On Mon, Aug 13, 2012 at 12:33 PM, aviad rozenhek <avia...@gmail.com> wrote:
> unary minus operator applied to unsigned type, result still unsigned
>
>
> I get this compiler warning when using any if the specialized AVERROR_XXX
> macros, like AVERROR_BSF_NOT_FOUND or AVERROR_DECODER_NOT_FOUND.
>
> the reason is because
>
>> #define AVERROR_BSF_NOT_FOUND (-MKTAG(0xF8,'B','S','F')) ///<
>> Bitstream filter not found
>
>
> and the result from MKTAG is *unsigned* .
>
> therefore I suggest to change the code thusly:
>
> #define DEFINE_AVERROR(a, b, c, d) (-(int32_t)MKTAG(a, b, c, d))
>
> #define AVERROR_BSF_NOT_FOUND ( DEFINE_AVERROR ('B','S','F')) ///<
> Bitstream filter not found
> #define AVERROR_DECODER_NOT_FOUND ( DEFINE_AVERROR ('D','E','C')) ///<
> Decoder not found
> #define AVERROR_DEMUXER_NOT_FOUND ( DEFINE_AVERROR ('D','E','M')) ///<
> Demuxer not found
> #define AVERROR_ENCODER_NOT_FOUND ( DEFINE_AVERROR ('E','N','C')) ///<
> Encoder not found
> #define AVERROR_EOF ( DEFINE_AVERROR ( 'E','O','F')) ///<
> End of file
> #define AVERROR_EXIT ( DEFINE_AVERROR ( 'E','X','T')) ///<
> Immediate exit was requested; the called function should not be restarted
> #define AVERROR_FILTER_NOT_FOUND ( DEFINE_AVERROR ('F','I','L')) ///<
> Filter not found
> #define AVERROR_INVALIDDATA ( DEFINE_AVERROR ( 'I','N','D')) ///<
> Invalid data found when processing input
> #define AVERROR_MUXER_NOT_FOUND ( DEFINE_AVERROR ('M','U','X')) ///<
> Muxer not found
> #define AVERROR_OPTION_NOT_FOUND ( DEFINE_AVERROR ('O','P','T')) ///<
> Option not found
> #define AVERROR_PATCHWELCOME ( DEFINE_AVERROR ( 'P','A','W')) ///<
> Not yet implemented in Libav, patches welcome
> #define AVERROR_PROTOCOL_NOT_FOUND ( DEFINE_AVERROR ('P','R','O')) ///<
> Protocol not found
> #define AVERROR_STREAM_NOT_FOUND ( DEFINE_AVERROR ('S','T','R')) ///<
> Stream not found
> #define AVERROR_BUG ( DEFINE_AVERROR ( 'B','U','G')) ///<
> Bug detected, please report the issue
>
>
>
> --
> Aviad Rozenhek
>
how about we stop using the high byte [which contains the sign, thus making
the tag convertible to signed, like so, would this work?
#define MKTAG(a,b,c,d) ((a) | ((b) << 8) | ((c) << 16) | ((*unsigned*)(d)
> << 24))
#define DEFINE_AVERROR_3CC_TAG(a, b, c) (-(int32_t)MKTAG(a, b, c, 0))
#define AVERROR_BSF_NOT_FOUND ( DEFINE_AVERROR (0xF8,'B','S','F'))
///< Bitstream filter not found
#define AVERROR_DECODER_NOT_FOUND ( DEFINE_AVERROR (0xF8,'D','E','C'))
///< Decoder not found
#define AVERROR_DEMUXER_NOT_FOUND ( DEFINE_AVERROR (0xF8,'D','E','M'))
///< Demuxer not found
#define AVERROR_ENCODER_NOT_FOUND ( DEFINE_AVERROR (0xF8,'E','N','C'))
///< Encoder not found
#define AVERROR_EOF ( DEFINE_AVERROR ( 'E','O','F',' '))
///< End of file
#define AVERROR_EXIT ( DEFINE_AVERROR ( 'E','X','I','T'))
///< Immediate exit was requested; the called function should not be
restarted
#define AVERROR_FILTER_NOT_FOUND ( DEFINE_AVERROR (0xF8,'F','I','L'))
///< Filter not found
#define AVERROR_INVALIDDATA ( DEFINE_AVERROR ( 'I','N','D','A'))
///< Invalid data found when processing input
#define AVERROR_MUXER_NOT_FOUND ( DEFINE_AVERROR (0xF8,'M','U','X'))
///< Muxer not found
#define AVERROR_OPTION_NOT_FOUND ( DEFINE_AVERROR (0xF8,'O','P','T'))
///< Option not found
#define AVERROR_PATCHWELCOME ( DEFINE_AVERROR ( 'P','A','W','E'))
///< Not yet implemented in Libav, patches welcome
#define AVERROR_PROTOCOL_NOT_FOUND ( DEFINE_AVERROR (0xF8,'P','R','O'))
///< Protocol not found
#define AVERROR_STREAM_NOT_FOUND ( DEFINE_AVERROR (0xF8,'S','T','R'))
///< Stream not found
#define AVERROR_BUG ( DEFINE_AVERROR ( 'B','U','G',' '))
///< Bug detected, please report the issue
--
Aviad Rozenhek
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