ffmpeg failed to drop stream with unsupported codec [duplicate] - ffmpeg

Question

I have downloaded a [short media][1] i intend to convert then i will use the result as basis to practice and test any and all FFMPEG commands i learn or use later.
That video seems to have an unknown invalid stream which never disappears no matter everything i tried to discard it. When i try to work with it later i get various problems like missing codec or no stream which is not the focus here but the reason why i got stubborn to remove the things i cannot deal with.
The following probing prints a warning in yellow color on last row.
> ffprobe -hide_banner -show_streams Movie_Countdown-youtube_I1vMKZ1kvg0.mov
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'Movie_Countdown-youtube_I1vMKZ1kvg0.mov':
Metadata:
major_brand : qt
minor_version : 537199360
compatible_brands: qt
creation_time : 2015-05-20T13:45:55.000000Z
Duration: 00:00:10.00, start: 0.000000, bitrate: 11474 kb/s
Stream #0:0(eng): Video: h264 (Main) (avc1 / 0x31637661), yuv420p(tv, bt709), 1920x1080, 9930 kb/s, SAR 1:1 DAR 16:9, 25 fps, 25 tbr, 25 tbn, 50 tbc (default)
Metadata:
creation_time : 2015-05-20T13:45:55.000000Z
handler_name : Apple Video Media Handler
encoder : H.264
timecode : 00:00:00:00
Stream #0:1(eng): Audio: pcm_s16le (sowt / 0x74776F73), 48000 Hz, stereo, s16, 1536 kb/s (default)
Metadata:
creation_time : 2015-05-20T13:45:56.000000Z
handler_name : Apple Sound Media Handler
timecode : 00:00:00:00
Stream #0:2(eng): Data: none (tmcd / 0x64636D74), 0 kb/s (default)
Metadata:
creation_time : 2015-05-20T13:46:11.000000Z
handler_name : Time Code Media Handler
timecode : 00:00:00:00
Unsupported codec with id 0 for input stream 2
Below the streams output. I split the text so you see the warning without searching in the middle.
[STREAM]
index=0
codec_name=h264
codec_long_name=H.264 / AVC / MPEG-4 AVC / MPEG-4 part 10
profile=Main
codec_type=video
codec_time_base=1/50
codec_tag_string=avc1
codec_tag=0x31637661
width=1920
height=1080
coded_width=1920
coded_height=1088
closed_captions=0
has_b_frames=0
sample_aspect_ratio=1:1
display_aspect_ratio=16:9
pix_fmt=yuv420p
level=40
color_range=tv
color_space=bt709
color_transfer=bt709
color_primaries=bt709
chroma_location=left
field_order=unknown
timecode=N/A
refs=1
is_avc=true
nal_length_size=4
id=N/A
r_frame_rate=25/1
avg_frame_rate=25/1
time_base=1/25
start_pts=0
start_time=0.000000
duration_ts=250
duration=10.000000
bit_rate=9930739
max_bit_rate=N/A
bits_per_raw_sample=8
nb_frames=250
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
DISPOSITION:timed_thumbnails=0
TAG:creation_time=2015-05-20T13:45:55.000000Z
TAG:language=eng
TAG:handler_name=Apple Video Media Handler
TAG:encoder=H.264
TAG:timecode=00:00:00:00
[/STREAM]
[STREAM]
index=1
codec_name=pcm_s16le
codec_long_name=PCM signed 16-bit little-endian
profile=unknown
codec_type=audio
codec_time_base=1/48000
codec_tag_string=sowt
codec_tag=0x74776f73
sample_fmt=s16
sample_rate=48000
channels=2
channel_layout=stereo
bits_per_sample=16
id=N/A
r_frame_rate=0/0
avg_frame_rate=0/0
time_base=1/48000
start_pts=0
start_time=0.000000
duration_ts=480000
duration=10.000000
bit_rate=1536000
max_bit_rate=N/A
bits_per_raw_sample=N/A
nb_frames=480000
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
DISPOSITION:timed_thumbnails=0
TAG:creation_time=2015-05-20T13:45:56.000000Z
TAG:language=eng
TAG:handler_name=Apple Sound Media Handler
TAG:timecode=00:00:00:00
[/STREAM]
[STREAM]
