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:    2015-08-28
libavdevice:   2015-08-28
libavfilter:   2015-08-28
libavformat:   2015-08-28
libavresample: 2015-08-28
libswscale:    2015-08-28
libavutil:     2015-08-28


API changes, most recent first:
2015-xx-xx - xxxxxxx - lavc 57.6.0 - avcodec.h

2015-xx-xx - lavc 57.7.0 - avcodec.h
  xxxxxx - Deprecate av_free_packet(). Use av_packet_unref() as replacement,
           it resets the packet in a more consistent way.
  xxxxxx - Deprecate av_dup_packet(), it is a no-op for most cases.
           Use av_packet_ref() to make a non-refcounted AVPacket refcounted.
  xxxxxx - Add av_packet_alloc(), av_packet_clone(), av_packet_free().
           They match the AVFrame functions with the same name.

2015-xx-xx - xxxxxxx - lavc 57.5.0 - avcodec.h
  Add data and linesize array to AVSubtitleRect, to be used instead of
  the ones from the embedded AVPicture.

2015-xx-xx - xxxxxxx - lavc 57.0.0 - qsv.h
  Add an API for allocating opaque surfaces.

2015-xx-xx - xxxxxxx - lavu 55.2.0 - dict.h
  Change return type of av_dict_copy() from void to int, so that a proper
  error code can be reported.

2015-09-29 - 948f3c1 - lavc 57.0.0 - avcodec.h
  Change type of AVPacket.duration from int to int64_t.

2015-09-18 - e3d4784 - lavc 57.2.0 - d3d11va.h
  Add av_d3d11va_alloc_context(). This function must from now on be used for
  allocating AVD3D11VAContext.

2015-09-07 - lavu 55.0.0
  b8b5d82 - Change type of AVPixFmtDescriptor.flags from uint8_t to uint64_t.
  6b3ef7f - Change type of AVComponentDescriptor fields from uint16_t to int
            and drop bit packing.
  2268db2 - Add step, offset, and depth to AVComponentDescriptor to replace
            the deprecated step_minus1, offset_plus1, and depth_minus1.

2015-07-31 - lavu 54.17.0
  7a7df34 - Add av_blowfish_alloc().
  ae36545 - Add av_rc4_alloc().
  5d8bea3 - Add av_xtea_alloc().
  d9e8b47 - Add av_des_alloc().

2015-07-29 - 7e38340 - lavu 54.16.0 - hmac.h
  Add AV_HMAC_SHA224 and AV_HMAC_SHA256.

2015-07-27 - lavc 56.35.0 - avcodec.h
  7c6eb0a - Rename CODEC_FLAG* defines to AV_CODEC_FLAG*.
  def9785 - Rename CODEC_CAP_* defines to AV_CODEC_CAP_*.
  059a934 - Rename FF_INPUT_BUFFER_PADDING_SIZE and FF_MIN_BUFFER_SIZE
            to AV_INPUT_BUFFER_PADDING_SIZE and AV_INPUT_BUFFER_MIN_SIZE.

2015-07-20 - 5d3addb - lavc 56.33.0 - avcodec.h
  Add AV_PKT_DATA_QUALITY_FACTOR to export the quality value of an AVPacket.

2015-07-02 - 1316df7 - lavu 56.15.0
  Add av_version_info().