02X", Data[n]);
}
printf("\n");
}
void PesDump(const char *Name, const u_char *Data, int Length)
{
TsDump(Name, Data, Length);
}
// --- cFrameDetector --------------------------------------------------------
#define EMPTY_SCANNER (0xFFFFFFFF)
cFrameDetector::cFrameDetector(int Pid, int Type)
{
SetPid(Pid, Type);
synced = false;
newFrame = independentFrame = false;
numPtsValues = 0;
numIFrames = 0;
frameDuration = 0;
framesInPayloadUnit = framesPerPayloadUnit = 0;
payloadUnitOfFrame = 0;
scanning = false;
scanner = EMPTY_SCANNER;
}
static int CmpUint32(const void *p1, const void *p2)
{
if (*(uint32_t *)p1 < *(uint32_t *)p2) return -1;
if (*(uint32_t *)p1 > *(uint32_t *)p2) return 1;
return 0;
}
void cFrameDetector::SetPid(int Pid, int Type)
{
pid = Pid;
type = Type;
isVideo = type == 0x01 || type == 0x02 || type == 0x1B; // MPEG 1, 2 or 4
}
void cFrameDetector::Reset(void)
{
newFrame = independentFrame = false;
payloadUnitOfFrame = 0;
scanning = false;
scanner = EMPTY_SCANNER;
}
int cFrameDetector::Analyze(const uchar *Data, int Length)
{
int SeenPayloadStart = false;
int Processed = 0;
newFrame = independentFrame = false;
while (Length >= TS_SIZE) {
if (Data[0] != TS_SYNC_BYTE) {
int Skipped = 1;
while (Skipped < Length && (Data[Skipped] != TS_SYNC_BYTE || Length - Skipped > TS_SIZE && Data[Skipped + TS_SIZE] != TS_SYNC_BYTE))
Skipped++;
esyslog("ERROR: skipped %d bytes to sync on start of TS packet", Skipped);
return Processed + Skipped;
}
if (TsHasPayload(Data) && !TsIsScrambled(Data)) {
int Pid = TsPid(Data);
if (Pid == pid) {
if (TsPayloadStart(Data)) {
SeenPayloadStart = true;
if (synced && Processed)
return Processed;
if (Length < MIN_TS_PACKETS_FOR_FRAME_DETECTOR * TS_SIZE)
return Processed; // need more data, in case the frame type is not stored in the first TS packet
if (!frameDuration) {
// frame duration unknown, so collect a sequence of PTS values:
if (numPtsValues < MaxPtsValues && numIFrames < 2) { // collect a sequence containing at least two I-frames
const uchar *Pes = Data + TsPayloadOffset(Data);
if (PesHasPts(Pes)) {
ptsValues[numPtsValues] = PesGetPts(Pes);
// check for rollover:
if (numPtsValues && ptsValues[numPtsValues - 1] > 0xF0000000 && ptsValues[numPtsValues] < 0x10000000) {
dbgframes("#");
numPtsValues = 0;
numIFrames = 0;
}
else
numPtsValues++;
}
}
else {
// find the smallest PTS delta:
qsort(ptsValues, numPtsValues, sizeof(uint32_t), CmpUint32);
numPtsValues--;
for (int i = 0; i < numPtsValues; i++)
ptsValues[i] = ptsValues[i + 1] - ptsValues[i];
qsort(ptsValues, numPtsValues, sizeof(uint32_t), CmpUint32);
uint32_t Delta = ptsValues[0];
// determine frame info:
if (isVideo) {
if (Delta % 3600 == 0)
frameDuration = 3600; // PAL, 25 fps, exact timing
else if (abs(Delta % 3600) == 3599 || abs(Delta % 3600) == 1)
frameDuration = 3600; // PAL, 25 fps, timing with jitter
else if (Delta % 3003 == 0)
frameDuration = 3003; // NTSC, 29.97 fps
else if (abs(Delta - 1800) <= 1) {
frameDuration = 3600; // PAL, 25 fps
framesPerPayloadUnit = -2;
}
else if (Delta == 1501) {
frameDuration = 3003; // NTSC, 29.97 fps
framesPerPayloadUnit = -2;
}
else {
frameDuration = 3600; // unknown, assuming 25 fps
dsyslog("unknown frame duration (%d), assuming 25 fps", Delta);
}
}
else // audio
frameDuration = Delta; // PTS of audio frames is always increasing
dbgframes("\nframe duration = %d FPS = %5.2f FPPU = %d\n", frameDuration, 90000.0 / frameDuration, framesPerPayloadUnit);
}
}
scanner = EMPTY_SCANNER;
scanning = true;
}
if (scanning) {
int PayloadOffset = TsPayloadOffset(Data);
if (TsPayloadStart(Data)) {
PayloadOffset += PesPayloadOffset(Data + PayloadOffset);
if (!framesPerPayloadUnit)
framesPerPayloadUnit = framesInPayloadUnit;
if (DebugFrames && !synced)
dbgframes("/");
}
for (int i = PayloadOffset; scanning && i < TS_SIZE; i++) {
scanner <<= 8;
scanner |= Data[i];
switch (type) {
case 0x01: // MPEG 1 video
case 0x02: // MPEG 2 video
if (scanner == 0x00000100) { // Picture Start Code
scanner = EMPTY_SCANNER;
if (synced && !SeenPayloadStart && Processed)
return Processed; // flush everything before this new frame
newFrame = true;
independentFrame = ((Data[i + 2] >> 3) & 0x07) == 1; // I-Frame
if (synced) {
if (framesPerPayloadUnit <= 1)
scanning = false;
}
else {
framesInPayloadUnit++;
if (independentFrame)
numIFrames++;
dbgframes("%d ", (Data[i + 2] >> 3) & 0x07);
}
if (synced)
return Processed + TS_SIZE; // flag this new frame
}
break;
case 0x1B: // MPEG 4 video
if (scanner == 0x00000109) { // Access Unit Delimiter
scanner = EMPTY_SCANNER;
if (synced && !SeenPayloadStart && Processed)
return Processed; // flush everything before this new frame
newFrame = true;
independentFrame = Data[i + 1] == 0x10;
if (synced) {
if (framesPerPayloadUnit < 0) {
payloadUnitOfFrame = (payloadUnitOfFrame + 1) % -framesPerPayloadUnit;
if (payloadUnitOfFrame != 0 && independentFrame)
payloadUnitOfFrame = 0;
if (payloadUnitOfFrame)
newFrame = false;
}
if (framesPerPayloadUnit <= 1)
scanning = false;
}
else {
framesInPayloadUnit++;
if (independentFrame)
numIFrames++;
dbgframes("%02X ", Data[i + 1]);
}
if (synced)
return Processed + TS_SIZE; // flag this new frame
}
break;
case 0x04: // MPEG audio
case 0x06: // AC3 audio
if (synced && Processed)
return Processed;
newFrame = true;
independentFrame = true;
if (!synced) {
framesInPayloadUnit = 1;
if (TsPayloadStart(Data))
numIFrames++;
}
scanning = false;
break;
default: esyslog("ERROR: unknown stream type %d (PID %d) in frame detector", type, pid);
pid = 0; // let's just ignore any further data
}
}
if (!synced && frameDuration && independentFrame) {
synced = true;
dbgframes("*");
Reset();
return Processed + TS_SIZE;
}
}
}
else if (Pid == PATPID && synced && Processed)
return Processed; // allow the caller to see any PAT packets
}
Data += TS_SIZE;
Length -= TS_SIZE;
Processed += TS_SIZE;
}
return Processed;
}
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