[FFmpeg-devel] [PATCH v7 0/3] avutil/log: Add log flag to control printing of memory addresses

[ffmpegagent <ffmpegagent@gmail.com>]

--and disable by default in fftools. The benefits are:

 * Smaller log file sizes
 * Makes log files better readable
 * Allows comparing and viewing log file diffs without almost every line
   being different due to those addresses


Before
======

[hevc @ 0000018e72a89cc0] nal_unit_type:
[hevc @ 0000018e72a89cc0] Decoding PPS
[hevc @ 0000018e72a89cc0] nal_unit_type: 39(SEI_P.. [hevc @
0000018e72a89cc0] Decoding SEI
[mp4 @ 0000018e72a8e240] All [mp4 @ 0000018e72a8e240] Afte [hevc @
0000018e742f6b40] Decoded frame with POC .. detected 16 logical cores
[Parsed_scale_0 @ 0000018e74382f40] Setting 'w' t.. [Parsed_scale_0 @
0000018e74382f40] Setting 'h' t.. [Parsed_scale_1 @ 0000018e74382440]
Setting 'w' t.. [mjpeg @ 0000018e743210c0] Forcing thread count t.. [mjpeg @
0000018e743210c0] intra_quant_bias = 96


After
=====

[hevc] nal_unit_type: [hevc] Decoding PPS
[hevc] nal_unit_type: 39(SEI_P.. [hevc] Decoding SEI
[mp4] All info found
[mp4] After avformat_find_ [hevc] Decoded frame with POC 2.
[Parsed_scale_0] Setting 'w' t.. [Parsed_scale_0] Setting 'h' t..
[Parsed_scale_1] Setting 'w' t.. [mjpeg] Forcing thread count t.. [mjpeg]
intra_quant_bias = 96


Versions
========


V2
==

 * Added log flag for optionally restoring the previous behavior (as
   requested by Gyan)


V3
==

 * Externalize the prefix formatting with a prefix_format callback


V4
==

 * Implement a custom logging callback function for fftools instead of the
   prefix formatting callback (as suggested by Hendrik Leppkes)


V5
==

 * Remove unused var
 * Add missing include to fix build error on PPC (thanks, Michael)


V6
==

 * No more changes to avutil involved
 * Let fftools have its own management of log level and flags (as figured to
   be most likely what Nicolas George was alluding to)


V7
==

 * Minimal version without "simple id" substitution
 * Defaults for printing mem addresses:
   * fftools: off
   * avutil: on

softworkz (3):
  avutil/log: Add log flag AV_LOG_PRINT_MEMADDRESSES
  fftools/opt_common: add memaddresses log flag
  doc/fftools-common-opts: document memaddresses log flag

 doc/APIchanges               |  3 +++
 doc/fftools-common-opts.texi |  2 ++
 fftools/opt_common.c         | 10 ++++++++++
 libavutil/log.c              |  8 +++++---
 libavutil/log.h              |  5 +++++
 libavutil/version.h          |  2 +-
 6 files changed, 26 insertions(+), 4 deletions(-)


base-commit: 02eda84bf2fcf0db7793872204b0f564a6557232
Published-As: https://github.com/ffstaging/FFmpeg/releases/tag/pr-ffstaging-59%2Fsoftworkz%2Fsubmit_logaddresses-v7
Fetch-It-Via: git fetch https://github.com/ffstaging/FFmpeg pr-ffstaging-59/softworkz/submit_logaddresses-v7
Pull-Request: https://github.com/ffstaging/FFmpeg/pull/59

Range-diff vs v6:

 1:  8080f15800 < -:  ---------- fftools: Add a local logging callback function
 2:  bab6b91549 ! 1:  6c2d6f1e97 fftools/opt_common: add memaddresses log flag
     @@ Metadata
      Author: softworkz <softworkz@hotmail.com>
      
