mirror of https://git.ffmpeg.org/ffmpeg.git
Add release notes for 12.
This commit is contained in:
Anton Khirnov
parent
d68fb14758
commit
65dc7ca4c8
|
|
@ -1,48 +1,31 @@
|
|||
Release Notes
|
||||
=============
|
||||
|
||||
* 11 "One Louder"
|
||||
* 12 "Not Enough Trocadero"
|
||||
|
||||
General notes
|
||||
-------------
|
||||
|
||||
With this release we are trying to answer the numerous calls from our users for
|
||||
shorter development cycles. From now on we will aim for approximately two major
|
||||
releases per year.
|
||||
This release once again bumps the major versions of all the libraries, removing
|
||||
some long-deprecated APIs. This means that it is neither API nor ABI-compatible
|
||||
with the previous release. The users who still did not update their code are
|
||||
advised to look at the next section of these release notes, the doc/APIchanges
|
||||
file and the API migration guide on our wiki. If those are not sufficient, do
|
||||
not hesitate to contact us on IRC or through the user mailing list.
|
||||
|
||||
Libav 11 is API-, but not ABI-compatible with the previous major release. This
|
||||
means that the code using our libraries needs to be rebuilt, but no source
|
||||
changes should be required. Note however, that a number of old APIs remain
|
||||
deprecated and will be dropped in the near future. All users are strongly
|
||||
encouraged to update their code as soon as possible. The doc/APIchanges file in
|
||||
the Libav source tree and the migration guide on the wiki should help with
|
||||
migration to the new APIs. If those are not sufficient, do not hesitate to
|
||||
contact us on IRC or through the user mailing list.
|
||||
Among the main highlights of this release are several additions related to
|
||||
hardware acceleration. There is a new API for managing hardware devices and
|
||||
frame pools, which allows to add new features such as zero-copy
|
||||
hardware-accelerated filtering with libavfilter and should reduce the
|
||||
boilerplate code required for existing hardware-accelerated decoders. We have
|
||||
added QuickSync decoding and encoding, NVENC encoding and CUDA image scaling,
|
||||
VAAPI encoding and image scaling, OpenMAX encoding, MMAL decoding and Direct3D11
|
||||
decoding.
|
||||
|
||||
One specific API issue in libavformat deserves mentioning here. When using
|
||||
libavcodec for decoding or encoding and libavformat for demuxing or muxing,
|
||||
the standard practice was to use the stream codec context (AVStream.codec) for
|
||||
actual decoding or encoding. There are multiple problems with this pattern
|
||||
(the main one is that the decoder/demuxer or encoder/muxer are not necessarily
|
||||
synchronized and may overwrite each other's state), so it is now strongly
|
||||
discouraged and will likely be deprecated in the future. Users should instead
|
||||
allocate a separate decoding or encoding context and populate it from the
|
||||
demuxing codec context (or the reverse for encoding) with the
|
||||
avcodec_copy_context() function.
|
||||
|
||||
The main highlights of this release include native Opus, VP7, OpenEXR, and On2
|
||||
AVC decoders, HEVC encoding through libx265, new APIs for exporting ReplayGain
|
||||
and display transformation metadata and countless bug fixes. A large effort was
|
||||
also expended on internal cleanups which are not very visible to our users,
|
||||
but should make the codebase cleaner, safer and easier to maintain and extend.
|
||||
One point worth mentioning is refactoring the large monolithic framework for
|
||||
architecture-specific codec optimizations into small blocks, which reduces the
|
||||
size of configurations that selectively enable or disable certain codecs.
|
||||
|
||||
The avserver streaming tool, which has not been maintained for many years and
|
||||
was mostly broken, was removed from the tree. It was decided that it is a
|
||||
significant maintenance burden and that we do our users no service by pretending
|
||||
to support it, while we in fact do not.
|
||||
Other significant additions not related to hardware acceleration include
|
||||
decoders for Canopus HQ/HQA and HQX, Go2Meeting, AAC ELD, TDSC, Hap, DXV, SPV1,
|
||||
and a new ASF demuxer written according to the specification. There were also
|
||||
countless smaller changes and bug fixes.
|
||||
|
||||
See the Changelog file for a more extensive list of significant changes.
|
||||
|
||||
|
|
@ -54,22 +37,38 @@ have been deprecated and are scheduled for removal in the next release.
|
|||
Significant API changes include:
|
||||
|
||||
[libavcodec]
|
||||
+ Added the avcodec_copy_context() function that must from now on be used for
|
||||
freeing codec contexts.
|
||||
+- Added a new VDA hardware acceleration API, since the old one was broken and
|
||||
not fixable in a compatible way. Deprecated the old VDA API.
|
||||
+ Added an object for storing codec parameters (AVCodecParameters) and its
|
||||
related API. It will now replace AVCodecContext everywhere except the actual
|
||||
encoders/decoders.
|
||||
+- Added a new API for handling refcounted AVPackets, mirroring the AVFrame API.
|
||||
Deprecated certain old ill-defined AVPacket functions.
|
||||
+- Added a new API for audio/video encoding and decoding, with decoupled input
|
||||
and output. This will e.g. allow a decoder to produce multiple output frames
|
||||
for a single input packet, which was not possible with the previous API. All
|
||||
users are strongly encouraged to switch to this new API as soon as possible,
|
||||
since certain decoders and encoders might start requiring the new API to be
|
||||
used.
|
||||
+- Added a new API for bitstream filtering, which works with refcounted
|
||||
AVPackets and is more clearly defined and documented. The old bitstream
|
||||
filtering API is now deprecated.
|
||||
|
||||
[libavformat]
|
||||
+ Added support for exporting stream-global (as opposed to per-packet) side
|
||||
data. This feature is now used by some demuxers to export ReplayGain or
|
||||
display transformation matrix (aka rotation) or stereoscopic 3D mode.
|
||||
+ Added an API for live metadata updates through event flags.
|
||||
+- Changed the way to provide a hint about the desired timebase to muxers.
|
||||
Previously it was done by setting AVStream.codec.time_base. Now callers
|
||||
should set AVStream.time_base.
|
||||
+ Added new IO callbacks to AVFormatContext, allowing the caller to provide
|
||||
custom IO for certain special muxers and demuxers.
|
||||
+- Replaced AVStream.codec (AVCodecContext) with AVStream.codecpar
|
||||
(AVCodecParameters) as the means of signalling codec parameters between the
|
||||
muxers/demuxers and the caller.
|
||||
|
||||
[libavresample]
|
||||
+ Added an API for working with AVFrames.
|
||||
[libavutil]
|
||||
+ Added a new API (hwcontext.h) for handling hardware acceleration devices and
|
||||
hardware frame pools.
|
||||
|
||||
[libavfilter]
|
||||
+ Added a new struct, AVBufferSrcParameters, for passing the stream parameters
|
||||
to the buffer source. It is now the recommended way of configuring the buffer
|
||||
source.
|
||||
+ Added AVFilterContext.hw_device_ctx and AVFilterLink.hw_frames_ctx that allow
|
||||
hardware frames to be used in filter graphs.
|
||||
|
||||
Please see the file doc/APIchanges for details along with similar
|
||||
programmer-centric information.
|
||||
|
|
|
|||
Loading…
Reference in New Issue