[FFmpeg-devel] [PATCHv2] all: fix enum definition for large values

[Ronald S. Bultje]

Hi,

On Tue, Oct 27, 2015 at 8:53 PM, Ganesh Ajjanagadde <gajjanagadde at gmail.com>
wrote:

> ISO C restricts enumerator values to the range of int. Thus (for instance)
> 0x80000000
> unfortunately does not work, and throws a warning with -Wpedantic on
> clang 3.7.
>
> This fixes it by using alternative expressions that result in identical
> values but do not have this issue.
>
> Tested with FATE.
>
> Signed-off-by: Ganesh Ajjanagadde <gajjanagadde at gmail.com>
> ---
>  libavcodec/dca_syncwords.h | 26 ++++++++++++--------------
>  libavformat/cinedec.c      |  2 +-
>  libavformat/mov_chan.c     |  2 +-
>  3 files changed, 14 insertions(+), 16 deletions(-)
>
> diff --git a/libavcodec/dca_syncwords.h b/libavcodec/dca_syncwords.h
> index 3466b6b..6981cb8 100644
> --- a/libavcodec/dca_syncwords.h
> +++ b/libavcodec/dca_syncwords.h
> @@ -19,19 +19,17 @@
>  #ifndef AVCODEC_DCA_SYNCWORDS_H
>  #define AVCODEC_DCA_SYNCWORDS_H
>
> -enum DCASyncwords {
> -    DCA_SYNCWORD_CORE_BE        = 0x7FFE8001U,
> -    DCA_SYNCWORD_CORE_LE        = 0xFE7F0180U,
> -    DCA_SYNCWORD_CORE_14B_BE    = 0x1FFFE800U,
> -    DCA_SYNCWORD_CORE_14B_LE    = 0xFF1F00E8U,
> -    DCA_SYNCWORD_XCH            = 0x5A5A5A5AU,
> -    DCA_SYNCWORD_XXCH           = 0x47004A03U,
> -    DCA_SYNCWORD_X96            = 0x1D95F262U,
> -    DCA_SYNCWORD_XBR            = 0x655E315EU,
> -    DCA_SYNCWORD_LBR            = 0x0A801921U,
> -    DCA_SYNCWORD_XLL            = 0x41A29547U,
> -    DCA_SYNCWORD_SUBSTREAM      = 0x64582025U,
> -    DCA_SYNCWORD_SUBSTREAM_CORE = 0x02B09261U,
> -};
> +#define    DCA_SYNCWORD_CORE_BE              0x7FFE8001U
> +#define    DCA_SYNCWORD_CORE_LE              0xFE7F0180U
> +#define    DCA_SYNCWORD_CORE_14B_BE          0x1FFFE800U
> +#define    DCA_SYNCWORD_CORE_14B_LE          0xFF1F00E8U
> +#define    DCA_SYNCWORD_XCH                  0x5A5A5A5AU
> +#define    DCA_SYNCWORD_XXCH                 0x47004A03U
> +#define    DCA_SYNCWORD_X96                  0x1D95F262U
> +#define    DCA_SYNCWORD_XBR                  0x655E315EU
> +#define    DCA_SYNCWORD_LBR                  0x0A801921U
> +#define    DCA_SYNCWORD_XLL                  0x41A29547U
> +#define    DCA_SYNCWORD_SUBSTREAM            0x64582025U
> +#define    DCA_SYNCWORD_SUBSTREAM_CORE       0x02B09261U
>

This one is fine.


> --- a/libavformat/cinedec.c
> +++ b/libavformat/cinedec.c
> @@ -50,7 +50,7 @@ enum {
>      CFA_BAYER     = 3,  /**< GB/RG */
>      CFA_BAYERFLIP = 4,  /**< RG/GB */
>
> -    CFA_TLGRAY    = 0x80000000,
> +    CFA_TLGRAY    = INT32_MIN,
>      CFA_TRGRAY    = 0x40000000,
>      CFA_BLGRAY    = 0x20000000,
>      CFA_BRGRAY    = 0x10000000
> diff --git a/libavformat/mov_chan.c b/libavformat/mov_chan.c
> index a2fa8d6..f6181e2 100644
> --- a/libavformat/mov_chan.c
> +++ b/libavformat/mov_chan.c
> @@ -45,7 +45,7 @@
>   *            do not specify a particular ordering of those channels."
>   */
>  enum MovChannelLayoutTag {
> -    MOV_CH_LAYOUT_UNKNOWN               = 0xFFFF0000,
> +    MOV_CH_LAYOUT_UNKNOWN               = -( 1 << 16),
>      MOV_CH_LAYOUT_USE_DESCRIPTIONS      = (  0 << 16) | 0,
>      MOV_CH_LAYOUT_USE_BITMAP            = (  1 << 16) | 0,
>      MOV_CH_LAYOUT_DISCRETEINORDER       = (147 << 16) | 0,
> --
> 2.6.2


I personally don't really like these... I think both obfuscate the meaning
of the flag values, particularly the first one.

Ronald