APIchanges

Never assume the API of libav* to be stable unless at least 1 month has passed
since the last major version increase.

The last version increases were:
libavcodec:    2013-03-xx
libavdevice:   2013-03-xx
libavfilter:   2013-12-xx
libavformat:   2013-03-xx
libavresample: 2012-10-05
libswscale:    2011-06-20
libavutil:     2013-12-xx


API changes, most recent first:

2014-xx-xx - xxxxxxx - lavu 53.04.0  - opt.h
  Add AV_OPT_FLAG_EXPORT and AV_OPT_FLAG_READONLY to mark options meant (only)
  for reading.

2014-xx-xx - xxxxxxx - lavu 53.03.01 - opt.h
  Deprecate unused AV_OPT_FLAG_METADATA.

2014-02-xx - xxxxxxx - lavu 53.3.0 - frame.h
  Add AV_FRAME_DATA_DOWNMIX_INFO value to the AVFrameSideDataType enum and
  downmix_info.h API, which identify downmix-related metadata.

2014-02-04 - d9ae103 - lavf 55.11.0 - avformat.h
  Add AVFormatContext.max_interleave_delta for controlling amount of buffering
  when interleaving.

2014-01-20 - 93c553c - lavc 55.32.1 - avcodec.h
  Edges are not required anymore on video buffers allocated by get_buffer2()
  (i.e. as if the CODEC_FLAG_EMU_EDGE flag was always on). Deprecate
  CODEC_FLAG_EMU_EDGE and avcodec_get_edge_width().

2014-01-05 - 5b4797a - lavu 53.2.0 - frame.h
  Add AV_FRAME_DATA_MATRIXENCODING value to the AVFrameSideDataType enum, which
  identifies AVMatrixEncoding data.

2014-01-05 - 5c437fb - lavu 53.1.0 - channel_layout.h
  Add values for various Dolby flags to the AVMatrixEncoding enum.

2013-12-20 - 2a41826 - lavc 55.30.0 - avcodec.h
  Add HEVC profiles

2013-12-11 - b9fb59d,9431356,d7b3ee9 - lavc 55.28.1 - avcodec.h
  av_frame_alloc(), av_frame_unref() and av_frame_free() now can and should be
  used instead of avcodec_alloc_frame(), avcodec_get_frame_defaults() and
  avcodec_free_frame() respectively. The latter three functions are deprecated.

2013-12-09 - 7e244c6- - lavu 52.20.0 - frame.h
  Add AV_FRAME_DATA_STEREO3D value to the AVFrameSideDataType enum and
  stereo3d.h API, that identify codec-independent stereo3d information.

2013-11-26 - 1eaac1d- - lavu 52.19.0 - frame.h
  Add AV_FRAME_DATA_A53_CC value to the AVFrameSideDataType enum, which
  identifies ATSC A53 Part 4 Closed Captions data.

2013-11-14 - cce3e0a - lavu 52.18.0 - mem.h
  Move av_fast_malloc() and av_fast_realloc() for libavcodec to libavutil.

2013-11-14 - 8941971 - lavc 55.27.0 - avcodec.h
  Deprecate AVCodecContext.error_rate, it is replaced by the 'error_rate'
  private option of the mpegvideo encoder family.

2013-11-14 - 728c465 - lavc 55.26.0 - vdpau.h
  Add av_vdpau_get_profile().
  Add av_vdpau_alloc_context(). This function must from now on be
  used for allocating AVVDPAUContext.

2013-11-04 - cd8f772 - lavc 55.25.0 - avcodec.h
  Add ITU-R BT.2020 and other not yet included values to color primaries,
  transfer characteristics and colorspaces.

2013-10-31 - 28096e0 - lavu 52.17.0 - avframe.h
  Add AVFrame.flags and AV_FRAME_FLAG_CORRUPT.

2013-09-28 - 0767bfd - lavfi 3.11.0 - avfilter.h
  Add AVFilterGraph.execute and AVFilterGraph.opaque for custom slice threading
  implementations.

2013-09-21 - e208e6d - lavu 52.16.0 - pixfmt.h
  Add interleaved 4:2:2 8/10-bit formats AV_PIX_FMT_NV16 and
  AV_PIX_FMT_NV20.

2013-09-16 - 3feb3d6 - lavu 52.15.0 - mem.h
  Add av_reallocp.

2013-08-10 - 5a9a9d4 - lavc 55.16.0 - avcodec.h
  Extend AVPacket API with av_packet_unref, av_packet_ref,
  av_packet_move_ref, av_packet_copy_props, av_packet_free_side_data.

2013-08-05 - f824535 - lavc 55.13.0 - avcodec.h
  Deprecate the bitstream-related members from struct AVVDPAUContext.
  The bistream buffers no longer need to be explicitly freed.

2013-08-05 - 549294f - lavc 55.12.0 - avcodec.h
  Deprecate the CODEC_CAP_HWACCEL_VDPAU codec capability. Use CODEC_CAP_HWACCEL
  and select the AV_PIX_FMT_VDPAU format with get_format() instead.

2013-08-05 - a0ad5d0 - lavu 52.14.0 - pixfmt.h
  Deprecate AV_PIX_FMT_VDPAU_*. Use AV_PIX_FMT_VDPAU instead.

2013-08-02 - a8b1927 - lavc 55.11.0 - avcodec.h
  Add output_picture_number to AVCodecParserContext.

