[FFmpeg-devel] [PATCH] avcodec/libx264: silence -Waddress

[Ronald S. Bultje]

Hi,

On Thu, Sep 17, 2015 at 7:03 AM, Ganesh Ajjanagadde <gajjanagadde at gmail.com>
wrote:

> On Thu, Sep 17, 2015 at 6:15 AM, Hendrik Leppkes <h.leppkes at gmail.com>
> wrote:
> > On Thu, Sep 17, 2015 at 12:19 AM, Ganesh Ajjanagadde
> > <gajjanagadde at gmail.com> wrote:
> >> This patch moves the pointer validity check outside the macro,
> >> and silences the -Waddress observed with GCC 5.2.
> >>
> >> Signed-off-by: Ganesh Ajjanagadde <gajjanagadde at gmail.com>
> >> ---
> >>  libavcodec/libx264.c | 8 +++++---
> >>  1 file changed, 5 insertions(+), 3 deletions(-)
> >>
> >> diff --git a/libavcodec/libx264.c b/libavcodec/libx264.c
> >> index 58fcfb0..c7c772e 100644
> >> --- a/libavcodec/libx264.c
> >> +++ b/libavcodec/libx264.c
> >> @@ -346,7 +346,7 @@ static av_cold int X264_close(AVCodecContext *avctx)
> >>  #define OPT_STR(opt, param)
>        \
> >>      do {
>         \
> >>          int ret;
>         \
> >> -        if (param && (ret = x264_param_parse(&x4->params, opt, param))
> < 0) { \
> >> +        if ((ret = x264_param_parse(&x4->params, opt, param)) < 0) { \
> >>              if(ret == X264_PARAM_BAD_NAME)
>         \
> >>                  av_log(avctx, AV_LOG_ERROR,
>        \
> >>                          "bad option '%s': '%s'\n", opt, param);
>        \
> >> @@ -437,7 +437,8 @@ static av_cold int X264_init(AVCodecContext *avctx)
> >>      x4->params.i_log_level          = X264_LOG_DEBUG;
> >>      x4->params.i_csp                = convert_pix_fmt(avctx->pix_fmt);
> >>
> >> -    OPT_STR("weightp", x4->wpredp);
> >> +    if (x4->wpredp)
> >> +        OPT_STR("weightp", x4->wpredp);
> >>
> >>      if (avctx->bit_rate) {
> >>          x4->params.rc.i_bitrate   = avctx->bit_rate / 1000;
> >> @@ -467,7 +468,8 @@ static av_cold int X264_init(AVCodecContext *avctx)
> >>              (float)avctx->rc_initial_buffer_occupancy /
> avctx->rc_buffer_size;
> >>      }
> >>
> >> -    OPT_STR("level", x4->level);
> >> +    if (x4->level)
> >> +        OPT_STR("level", x4->level);
> >>
> >>      if (avctx->i_quant_factor > 0)
> >>          x4->params.rc.f_ip_factor         = 1 /
> fabs(avctx->i_quant_factor);
> >
> >
> > Instead of adding explicit checks here, why not make the file more
> > consistent and use PARSE_X264_OPT for the things from the x4 context
> > (like its already done for a bunch of other variables), and only use
> > OPT_STR for the two special cases further down (without the check
> > then)
>
> The behavior then won't be identical before and after the patch; e.g
> the log portion of PARSE_X264_OPT is different from that of OPT_STR.
> The current patch retains identical behavior. In particular, your
> change does change the "user-facing" output slightly. Unless you (or
> someone else) can confirm that it is irrelevant; I do not think your
> proposal is good.


How does it change? I don't think that's necessarily a terrible thing. If
it's just cosmetic, we can live with it.

Ronald