Exporting blank screen! tried everything mentioned in forum

Bug
1

Hello,
I am using Shotcut version 20.11.28 on Windows 10 64-bit OS. When i try to export a video on my timeline it produces blank video. The video is blank when i play on shotcut too. I just export default settings didnt change anything , i tried with youtube preset and also DEFAULT presets… The job finishes but the video is blank. I didnt enable hardware encoding… No filters, very simple plain video …
The Job log just has errors for
error opening shared object file ‘C:\Program Files\Shotcut\lib\ladspa/AUTHORS’: “C:\Program Files\Shotcut\lib\ladspa\AUTHORS”: The specified module could not be found.
plugin_mgr_get_object_file_plugins: error opening shared object file ‘C:\Program Files\Shotcut\lib\ladspa/COPYING’: “C:\Program Files\Shotcut\lib\ladspa\COPYING”: The specified module could not be found.
plugin_mgr_get_object_file_plugins: error opening shared object file ‘C:\Program Files\Shotcut\lib\ladspa/readme.txt’: “C:\Program Files\Shotcut\lib\ladspa\readme.txt”:

But one this is when i export with use preview scaling , it exports fine… Any help is greatly appreciated.

Thanks
Amith

2

So you see black in the preview inside Shotcut?
What is the display method (in the Preferences-Display Method menu)?
A screenshot of your project could be useful too.

3

Hello Thanks for getting back ! Yes the exported video is black in shotcut preview
Display method is DirectX ( Angle)
Please let me know if you want to see any specific screenshot… I just have put in the screenshot of exported video in preview

image
image1920×1024 102 KB

4

I don’t think it’s so obvious but to cover it I’ll say that in your project there are areas where there is no image.
Your video track (Prapthi) has video clips (and muted audio) at various points in the project. By placing the Shotcut player head over them, some image should appear in the Shotcut viewer.
In the areas I have marked in red there is no picture-video.
There is only video in the areas marked with green arrows.

image2
image21920×1024 113 KB

If there is no content in the video track, you will hear the music of the audio track (A1) and the black screen.
Here’s a snapshot of one of my projects.
In the viewer you can see the content of the two video tracks (V1 and V2) where V2 is the moustache cowboy (inside a fuzzy ellipsoid mask) on the bottom of the track V1
shotcut_k6Tk6a9BAw
shotcut_k6Tk6a9BAw1272×720 253 KB

5

Hello Thanks for getting back! Yes sure , i do understand that, When i place the head over the spots where there are vidoes on the timeline tracks they do come up in the preview but not in the final exported mp4. Just for the sake of it i even tried a full video ( without empty spots) and that is blank too. Also if its helpful, my video Resolution is 3840 X 2160… Is it something thats causing this ?

6

Is your project in automatic mode or did you select the resolution manually when starting the project (UHD 2160)?
You can modify this, if necessary in: Preferences–Video mode.

7

Those errors are expected and always appear. Ignore them. They are not really errors. You should attach the full export log.

