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|
/*****************************************************************
|
| AP4 - MP4 Compacter
|
| Copyright 2002-2011 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 <stdio.h>
#include <stdlib.h>
#include "Ap4.h"
/*----------------------------------------------------------------------
| constants
+---------------------------------------------------------------------*/
#define BANNER "MP4 Compacter - Version 1.0\n"\
"(Bento4 Version " AP4_VERSION_STRING ")\n"\
"(c) 2002-2011 Axiomatic Systems, LLC"
/*----------------------------------------------------------------------
| PrintUsageAndExit
+---------------------------------------------------------------------*/
static void
PrintUsageAndExit()
{
fprintf(stderr,
BANNER
"\n\n"
"usage: mp4compact [options] <input> <output>\n"
"Options:\n"
" --verbose\n"
);
exit(1);
}
/*----------------------------------------------------------------------
| AP4_CompactingProcessor
+---------------------------------------------------------------------*/
class AP4_CompactingProcessor : public AP4_Processor
{
public:
// inner classes
class TrackHandler : public AP4_Processor::TrackHandler
{
public:
TrackHandler(AP4_CompactingProcessor& outer, AP4_TrakAtom* trak_atom) :
m_Outer(outer),
m_TrakAtom(trak_atom),
m_StszAtom(NULL) {}
~TrackHandler();
virtual AP4_Result ProcessTrack();
virtual AP4_Result ProcessSample(AP4_DataBuffer& data_in,
AP4_DataBuffer& data_out) {
return data_out.SetData(data_in.GetData(), data_in.GetDataSize());
}
private:
AP4_CompactingProcessor& m_Outer;
AP4_TrakAtom* m_TrakAtom;
AP4_StszAtom* m_StszAtom;
};
// methods
AP4_CompactingProcessor(bool verbose) : m_Verbose(verbose), m_SizeReduction(0) {}
~AP4_CompactingProcessor();
virtual TrackHandler* CreateTrackHandler(AP4_TrakAtom* trak_atom) {
return new TrackHandler(*this, trak_atom);
}
// members
bool m_Verbose;
AP4_UI32 m_SizeReduction;
};
/*----------------------------------------------------------------------
| AP4_CompactingProcessor::~AP4_CompactingProcessor
+---------------------------------------------------------------------*/
AP4_CompactingProcessor::~AP4_CompactingProcessor()
{
if (m_Verbose) {
printf("Total stz2 reduction = %d bytes\n", m_SizeReduction);
}
}
/*----------------------------------------------------------------------
| AP4_CompactingProcessor::TrackHandler::~TrackHandler()
+---------------------------------------------------------------------*/
AP4_CompactingProcessor::TrackHandler::~TrackHandler()
{
delete m_StszAtom;
}
/*----------------------------------------------------------------------
| AP4_CompactingProcessor::TrackHandler::ProcessTrack
+---------------------------------------------------------------------*/
AP4_Result
AP4_CompactingProcessor::TrackHandler::ProcessTrack()
{
// find the stsz atom
AP4_ContainerAtom* stbl = AP4_DYNAMIC_CAST(AP4_ContainerAtom, m_TrakAtom->FindChild("mdia/minf/stbl"));
if (stbl == NULL) return AP4_SUCCESS;
AP4_StszAtom* stsz = AP4_DYNAMIC_CAST(AP4_StszAtom, stbl->GetChild(AP4_ATOM_TYPE_STSZ));
if (stsz == NULL) return AP4_SUCCESS;
// check if we can reduce the size of stsz by changing it to stz2
AP4_UI32 max_size = 0;
for (unsigned int i=1; i<=stsz->GetSampleCount(); i++) {
AP4_Size sample_size;
stsz->GetSampleSize(i, sample_size);
if (sample_size > max_size) {
max_size = sample_size;
}
}
AP4_UI08 field_size = 0;
if (max_size <= 0xFF) {
field_size = 1;
} else if (max_size <= 0xFFFF) {
field_size = 2;
}
if (m_Outer.m_Verbose) printf("Track %d: ", m_TrakAtom->GetId());
if (field_size == 0) {
if (m_Outer.m_Verbose) {
printf("no stz2 reduction possible\n");
}
return AP4_SUCCESS;
} else {
if (m_Outer.m_Verbose) {
unsigned int reduction = (4-field_size)*stsz->GetSampleCount();
printf("stz2 reduction = %d bytes\n", reduction);
m_Outer.m_SizeReduction += reduction;
}
}
// detach the original stsz atom so we can destroy it later
m_StszAtom = stsz;
stsz->Detach();
// create an stz2 atom and populate its entries
AP4_Stz2Atom* stz2 = new AP4_Stz2Atom(field_size);
for (unsigned int i=1; i<=m_StszAtom->GetSampleCount(); i++) {
AP4_Size sample_size;
m_StszAtom->GetSampleSize(i, sample_size);
stz2->AddEntry(sample_size);
}
stbl->AddChild(stz2);
return AP4_SUCCESS;
}
/*----------------------------------------------------------------------
| main
+---------------------------------------------------------------------*/
int
main(int argc, char** argv)
{
if (argc == 1) PrintUsageAndExit();
// parse options
const char* input_filename = NULL;
const char* output_filename = NULL;
bool verbose = false;
AP4_Result result;
// parse the command line arguments
char* arg;
while ((arg = *++argv)) {
if (!AP4_CompareStrings(arg, "--verbose")) {
verbose = true;
} else if (input_filename == NULL) {
input_filename = arg;
} else if (output_filename == NULL) {
output_filename = arg;
} else {
fprintf(stderr, "ERROR: unexpected argument (%s)\n", arg);
return 1;
}
}
// create the input stream
AP4_ByteStream* input = NULL;
result = AP4_FileByteStream::Create(input_filename, AP4_FileByteStream::STREAM_MODE_READ, input);
if (AP4_FAILED(result)) {
fprintf(stderr, "ERROR: cannot open input file (%s)\n", input_filename);
return 1;
}
// create the output stream
AP4_ByteStream* output = NULL;
result = AP4_FileByteStream::Create(output_filename, AP4_FileByteStream::STREAM_MODE_WRITE, output);
if (AP4_FAILED(result)) {
fprintf(stderr, "ERROR: cannot open output file (%s)\n", output_filename);
return 1;
}
// process the file
AP4_CompactingProcessor* processor = new AP4_CompactingProcessor(verbose);
result = processor->Process(*input, *output, NULL);
if (AP4_FAILED(result)) {
fprintf(stderr, "ERROR: failed to process the file (%d)\n", result);
}
// cleanup
delete processor;
input->Release();
output->Release();
return 0;
}
|
