user30501: I create a video from a slideshow using ffmpeg. I have a valid video at the end. VLC plays that video, YouTube also. I want to display the final product directly on twitter.
I checked the recommened specs according to resolution, framerate, aspect ration and size required for Twitter to accept this video.  But still when trying to add this video direcectly into Twitter I receive an error that "no video with supported format or MIME-Type found".
Ffmpeg does not display any error or warning.
Arguments:
ffmpeg -f image2pipe -framerate 1 -i pipe:.png -c:v libx264 -crf 21  -r 30 -y "Blathering.noaudio.mp4"

As you can see I create one image per frame (-framerate 1) but create a 30fps output file (-r 30)
The output from ffmpeg looks like this:
ffmpeg version git-2020-06-17-0b3bd00 Copyright (c) 2000-2020 the FFmpeg developers
  built with gcc 9.3.1 (GCC) 20200523
  configuration: --enable-gpl --enable-version3 --enable-sdl2 --enable-fontconfig --enable-gnutls --enable-iconv --enable-libass --enable-libdav1d --enable-libbluray --enable-libfreetype --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-libopus --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libsrt --enable-libtheora --enable-libtwolame --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxml2 --enable-libzimg --enable-lzma --enable-zlib --enable-gmp --enable-libvidstab --enable-libvmaf --enable-libvorbis --enable-libvo-amrwbenc --enable-libmysofa --enable-libspeex --enable-libxvid --enable-libaom --disable-w32threads --enable-libmfx --enable-ffnvcodec --enable-cuda-llvm --enable-cuvid --enable-d3d11va --enable-nvenc --enable-nvdec --enable-dxva2 --enable-avisynth --enable-libopenmpt --enable-amf
  libavutil      56. 55.100 / 56. 55.100
  libavcodec     58. 92.100 / 58. 92.100
  libavformat    58. 46.101 / 58. 46.101
  libavdevice    58. 11.100 / 58. 11.100
  libavfilter     7. 86.100 /  7. 86.100
  libswscale      5.  8.100 /  5.  8.100
  libswresample   3.  8.100 /  3.  8.100
  libpostproc    55.  8.100 / 55.  8.100
Input #0, image2pipe, from 'pipe:.png':
  Duration: N/A, bitrate: N/A
    Stream #0:0: Video: png, rgba(pc), 680x420 [SAR 3779:3779 DAR 34:21], 1 fps, 1 tbr, 1 tbn, 1 tbc
Stream mapping:
  Stream #0:0 -> #0:0 (png (native) -> h264 (libx264))
[libx264 @ 00000217ad682780] using SAR=1/1
[libx264 @ 00000217ad682780] using cpu capabilities: MMX2 SSE2Fast SSSE3 SSE4.2 AVX FMA3 BMI2 AVX2
[libx264 @ 00000217ad682780] profile High 4:4:4 Predictive, level 3.0, 4:4:4, 8-bit
[libx264 @ 00000217ad682780] 264 - core 160 - H.264/MPEG-4 AVC codec - Copyleft 2003-2020 - http://www.videolan.org/x264.html - options: cabac=1 ref=3 deblock=1:0:0 analyse=0x3:0x113 me=hex subme=7 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=4 threads=12 lookahead_threads=2 sliced_threads=0 nr=0 decimate=1 interlaced=0 bluray_compat=0 constrained_intra=0 bframes=3 b_pyramid=2 b_adapt=1 b_bias=0 direct=1 weightb=1 open_gop=0 weightp=2 keyint=250 keyint_min=25 scenecut=40 intra_refresh=0 rc_lookahead=40 rc=crf mbtree=1 crf=21.0 qcomp=0.60 qpmin=0 qpmax=69 qpstep=4 ip_ratio=1.40 aq=1:1.00
Output #0, mp4, to 'Blathering.noaudio.mp4':
  Metadata:
    encoder         : Lavf58.46.101
    Stream #0:0: Video: h264 (libx264) (avc1 / 0x31637661), yuv444p, 680x420 [SAR 1:1 DAR 34:21], q=-1--1, 30 fps, 15360 tbn, 30 tbc
    Metadata:
      encoder         : Lavc58.92.100 libx264
    Side data:
      cpb: bitrate max/min/avg: 0/0/0 buffer size: 0 vbv_delay: N/A
frame=  150 fps=0.0 q=-1.0 Lsize=      17kB time=00:00:04.90 bitrate=  29.2kbits/s dup=145 drop=0 speed=  29x
video:15kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 17.439800%
[libx264 @ 00000217ad682780] frame I:1     Avg QP:12.52  size:  9283
[libx264 @ 00000217ad682780] frame P:38    Avg QP:10.45  size:    53
[libx264 @ 00000217ad682780] frame B:111   Avg QP:11.67  size:    29
[libx264 @ 00000217ad682780] consecutive B-frames:  1.3%  0.0%  0.0% 98.7%
[libx264 @ 00000217ad682780] mb I  I16..4: 66.0% 25.8%  8.3%
[libx264 @ 00000217ad682780] mb P  I16..4:  0.0%  0.0%  0.0%  P16..4:  0.0%  0.0%  0.0%  0.0%  0.0%    skip:99.9%
[libx264 @ 00000217ad682780] mb B  I16..4:  0.0%  0.0%  0.0%  B16..8:  0.5%  0.0%  0.0%  direct: 0.0%  skip:99.5%  L0:64.2% L1:35.8% BI: 0.0%
[libx264 @ 00000217ad682780] 8x8 transform intra:25.9% inter:0.0%
[libx264 @ 00000217ad682780] coded y,u,v intra: 5.2% 3.2% 3.1% inter: 0.0% 0.0% 0.0%
[libx264 @ 00000217ad682780] i16 v,h,dc,p: 89% 11%  0%  0%
[libx264 @ 00000217ad682780] i8 v,h,dc,ddl,ddr,vr,hd,vl,hu: 60%  4% 36%  0%  0%  0%  0%  0%  0%
[libx264 @ 00000217ad682780] i4 v,h,dc,ddl,ddr,vr,hd,vl,hu: 27% 36% 19%  2%  3%  3%  5%  2%  4%
[libx264 @ 00000217ad682780] Weighted P-Frames: Y:0.0% UV:0.0%
[libx264 @ 00000217ad682780] ref P L0: 86.2%  3.4% 10.3%
[libx264 @ 00000217ad682780] ref B L0: 51.9% 48.1%
[libx264 @ 00000217ad682780] kb/s:23.31

