APIchanges

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

The last version increases were:
libavcodec:    2015-08-28
libavdevice:   2015-08-28
libavfilter:   2015-08-28
libavformat:   2015-08-28
libavresample: 2015-08-28
libpostproc:   2015-08-28
libswresample: 2015-08-28
libswscale:    2015-08-28
libavutil:     2015-08-28


API changes, most recent first:

2017-xx-xx - xxxxxxxxxx
  Change av_sha_update(), av_sha512_update() and av_md5_sum()/av_md5_update() length
  parameter type to size_t at next major bump.

2017-05-05 - xxxxxxxxxx - lavc 57.94.100 - avcodec.h
  The cuvid decoders now support AVCodecContext.hw_device_ctx, which removes
  the requirement to set an incomplete AVCodecContext.hw_frames_ctx only to
  set the Cuda device handle.

2017-04-11 - 8378466507 - lavu 55.61.100 - avstring.h
  Add av_strireplace().

2016-04-06 - 157e57a181 - lavc 57.92.100 - avcodec.h
  Add AV_PKT_DATA_CONTENT_LIGHT_LEVEL packet side data.

2016-04-06 - b378f5bd64 - lavu 55.60.100 - mastering_display_metadata.h
  Add AV_FRAME_DATA_CONTENT_LIGHT_LEVEL value, av_content_light_metadata_alloc()
  and av_content_light_metadata_create_side_data() API, and AVContentLightMetadata
  type to export content light level video properties.

2017-03-31 - 9033e8723c - lavu 55.57.100 - spherical.h
  Add av_spherical_projection_name().
  Add av_spherical_from_name().

2017-03-30 - 4cda23f1f1 - lavu 55.53.100 / 55.27.0 - hwcontext.h
  Add av_hwframe_map() and associated AV_HWFRAME_MAP_* flags.
  Add av_hwframe_ctx_create_derived().

2017-03-29 - bfdcdd6d82 - lavu 55.52.100 - avutil.h
  add av_fourcc_make_string() function and av_fourcc2str() macro to replace
  av_get_codec_tag_string() from lavc.

2017-03-27 - ddef3d902f - lavf 57.68.100 - avformat.h
  Deprecate that demuxers export the stream rotation angle in AVStream.metadata
  (via an entry named "rotate"). Use av_stream_get_side_data() with
  AV_PKT_DATA_DISPLAYMATRIX instead, and read the rotation angle with
  av_display_rotation_get(). The same is done for muxing. Instead of adding a
  "rotate" entry to AVStream.metadata, AV_PKT_DATA_DISPLAYMATRIX side data has
  to be added to the AVStream.

2017-03-23 - 7e4ba776a2 - lavc 57.85.101 - avcodec.h
  vdpau hardware accelerated decoding now supports the new hwaccel API, which
  can create the decoder context and allocate hardware frame automatically.
  See AVCodecContext.hw_device_ctx and AVCodecContext.hw_frames_ctx.

2017-03-23 - 156bd8278f - lavc 57.85.100 - avcodec.h
  Add AVCodecContext.hwaccel_flags field. This will control some hwaccels at
  a later point.

2017-03-21 - fc9f14c7de - lavf 57.67.100 / 57.08.0 - avio.h
  Add AVIO_SEEKABLE_TIME flag.

2017-03-21 - d682ae70b4 - lavf 57.66.105, lavc 57.83.101 - avformat.h, avcodec.h
  Deprecate AVFMT_FLAG_KEEP_SIDE_DATA. It will be ignored after the next major
  bump, and libavformat will behave as if it were always set.
  Deprecate av_packet_merge_side_data() and av_packet_split_side_data().

2016-03-20 - 8200b16a9c - lavu 55.50.100 / 55.21.0 - imgutils.h
  Add av_image_copy_uc_from(), a version of av_image_copy() for copying
  from GPU mapped memory.

2017-03-20 - 9c2436e - lavu 55.49.100 - pixdesc.h
  Add AV_PIX_FMT_FLAG_BAYER pixel format flag.

2017-03-18 - 3796fb2692 - lavfi 6.77.100 - avfilter.h
  Deprecate AVFilterGraph.resample_lavr_opts
  It's never been used by avfilter nor passed to anything.

2017-02-10 - 1b7ffddb3a - lavu 55.48.100 / 55.33.0 - spherical.h
  Add AV_SPHERICAL_EQUIRECTANGULAR_TILE, av_spherical_tile_bounds(),
  and projection-specific properties (bound_left, bound_top, bound_right,
  bound_bottom, padding) to AVSphericalMapping.

2017-03-02 - ade7c1a232 - lavc 57.81.104 - videotoolbox.h
  AVVideotoolboxContext.cv_pix_fmt_type can now be set to 0 to output the
  native decoder format. (The default value is not changed.)

2017-03-02 - 554bc4eea8 - lavu 55.47.101, lavc 57.81.102, lavf 57.66.103
  Remove requirement to use AVOption or accessors to access certain fields
  in AVFrame, AVCodecContext, and AVFormatContext that were previously
  documented as "no direct access" allowed.

