ffmpeg | branch: master | Andreas Rheinhardt <[email protected]> | Wed Sep 14 02:21:41 2022 +0200| [62af385b917f2474498abeabd6057e6c60e2b9a9] | committer: Andreas Rheinhardt
avformat/dump: Avoid unnecessary implicit calculation of strlen av_strlcpy() returns the length of the src string to enable the caller to check for truncation. It is currently used in the following way in dump_metadata(): Every metadata value is searched for \b, \n, \v, \f, \r and then the data up to the first of these characters found is copied to a small temporary buffer via av_strlcpy() (but of course not more than fits into said buffer) and then printed; all characters up to the character found earlier are then treated as consumed. But this is bad performance-wise if the while string is big and contains many of these characters, because av_strlcpy() will unnecessarily calculate the length of the whole remaining string. (dump_metadata() actually ignored the return value of av_strlcpy().) Fix this by not copying the data to a temporary buffer at all. Instead just use %.*s to bound the number of characters output. Reviewed-by: Paul B Mahol <[email protected]> Signed-off-by: Andreas Rheinhardt <[email protected]> > http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=62af385b917f2474498abeabd6057e6c60e2b9a9 --- libavformat/dump.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) diff --git a/libavformat/dump.c b/libavformat/dump.c index e3f0056c20..cafcef36c6 100644 --- a/libavformat/dump.c +++ b/libavformat/dump.c @@ -145,10 +145,8 @@ static void dump_metadata(void *ctx, const AVDictionary *m, const char *indent) av_log(ctx, AV_LOG_INFO, "%s %-16s: ", indent, tag->key); while (*p) { - char tmp[256]; size_t len = strcspn(p, "\x8\xa\xb\xc\xd"); - av_strlcpy(tmp, p, FFMIN(sizeof(tmp), len+1)); - av_log(ctx, AV_LOG_INFO, "%s", tmp); + av_log(ctx, AV_LOG_INFO, "%.*s", (int)(FFMIN(255, len)), p); p += len; if (*p == 0xd) av_log(ctx, AV_LOG_INFO, " "); if (*p == 0xa) av_log(ctx, AV_LOG_INFO, "\n%s %-16s: ", indent, ""); _______________________________________________ ffmpeg-cvslog mailing list [email protected] https://ffmpeg.org/mailman/listinfo/ffmpeg-cvslog To unsubscribe, visit link above, or email [email protected] with subject "unsubscribe".
