declare unused parameters in callbacks as void
    use size_t
    xml/xtag.c: comment dead code
    freetype: use mdate() instead of time(), remove unused parameter from UnderlineGlyphYUVA()
    notify/growl: factorize NotifyGrowl()

    avi/avi_HeaderAdd_str{h,f}(): removes unused parameter
    mp4/Convert{SUBT,AVC1}() GetD263Tag() Get{Text,Vide}Box(): same
    mpeg/ts/BufferChainClean(): same
    ogg/OggCreate{Header,Footer}(): same

    declare unused parameters in vlc callbacks as void
    deinterlace/RenderX() & motionblur/Copy(): remove unused argument

    rtp: add the prototype for rtp_packetize_h264_nal()
    transcode: transcode_{spu,audio}_close(): removes unused argument
    mosaic_bridge: video_del_buffer(): removes unused argument

removes unused arguments

    use size_t instead of int to represent sizes
    removes unused parameters from:
        block_BytestreamInit()
        mpeg4_audio/LOASSyncInfo()
        cinepak/cinepak_Getv1()
        speex/SendPacket()
        subsass/ParseColor()
        ffmpeg/postprocess/InitPostproc() & PostprocPict()
        dvbsub/YuvaYuvp() & encode_pixel_line_{2,4,8}bp()
        faad/DoReordering()

vlc_block_helper.h:
    use size_t, removes unused parameter from block_BytestreamInit()

struct filter_t:
    removes unused parameters from pf_picture_link() & pf_picture_unlink()
    
cmml: fix a segfault (p_item isn't an input item, despite the name) present for some months, proving that nobody did use that code ?

- fix qmax/qmin if statements                                                                                  
- if user requests certain bitrate, set defaults to qmax=51,qmin=10 if
  user hasn't defined them otherwise. Should help normal user to get
  bitrate he/she requests.

remove unused parameters from:
        EqzFilter() (equalizer.c)
        stereo_to_mono(), mono(), stereo2mono_downmix() (channel_mixer/mono.c)

rc.c: disable update code

    Transform(): remove unused parameter
    avoids useless unused parameter warnings

(You really don't usually want your net_Read/net_Write to interrupted).
In the process, fix a deadlock in vlc_cond_wait() when waitpipe is used - fixes #1448