2017-02-13 - c1a5fca06f - lavc 57.80.100 - avcodec.h
  Add AVCodecContext.hw_device_ctx.

2017-02-11 - e3af49b14b - lavu 55.47.100 - frame.h
  Add AVFrame.opaque_ref.

2017-01-31 - 2eab48177d - lavu 55.46.100 / 55.20.0 - cpu.h
  Add AV_CPU_FLAG_SSSE3SLOW.

2017-01-24 - c4618f842a - lavu 55.45.100 - channel_layout.h
  Add av_get_extended_channel_layout()

2017-01-22 - 76c5a69e26 - lavu 55.44.100 - lfg.h
  Add av_lfg_init_from_data().

2017-01-17 - 2a4a8653b6 - lavc 57.74.100 - vaapi.h
  Deprecate struct vaapi_context and the vaapi.h installed header.
  Callers should set AVCodecContext.hw_frames_ctx instead.

2017-01-12 - dbe9dbed31 - lavfi 6.69.100 - buffersink.h
  Add av_buffersink_get_*() functions.

2017-01-06 - 9488032e10 - lavf 57.62.100 - avio.h
  Add avio_get_dyn_buf()

2016-12-10 - f542b152aa - lavu 55.43.100 - imgutils.h
  Add av_image_check_size2()

2016-12-07 - e7a6f8c972 - lavc 57.67.100 / 57.29.0 - avcodec.h
  Add AV_PKT_DATA_SPHERICAL packet side data to export AVSphericalMapping
  information from containers.

2016-12-07 - 8f58ecc344 - lavu 55.42.100 / 55.30.0 - spherical.h
  Add AV_FRAME_DATA_SPHERICAL value, av_spherical_alloc() API and
  AVSphericalMapping type to export and describe spherical video properties.

2016-11-18 - 2ab50647ff - lavf 57.58.100 - avformat.h
  Add av_stream_add_side_data().

2016-11-13 - 775a8477b7 - lavu 55.39.100 - hwcontext_vaapi.h
  Add AV_VAAPI_DRIVER_QUIRK_ATTRIB_MEMTYPE.

2016-11-13 - a8d51bb424 - lavu 55.38.100 - hwcontext_vaapi.h
  Add driver quirks field to VAAPI-specific hwdevice and enum with
  members AV_VAAPI_DRIVER_QUIRK_* to represent its values.

2016-11-10 - 638b216d4f - lavu 55.36.100 - pixfmt.h
  Add AV_PIX_FMT_GRAY12(LE/BE).

-------- 8< --------- FFmpeg 3.2 was cut here -------- 8< ---------

2016-10-24 - 73ead47 - lavf 57.55.100 - avformat.h
  Add AV_DISPOSITION_TIMED_THUMBNAILS

2016-10-24 - a246fef - lavf 57.54.100 - avformat.h
  Add avformat_init_output() and AVSTREAM_INIT_IN_ macros

2016-10-22 - f5495c9 - lavu 55.33.100 - avassert.h
  Add av_assert0_fpu() / av_assert2_fpu()

2016-10-07 - 3f9137c / 32c8359 - lavc 57.61.100 / 57.24.0 - avcodec.h
  Decoders now export the frame timestamp as AVFrame.pts. It was
  previously exported as AVFrame.pkt_pts, which is now deprecated.

  Note: When decoding, AVFrame.pts uses the stream/packet timebase,
  and not the codec timebase.

2016-09-28 - eba0414 - lavu 55.32.100 / 55.16.0 - hwcontext.h hwcontext_qsv.h
  Add AV_HWDEVICE_TYPE_QSV and a new installed header with QSV-specific
  hwcontext definitions.

2016-09-26 - 32c25f0 - lavc 57.59.100 / 57.23.0 - avcodec.h
  AVCodecContext.hw_frames_ctx now may be used by decoders.

2016-09-27 - f0b6f72 - lavf 57.51.100 - avformat.h
  Add av_stream_get_codec_timebase()

2016-09-27 - 23c0779 - lswr 2.2.100 - swresample.h
  Add swr_build_matrix().

2016-09-23 - 30d3e36 - lavc 57.58.100 - avcodec.h
  Add AV_CODEC_CAP_AVOID_PROBING codec capability flag.

2016-09-14 - ae1dd0c - lavf 57.49.100 - avformat.h
  Add avformat_transfer_internal_stream_timing_info helper to help with stream
  copy.

2016-08-29 - 4493390 - lavfi 6.58.100 - avfilter.h
  Add AVFilterContext.nb_threads.

2016-08-15 - c3c4c72 - lavc 57.53.100 - avcodec.h
  Add trailing_padding to AVCodecContext to match the corresponding
  field in AVCodecParameters.

2016-08-15 - b746ed7 - lavc 57.52.100 - avcodec.h
  Add a new API for chained BSF filters and passthrough (null) BSF --
  av_bsf_list_alloc(), av_bsf_list_free(), av_bsf_list_append(),
  av_bsf_list_append2(), av_bsf_list_finalize(), av_bsf_list_parse_str()
  and av_bsf_get_null_filter().

2016-08-04 - 82a33c8 - lavf 57.46.100 - avformat.h