Remuxing 25 fps single frame file to nut container seemingly results in a frame rate of 52000 FPS

[rmk]

See command lines and output. The resulting file is reported by both ffmpeg and ffprobe as having 52000 fps (if I interprete it correctly) and not as the input file as 25 fps.

ffmpeg -i black_frame_full_hd_ffv1_yuv444p.mov -c copy -y out.nut
ffmpeg version N-62704-g92cc6d5 Copyright (c) 2000-2014 the FFmpeg developers

built on May 6 2014 17:19:30 with Apple LLVM version 5.1 (clang-503.0.40) (based on LLVM 3.4svn)
configuration: --enable-gpl
libavutil 52. 78.100 / 52. 78.100
libavcodec 55. 59.100 / 55. 59.100
libavformat 55. 37.101 / 55. 37.101
libavdevice 55. 13.100 / 55. 13.100
libavfilter 4. 4.100 / 4. 4.100
libswscale 2. 6.100 / 2. 6.100
libswresample 0. 18.100 / 0. 18.100
libpostproc 52. 3.100 / 52. 3.100

Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'black_frame_full_hd_ffv1_yuv444p.mov':

Metadata:

major_brand : qt
minor_version : 512
compatible_brands: qt
encoder : Lavf55.24.100

Duration: 00:00:00.04, start: 0.000000, bitrate: 630 kb/s

Stream #0:0(eng): Video: ffv1 (FFV1 / 0x31564646), yuv444p, 1920x1080, 472 kb/s, 25 fps, 25 tbr, 12800 tbn, 12800 tbc (default)
Metadata:

handler_name : DataHandler

Output #0, nut, to 'out.nut':

Metadata:

major_brand : qt
minor_version : 512
compatible_brands: qt
encoder : Lavf55.37.101
Stream #0:0: Video: ffv1 (FFV1 / 0x31564646), yuv444p, 1920x1080, q=2-31, 472 kb/s, 25 fps, 51200 tbn, 12800 tbc (default)
Metadata:

X-Language : eng
handler_name : DataHandler

Stream mapping:

Stream #0:0 -> #0:0 (copy)

Press [q] to stop, ? for help
frame= 1 fps=0.0 q=-1.0 Lsize= 3kB time=00:00:00.00 bitrate=286256.4kbits/s
video:2kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 18.262712%

ffprobe -i out.nut -show_streams
ffprobe version N-62704-g92cc6d5 Copyright (c) 2007-2014 the FFmpeg developers

built on May 6 2014 17:19:30 with Apple LLVM version 5.1 (clang-503.0.40) (based on LLVM 3.4svn)
configuration: --enable-gpl
libavutil 52. 78.100 / 52. 78.100
libavcodec 55. 59.100 / 55. 59.100
libavformat 55. 37.101 / 55. 37.101
libavdevice 55. 13.100 / 55. 13.100
libavfilter 4. 4.100 / 4. 4.100
libswscale 2. 6.100 / 2. 6.100
libswresample 0. 18.100 / 0. 18.100
libpostproc 52. 3.100 / 52. 3.100

Input #0, nut, from 'out.nut':

Metadata:

major_brand : qt
minor_version : 512
compatible_brands: qt
encoder : Lavf55.37.101

Duration: 00:00:00.00, start: 0.000000, bitrate: N/A

Stream #0:0(eng): Video: ffv1 (FFV1 / 0x31564646), yuv444p, 1920x1080, 51200 tbr, 51200 tbn, 51200 tbc (default)
Metadata:

handler_name : DataHandler

[STREAM]
index=0
codec_name=ffv1
codec_long_name=FFmpeg video codec #1
profile=unknown
codec_type=video
codec_time_base=1/51200
codec_tag_string=FFV1
codec_tag=0x31564646
width=1920
height=1080
has_b_frames=0
sample_aspect_ratio=0:1
display_aspect_ratio=0:1
pix_fmt=yuv444p
level=-99
timecode=N/A
id=N/A
r_frame_rate=51200/1
avg_frame_rate=0/0
time_base=1/51200
start_pts=0
start_time=0.000000
duration_ts=N/A
duration=N/A
bit_rate=N/A
nb_frames=N/A
nb_read_frames=N/A
nb_read_packets=N/A
DISPOSITION:default=1
DISPOSITION:dub=0
DISPOSITION:original=0
DISPOSITION:comment=0
DISPOSITION:lyrics=0
DISPOSITION:karaoke=0
DISPOSITION:forced=0
DISPOSITION:hearing_impaired=0
DISPOSITION:visual_impaired=0
DISPOSITION:clean_effects=0
DISPOSITION:attached_pic=0
TAG:language=eng
TAG:handler_name=DataHandler
STREAM

[Michael Niedermayer]

Fixed in
add46edf33a72b5b3d3af3761d7b372d16769911
28a6f970f64c4d5c1326dd68393bedf73cc42e10
3b537eab27bb34f5f63b06097fbd52ff5941c3f6