[FFmpeg-devel] [PATCH v3 2/3] avutil/log: add av_log_set_opts function

wm4 nfxjfg at googlemail.com
Thu Mar 29 13:58:55 EEST 2018


On Thu, 29 Mar 2018 08:58:12 +0200
Tobias Rapp <t.rapp at noa-archive.com> wrote:

> On 28.03.2018 17:11, wm4 wrote:
> > On Wed, 28 Mar 2018 17:03:39 +0200
> > Tobias Rapp <t.rapp at noa-archive.com> wrote:
> >   
> >> Allows to set log level and flag values from string.
> >>
> >> Signed-off-by: Tobias Rapp <t.rapp at noa-archive.com>
> >> ---
> >>   doc/APIchanges      |  3 +++
> >>   libavutil/log.c     | 76 +++++++++++++++++++++++++++++++++++++++++++++++++++++
> >>   libavutil/log.h     | 16 +++++++++++
> >>   libavutil/version.h |  2 +-
> >>   4 files changed, 96 insertions(+), 1 deletion(-)
> >>
> >> diff --git a/doc/APIchanges b/doc/APIchanges
> >> index 83c7a40..2d14452 100644
> >> --- a/doc/APIchanges
> >> +++ b/doc/APIchanges
> >> @@ -15,6 +15,9 @@ libavutil:     2017-10-21
> >>   
> >>   API changes, most recent first:
> >>   
> >> +2018-03-xx - xxxxxxx - lavu 56.13.100 - log.h
> >> +  Add av_log_set_opts().
> >> +
> >>   2018-03-xx - xxxxxxx - lavc 58.16.100 - avcodec.h
> >>     Add FF_SUB_CHARENC_MODE_IGNORE.
> >>   
> >> diff --git a/libavutil/log.c b/libavutil/log.c
> >> index 0a99d01..af32cd6 100644
> >> --- a/libavutil/log.c
> >> +++ b/libavutil/log.c
> >> @@ -34,6 +34,7 @@
> >>   #endif
> >>   #include <stdarg.h>
> >>   #include <stdlib.h>
> >> +#include "avassert.h"
> >>   #include "avutil.h"
> >>   #include "bprint.h"
> >>   #include "common.h"
> >> @@ -402,6 +403,81 @@ void av_log_set_callback(void (*callback)(void*, int, const char*, va_list))
> >>       av_log_callback = callback;
> >>   }
> >>   
> >> +int av_log_set_opts(const char *arg)
> >> +{
> >> +    const struct { const char *name; int level; } log_levels[] = {
> >> +        { "quiet"  , AV_LOG_QUIET   },
> >> +        { "panic"  , AV_LOG_PANIC   },
> >> +        { "fatal"  , AV_LOG_FATAL   },
> >> +        { "error"  , AV_LOG_ERROR   },
> >> +        { "warning", AV_LOG_WARNING },
> >> +        { "info"   , AV_LOG_INFO    },
> >> +        { "verbose", AV_LOG_VERBOSE },
> >> +        { "debug"  , AV_LOG_DEBUG   },
> >> +        { "trace"  , AV_LOG_TRACE   },
> >> +    };
> >> +    const char *token;
> >> +    char *tail;
> >> +    int flags = av_log_get_flags();
> >> +    int level = av_log_get_level();
> >> +    int cmd, i = 0;
> >> +
> >> +    av_assert0(arg);
> >> +    while (*arg) {
> >> +        token = arg;
> >> +        if (*token == '+' || *token == '-') {
> >> +            cmd = *token++;
> >> +        } else {
> >> +            cmd = 0;
> >> +        }
> >> +        if (!i && !cmd) {
> >> +            flags = 0;  /* missing relative prefix, build absolute value */
> >> +        }
> >> +        if (!strncmp(token, "repeat", 6)) {
> >> +            if (cmd == '-') {
> >> +                flags |= AV_LOG_SKIP_REPEATED;
> >> +            } else {
> >> +                flags &= ~AV_LOG_SKIP_REPEATED;
> >> +            }
> >> +            arg = token + 6;
> >> +        } else if (!strncmp(token, "level", 5)) {
> >> +            if (cmd == '-') {
> >> +                flags &= ~AV_LOG_PRINT_LEVEL;
> >> +            } else {