index=2
codec_name=unknown
codec_long_name=unknown
profile=unknown
codec_type=data
codec_tag_string=tmcd
codec_tag=0x64636d74
id=N/A
r_frame_rate=0/0
avg_frame_rate=25/1
time_base=1/25
start_pts=0
start_time=0.000000
duration_ts=250
duration=10.000000
bit_rate=3
max_bit_rate=N/A
bits_per_raw_sample=N/A
nb_frames=1
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
DISPOSITION:timed_thumbnails=0
TAG:creation_time=2015-05-20T13:46:11.000000Z
TAG:language=eng
TAG:handler_name=Time Code Media Handler
TAG:timecode=00:00:00:00
[/STREAM]
I scaled it down and recoded it for starters and i tried to discard the data stream with -dn and failed other methods i will mention at the end.
The output so far suggests that discarding should have worked since alternative datas are 0kB and no stream 2 is listed.
> ffmpeg -hide_banner -dn -i C:\Users\admin-dix\Downloads\Movie_Countdown-youtube_I1vMKZ1kvg0.mov -vf "scale=h=450:w=800" -f mp4 -c:a aac -c:v libx264 mov_countdown.mp4
Output #0, mp4, to 'mov_countdown.mp4':
Metadata:
major_brand : qt
minor_version : 537199360
compatible_brands: qt
encoder : Lavf58.45.100
Stream #0:0(eng): Video: h264 (libx264) (avc1 / 0x31637661), yuv420p(progressive), 800x450 [SAR 1:1 DAR 16:9], q=-1--1, 0.04 fps, 12800 tbn, 25 tbc (default)
Metadata:
creation_time : 2015-05-20T13:45:55.000000Z
handler_name : Apple Video Media Handler
timecode : 00:00:00:00
encoder : Lavc58.91.100 libx264
Side data:
cpb: bitrate max/min/avg: 0/0/0 buffer size: 0 vbv_delay: N/A
Stream #0:1(eng): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 128 kb/s (default)
Metadata:
creation_time : 2015-05-20T13:45:56.000000Z
handler_name : Apple Sound Media Handler
timecode : 00:00:00:00
encoder : Lavc58.91.100 aac
frame= 250 fps= 43 q=-1.0 Lsize= 342kB time=00:00:10.00 bitrate= 280.1kbits/s speed= 1.7x
video:175kB audio:159kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 2.710857%
Then ffprobe disagrees, there is still the stream and the warning.
ffprobe mov_countdown.mp4
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'mov_countdown.mp4':
Metadata:
major_brand : isom
minor_version : 512
compatible_brands: isomiso2avc1mp41
encoder : Lavf58.45.100
Duration: 00:00:10.02, start: 0.000000, bitrate: 279 kb/s
Stream #0:0(eng): Video: h264 (High) (avc1 / 0x31637661), yuv420p, 800x450 [SAR 1:1 DAR 16:9], 142 kb/s, 25 fps, 25 tbr, 12800 tbn, 50 tbc (default)
Metadata:
handler_name : Apple Video Media Handler
timecode : 00:00:00:00
Stream #0:1(eng): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 129 kb/s (default)
Metadata:
handler_name : Apple Sound Media Handler
Stream #0:2(eng): Data: none (tmcd / 0x64636D74), 0 kb/s
Metadata:
handler_name : Apple Video Media Handler
timecode : 00:00:00:00
Unsupported codec with id 0 for input stream 2
I tried negative mapping as per this answer -map 0:d which failed. I did not understand -discard option as ffmpeg documentation refers to from the -vn,-an,-dn entries as it does not specify a stream.
Why does it do that and how can i remove that stream i do not know and do not want to care about in future tests ?
[1]: Clean Retro Movie Countdown - YouTube from Philippe Moesch https://www.youtube.com/watch?v=I1vMKZ1kvg0

Answer 1

The data stream is a timecode stream. When ffmpeg reads a MOV/MP4 file with such a stream, it stores the timecode as metadata. If the output muxer is MOV/MP4, it will read that metadata and store that timecode as a data track. Add -write_tmcd false to disable this behaviour.