We now use an index of samples made of block of samples delimited by keyframes. The search is performed using a binary search. This allows to quickly find which blocks are found within the media cache.
On a 8 core mac pro, this leads to a 67% improvement on CPU time spent playing a long MP4 video (from 112s CPU to 45s CPU)
The optimisation is only possible if all mp4 data chunks are continuous (which they almost always are)
The bulk of this commit was generated with a script, executed at the top
level of a typical source code checkout. The only non-machine-generated
part was modifying MFBT's moz.build to reflect the new naming.
CLOSED TREE makes big refactorings like this a piece of cake.
# The main substitution.
find . -name '*.cpp' -o -name '*.cc' -o -name '*.h' -o -name '*.mm' -o -name '*.idl'| \
xargs perl -p -i -e '
s/nsRefPtr\.h/RefPtr\.h/g; # handle includes
s/nsRefPtr ?</RefPtr</g; # handle declarations and variables
'
# Handle a special friend declaration in gfx/layers/AtomicRefCountedWithFinalize.h.
perl -p -i -e 's/::nsRefPtr;/::RefPtr;/' gfx/layers/AtomicRefCountedWithFinalize.h
# Handle nsRefPtr.h itself, a couple places that define constructors
# from nsRefPtr, and code generators specially. We do this here, rather
# than indiscriminantly s/nsRefPtr/RefPtr/, because that would rename
# things like nsRefPtrHashtable.
perl -p -i -e 's/nsRefPtr/RefPtr/g' \
mfbt/nsRefPtr.h \
xpcom/glue/nsCOMPtr.h \
xpcom/base/OwningNonNull.h \
ipc/ipdl/ipdl/lower.py \
ipc/ipdl/ipdl/builtin.py \
dom/bindings/Codegen.py \
python/lldbutils/lldbutils/utils.py
# In our indiscriminate substitution above, we renamed
# nsRefPtrGetterAddRefs, the class behind getter_AddRefs. Fix that up.
find . -name '*.cpp' -o -name '*.h' -o -name '*.idl' | \
xargs perl -p -i -e 's/nsRefPtrGetterAddRefs/RefPtrGetterAddRefs/g'
if [ -d .git ]; then
git mv mfbt/nsRefPtr.h mfbt/RefPtr.h
else
hg mv mfbt/nsRefPtr.h mfbt/RefPtr.h
fi
--HG--
rename : mfbt/nsRefPtr.h => mfbt/RefPtr.h
The LayersBackend can be defined at construction time, however if a parent MediaDecoder exists, the value will be overwritten by the MediaDecoderOwner value.
--HG--
extra : rebase_source : fefad83560d5bfa2aee9f665fe138397eb390019
The PDMFactory will run more accurate checks based on the TrackInfo object and will fail to create a decoder if the type is unsupported. So use that instead
The PDMFactory will run more accurate checks based on the TrackInfo object and will fail to create a decoder if the type is unsupported. So use that instead
In MP4TrackDemuxer constructor, getting the track info and indices could potentially fail, triggering crashing assertions.
The fallible work is now done before calling the constructor, and if it fails a nullptr is returned, which is correctly handled in MediaFormatReader.
Also reordered some MP4TrackDemuxer members for more natural construction.
By default we only use libav 9 or FFmpeg 1.2 if found on the system.
If media.fragmented-mp4.ffmpeg.enabled is set, will allow use of libav 0.7 and ffmpeg 0.8 or later.
A MediaDataDemuxer is now not to resolve the init promise until it has all the metadata.
Except MediaSource, all demuxers would be doing blocking read to scan for the metadata, and having partial metadata would be an error.
For MediaSource, we pass the NotifyDataArrived message which will cause the MediaSourceDemuxer to re-attempt to search for the metadata.
When used within MediaSource's TrackBuffersManager, a demuxer will never be created until we have received a complete init segment (this task is performed by the various ContainerParsers)
The patch removes 455 occurrences of FAIL_ON_WARNINGS from moz.build files, and
adds 78 instances of ALLOW_COMPILER_WARNINGS. About half of those 78 are in
code we control and which should be removable with a little effort.
--HG--
extra : rebase_source : 82e3387abfbd5f1471e953961d301d3d97ed2973
A typical non-fragmented mp4 would have the ftyp atom located at the beginning of the mp4 and the moov at the end. We would to calculate the location of the metadata by spanning the byte range of the two atoms.
As such, we would typically allocate an amount of memory equivalent to the size of the mp4.
Instead we now reconstruct the metadata to only have the ftyp and moov atoms contiguously.
A typical non-fragmented mp4 would have the ftyp atom located at the beginning of the mp4 and the moov at the end. We would to calculate the location of the metadata by spanning the byte range of the two atoms.
As such, we would typically allocate an amount of memory equivalent to the size of the mp4.
Instead we now reconstruct the metadata to only have the ftyp and moov atoms contiguously.
Jean-Yves Avenard
Nathan Froyd
sajitk
Wes Kocher
JW Wang
Chris Pearce
John Lin
Nigel Babu
Carsten "Tomcat" Book
Gerald Squelart
Nicholas Nethercote
Roman Reiss