       ## Commit message ##
     -    fftools/opt_common: add memaddresses log flag
     +    avutil/log: Add log flag AV_LOG_PRINT_MEMADDRESSES
      
     -    This commit adds the memaddresses log flag.
     -    When specifying this flag at the command line, context prefixes will
     -    be printed with memory addresses like in earlier ffmpeg versions.
     -    Memory addresses are no longer printed by default.
     -
     -    The benefits are:
     -
     -    - Smaller log file sizes
     -    - The disambiguation is much easier to recognize and to follow
     -    - It eventually allows comparing and viewing log file diffs
     -      without almost every line being different due to those addresses
     -
     -    Example with memaddresses flag:
     -
     -    [hevc @ 0000018e72a89cc0] .....
     -
     -    without (new behavior):
     -
     -    [hevc #0] .....
     +    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.
      
          Signed-off-by: softworkz <softworkz@hotmail.com>
      
     - ## fftools/cmdutils.c ##
     + ## doc/APIchanges ##
      @@
     - #include "libavutil/dict.h"
     - #include "libavutil/opt.h"
     - #include "cmdutils.h"
     + 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
      +
     - #include "fftools_log.h"
     - #include "fopen_utf8.h"
     - #include "opt_common.h"
     + API changes, most recent first:
     + 
     + 2025-04-07 - 19e9a203b7 - lavu 60.01.100 - dict.h
      
     - ## fftools/fftools_log.c ##
     -@@ fftools/fftools_log.c: static inline struct tm *ff_localtime_r(const time_t* clock, struct tm *result)
     - #define localtime_r ff_localtime_r
     + ## libavutil/log.c ##
     +@@ libavutil/log.c: static AVMutex mutex = AV_MUTEX_INITIALIZER;
       #endif
       
     -+#define MAX_CLASS_IDS 1000
     -+static struct class_ids {
     -+    void *avcl;
     -+    uint64_t class_hash;
     -+    unsigned id;
     -+} class_ids[MAX_CLASS_IDS];
     -+
     -+static uint64_t fnv_hash(const char *str)
     -+{
     -+    // FNV-1a 64-bit hash algorithm
     -+    uint64_t hash = 0xcbf29ce484222325ULL;
     -+    while (*str) {
     -+        hash ^= (unsigned char)*str++;
     -+        hash *= 0x100000001b3ULL;
     -+    }
     -+    return hash;
     -+}
     -+
     -+static unsigned get_class_id(void* avcl)
     -+{
     -+    AVClass* avc = avcl ? *(AVClass **) avcl : NULL;
     -+    unsigned i, nb_ids = 0;
     -+    uint64_t class_hash;
     -+
     -+    for (i = 0; i < MAX_CLASS_IDS && class_ids[i].avcl; i++) {
     -+        if (class_ids[i].avcl == avcl)
     -+            return class_ids[i].id;
     -+    }
     -+
     -+    class_hash = fnv_hash(avc->class_name);
     -+
     -+    for (i = 0; i < MAX_CLASS_IDS; i++) {
     -+        if (class_ids[i].class_hash == class_hash)
     -+            nb_ids++;
     -+
     -+        if (!class_ids[i].avcl) {
     -+            class_ids[i].avcl = avcl;
     -+            class_ids[i].class_hash = class_hash;
     -+            class_ids[i].id = nb_ids;
     -+            return class_ids[i].id;
     -+        }
     -+    }
     -+
     -+    // exceeded MAX_CLASS_IDS entries in class_ids[]
     -+    return 0;
     -+}
     -+
     - static AVMutex mutex = AV_MUTEX_INITIALIZER;
     + static int av_log_level = AV_LOG_INFO;
     +-static int flags;
     ++static int flags = AV_LOG_PRINT_MEMADDRESSES;
       