8

No my video mode is automatic… Thanks! I just verified again

image
image658×825 39.5 KB

9

Sure, i realized that in the forum : Here are the full logs , Thank you!
plugin_mgr_get_object_file_plugins: error opening shared object file ‘C:\Program Files\Shotcut\lib\ladspa/AUTHORS’: “C:\Program Files\Shotcut\lib\ladspa\AUTHORS”: The specified module could not be found.
plugin_mgr_get_object_file_plugins: error opening shared object file ‘C:\Program Files\Shotcut\lib\ladspa/COPYING’: “C:\Program Files\Shotcut\lib\ladspa\COPYING”: The specified module could not be found.
plugin_mgr_get_object_file_plugins: error opening shared object file ‘C:\Program Files\Shotcut\lib\ladspa/readme.txt’: “C:\Program Files\Shotcut\lib\ladspa\readme.txt”:
[libx264 @ 000000000274b240] using SAR=1/1
[libx264 @ 000000000274b240] using cpu capabilities: MMX2 SSE2Fast SSSE3 SSE4.2 AVX FMA3 BMI2 AVX2
[h264 @ 000000000274a4c0] Reinit context to 3840x2160, pix_fmt: yuvj420p
[libx264 @ 000000000274b240] profile High, level 5.2, 4:2:0, 8-bit
[libx264 @ 000000000274b240] 264 - core 159 r2991M 1771b55 - H.264/MPEG-4 AVC codec - Copyleft 2003-2019 - http://www.videolan.org/x264.html - options: cabac=1 ref=2 deblock=1:0:0 analyse=0x3:0x113 me=hex subme=6 psy=1 psy_rd=1.00:0.00 mixed_ref=1 me_range=16 chroma_me=1 trellis=1 8x8dct=1 cqm=0 deadzone=21,11 fast_pskip=1 chroma_qp_offset=-2 threads=12 lookahead_threads=2 sliced_threads=0 nr=0 decimate=1 interlaced=0 bluray_compat=0 constrained_intra=0 bframes=2 b_pyramid=2 b_adapt=1 b_bias=0 direct=1 weightb=1 open_gop=0 weightp=1 keyint=15 keyint_min=1 scenecut=40 intra_refresh=0 rc_lookahead=15 rc=crf mbtree=1 crf=23.0 qcomp=0.60 qpmin=0 qpmax=69 qpstep=4 ip_ratio=1.40 aq=1:1.00
[h264 @ 0000000005153200] Reinit context to 3840x2160, pix_fmt: yuvj420p
[h264 @ 0000000005153680] Reinit context to 3840x2160, pix_fmt: yuvj420p
[producer avformat] audio: total_streams 1 max_stream 1 total_channels 2 max_channels 2
[AVIOContext @ 0000000002660640] Statistics: 5093941 bytes read, 2 seeks
[producer avformat-novalidate] C:/Personal/Pooja_Youtube_dance/Actual Videos/Prapthi/P5.mp4
checking VFR: pkt.duration 1500
[producer avformat-novalidate] C:/Personal/Pooja_Youtube_dance/Actual Videos/Prapthi/P5.mp4
checking VFR: pkt.duration 1502
[producer avformat-novalidate] C:/Personal/Pooja_Youtube_dance/Actual Videos/Prapthi/P5.mp4
checking VFR: pkt.duration 1500
[producer avformat-novalidate] C:/Personal/Pooja_Youtube_dance/Actual Videos/Prapthi/P5.mp4
checking VFR: pkt.duration 1501
[mp4 @ 00000000026f8f00] Using AVStream.codec to pass codec parameters to muxers is deprecated, use AVStream.codecpar instead.
[mp4 @ 00000000026f8f00] Using AVStream.codec to pass codec parameters to muxers is deprecated, use AVStream.codecpar instead.
[mp4 @ 00000000026f8f00] Starting second pass: moving the moov atom to the beginning of the file
[AVIOContext @ 0000000004ec4040] Statistics: 339791 bytes read, 0 seeks
[libx264 @ 000000000274b240] frame I:21 Avg QP:10.14 size: 1561
[libx264 @ 000000000274b240] frame P:102 Avg QP:13.63 size: 241
[libx264 @ 000000000274b240] frame B:184 Avg QP:16.00 size: 236
[libx264 @ 000000000274b240] consecutive B-frames: 6.8% 13.0% 80.1%
[libx264 @ 000000000274b240] mb I I16…4: 100.0% 0.0% 0.0%
[libx264 @ 000000000274b240] mb P I16…4: 0.0% 0.0% 0.0% P16…4: 0.0% 0.0% 0.0% 0.0% 0.0% skip:100.0%
[libx264 @ 000000000274b240] mb B I16…4: 0.0% 0.0% 0.0% B16…8: 0.0% 0.0% 0.0% direct: 0.0% skip:100.0%
[libx264 @ 000000000274b240] 8x8 transform intra:0.0%
[libx264 @ 000000000274b240] coded y,uvDC,uvAC intra: 0.0% 0.0% 0.0% inter: 0.0% 0.0% 0.0%
[libx264 @ 000000000274b240] i16 v,h,dc,p: 99% 0% 1% 0%
[libx264 @ 000000000274b240] i8c dc,h,v,p: 100% 0% 0% 0%
[libx264 @ 000000000274b240] Weighted P-Frames: Y:0.0% UV:0.0%
[libx264 @ 000000000274b240] kb/s:157.34
[aac @ 000000000274adc0] Qavg: 17446.555
[AVIOContext @ 0000000004ec3440] Statistics: 4 seeks, 7 writeouts

