Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Add AC3 Atom support to MP4Info and MP4Dump #122

Open
wants to merge 5 commits into
base: master
Choose a base branch
from
Open
Show file tree
Hide file tree
Changes from all commits
Commits
File filter

Filter by extension

Filter by extension

Conversations
Failed to load comments.
Jump to
Jump to file
Failed to load files.
Diff view
Diff view
37 changes: 37 additions & 0 deletions Source/C++/Apps/Mp4Info/Mp4Info.cpp
Expand Up @@ -422,6 +422,23 @@ ShowSampleDescription_Text(AP4_SampleDescription& description, bool verbose)
}

// Dolby Digital specifics
if (desc->GetFormat() == AP4_SAMPLE_FORMAT_AC_3) {
AP4_Dac3Atom* dac3 = AP4_DYNAMIC_CAST(AP4_Dac3Atom, desc->GetDetails().GetChild(AP4_ATOM_TYPE('d', 'a', 'c', '3')));
if (dac3) {
printf(" AC3 stream:\n");
printf(" fscod = %d\n", dac3->GetFscod());
printf(" bsid = %d\n", dac3->GetBsid());
printf(" bsmod = %d\n", dac3->GetBsmod());
printf(" acmod = %d\n", dac3->GetAcmod());
printf(" lfeon = %d\n", dac3->GetLfeon());
printf(" bit_rate_code = %d\n", dac3->GetBitRateCode());
printf(" AC3 dac3 payload: [");
ShowData(dac3->GetRawBytes());
printf("]\n");
}
}

// Enhanced Dolby Digital specifics
if (desc->GetFormat() == AP4_SAMPLE_FORMAT_EC_3) {
AP4_Dec3Atom* dec3 = AP4_DYNAMIC_CAST(AP4_Dec3Atom, desc->GetDetails().GetChild(AP4_ATOM_TYPE('d', 'e', 'c', '3')));
if (dec3) {
Expand Down Expand Up @@ -619,6 +636,26 @@ ShowSampleDescription_Json(AP4_SampleDescription& description, bool verbose)
}

// Dolby Digital specifics
if (desc->GetFormat() == AP4_SAMPLE_FORMAT_AC_3) {
AP4_Dac3Atom* dac3 = AP4_DYNAMIC_CAST(AP4_Dac3Atom, desc->GetDetails().GetChild(AP4_ATOM_TYPE('d', 'a', 'c', '3')));
if (dac3) {
printf(",\n");
printf("\"dolby_digital_info\": {\n");
printf(" \"fscod\": %d,\n", dac3->GetFscod());
printf(" \"bsid\": %d,\n", dac3->GetBsid());
printf(" \"bsmod\": %d,\n", dac3->GetBsmod());
printf(" \"acmod\": %d,\n", dac3->GetAcmod());
printf(" \"lfeon\": %d,\n", dac3->GetLfeon());
printf(" \"bit_rate_code\": %d,\n", dac3->GetBitRateCode());
printf(" \"dec3_payload\": \"");
ShowData(dac3->GetRawBytes());
printf("\"}");
}
}



