[FFmpeg-devel] [PATCH] avfilter/af_atempo: offset all output timestamps by same amount of first input timestamp

[Pavel Koshevoy]

btw, I don't know if there is already a way to do this with an existing utility 
function... there probably is and I just don't know about it.

I wrote this debugging helper to help me verify input/output PTS in atempo, I 
can send a patch if it's useful.  Alternatively, I'd like to know what the right 
way to get the same result would be with existing utility functions


static const char * hh_mm_ss_msec(char buf[15], AVRational b, int64_t t)
{
   char * str = buf;
   t = av_rescale_q(t, b, (AVRational){ 1, 1000 });

   if (t < 0)
   {
     *str++ = '-';
     t = -t;
   }

   // msec:
   {
     char * p = str + 8;
     p[4] = 0;

     p[3] = '0' + (t % 10);
     t /= 10;

     p[2] = '0' + (t % 10);
     t /= 10;

     p[1] = '0' + (t % 10);
     t /= 10;

     p[0] = '.';
   }

   // seconds:
   {
     int64_t v = t % 60;
     char * p = str + 5;

     p[2] = '0' + (v % 10);
     v /= 10;

     p[1] = '0' + v;
     t /= 60;

     p[0] = ':';
   }

   // minutes:
   {
     int64_t v = t % 60;
     char * p = str + 2;

     p[2] = '0' + (v % 10);
     v /= 10;

     p[1] = '0' + v;
     t /= 60;

     p[0] = ':';
   }

   // hours:
   {
     int64_t v = t % 100;
     str[1] = '0' + (v % 10);
     v /= 10;

     str[0] = '0' + v;
   }

   return buf;
}



// elsewhere
     char buf_src[15];
     char buf_dst[15];

...

     av_log(outlink->src, AV_LOG_WARNING,
            "FIXME: pkoshevoy: atempo pts: %s -> %s\n",
            hh_mm_ss_msec(buf_src,
                          (AVRational){ 1, outlink->sample_rate },
                          yae_curr_frag(atempo)->position[0] -
                          yae_curr_frag(atempo)->nsamples),
            hh_mm_ss_msec(buf_dst,
                          outlink->time_base,
                          atempo->dst_buffer->pts));


// and the output looks like this:
[Parsed_atempo_2 @ 0x6a5ec0] FIXME: pkoshevoy: atempo pts: 00:00:29.991 -> 00:00:29.989
[Parsed_atempo_2 @ 0x6a5ec0] FIXME: pkoshevoy: atempo pts: 00:00:29.991 -> 00:00:30.002
[Parsed_atempo_2 @ 0x6a5ec0] FIXME: pkoshevoy: atempo pts: 00:00:30.043 -> 00:00:30.015
[Parsed_atempo_2 @ 0x6a5ec0] FIXME: pkoshevoy: atempo pts: 00:00:30.043 -> 00:00:30.028
[Parsed_atempo_2 @ 0x6a5ec0] FIXME: pkoshevoy: atempo pts: 00:00:30.093 -> 00:00:30.041
[Parsed_atempo_2 @ 0x6a5ec0] FIXME: pkoshevoy: atempo pts: 00:00:30.093 -> 00:00:30.054