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mp4dump: enable dumping of tracks from MP4 fragments #700

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mp4dump: enable dumping of tracks from MP4 fragments #700

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51 changes: 33 additions & 18 deletions Source/C++/Apps/Mp4Dump/Mp4Dump.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -100,14 +100,14 @@ CreateTrackDumpByteStream(const char* mp4_filename,
| DumpSamples
+---------------------------------------------------------------------*/
static void
DumpSamples(AP4_Track* track, AP4_ByteStream* dump)
DumpSamples(AP4_Ordinal track_id, AP4_LinearReader* reader, AP4_ByteStream* dump)
{
// write the data
AP4_Sample sample;
AP4_DataBuffer sample_data;
AP4_Ordinal index = 0;

while (AP4_SUCCEEDED(track->ReadSample(index, sample, sample_data))) {
while (AP4_SUCCEEDED(reader->ReadNextSample(track_id, sample, sample_data))) {
// write the sample size
dump->WriteUI32(sample_data.GetDataSize());

Expand All @@ -125,7 +125,8 @@ DumpSamples(AP4_Track* track, AP4_ByteStream* dump)
| DecryptAndDumpSamples
+---------------------------------------------------------------------*/
static void
DecryptAndDumpSamples(AP4_Track* track,
DecryptAndDumpSamples(AP4_Ordinal track_id,
AP4_LinearReader* reader,
AP4_SampleDescription* sample_desc,
const AP4_UI08* key,
AP4_Size key_size,
Expand All @@ -149,7 +150,7 @@ DecryptAndDumpSamples(AP4_Track* track,
AP4_DataBuffer encrypted_data;
AP4_DataBuffer decrypted_data;
AP4_Ordinal index = 0;
while (AP4_SUCCEEDED(track->ReadSample(index, sample, encrypted_data))) {
while (AP4_SUCCEEDED(reader->ReadNextSample(track_id, sample, encrypted_data))) {
if (AP4_FAILED(decrypter->DecryptSampleData(encrypted_data, decrypted_data))) {
fprintf(stderr, "ERROR: failed to decrypt sample\n");
return;
Expand All @@ -171,19 +172,37 @@ DecryptAndDumpSamples(AP4_Track* track,
+---------------------------------------------------------------------*/
void
DumpTrackData(const char* mp4_filename,
AP4_File& mp4_file,
AP4_ByteStream* mp4_stream,
const AP4_Array<AP4_Ordinal>& tracks_to_dump,
const AP4_ProtectionKeyMap& key_map)
{
AP4_Position original_pos;
mp4_stream->Tell(original_pos);

mp4_stream->Seek(0);
AP4_File mp4_file(*mp4_stream);

mp4_stream->Seek(0);
AP4_LinearReader reader(*mp4_file.GetMovie(), mp4_stream);

// dump all the tracks that need to be dumped
AP4_Cardinal tracks_to_dump_count = tracks_to_dump.ItemCount();
for (AP4_Ordinal i=0; i<tracks_to_dump_count; i++) {
AP4_Ordinal track_id = tracks_to_dump[i];

if (reader.EnableTrack(track_id) != AP4_SUCCESS) {
fprintf(stderr, "track not found (id = %d)", track_id);
break;
}
}

for (AP4_Ordinal i=0; i<tracks_to_dump_count; i++) {
// get the track
AP4_Ordinal track_id = tracks_to_dump[i];
AP4_Track* track = mp4_file.GetMovie()->GetTrack(track_id);
if (track == NULL) {
fprintf(stderr, "track not found (id = %d)", track_id);
return;
break;
}

// get the sample description
Expand All @@ -194,7 +213,7 @@ DumpTrackData(const char* mp4_filename,

// get the dump data byte stream
AP4_ByteStream* dump = CreateTrackDumpByteStream(mp4_filename, track_id);
if (dump == NULL) return;
if (dump == NULL) break;

printf("\nDumping data for track %d:\n", track_id);
switch(sample_description ?
Expand All @@ -204,22 +223,23 @@ DumpTrackData(const char* mp4_filename,
{
const AP4_DataBuffer* key = key_map.GetKey(track_id);
if (key == NULL) {
fprintf(stderr,
fprintf(stderr,
"WARNING: No key found for encrypted track %d... "
"dumping encrypted samples\n",
track_id);
DumpSamples(track, dump);
DumpSamples(track_id, &reader, dump);
} else {
DecryptAndDumpSamples(track, sample_description, key->GetData(), key->GetDataSize(), dump);
DecryptAndDumpSamples(track_id, &reader, sample_description, key->GetData(), key->GetDataSize(), dump);
}
}
break;
default:
DumpSamples(track, dump);
DumpSamples(track_id, &reader, dump);

}
dump->Release();
}
mp4_stream->Seek(original_pos);
}

/*----------------------------------------------------------------------
Expand Down Expand Up @@ -359,12 +379,7 @@ main(int argc, char** argv)

// inspect the track data if needed
if (tracks_to_dump.ItemCount() != 0) {
// rewind
input->Seek(0);

// dump the track data
AP4_File file(*input);
DumpTrackData(filename, file, tracks_to_dump, key_map);
DumpTrackData(filename, input, tracks_to_dump, key_map);
}

if (input) input->Release();
Expand Down