// Enhanced Dolby Digital specifics
if (desc->GetFormat() == AP4_SAMPLE_FORMAT_EC_3) {
AP4_Dec3Atom* dec3 = AP4_DYNAMIC_CAST(AP4_Dec3Atom, desc->GetDetails().GetChild(AP4_ATOM_TYPE('d', 'e', 'c', '3')));
if (dec3) {
Expand Down
1 change: 1 addition & 0 deletions Source/C++/Core/Ap4.h
Expand Up @@ -310,6 +310,7 @@
#include "Ap4TfraAtom.h"
#include "Ap4SbgpAtom.h"
#include "Ap4MfroAtom.h"
#include "Ap4Dac3Atom.h"
#include "Ap4Dec3Atom.h"
#include "Ap4SidxAtom.h"
#include "Ap4AdtsParser.h"
Expand Down
1 change: 1 addition & 0 deletions Source/C++/Core/Ap4Atom.h
Expand Up @@ -489,6 +489,7 @@ const AP4_Atom::Type AP4_ATOM_TYPE_UUID = AP4_ATOM_TYPE('u','u','i','d');
const AP4_Atom::Type AP4_ATOM_TYPE_8ID_ = AP4_ATOM_TYPE('8','i','d',' ');
const AP4_Atom::Type AP4_ATOM_TYPE_8BDL = AP4_ATOM_TYPE('8','b','d','l');
const AP4_Atom::Type AP4_ATOM_TYPE_AC_3 = AP4_ATOM_TYPE('a','c','-','3');
const AP4_Atom::Type AP4_ATOM_TYPE_DAC3 = AP4_ATOM_TYPE('d','a','c','3');
const AP4_Atom::Type AP4_ATOM_TYPE_EC_3 = AP4_ATOM_TYPE('e','c','-','3');
const AP4_Atom::Type AP4_ATOM_TYPE_DTSC = AP4_ATOM_TYPE('d','t','s','c');
const AP4_Atom::Type AP4_ATOM_TYPE_DTSH = AP4_ATOM_TYPE('d','t','s','h');
Expand Down
8 changes: 8 additions & 0 deletions Source/C++/Core/Ap4AtomFactory.cpp
Expand Up @@ -101,6 +101,7 @@
#include "Ap4AinfAtom.h"
#include "Ap4PsshAtom.h"
#include "Ap4Dec3Atom.h"
#include "Ap4Dac3Atom.h"
#include "Ap4SidxAtom.h"
#include "Ap4SbgpAtom.h"
#include "Ap4SgpdAtom.h"
Expand Down Expand Up @@ -711,6 +712,13 @@ AP4_AtomFactory::CreateAtomFromStream(AP4_ByteStream& stream,
atom = AP4_Dec3Atom::Create(size_32, stream);
}
break;
case AP4_ATOM_TYPE_DAC3:
if (atom_is_large) return AP4_ERROR_INVALID_FORMAT;
if (GetContext() == AP4_ATOM_TYPE_AC_3) {

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

If you want to support encrypted audio tracks, you could do so by changing this line to the following:
if (GetContext() == AP4_ATOM_TYPE_AC_3 || GetContext() == AP4_ATOM_TYPE_ENCA) {

atom = AP4_Dac3Atom::Create(size_32, stream);
}
break;


// track ref types
case AP4_ATOM_TYPE_HINT:
Expand Down
113 changes: 113 additions & 0 deletions Source/C++/Core/Ap4Dac3Atom.cpp
@@ -0,0 +1,113 @@
/*****************************************************************
|
| AP4 - dac3 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 "Ap4Dac3Atom.h"
#include "Ap4AtomFactory.h"
#include "Ap4Utils.h"
#include "Ap4Types.h"

/*----------------------------------------------------------------------
| dynamic cast support
+---------------------------------------------------------------------*/
AP4_DEFINE_DYNAMIC_CAST_ANCHOR(AP4_Dac3Atom)

/*----------------------------------------------------------------------
| AP4_Dac3Atom::Create
+---------------------------------------------------------------------*/
AP4_Dac3Atom*
AP4_Dac3Atom::Create(AP4_Size size, AP4_ByteStream& stream)
{
// read the raw bytes in a buffer
unsigned int payload_size = size-AP4_ATOM_HEADER_SIZE;
AP4_DataBuffer payload_data(payload_size);
AP4_Result result = stream.Read(payload_data.UseData(), payload_size);
if (AP4_FAILED(result)) return NULL;

// check the version
const AP4_UI08* payload = payload_data.GetData();
return new AP4_Dac3Atom(size, payload);
}

/*----------------------------------------------------------------------
| AP4_Dac3Atom::AP4_Dac3Atom
+---------------------------------------------------------------------*/
AP4_Dac3Atom::AP4_Dac3Atom(AP4_UI32 size, const AP4_UI08* payload) :
AP4_Atom(AP4_ATOM_TYPE_DAC3, size),
m_Fscod(0),
m_Bsid(0),
m_Bsmod(0),
m_Acmod(0),
m_Lfeon(0),
m_BitRateCode(0),
m_Reserved(0)
{
// make a copy of our configuration bytes
unsigned int payload_size = size-AP4_ATOM_HEADER_SIZE;
m_RawBytes.SetData(payload, payload_size);

// sanity check
if (payload_size < 2) return;

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Wouldn't we want a payload of at least 3 bytes (as we read payload[2] line 86) ?

Copy link
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

You're right, this should be < 3


// parse the payload
m_Fscod = (payload[0]>>6) & 0x3;
m_Bsid = (payload[0]>>1) & 0x1F;
m_Bsmod = (payload[0]<<2 | payload[1]>>6) & 0x3;

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

payload[0] << 2 is meaningless as the line ends with & 0x3. Perhaps we want & 0x7 ?