2013-06-24 - 95d5246 - lavc 55.10.0 - avcodec.h
  Add MPEG-2 AAC profiles

2013-06-04 - fc962d4 - lavu 52.13.0 - mem.h
  Add av_realloc_array and av_reallocp_array

2013-05-24 - 129bb23 - lavfi 3.10.0 - avfilter.h
  Add support for slice multithreading to lavfi. Filters supporting threading
  are marked with AVFILTER_FLAG_SLICE_THREADS.
  New fields AVFilterContext.thread_type, AVFilterGraph.thread_type and
  AVFilterGraph.nb_threads (accessible directly or through AVOptions) may be
  used to configure multithreading.

2013-05-24 - 2a6eaea - lavu 52.12.0 - cpu.h
  Add av_cpu_count() function for getting the number of logical CPUs.

2013-05-24 - b493847 - lavc 55.7.0 - avcodec.h
  Add picture_structure to AVCodecParserContext.

2013-05-15 - e6c4ac7 - lavu 52.11.0 - pixdesc.h
  Replace PIX_FMT_* flags with AV_PIX_FMT_FLAG_*.

2013-04-03 - 507b1e4 - lavc 55.4.0 - avcodec.h
  Add field_order to AVCodecParserContext.

2013-04-19 - 5e83d9a - lavc 55.2.0 - avcodec.h
  Add CODEC_FLAG_UNALIGNED to allow decoders to produce unaligned output.

2013-04-11 - lavfi 3.8.0
  38f0c07 - Move all content from avfiltergraph.h to avfilter.h. Deprecate
            avfilterhraph.h, user applications should include just avfilter.h
  bc1a985 - Add avfilter_graph_alloc_filter(), deprecate avfilter_open() and
            avfilter_graph_add_filter().
  1113672 - Add AVFilterContext.graph pointing to the AVFilterGraph that contains the
            filter.
  48a5ada - Add avfilter_init_str(), deprecate avfilter_init_filter().
  1ba95a9 - Add avfilter_init_dict().
  7cdd737 - Add AVFilter.flags field and AVFILTER_FLAG_DYNAMIC_{INPUTS,OUTPUTS} flags.
  7e8fe4b - Add avfilter_pad_count() for counting filter inputs/outputs.
  fa2a34c - Add avfilter_next(), deprecate av_filter_next().
            Deprecate avfilter_uninit().

2013-04-09 - lavfi 3.7.0 - avfilter.h
  b439c99 - Add AVFilter.priv_class for exporting filter options through the
            AVOptions API in the similar way private options work in lavc and lavf.
  8114c10 - Add avfilter_get_class().
  Switch all filters to use AVOptions.

2013-03-19 - 2c328a9 - lavu 52.9.0 - pixdesc.h
  Add av_pix_fmt_count_planes() function for counting planes in a pixel format.

2013-03-16 - 42c7c61 - lavfi 3.6.0
  Add AVFilterGraph.nb_filters, deprecate AVFilterGraph.filter_count.

2013-03-08 - Reference counted buffers - lavu 52.8.0, lavc 55.0.0, lavf 55.0.0,
lavd 54.0.0, lavfi 3.5.0
  8e401db, 1cec062 - add a new API for reference counted buffers and buffer
                     pools (new header libavutil/buffer.h).
  1afddbe - add AVPacket.buf to allow reference counting for the AVPacket data.
            Add av_packet_from_data() function for constructing packets from
            av_malloc()ed data.
  7ecc2d4 - move AVFrame from lavc to lavu (new header libavutil/frame.h), add
            AVFrame.buf/extended_buf to allow reference counting for the AVFrame
            data. Add new API for working with reference-counted AVFrames.
  759001c - add the refcounted_frames field to AVCodecContext to make audio and
            video decoders return reference-counted frames. Add get_buffer2()
            callback to AVCodecContext which allocates reference-counted frames.
            Add avcodec_default_get_buffer2() as the default get_buffer2()
            implementation.
            Deprecate AVCodecContext.get_buffer() / release_buffer() /
            reget_buffer(), avcodec_default_get_buffer(),
            avcodec_default_reget_buffer(), avcodec_default_release_buffer().
            Remove avcodec_default_free_buffers(), which should not have ever
            been called from outside of lavc.
            Deprecate the following AVFrame fields:
                * base -- is now stored in AVBufferRef
                * reference, type, buffer_hints -- are unnecessary in the new API
                * hwaccel_picture_private, owner, thread_opaque -- should not
                  have been acessed from outside of lavc
                * qscale_table, qstride, qscale_type, mbskip_table, motion_val,
                  mb_type, dct_coeff, ref_index -- mpegvideo-specific tables,
                  which are not exported anymore.
  7e35037 - switch libavfilter to use AVFrame instead of AVFilterBufferRef. Add
            av_buffersrc_add_frame(), deprecate av_buffersrc_buffer().
            Add av_buffersink_get_frame() and av_buffersink_get_samples(),
            deprecate av_buffersink_read() and av_buffersink_read_samples().
            Deprecate AVFilterBufferRef and all functions for working with it.

2013-03-17 - 12c5c1d - lavu 52.8.0 - avstring.h
  Add av_isdigit, av_isgraph, av_isspace, av_isxdigit.

2013-02-23 - 9f12235 - lavfi 3.4.0 - avfiltergraph.h
  Add resample_lavr_opts to AVFilterGraph for setting libavresample options
  for auto-inserted resample filters.