[FFmpeg-devel] [PATCH v7 1/3] avutil/log: Add log flag AV_LOG_PRINT_MEMADDRESSES

[Andreas Rheinhardt]

softworkz:
> From: softworkz <softworkz at hotmail.com>
> 
> which is controls prefix formatting. With this flag set, the prefix is
> printed including the memory address, otherwise it is omitted.
> In libavutil, the flag is set by default, retaining the previous
> behavior. fftools remove the flag as default.

The implementation of this flag is counter to the usual one: It is
enabled by default, but every av_log_set_flags() that does not set
AV_LOG_PRINT_MEMADDRESSES implicitly disables printing memory addresses.
This means that it will affect users that do not opt into this. I don't
think this is intended or that the new system makes sense.
(Due to the av_log_set_flags(AV_LOG_SKIP_REPEATED) performed early in
the main function of the fftools, they are of this kind even with this
patch alone.)

> 
> Signed-off-by: softworkz <softworkz at hotmail.com>
> ---
>  doc/APIchanges      | 3 +++
>  libavutil/log.c     | 8 +++++---
>  libavutil/log.h     | 5 +++++
>  libavutil/version.h | 2 +-
>  4 files changed, 14 insertions(+), 4 deletions(-)
> 
> diff --git a/doc/APIchanges b/doc/APIchanges
> index 65bf5a9419..27afa5ba81 100644
> --- a/doc/APIchanges
> +++ b/doc/APIchanges
> @@ -1,5 +1,8 @@
>  The last version increases of all libraries were on 2025-03-28
>  
> +2025-03-xx - xxxxxxxxxx - lavu 60.2.100 - log.h
> +  Add flag AV_LOG_PRINT_MEMADDRESSES
> +
>  API changes, most recent first:
>  
>  2025-04-07 - 19e9a203b7 - lavu 60.01.100 - dict.h
> diff --git a/libavutil/log.c b/libavutil/log.c
> index c5ee876a88..7ce23cc31f 100644
> --- a/libavutil/log.c
> +++ b/libavutil/log.c
> @@ -56,7 +56,7 @@ static AVMutex mutex = AV_MUTEX_INITIALIZER;
>  #endif
>  
>  static int av_log_level = AV_LOG_INFO;
> -static int flags;
> +static int flags = AV_LOG_PRINT_MEMADDRESSES;
>  
>  #define NB_LEVELS 8
>  #if defined(_WIN32) && HAVE_SETCONSOLETEXTATTRIBUTE && HAVE_GETSTDHANDLE
> @@ -327,16 +327,18 @@ static void format_line(void *avcl, int level, const char *fmt, va_list vl,
>  
>      if(type) type[0] = type[1] = AV_CLASS_CATEGORY_NA + 16;
>      if (*print_prefix && avc) {
> +        const char *p_fmt = flags & AV_LOG_PRINT_MEMADDRESSES ? "[%s @ %p] " : "[%s] ";
> +
>          if (avc->parent_log_context_offset) {
>              AVClass** parent = *(AVClass ***) (((uint8_t *) avcl) +
>                                     avc->parent_log_context_offset);
>              if (parent && *parent) {
> -                av_bprintf(part+0, "[%s @ %p] ",
> +                av_bprintf(part+0, p_fmt,
>                             item_name(parent, *parent), parent);
>                  if(type) type[0] = get_category(parent);
>              }
>          }
> -        av_bprintf(part+1, "[%s @ %p] ",
> +        av_bprintf(part+1, p_fmt,
>                     item_name(avcl, avc), avcl);
>          if(type) type[1] = get_category(avcl);
>      }
> diff --git a/libavutil/log.h b/libavutil/log.h
> index dd094307ce..450b4544b9 100644
> --- a/libavutil/log.h
> +++ b/libavutil/log.h
> @@ -416,6 +416,11 @@ int av_log_format_line2(void *ptr, int level, const char *fmt, va_list vl,
>   */
>  #define AV_LOG_PRINT_DATETIME 8
>  
> +/**
> + * Print memory addresses instead of logical ids in the AVClass prefix.

The logical id system has been removed from this patchset.

> + */
> +#define AV_LOG_PRINT_MEMADDRESSES 16

AV_LOG_PRINT_MEMADDRESS seems better given that every av_log() will
likely only print one memaddress.

> +
>  void av_log_set_flags(int arg);
>  int av_log_get_flags(void);
>  
> diff --git a/libavutil/version.h b/libavutil/version.h
> index 5139883569..4717cd562b 100644
> --- a/libavutil/version.h
> +++ b/libavutil/version.h
> @@ -79,7 +79,7 @@
>   */
>  
>  #define LIBAVUTIL_VERSION_MAJOR  60
> -#define LIBAVUTIL_VERSION_MINOR   1
> +#define LIBAVUTIL_VERSION_MINOR   2
>  #define LIBAVUTIL_VERSION_MICRO 100
>  
>  #define LIBAVUTIL_VERSION_INT   AV_VERSION_INT(LIBAVUTIL_VERSION_MAJOR, \