Copy link
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Good catch. This should be masked with 0x7, not 0x3, as the field is 3 bits wide. Thanks for spotting that.

m_Acmod = (payload[1]>>3) & 0x7;
m_Lfeon = (payload[1]>>2) & 0x1;
m_BitRateCode = (payload[1]<<3 | payload[2]>>5) & 0x1F;
m_Reserved = payload[2] & 0x1F;

}

/*----------------------------------------------------------------------
| AP4_Dac3Atom::WriteFields
+---------------------------------------------------------------------*/
AP4_Result
AP4_Dac3Atom::WriteFields(AP4_ByteStream& stream)
{
return stream.Write(m_RawBytes.GetData(), m_RawBytes.GetDataSize());
}

/*----------------------------------------------------------------------
| AP4_Dac3Atom::InspectFields
+---------------------------------------------------------------------*/
AP4_Result
AP4_Dac3Atom::InspectFields(AP4_AtomInspector& inspector)
{
inspector.AddField("fscod", m_Fscod);
inspector.AddField("bsid", m_Bsid);
inspector.AddField("bsmod", m_Bsmod);
inspector.AddField("acmod", m_Acmod);
inspector.AddField("lfeon", m_Lfeon);
inspector.AddField("bit_rate_code", m_BitRateCode);

return AP4_SUCCESS;
}
83 changes: 83 additions & 0 deletions Source/C++/Core/Ap4Dac3Atom.h
@@ -0,0 +1,83 @@
/*****************************************************************
|
| AP4 - dac3 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.
|
****************************************************************/

#ifndef _AP4_DAC3_ATOM_H_
#define _AP4_DAC3_ATOM_H_

/*----------------------------------------------------------------------
| includes
+---------------------------------------------------------------------*/
#include "Ap4Atom.h"
#include "Ap4Array.h"

/*----------------------------------------------------------------------
| constants
+---------------------------------------------------------------------*/

/*----------------------------------------------------------------------
| AP4_Dac3Atom
+---------------------------------------------------------------------*/
class AP4_Dac3Atom : public AP4_Atom
{
public:
AP4_IMPLEMENT_DYNAMIC_CAST_D(AP4_Dac3Atom, AP4_Atom)

// class methods
static AP4_Dac3Atom* Create(AP4_Size size, AP4_ByteStream& stream);

// methods
virtual AP4_Result InspectFields(AP4_AtomInspector& inspector);
virtual AP4_Result WriteFields(AP4_ByteStream& stream);
virtual AP4_Atom* Clone() { return new AP4_Dac3Atom(m_Size32, m_RawBytes.GetData()); }

// accessors
const AP4_DataBuffer& GetRawBytes() const { return m_RawBytes; }
unsigned int GetFscod() const { return m_Fscod; }
unsigned int GetBsid() const { return m_Bsid; }
unsigned int GetBsmod() const { return m_Bsmod; }
unsigned int GetAcmod() const { return m_Acmod; }
unsigned int GetLfeon() const { return m_Lfeon; }
unsigned int GetBitRateCode() const { return m_BitRateCode; }
unsigned int GetReserved() const { return m_Reserved; }

private:
// methods
AP4_Dac3Atom(AP4_UI32 size, const AP4_UI08* payload);

// members
unsigned int m_Fscod;
unsigned int m_Bsid;
unsigned int m_Bsmod;
unsigned int m_Acmod;
unsigned int m_Lfeon;
unsigned int m_BitRateCode;
unsigned int m_Reserved;
AP4_DataBuffer m_RawBytes;
};

#endif // _AP4_DAC3_ATOM_H_
4 changes: 2 additions & 2 deletions Source/Python/utils/mp4utils.py
Expand Up @@ -843,11 +843,11 @@ def GetDolbyDigitalChannels(track):
sample_desc = track.info['sample_descriptions'][0]
if 'dolby_digital_info' not in sample_desc:
return (track.channels, [])
dd_info = sample_desc['dolby_digital_info']['substreams'][0]
dd_info = sample_desc['dolby_digital_info']['substreams'][0] if sample_desc['coding'] == 'ec-3' else sample_desc['dolby_digital_info']
channels = DolbyDigital_acmod[dd_info['acmod']][:]
if dd_info['lfeon'] == 1:
channels.append('LFE')
if dd_info['num_dep_sub'] and 'chan_loc' in dd_info:
if 'num_dep_sub' in dd_info and dd_info['num_dep_sub'] and 'chan_loc' in dd_info:
chan_loc_value = dd_info['chan_loc']
for i in range(9):
if chan_loc_value & (1<<i):
Expand Down