[FFmpeg-devel] [PATCH] avutil/log: Replace addresses in log output with simple ids

[Gyan Doshi]

On 2025-03-05 09:08 pm, softworkz wrote:
> From: softworkz <softworkz at hotmail.com>
>
> ..and individual numbering. 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

I like being able to get rid of the addresses, but it should be 
user-selectable via a flag.

Regards,
Gyan


>
> Signed-off-by: softworkz <softworkz at hotmail.com>
> ---
>      avutil/log: Replace addresses in log output with simple ids
>      
>      ..and individual numbering. 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
>      
>      
>      Before
>      ======
>      
>      [hevc @ 0000018e72a89cc0] nal_unit_type: 34(PPS), nuh_layer_id: 0,
>      tempora.. [hevc @ 0000018e72a89cc0] Decoding PPS [hevc @
>      0000018e72a89cc0] nal_unit_type: 39(SEI_PREFIX), nuh_layer_id: 0, [hevc
>      @ 0000018e72a89cc0] Decoding SEI [mov,mp4,m4a,3gp,3g2,mj2 @
>      0000018e72a8e240] All info found [mov,mp4,m4a,3gp,3g2,mj2 @
>      0000018e72a8e240] After avformat_find_stream_in.. [hevc @
>      0000018e742f6b40] Decoded frame with POC 2. detected 16 logical cores
>      [Parsed_scale_0 @ 0000018e74382f40] Setting 'w' to value '320'
>      [Parsed_scale_0 @ 0000018e74382f40] Setting 'h' to value '180'
>      [Parsed_scale_1 @ 0000018e74382440] Setting 'w' to value '320' [mjpeg @
>      0000018e743210c0] Forcing thread count to 1 for MJPEG encoding, u..
>      [mjpeg @ 0000018e743210c0] intra_quant_bias = 96 inter_quant_bias = 0
>      
>      
>      After
>      =====
>      
>      [hevc #0] nal_unit_type: 34(PPS), nuh_layer_id: 0, temporal_id: 0 [hevc
>      #0] Decoding PPS [hevc #0] nal_unit_type: 39(SEI_PREFIX), nuh_layer_id:
>      0, temporal_id: 0 [hevc #0] Decoding SEI [mov,mp4,m4a,3gp,3g2,mj2 #0]
>      All info found [mov,mp4,m4a,3gp,3g2,mj2 #0] After
>      avformat_find_stream_info() pos: 310096.. [hevc #1] Decoded frame with
>      POC 2. [Parsed_scale_0 #0] Setting 'w' to value '320' [Parsed_scale_0
>      #0] Setting 'h' to value '180' [Parsed_scale_2 #2] w:320 h:180
>      fmt:yuv420p10le sar:0/1 -> w:320 h:180 fmt.. [mjpeg #2] Forcing thread
>      count to 1 for MJPEG encoding, use -thread_type [mjpeg #2]
>      intra_quant_bias = 96 inter_quant_bias = 0
>
> Published-As: https://github.com/ffstaging/FFmpeg/releases/tag/pr-ffstaging-59%2Fsoftworkz%2Fsubmit_logaddresses-v1
> Fetch-It-Via: git fetch https://github.com/ffstaging/FFmpeg pr-ffstaging-59/softworkz/submit_logaddresses-v1
> Pull-Request: https://github.com/ffstaging/FFmpeg/pull/59
>
>   libavutil/log.c | 57 +++++++++++++++++++++++++++++++++++++++++++++----
>   1 file changed, 53 insertions(+), 4 deletions(-)
>
> diff --git a/libavutil/log.c b/libavutil/log.c
> index c5ee876a88..50c8c41ef8 100644
> --- a/libavutil/log.c
> +++ b/libavutil/log.c
> @@ -57,6 +57,55 @@ static AVMutex mutex = AV_MUTEX_INITIALIZER;
>   
>   static int av_log_level = AV_LOG_INFO;
>   static int flags;
> +static int nb_class_ids;
> +
> +#define NB_CLASS_IDS 1000
> +static struct class_ids {
> +    void *avcl;
> +    uint64_t class_hash;
> +    unsigned id;
> +} class_ids[NB_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;
> +    const char* class_name = avc->item_name(avcl);
> +    unsigned i, nb_ids = 0;
> +    uint64_t class_hash;
> +
> +    for (i = 0; i < NB_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 < NB_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 NB_CLASS_IDS entries in class_ids[]
> +    return 0;
> +}
>   
>   #define NB_LEVELS 8
>   #if defined(_WIN32) && HAVE_SETCONSOLETEXTATTRIBUTE && HAVE_GETSTDHANDLE
> @@ -331,13 +380,13 @@ static void format_line(void *avcl, int level, const char *fmt, va_list vl,
>               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);
> +                av_bprintf(part+0, "[%s #%u] ",
> +                           item_name(parent, *parent), get_class_id(parent));
>                   if(type) type[0] = get_category(parent);
>               }
>           }
> -        av_bprintf(part+1, "[%s @ %p] ",
> -                   item_name(avcl, avc), avcl);
> +        av_bprintf(part+1, "[%s #%u] ",
> +                   item_name(avcl, avc), get_class_id(avcl));
>           if(type) type[1] = get_category(avcl);
>       }
>   
>
> base-commit: 5c5be37daff4f4ecbe0c20d6a9f0fdad6eadc9c8