The Codec information are the following:

This is pure Images, no audio at this point in the video. Is there a parameter I am missing? IMHO this looks like a very common video file I create there.

user1871: PNG contain RGB data and video contains YUV pixels. FFmpeg will select yuv444p to preserve chroma sampling resolution but that pixel format is not widely compatible. Force yuv420p output.
Use
ffmpeg -f image2pipe -framerate 1 -i pipe:.png -c:v libx264 -pix_fmt yuv420p -crf 21 -r 30 -y "Blathering.noaudio.mp4"

30501: <p>I create a video from a slideshow using ffmpeg. I have a valid video at the end. VLC plays that video, YouTube also. I want to display the final product directly on twitter.</p>
<p>I checked the <a href="https://help.twitter.com/en/using-twitter/twitter-videos" rel="nofollow noreferrer">recommened specs</a> according to resolution, framerate, aspect ration and size required for Twitter to accept this video.  But still when trying to add this video direcectly into Twitter I receive an error that &quot;no video with supported format or MIME-Type found&quot;.</p>
<p>Ffmpeg does not display any error or warning.</p>
<p>Arguments:</p>
<pre><code>ffmpeg -f image2pipe -framerate 1 -i pipe:.png -c:v libx264 -crf 21  -r 30 -y &quot;Blathering.noaudio.mp4&quot;
</code></pre>
<p>As you can see I create one image per frame (-framerate 1) but create a 30fps output file (-r 30)</p>
<p>The output from ffmpeg looks like this:</p>
<pre><code>ffmpeg version git-2020-06-17-0b3bd00 Copyright (c) 2000-2020 the FFmpeg developers
  built with gcc 9.3.1 (GCC) 20200523
  configuration: --enable-gpl --enable-version3 --enable-sdl2 --enable-fontconfig --enable-gnutls --enable-iconv --enable-libass --enable-libdav1d --enable-libbluray --enable-libfreetype --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-libopus --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libsrt --enable-libtheora --enable-libtwolame --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxml2 --enable-libzimg --enable-lzma --enable-zlib --enable-gmp --enable-libvidstab --enable-libvmaf --enable-libvorbis --enable-libvo-amrwbenc --enable-libmysofa --enable-libspeex --enable-libxvid --enable-libaom --disable-w32threads --enable-libmfx --enable-ffnvcodec --enable-cuda-llvm --enable-cuvid --enable-d3d11va --enable-nvenc --enable-nvdec --enable-dxva2 --enable-avisynth --enable-libopenmpt --enable-amf
  libavutil      56. 55.100 / 56. 55.100
  libavcodec     58. 92.100 / 58. 92.100
  libavformat    58. 46.101 / 58. 46.101
  libavdevice    58. 11.100 / 58. 11.100
  libavfilter     7. 86.100 /  7. 86.100
  libswscale      5.  8.100 /  5.  8.100
  libswresample   3.  8.100 /  3.  8.100
  libpostproc    55.  8.100 / 55.  8.100
Input #0, image2pipe, from 'pipe:.png':
  Duration: N/A, bitrate: N/A
    Stream #0:0: Video: png, rgba(pc), 680x420 [SAR 3779:3779 DAR 34:21], 1 fps, 1 tbr, 1 tbn, 1 tbc
Stream mapping:
  Stream #0:0 -&gt; #0:0 (png (native) -&gt; h264 (libx264))
[libx264 @ 00000217ad682780] using SAR=1/1
[libx264 @ 00000217ad682780] using cpu capabilities: MMX2 SSE2Fast SSSE3 SSE4.2 AVX FMA3 BMI2 AVX2
