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|
/*****************************************************************
|
| AP4 - trun Atoms
|
| Copyright 2002-2008 Axiomatic Systems, LLC
|
|
| This file is part of Bento4/AP4 (MP4 Atom Processing Library).
|
| Unless you have obtained Bento4 under a difference license,
| this version of Bento4 is Bento4|GPL.
| Bento4|GPL is free software; you can redistribute it and/or modify
| it under the terms of the GNU General Public License as published by
| the Free Software Foundation; either version 2, or (at your option)
| any later version.
|
| Bento4|GPL is distributed in the hope that it will be useful,
| but WITHOUT ANY WARRANTY; without even the implied warranty of
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
| GNU General Public License for more details.
|
| You should have received a copy of the GNU General Public License
| along with Bento4|GPL; see the file COPYING. If not, write to the
| Free Software Foundation, 59 Temple Place - Suite 330, Boston, MA
| 02111-1307, USA.
|
****************************************************************/
/*----------------------------------------------------------------------
| includes
+---------------------------------------------------------------------*/
#include "Ap4TrunAtom.h"
#include "Ap4Utils.h"
/*----------------------------------------------------------------------
| dynamic cast support
+---------------------------------------------------------------------*/
AP4_DEFINE_DYNAMIC_CAST_ANCHOR(AP4_TrunAtom)
/*----------------------------------------------------------------------
| AP4_TrunAtom::Create
+---------------------------------------------------------------------*/
AP4_TrunAtom*
AP4_TrunAtom::Create(AP4_Size size, AP4_ByteStream& stream)
{
AP4_UI08 version;
AP4_UI32 flags;
if (size < AP4_FULL_ATOM_HEADER_SIZE) return NULL;
if (AP4_FAILED(AP4_Atom::ReadFullHeader(stream, version, flags))) return NULL;
if (version > 1) return NULL;
return new AP4_TrunAtom(size, version, flags, stream);
}
/*----------------------------------------------------------------------
| AP4_TrunAtom::ComputeRecordFieldsCount
+---------------------------------------------------------------------*/
unsigned int
AP4_TrunAtom::ComputeRecordFieldsCount(AP4_UI32 flags)
{
// count the number of bits set to 1 in the second byte of the flags
unsigned int count = 0;
for (unsigned int i=0; i<8; i++) {
if (flags & (1<<(i+8))) ++count;
}
return count;
}
/*----------------------------------------------------------------------
| AP4_TrunAtom::ComputeOptionalFieldsCount
+---------------------------------------------------------------------*/
unsigned int
AP4_TrunAtom::ComputeOptionalFieldsCount(AP4_UI32 flags)
{
// count the number of bits set to 1 in the LSB of the flags
unsigned int count = 0;
for (unsigned int i=0; i<8; i++) {
if (flags & (1<<i)) ++count;
}
return count;
}
/*----------------------------------------------------------------------
| AP4_TrunAtom::AP4_TrunAtom
+---------------------------------------------------------------------*/
AP4_TrunAtom::AP4_TrunAtom(AP4_UI32 flags,
AP4_SI32 data_offset,
AP4_UI32 first_sample_flags) :
AP4_Atom(AP4_ATOM_TYPE_TRUN, AP4_FULL_ATOM_HEADER_SIZE+4, 0, flags),
m_DataOffset(data_offset),
m_FirstSampleFlags(first_sample_flags)
{
m_Size32 += 4 * ComputeOptionalFieldsCount(flags);
}
