Update Changelog

Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

Changelog

@@ -2,7 +2,30 @@ Entries are sorted chronologically from oldest to youngest within each release,
 releases are sorted from youngest to oldest.
 
 version 2.8.4
-- avcodec/aarch64/neon.S: Update neon.s for transpose_4x4H
+- rawdec: only exempt BIT0 with need_copy from buffer sanity check
+- mlvdec: check that index_entries exist
+- avcodec/mpeg4videodec: also for empty partitioned slices
+- avcodec/h264_refs: Fix long_idx check
+- avcodec/h264_mc_template: prefetch list1 only if it is used in the MB
+- avcodec/h264_slice: Simplify ref2frm indexing
+- avfilter/vf_mpdecimate: Add missing emms_c()
+- sonic: make sure num_taps * channels is not larger than frame_size
+- opus_silk: fix typo causing overflow in silk_stabilize_lsf
+- ffm: reject invalid codec_id and codec_type
+- golomb: always check for invalid UE golomb codes in get_ue_golomb
+- sbr_qmf_analysis: sanitize input for 32-bit imdct
+- sbrdsp_fixed: assert that input values are in the valid range
+- aacsbr: ensure strictly monotone time borders
+- aacenc: update max_sfb when num_swb changes
+- aaccoder: prevent crash of anmr coder
+- ffmdec: reject zero-sized chunks
+- swscale/x86/rgb2rgb_template: Fallback to mmx in interleaveBytes() if the alignment is insufficient for SSE*
+- swscale/x86/rgb2rgb_template: Do not crash on misaligend stride
+- avformat/mxfenc: Do not crash if there is no packet in the first stream
+- lavf/tee: fix side data double free.
+- avformat/hlsenc: Check the return code of avformat_write_header()
+- avformat/mov: Enable parser for mp3s by old HandBrake
+- avformat/mxfenc: Fix integer overflow in length computation
 - avformat/utils: estimate_timings_from_pts - increase retry counter, fixes invalid duration for ts files with hevc codec
 - avformat/matroskaenc: Check codecdelay before use
 - avutil/mathematics: Fix division by 0