[x265] Videos encoded with x265 have wrong framerate

[Steve Borho]

On Mon, Feb 24, 2014 at 4:37 PM, Niccolò Belli
<darkbasic at linuxsystems.it> wrote:
> Hi,
> I encode my videos with
>
> ffmpeg -v 0 -i ~/PlanetEarthBirds.mkv -threads 4 -vsync 0 -an -pix_fmt yuv420p
> -f yuv4mpegpipe - | ./x265 - --y4m --preset placebo --crf 28 -o prova.h265
>
> The source is 23.98 fps but the encoded video shows 25 fps instead:
>
> Stream #0:0: Video: hevc (Main), yuv420p(tv), 1920x1080, 25 fps, 25 tbr, 1200k
> tbn, 25 tbc
>
> VIDEO:  [HEVC]  1920x1080  0bpp  25.000 fps    0.0 kbps ( 0.0 kbyte/s)
>
> If I encode the same video in the same way using x264 it works flawlessly:
>
> Stream #0:0: Video: h264 (Constrained Baseline), yuv420p, 1920x1080 [SAR 1:1
> DAR 16:9], 23.98 fps, 23.98 tbr, 1200k tbn, 47.95 tbc
>
> VIDEO:  [H264]  1920x1080  0bpp  23.976 fps    0.0 kbps ( 0.0 kbyte/s)
>
> Encoding with --fps 23.976 does not help.

Hello Niccolò,

There has been a large amount of work done on this in just the last
week, and we're still picking through the details.  Previously, x265
would never add a VUI header with timing info to the bitstream, so the
frame rate was never signaled.  On the tip, the VUI and timing info
are now optional, you have to pass the --timinginfo flag to enable
them.

We should probably make timing info default to enabled.

-- 
Steve Borho