[FFmpeg-user] Feature request: show the "speed" of audio only conversions

[Moritz Barsnick]

Hi Roger, users,

On Tue, Jun 30, 2015 at 15:49:34 -0600, Roger Pack wrote:
> On 6/11/15, Moritz Barsnick <barsnick at gmx.net> wrote:
> > On Thu, Jun 11, 2015 at 10:31:54 -0600, Roger Pack wrote:
> > Which is something like a "5.3x" display, such as lame shows it (I
> > think).
> >
> > I think that is just as valid a request for video. I do see the fps,
> > but I need to do quick head-math and know the fps of the source.
> >
> > That said, there may be some ambiguity with regards to which base to
> > take: Input PTS, output PTS; what about jumps in PTS? Can this work
> > when copying? I'm thinking out loud too much. ;)

I have done some thinking, and I am convinced I need this feature.

> It would be a huge win to get an "estimated time to completion" as well :)

This is too tricky in this part of the code. I think the muxers and
demuxers handle durations, and it becomes more complicated if VBR, trim
filters, enable expressions and other complicated stuff are involved.
So while an ETA (or a progress in percent) would be nice, I can't wrap
my head around it.

That said, here's a not-so-quick shot at a speed display (attached). I
made some other approaches with some other calculations, but it never
made enough sense.

I used "%.3g" for the printf format, as I like the number of relevant
digits this way. I haven't looked at the portability of %g across
supported compilers though.

I haven't bothered writing any info into the "progress information"
(&buf_script) at this point. I probably should for consistency.

Disclaimer: I don't know if we should even try to get this upstream.
I'm just playing with the possibilities. ;-) Just for you and me,
Roger.

[That function could really really really make use of a macro for
 snprintf(buf + strlen(buf), sizeof(buf) - strlen(buf), ...);
 14 occurrences!
 ;-) ]

Moritz
-------------- next part --------------
--- ffmpeg-build-2015-08-31/ffmpeg.c	2015-08-29 19:20:04.000000000 +0200
+++ ffmpeg-build-2015-08-31-speedrate/ffmpeg.c	2015-09-03 10:57:01.000000000 +0200
@@ -1536,10 +1536,12 @@
     AVCodecContext *enc;
     int frame_number, vid, i;
     double bitrate;
+    double speed;
     int64_t pts = INT64_MIN;
     static int64_t last_time = -1;
     static int qp_histogram[52];
     int hours, mins, secs, us;
+    float t;
 
     if (!print_stats && !is_last_report && !progress_avio)
         return;
@@ -1554,6 +1556,8 @@
         last_time = cur_time;
     }
 
+    t = (cur_time-timer_start) / 1000000.0;
+
 
     oc = output_files[0]->ctx;
 
@@ -1577,7 +1581,7 @@
                        ost->file_index, ost->index, q);
         }
         if (!vid && enc->codec_type == AVMEDIA_TYPE_VIDEO) {
-            float fps, t = (cur_time-timer_start) / 1000000.0;
+            float fps;
 
             frame_number = ost->frame_number;
             fps = t > 1 ? frame_number / t : 0;
@@ -1645,6 +1649,7 @@
     mins %= 60;
 
     bitrate = pts && total_size >= 0 ? total_size * 8 / (pts / 1000.0) : -1;
+    speed = t != 0.0 ? (double)pts / AV_TIME_BASE / t : -1;
 
     if (total_size < 0) snprintf(buf + strlen(buf), sizeof(buf) - strlen(buf),
                                  "size=N/A time=");
@@ -1676,6 +1681,12 @@
     av_bprintf(&buf_script, "dup_frames=%d\n", nb_frames_dup);
     av_bprintf(&buf_script, "drop_frames=%d\n", nb_frames_drop);
 
+    if (speed < 0) {
+        snprintf(buf + strlen(buf), sizeof(buf) - strlen(buf)," speed=N/A");
+    } else {
+        snprintf(buf + strlen(buf), sizeof(buf) - strlen(buf)," speed=%.3gx", speed);
+    }
+    
     if (print_stats || is_last_report) {
         const char end = is_last_report ? '\n' : '\r';
         if (print_stats==1 && AV_LOG_INFO > av_log_get_level()) {