/*----------------------------------------------------------------------
| AP4_TrunAtom::AP4_TrunAtom
+---------------------------------------------------------------------*/
AP4_TrunAtom::AP4_TrunAtom(AP4_UI32 size,
AP4_UI08 version,
AP4_UI32 flags,
AP4_ByteStream& stream) :
AP4_Atom(AP4_ATOM_TYPE_TRUN, size, version, flags)
{
if (size < AP4_FULL_ATOM_HEADER_SIZE + 4) {
return;
}
AP4_UI32 sample_count = 0;
stream.ReadUI32(sample_count);
AP4_Size bytes_left = size - AP4_FULL_ATOM_HEADER_SIZE - 4;
// read optional fields
int optional_fields_count = (int)ComputeOptionalFieldsCount(flags);
if (flags & AP4_TRUN_FLAG_DATA_OFFSET_PRESENT) {
AP4_UI32 offset = 0;
if (bytes_left < 4 || AP4_FAILED(stream.ReadUI32(offset))) {
return;
}
m_DataOffset = (AP4_SI32)offset;
if (optional_fields_count == 0) {
return;
}
--optional_fields_count;
bytes_left -= 4;
}
if (flags & AP4_TRUN_FLAG_FIRST_SAMPLE_FLAGS_PRESENT) {
if (bytes_left < 4 || AP4_FAILED(stream.ReadUI32(m_FirstSampleFlags))) {
return;
}
if (optional_fields_count == 0) {
return;
}
--optional_fields_count;
bytes_left -= 4;
}
// discard unknown optional fields
for (int i=0; i<optional_fields_count; i++) {
AP4_UI32 discard;
if (bytes_left < 4 || AP4_FAILED(stream.ReadUI32(discard))) {
return;
}
bytes_left -= 4;
}
int record_fields_count = (int)ComputeRecordFieldsCount(flags);
if (record_fields_count && ((bytes_left / (record_fields_count*4)) < sample_count)) {
// not enough data for all samples, the format is invalid
return;
}
if (AP4_FAILED(m_Entries.SetItemCount(sample_count))) {
return;
}
for (unsigned int i=0; i<sample_count; i++) {
if (flags & AP4_TRUN_FLAG_SAMPLE_DURATION_PRESENT) {
if (bytes_left < 4 || AP4_FAILED(stream.ReadUI32(m_Entries[i].sample_duration))) {
return;;
}
// Workaround for dazn streams, which provide 24 -> 1 sequences
if (i && m_Entries[i].sample_duration == 1 && m_Entries[i - 1].sample_duration > 1)
{
m_Entries[i].sample_duration = m_Entries[i - 1].sample_duration >> 1;
m_Entries[i - 1].sample_duration -= m_Entries[i].sample_duration;
}
--record_fields_count;
bytes_left -= 4;
}
if (flags & AP4_TRUN_FLAG_SAMPLE_SIZE_PRESENT) {
if (bytes_left < 4 || AP4_FAILED(stream.ReadUI32(m_Entries[i].sample_size))) {
return;
}
--record_fields_count;
bytes_left -= 4;
}
if (flags & AP4_TRUN_FLAG_SAMPLE_FLAGS_PRESENT) {
if (bytes_left < 4 || AP4_FAILED(stream.ReadUI32(m_Entries[i].sample_flags))) {
return;
}
--record_fields_count;
bytes_left -= 4;
}
if (flags & AP4_TRUN_FLAG_SAMPLE_COMPOSITION_TIME_OFFSET_PRESENT) {
if (bytes_left < 4 || AP4_FAILED(stream.ReadUI32(m_Entries[i].sample_composition_time_offset))) {
return;
}
--record_fields_count;
bytes_left -= 4;
}
// skip unknown fields
for (int j=0;j<record_fields_count; j++) {
AP4_UI32 discard;
if (bytes_left < 4 || AP4_FAILED(stream.ReadUI32(discard))) {
return;
}
bytes_left -= 4;
}
}
}
/*----------------------------------------------------------------------
| AP4_TrunAtom::UpdateFlags
+---------------------------------------------------------------------*/
void
AP4_TrunAtom::UpdateFlags(AP4_UI32 flags)
{
m_Flags = flags;
m_Size32 = AP4_FULL_ATOM_HEADER_SIZE + 4 + 4 * ComputeOptionalFieldsCount(flags);
}
/*----------------------------------------------------------------------
| AP4_TrunAtom::SetEntries
+---------------------------------------------------------------------*/
AP4_Result