> >> +                flags |= AV_LOG_PRINT_LEVEL;
> >> +            }
> >> +            arg = token + 5;
> >> +        } else {
> >> +            break;
> >> +        }
> >> +        i++;
> >> +    }
> >> +    if (!*arg) {
> >> +        goto end;
> >> +    } else if (*arg == '+') {
> >> +        arg++;
> >> +    } else if (!i) {
> >> +        flags = av_log_get_flags();  /* level value without prefix, reset flags */
> >> +    }
> >> +
> >> +    for (i = 0; i < FF_ARRAY_ELEMS(log_levels); i++) {
> >> +        if (!strcmp(arg, log_levels[i].name)) {
> >> +            level = log_levels[i].level;
> >> +            goto end;
> >> +        }
> >> +    }
> >> +
> >> +    level = strtol(arg, &tail, 10);
> >> +    if (*tail) {
> >> +        return -1;
> >> +    }
> >> +
> >> +end:
> >> +    av_log_set_flags(flags);
> >> +    av_log_set_level(level);
> >> +    return 0;
> >> +}
> >> +
> >>   static void missing_feature_sample(int sample, void *avc, const char *msg,
> >>                                      va_list argument_list)
> >>   {
> >> diff --git a/libavutil/log.h b/libavutil/log.h
> >> index d9554e6..97010f7 100644
> >> --- a/libavutil/log.h
> >> +++ b/libavutil/log.h
> >> @@ -356,6 +356,22 @@ void av_log_set_flags(int arg);
> >>   int av_log_get_flags(void);
> >>   
> >>   /**
> >> + * Set log flags and level as an option string. Accepts "repeat" and "level"
> >> + * flags mapped to AV_LOG_SKIP_REPEATED (inverted) and AV_LOG_PRINT_LEVEL,
> >> + * followed by the log level specified either by name ("warning", "info",
> >> + * "verbose", etc.) or by number.
> >> + *
> >> + * When flags are prefixed with "+" or "-" the change is relative to the
> >> + * current flags value. When both flags and level are present a "+" separator
> >> + * is expected between last flag and before level.
> >> + *
> >> + * @param  arg  log option string
> >> + * @return Returns a negative value if parsing the option string failed,
> >> + *         otherwise returns 0.
> >> + */
> >> +int av_log_set_opts(const char *arg);
> >> +
> >> +/**
> >>    * @}
> >>    */
> >>   
> >> diff --git a/libavutil/version.h b/libavutil/version.h
> >> index d3dd2df..296c24b 100644
> >> --- a/libavutil/version.h
> >> +++ b/libavutil/version.h
> >> @@ -79,7 +79,7 @@
> >>    */
> >>   
> >>   #define LIBAVUTIL_VERSION_MAJOR  56
> >> -#define LIBAVUTIL_VERSION_MINOR  12
> >> +#define LIBAVUTIL_VERSION_MINOR  13
> >>   #define LIBAVUTIL_VERSION_MICRO 100
> >>   
> >>   #define LIBAVUTIL_VERSION_INT   AV_VERSION_INT(LIBAVUTIL_VERSION_MAJOR, \  
> > 
> > Seems like a step backwards. Why can't it stay in the fftools thing?  
> 
> When v2 of the patch was reviewed in 
> http://ffmpeg.org/pipermail/ffmpeg-devel/2018-March/227077.html it was 
> suggested to move the code into libavutil so that other applications can 
> make use of it. I agree that it can be useful for command-line apps that 
> interface with libav* to provide a loglevel option which accepts 
> info/verbose/etc. name strings without the need to do an own 
> string-to-level parsing.

That seems completely unnecessary. Applications will have their own
conventions and option parsers.


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