Log Message:
Changes 2.2.1:
* avcodec/dirac_arith: Fix build with PIC and stack-check options
* swscale/x86/swscale_template: loose hardcoded dstw_offset
* swresample/resample: use av_malloc_array() where appropriate
* swresample/dither: use av_malloc_array()
* swresample/resample: Limit filter length
* avcodec/msrle: check return code for success before use
* avcodec/pthread_frame: fix missing unlock on error
* examples/avio_reading: fix null dereference on error
* avformat/omadec: fix probetest failure
* avcodec/wma: use av_freep(), do not leave stale pointers in memory
* lavu/opt: validate range before dereference
* avcodec/h264: clear cur_pic structure instead of duplicating it in \ 
ff_h264_update_thread_context()
* avfilter/vf_pullup: fix gray8
* avcodec/libx264: move where x264opts is applied down so it isnt overridden by \ 
avctx & defaults