On 5/5/2017 12:20 AM, Carl Eugen Hoyos wrote:
2017-05-05 3:29 GMT+02:00 Aaron Levinson <alevi...@aracnet.com>:
On 5/4/2017 4:27 PM, Carl Eugen Hoyos wrote:
Hi!
Attached patch is one possibility to fix the following warning with gcc 7:
libavutil/timecode.c: In function ‘av_timecode_make_string’:
libavutil/timecode.c:103:60: warning: ‘%02d’ directive output may be
truncated
writing between 2 and 10 bytes into a region of size between 0 and 7
[-Wformat-truncation=]
snprintf(buf, AV_TIMECODE_STR_SIZE, "%s%02d:%02d:%02d%c%02d",
^~~~
libavutil/timecode.c:103:41: note: directive argument in the range [0,
2147483647]
snprintf(buf, AV_TIMECODE_STR_SIZE, "%s%02d:%02d:%02d%c%02d",
^~~~~~~~~~~~~~~~~~~~~~~~
libavutil/timecode.c:103:5: note: ‘snprintf’ output between 12 and 32
bytes
into a destination of size 16
snprintf(buf, AV_TIMECODE_STR_SIZE, "%s%02d:%02d:%02d%c%02d",
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
neg ? "-" : "",
~~~~~~~~~~~~~~~
hh, mm, ss, drop ? ';' : ':', ff);
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Several similar warnings are printed, an alternative is to disable the
warning.
The warning seemed wrong on first sight but may actually be correct, we
accept invalid fps for timecode.
Regarding the change in your patch:
-#define AV_TIMECODE_STR_SIZE 16
+#define AV_TIMECODE_STR_SIZE 23
It seems like 23 characters wouldn't be sufficient based on the warning:
"output between 12 and 32 bytes into a destination of size 16". I would
guess that you would need at least 32 characters and perhaps one more (?)
for the terminating null character to avoid that warning.
How can I reproduce / test your findings?
#define AV_TIMECODE_STR_SIZE 32 or 33 and confirm that gcc 7 warnings go
away.
Aaron Levinson
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