[libx264 @ 00000217ad682780] profile High 4:4:4 Predictive, level 3.0, 4:4:4, 8-bit
[libx264 @ 00000217ad682780] 264 - core 160 - H.264/MPEG-4 AVC codec - Copyleft 2003-2020 - http://www.videolan.org/x264.html - options: cabac=1 ref=3 deblock=1:0:0 analyse=0x3:0x113 me=hex subme=7 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=4 threads=12 lookahead_threads=2 sliced_threads=0 nr=0 decimate=1 interlaced=0 bluray_compat=0 constrained_intra=0 bframes=3 b_pyramid=2 b_adapt=1 b_bias=0 direct=1 weightb=1 open_gop=0 weightp=2 keyint=250 keyint_min=25 scenecut=40 intra_refresh=0 rc_lookahead=40 rc=crf mbtree=1 crf=21.0 qcomp=0.60 qpmin=0 qpmax=69 qpstep=4 ip_ratio=1.40 aq=1:1.00
Output #0, mp4, to 'Blathering.noaudio.mp4':
  Metadata:
    encoder         : Lavf58.46.101
    Stream #0:0: Video: h264 (libx264) (avc1 / 0x31637661), yuv444p, 680x420 [SAR 1:1 DAR 34:21], q=-1--1, 30 fps, 15360 tbn, 30 tbc
    Metadata:
      encoder         : Lavc58.92.100 libx264
    Side data:
      cpb: bitrate max/min/avg: 0/0/0 buffer size: 0 vbv_delay: N/A
frame=  150 fps=0.0 q=-1.0 Lsize=      17kB time=00:00:04.90 bitrate=  29.2kbits/s dup=145 drop=0 speed=  29x
video:15kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 17.439800%
[libx264 @ 00000217ad682780] frame I:1     Avg QP:12.52  size:  9283
[libx264 @ 00000217ad682780] frame P:38    Avg QP:10.45  size:    53
[libx264 @ 00000217ad682780] frame B:111   Avg QP:11.67  size:    29
[libx264 @ 00000217ad682780] consecutive B-frames:  1.3%  0.0%  0.0% 98.7%
[libx264 @ 00000217ad682780] mb I  I16..4: 66.0% 25.8%  8.3%
[libx264 @ 00000217ad682780] mb P  I16..4:  0.0%  0.0%  0.0%  P16..4:  0.0%  0.0%  0.0%  0.0%  0.0%    skip:99.9%
[libx264 @ 00000217ad682780] mb B  I16..4:  0.0%  0.0%  0.0%  B16..8:  0.5%  0.0%  0.0%  direct: 0.0%  skip:99.5%  L0:64.2% L1:35.8% BI: 0.0%
[libx264 @ 00000217ad682780] 8x8 transform intra:25.9% inter:0.0%
[libx264 @ 00000217ad682780] coded y,u,v intra: 5.2% 3.2% 3.1% inter: 0.0% 0.0% 0.0%
[libx264 @ 00000217ad682780] i16 v,h,dc,p: 89% 11%  0%  0%
[libx264 @ 00000217ad682780] i8 v,h,dc,ddl,ddr,vr,hd,vl,hu: 60%  4% 36%  0%  0%  0%  0%  0%  0%
[libx264 @ 00000217ad682780] i4 v,h,dc,ddl,ddr,vr,hd,vl,hu: 27% 36% 19%  2%  3%  3%  5%  2%  4%
[libx264 @ 00000217ad682780] Weighted P-Frames: Y:0.0% UV:0.0%
[libx264 @ 00000217ad682780] ref P L0: 86.2%  3.4% 10.3%
[libx264 @ 00000217ad682780] ref B L0: 51.9% 48.1%
[libx264 @ 00000217ad682780] kb/s:23.31
</code></pre>
<p>The Codec information are the following:</p>
<p><a href="https://i.stack.imgur.com/qtHvk.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/qtHvk.png" alt="codec" /></a></p>
<p>This is pure Images, no audio at this point in the video. Is there a parameter I am missing? IMHO this looks like a very common video file I create there.</p>
 1871: <p>PNG contain RGB data and video contains YUV pixels. FFmpeg will select <code>yuv444p</code> to preserve chroma sampling resolution but that pixel format is not widely compatible. Force <code>yuv420p</code> output.</p>
<p>Use
<code>ffmpeg -f image2pipe -framerate 1 -i pipe:.png -c:v libx264 -pix_fmt yuv420p -crf 21 -r 30 -y &quot;Blathering.noaudio.mp4&quot;</code></p>