AP4_TrunAtom::SetEntries(const AP4_Array<Entry>& entries)
{
// resize the entry array
m_Entries.SetItemCount(entries.ItemCount());
// copy entries
AP4_Cardinal entry_count = entries.ItemCount();
for (unsigned int i=0; i<entry_count; i++) {
m_Entries[i] = entries[i];
}
// update the atom size
unsigned int record_fields_count = ComputeRecordFieldsCount(m_Flags);
m_Size32 += entries.ItemCount()*record_fields_count*4;
// notify the parent
if (m_Parent) m_Parent->OnChildChanged(this);
return AP4_SUCCESS;
}
/*----------------------------------------------------------------------
| AP4_TrunAtom::WriteFields
+---------------------------------------------------------------------*/
AP4_Result
AP4_TrunAtom::WriteFields(AP4_ByteStream& stream)
{
AP4_Result result;
result = stream.WriteUI32(m_Entries.ItemCount());
if (AP4_FAILED(result)) return result;
if (m_Flags & AP4_TRUN_FLAG_DATA_OFFSET_PRESENT) {
result = stream.WriteUI32((AP4_UI32)m_DataOffset);
if (AP4_FAILED(result)) return result;
}
if (m_Flags & AP4_TRUN_FLAG_FIRST_SAMPLE_FLAGS_PRESENT) {
result = stream.WriteUI32(m_FirstSampleFlags);
if (AP4_FAILED(result)) return result;
}
AP4_UI32 sample_count = m_Entries.ItemCount();
for (unsigned int i=0; i<sample_count; i++) {
if (m_Flags & AP4_TRUN_FLAG_SAMPLE_DURATION_PRESENT) {
result = stream.WriteUI32(m_Entries[i].sample_duration);
if (AP4_FAILED(result)) return result;
}
if (m_Flags & AP4_TRUN_FLAG_SAMPLE_SIZE_PRESENT) {
result = stream.WriteUI32(m_Entries[i].sample_size);
if (AP4_FAILED(result)) return result;
}
if (m_Flags & AP4_TRUN_FLAG_SAMPLE_FLAGS_PRESENT) {
result = stream.WriteUI32(m_Entries[i].sample_flags);
if (AP4_FAILED(result)) return result;
}
if (m_Flags & AP4_TRUN_FLAG_SAMPLE_COMPOSITION_TIME_OFFSET_PRESENT) {
stream.WriteUI32(m_Entries[i].sample_composition_time_offset);
if (AP4_FAILED(result)) return result;
}
}
return AP4_SUCCESS;
}
/*----------------------------------------------------------------------
| AP4_TrunAtom::InspectFields
+---------------------------------------------------------------------*/
AP4_Result
AP4_TrunAtom::InspectFields(AP4_AtomInspector& inspector)
{
inspector.AddField("sample count", m_Entries.ItemCount());
if (m_Flags & AP4_TRUN_FLAG_DATA_OFFSET_PRESENT) {
inspector.AddField("data offset", m_DataOffset);
}
if (m_Flags & AP4_TRUN_FLAG_FIRST_SAMPLE_FLAGS_PRESENT) {
inspector.AddField("first sample flags", m_FirstSampleFlags, AP4_AtomInspector::HINT_HEX);
}
if (inspector.GetVerbosity() > 0) {
inspector.StartArray("entries");
AP4_UI32 sample_count = m_Entries.ItemCount();
for (unsigned int i = 0; i < sample_count; i++) {
inspector.StartObject(NULL, 0, true);
if (m_Flags & AP4_TRUN_FLAG_SAMPLE_DURATION_PRESENT) {
inspector.AddField(inspector.GetVerbosity() >= 2 ? "sample_duration" : "d",
m_Entries[i].sample_duration);
}
if (m_Flags & AP4_TRUN_FLAG_SAMPLE_SIZE_PRESENT) {
inspector.AddField(inspector.GetVerbosity() >= 2 ? "sample_size" : "s",
m_Entries[i].sample_size);
}
if (m_Flags & AP4_TRUN_FLAG_SAMPLE_FLAGS_PRESENT) {
inspector.AddField(inspector.GetVerbosity() >= 2 ? "sample_flags" : "f",
m_Entries[i].sample_flags);
}
if (m_Flags & AP4_TRUN_FLAG_SAMPLE_COMPOSITION_TIME_OFFSET_PRESENT) {
inspector.AddField(inspector.GetVerbosity() >= 2 ? "sample_composition_time_offset" : "c",
m_Entries[i].sample_composition_time_offset);
}
inspector.EndObject();
}
inspector.EndArray();
}
return AP4_SUCCESS;
}
|