Completed successfully in 00:00:32

10

Everything looks fine in the export. There is probably a problem with your proxies. Turn off proxy and preview scaling in the app, and review it within the app preview. If the video of the clip is black, select it, go to Properties > Video tab > Track and change it from None.
If that fixed it, there might be something wrong about the ability to use proxy with these video clips. In Properties for the source clip, choose menu > More Information and paste that here.

11

Hello, Yes as you mentioned, I did turn off preview scaling and use proxy to off . Then the timeline video was black in the preview … Then i changed from none and it fixed it… Below is the information of the source file

# ffprobe output
[streams.stream.0]
index=0
codec_name=unknown
codec_long_name=unknown
profile=unknown
codec_type=data
codec_tag_string=mett
codec_tag=0x7474656d
id=N/A
r_frame_rate=0/0
avg_frame_rate=0/0
time_base=1/90000
start_pts=0
start_time=0:00:00.000000
duration_ts=408222
duration=0:00:04.535800
bit_rate=37.904000 Kbit/s
max_bit_rate=N/A
bits_per_raw_sample=N/A
nb_frames=136
nb_read_frames=N/A
nb_read_packets=N/A
[streams.stream.0.disposition]
default=1
dub=0
original=0
comment=0
lyrics=0
karaoke=0
forced=0
hearing_impaired=0
visual_impaired=0
clean_effects=0
attached_pic=0
timed_thumbnails=0
[streams.stream.0.tags]
creation_time=2020-12-16T20:27:34.000000Z
language=eng
handler_name=MetaHandle
[streams.stream.1]
index=1
codec_name=aac
codec_long_name=AAC (Advanced Audio Coding)
profile=unknown
codec_type=audio
codec_time_base=1/48000
codec_tag_string=mp4a
codec_tag=0x6134706d
sample_fmt=fltp
sample_rate=48 KHz
channels=2
channel_layout=stereo
bits_per_sample=0
id=N/A
r_frame_rate=0/0
avg_frame_rate=0/0
time_base=1/48000
start_pts=0
start_time=0:00:00.000000
duration_ts=217718
duration=0:00:04.535792
bit_rate=192.336000 Kbit/s
max_bit_rate=192 Kbit/s
bits_per_raw_sample=N/A
nb_frames=212
nb_read_frames=N/A
nb_read_packets=N/A
[streams.stream.1.disposition]
default=1
dub=0
original=0
comment=0
lyrics=0
karaoke=0
forced=0
hearing_impaired=0
visual_impaired=0
clean_effects=0
attached_pic=0
timed_thumbnails=0
[streams.stream.1.tags]
creation_time=2020-12-16T20:27:34.000000Z
language=eng
handler_name=SoundHandle
[streams.stream.2]
index=2
codec_name=h264
codec_long_name=H.264 / AVC / MPEG-4 AVC / MPEG-4 part 10
profile=High
codec_type=video
codec_time_base=5443/652800
codec_tag_string=avc1
codec_tag=0x31637661
width=3840
height=2160
coded_width=3840
coded_height=2160
has_b_frames=0
sample_aspect_ratio=1:1
display_aspect_ratio=16:9
pix_fmt=yuvj420p
level=51
color_range=pc
color_space=smpte170m
color_transfer=smpte170m
color_primaries=bt470bg
chroma_location=left
field_order=unknown
timecode=N/A
refs=1
is_avc=true
nal_length_size=4
id=N/A
r_frame_rate=60/1
avg_frame_rate=326400/5443
time_base=1/90000
start_pts=0
start_time=0:00:00.000000
duration_ts=408225
duration=0:00:04.535833
bit_rate=72.328273 Mbit/s
max_bit_rate=N/A
bits_per_raw_sample=8
nb_frames=272
nb_read_frames=N/A
nb_read_packets=N/A
[streams.stream.2.disposition]
default=1
dub=0
original=0
comment=0
lyrics=0
karaoke=0
forced=0
hearing_impaired=0
visual_impaired=0
clean_effects=0
attached_pic=0
timed_thumbnails=0
[streams.stream.2.tags]
creation_time=2020-12-16T20:27:34.000000Z
language=eng
handler_name=VideoHandle
[format]
filename=C:/Personal/Pooja_Youtube_dance/Actual Videos/Prapthi/P4.mp4
nb_streams=3
nb_programs=0
format_name=mov,mp4,m4a,3gp,3g2,mj2
format_long_name=QuickTime / MOV
start_time=0:00:00.000000
duration=0:00:04.535800
size=39.239832 Mibyte
bit_rate=72.571005 Mbit/s
probe_score=100
[format.tags]
major_brand=mp42
minor_version=0
compatible_brands=isommp42
creation_time=2020-12-16T20:27:34.000000Z
location=+42.5926-83.1454/
location-eng=+42.5926-83.1454/
com.android.capture.fps=60.000000
12

