[FFmpeg-devel] [PATCH 5/5] lavu/bprint: add URL escaping

[Nicolas George]

Le tridi 23 germinal, an CCXXV, Rodger Combs a écrit :
> ---
>  libavutil/avstring.h |  1 +
>  libavutil/bprint.c   | 11 +++++++++++
>  libavutil/version.h  |  2 +-
>  3 files changed, 13 insertions(+), 1 deletion(-)
> 
> diff --git a/libavutil/avstring.h b/libavutil/avstring.h
> index 68b753a569..ccedddd210 100644
> --- a/libavutil/avstring.h
> +++ b/libavutil/avstring.h
> @@ -315,6 +315,7 @@ enum AVEscapeMode {
>      AV_ESCAPE_MODE_BACKSLASH, ///< Use backslash escaping.
>      AV_ESCAPE_MODE_QUOTE,     ///< Use single-quote escaping.
>      AV_ESCAPE_MODE_XML,       ///< Use XML ampersand-escaping; requires UTF-8 input.
> +    AV_ESCAPE_MODE_URL,       ///< Use URL percent-escaping
>  };
>  
>  /**
> diff --git a/libavutil/bprint.c b/libavutil/bprint.c
> index 8e44c57346..7335acf3c9 100644
> --- a/libavutil/bprint.c
> +++ b/libavutil/bprint.c
> @@ -345,5 +345,16 @@ void av_bprint_escape(AVBPrint *dstbuf, const char *src, const char *special_cha
>              }
>          }
>          break;
> +
> +    case AV_ESCAPE_MODE_URL:
> +        for (; *src; src++) {

> +            int is_strictly_special = special_chars && strchr(special_chars, *src);

I think is_strictly_special is a misnomer in the existing code.

> +            if (is_strictly_special ||

> +                (!(flags & AV_ESCAPE_FLAG_STRICT) && !strchr("abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789-._~", *src)))

I am not entirely sure how strict escaping should work for this kind of
encoding, but there is no doubt that % itself must always be encoded.

Also, the condition you wrote would IMHO be more efficient written as:

	(unsigned)((*src | 32) - 'a') < 26 ||
	(unsigned)(*src - '0') < 10 ||
	*src == '-' || *src == '.' || *src == '_' || *src == '~'

Last, some cases allow and prefer space to be encoded as +; since %20 is
still valid, I say we go for uniformity.

> +                av_bprintf(dstbuf, "%%%02X", *src);
> +            else
> +                av_bprint_chars(dstbuf, *src, 1);
> +        }
> +        break;
>      }
>  }
> diff --git a/libavutil/version.h b/libavutil/version.h
> index bba39e0180..90d9137e08 100644
> --- a/libavutil/version.h
> +++ b/libavutil/version.h
> @@ -79,7 +79,7 @@
>   */
>  
>  #define LIBAVUTIL_VERSION_MAJOR  55
> -#define LIBAVUTIL_VERSION_MINOR  61
> +#define LIBAVUTIL_VERSION_MINOR  62
>  #define LIBAVUTIL_VERSION_MICRO 100
>  
>  #define LIBAVUTIL_VERSION_INT   AV_VERSION_INT(LIBAVUTIL_VERSION_MAJOR, \

Regards,

-- 
  Nicolas George
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