     - #define LINE_SZ 1024
     -@@ fftools/fftools_log.c: static void format_date_now(AVBPrint* bp_time, int include_date)
     -     }
     - }
     - 
     -+static void log_formatprefix(AVBPrint* buffer, AVClass** avcl)
     -+{
     -+    const int print_mem = ff_log_flags & FF_LOG_PRINT_MEMADDRESSES;
     -+    if (print_mem)
     -+        av_bprintf(buffer+0, "[%s @ %p] ", item_name(avcl, *avcl), avcl);
     -+    else
     -+        av_bprintf(buffer+0, "[%s #%u] ", item_name(avcl, *avcl), get_class_id(avcl));
     -+}
     -+
     - static void format_line(void *avcl, int level, const char *fmt, va_list vl,
     -                         AVBPrint part[5], int *print_prefix, int type[2])
     - {
     -@@ fftools/fftools_log.c: static void format_line(void *avcl, int level, const char *fmt, va_list vl,
     + #define NB_LEVELS 8
     + #if defined(_WIN32) && HAVE_SETCONSOLETEXTATTRIBUTE && HAVE_GETSTDHANDLE
     +@@ libavutil/log.c: 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);
     -+            AVClass** parent = *(AVClass ***) ((uint8_t *)avcl + 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] ",
     --                           item_name(parent, *parent), parent);
     -+                log_formatprefix(part, parent);
     ++                av_bprintf(part+0, p_fmt,
     +                            item_name(parent, *parent), parent);
                       if(type) type[0] = get_category(parent);
                   }
               }
      -        av_bprintf(part+1, "[%s @ %p] ",
     --                   item_name(avcl, avc), avcl);
     -+        log_formatprefix(part, avcl);
     -+
     ++        av_bprintf(part+1, p_fmt,
     +                    item_name(avcl, avc), avcl);
               if(type) type[1] = get_category(avcl);
           }
     - 
      
     - ## fftools/fftools_log.h ##
     -@@ fftools/fftools_log.h: int ff_log_get_flags(void);
     + ## libavutil/log.h ##
     +@@ libavutil/log.h: int av_log_format_line2(void *ptr, int level, const char *fmt, va_list vl,
        */
     - #define FF_LOG_PRINT_DATETIME 8
     + #define AV_LOG_PRINT_DATETIME 8
       
      +/**
      + * Print memory addresses instead of logical ids in the AVClass prefix.
      + */
     -+#define FF_LOG_PRINT_MEMADDRESSES 16
     ++#define AV_LOG_PRINT_MEMADDRESSES 16
      +
     + void av_log_set_flags(int arg);
     + int av_log_get_flags(void);
       
     - #endif /* FFTOOLS_FFTOOLS_LOG_H */
      
     - ## fftools/opt_common.c ##
     -@@ fftools/opt_common.c: int opt_loglevel(void *optctx, const char *opt, const char *arg)
     -             } else {
     -                 flags |= FF_LOG_PRINT_DATETIME;
     -             }
     -+        } else if (av_strstart(token, "memaddresses", &arg)) {
     -+            if (cmd == '-') {
     -+                flags &= ~FF_LOG_PRINT_MEMADDRESSES;
     -+            } else {
     -+                flags |= FF_LOG_PRINT_MEMADDRESSES;
     -+            }
     -         } else {
     -             break;
     -         }
     + ## libavutil/version.h ##
     +@@
     +  */
     + 
     + #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, \
 -:  ---------- > 2:  7c4cfd5f67 fftools/opt_common: add memaddresses log flag
 3:  ea2a970d23 ! 3:  6d3f305d0f doc/fftools-common-opts: document memaddresses log flag
     @@ Metadata
       ## Commit message ##
          doc/fftools-common-opts: document memaddresses log flag
      
     +    Signed-off-by: softworkz <softworkz@hotmail.com>
     +
       ## doc/fftools-common-opts.texi ##
      @@ doc/fftools-common-opts.texi: log to file.
       Indicates that log lines should be prefixed with time information.

-- 
ffmpeg-codebot
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