You are only viewing the Source, probably the export you just saved.
If you click on Project, and position your playhead to 1:34:53, you would see black as well.

2020-12-17_14-30-21
2020-12-17_14-30-211514×744 158 KB

13

Sorry, I didnt get what you meant here ? When i try to play the exported video in shotcut , its always on source , if i switch to project it plays from timeline ( which plays fine)
Did i misread what you meant?
Thanks
Amith

14

It appears you exported a video, then played it in Shotcut, which might be in your Source viewer.
Your screenshot shows a blank or black spot in your video.
Your timeline shows many blank spots as @ejmillan pointed out.

When you click over from Source to Project and the move the playhead to 1:34:53 (as shown in your screenshot) you are going to see black as well, because there will be nothing there to show.

15

Sure understood, I think i got back on that, where i exported a video without empty spots and is still blank!! Hope that was clear

Thanks
Amith

16

It appears you are showing us this, which is true, this is where there is no video. Exported video on Source tab.
shotcut_2020-12-17_14-53-34

When in reality, at least for me, there is video here:
Shown in Project window
shotcut_2020-12-17_14-54-43

Shown in Source window (exported video)
shotcut_2020-12-17_14-59-25

17

I see the problem. This video is incompatible with proxy in Shotcut. Shotcut keeps track of audio and video streams within a container file using an absolute index. Because the first stream is some data stream that is discarded when making the proxy, these index values are different and created this problem situation. This data stream is some kind of embedded subtitle, but it is odd that it is first in the file. It is also weird that its video uses a NTSC SD colorspace with 4K UHD resolution! Where did you get it?

18

This video was shot on Pixel 4a (5G) with 4k 60frames/sec … So looks like no workaround for this one right ? One thing is shotcut provides me the option to convert this file and looks like there is no issue when I convert ( but each converted clip is around 10gb :)) I don’t think i can afford that… The other option is i would get a lower quality and edit it … Let me know if those are the only options…

Thanks for lightning help here!

19

Are you using the MP4 option?

I converted this to a bug, but I am not certain yet when it will be fixed.

This video was shot on Pixel 4a

Did you use the standard camera app?

20

While converting it did give me an option to choose between good , better ( middle ) and best ( I think ) , how do i chose mp4 … I did chose the recommended middle one and yes it did not produce mp4, it produced mov I think

Yes standard camera app

Thanks