Mypal/media/libstagefright/binding/SinfParser.cpp

83 lines
1.6 KiB
C++

/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#include "mozilla/Unused.h"
#include "mp4_demuxer/SinfParser.h"
#include "mp4_demuxer/AtomType.h"
#include "mp4_demuxer/Box.h"
namespace mp4_demuxer {
Sinf::Sinf(Box& aBox)
: mDefaultIVSize(0)
, mDefaultEncryptionType()
{
SinfParser parser(aBox);
if (parser.GetSinf().IsValid()) {
*this = parser.GetSinf();
}
}
SinfParser::SinfParser(Box& aBox)
{
for (Box box = aBox.FirstChild(); box.IsAvailable(); box = box.Next()) {
if (box.IsType("schm")) {
ParseSchm(box);
} else if (box.IsType("schi")) {
ParseSchi(box);
}
}
}
void
SinfParser::ParseSchm(Box& aBox)
{
BoxReader reader(aBox);
if (reader->Remaining() < 8) {
return;
}
uint32_t type;
if (!reader->Skip(4) ||
!reader->ReadU32(type)) {
NS_WARNING("Failed to parse schm data");
return;
}
mSinf.mDefaultEncryptionType = type;
}
void
SinfParser::ParseSchi(Box& aBox)
{
for (Box box = aBox.FirstChild(); box.IsAvailable(); box = box.Next()) {
if (box.IsType("tenc")) {
ParseTenc(box);
}
}
}
void
SinfParser::ParseTenc(Box& aBox)
{
BoxReader reader(aBox);
if (reader->Remaining() < 24) {
return;
}
uint32_t isEncrypted;
const uint8_t* key;
if (!reader->Skip(4) || // flags -- ignore
!reader->ReadU24(isEncrypted) ||
!reader->ReadU8(mSinf.mDefaultIVSize) ||
!reader->Read(16, &key)) {
NS_WARNING("Failed to parse tenc data");
return;
}
memcpy(mSinf.mDefaultKeyID, key, 16);
}
}