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Médias (1)
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Video d’abeille en portrait
14 mai 2011, par
Mis à jour : Février 2012
Langue : français
Type : Video
Autres articles (54)
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Sur d’autres sites (9247)
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FFMPEG : How to get video encoded with transparency ? [duplicate]
23 juin 2022, par mnse_soI've an issue on ffmpeg usage. Guess it's my fault, but I don't understand why. I tried to study the documentation and the mass of google stuff regarding ffmpeg, but I did not find any hints for it which would help.


The issue is following.


I'm using ffmpeg with a pipe input as rawvideo (ARGB 8x8x8x8 pixel data). In general, it works and produces a correct video like a charm.

But now I'm stuck to get video with transparency, so I've changed to webm which supports transparency.

As I can see on the log it uses rawvideo ARGB input as expected and do the export as vp9/yuva420p which should provide alpha support also as expected.


ffmpeg.exe -y -use_wallclock_as_timestamps 1 -f rawvideo -pix_fmt argb -r 60.0 -s 600x600 -i - -q:v 0 video.webm

ffmpeg version 5.0.1-full_build-www.gyan.dev Copyright (c) 2000-2022 the FFmpeg developers
...
Input #0, rawvideo, from 'pipe:':
 Duration: N/A, start: 1655899073.916667, bitrate: 691200 kb/s
 Stream #0:0: Video: rawvideo (ARGB / 0x42475241), argb, 600x600, 691200 kb/s, 60 tbr, 60 tbn
Stream mapping:
 Stream #0:0 -> #0:0 (rawvideo (native) -> vp9 (libvpx-vp9))
[libvpx-vp9 @ 0000027775a49f80] v1.11.0-133-ga3afed22a
[libvpx-vp9 @ 0000027775a49f80] Neither bitrate nor constrained quality specified, using default CRF of 32
Output #0, webm, to 'video.webm':
 Metadata:
 encoder : Lavf59.16.100
 Stream #0:0: Video: vp9, yuva420p(tv, progressive), 600x600, q=2-31, 60 fps, 1k tbn
 Metadata:
 encoder : Lavc59.18.100 libvpx-vp9
...
frame= ...



But if I view the video it has no alpha.


So, then I checked the video with ffprobe and to my surprise it now tells me that the stream is encoded by yuv420p which not providing alpha support !


ffprobe.exe -i video.webm
ffprobe version 5.0.1-full_build-www.gyan.dev Copyright (c) 2007-2022 the FFmpeg developers
...
Input #0, matroska,webm, from 'video.webm':
 Metadata:
 ENCODER : Lavf59.16.100
 Duration: N/A, start: 0.000000, bitrate: N/A
 Stream #0:0: Video: vp9 (Profile 0), yuv420p(tv, progressive), 600x600, SAR 1:1 DAR 1:1, 60 fps, 60 tbr, 1k tbn
 Metadata:
 alpha_mode : 1
 ENCODER : Lavc59.18.100 libvpx-vp9
 



I've also tried many this and that options from several google research but non of them leads to the goal.


Any hints are welcome to get the video encoded with transparency.


PS : I also checked that the input pixels used for pipe input are containing correct alpha information.


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How to create thumbnails from HDR video with FFmpeg ?
22 juin 2022, par schneikaiI using FFmpeg to create thumbnails from HDR videos recorded with an iPhone but the colors of the generated JPG file look washed out. Here is a screenshot I took while running the video in a player and the other picture is a JPG generated with FFmpeg.


Screenshot from Movie :




Thumbnail from FFmpeg :




Here´s a link to the mov-file : https://www.dropbox.com/s/udowplvfspxq6ag/IMG_8357.MOV?dl=1


I use the standard command to generate the thumbnails :
ffmpeg -i IMG_8357.MOV -vframes 1 output.jpg


My FFmpeg Version is


ffmpeg version 5.0.1 Copyright (c) 2000-2022 the FFmpeg developers
built with Apple clang version 13.1.6 (clang-1316.0.21.2.5)
configuration: --prefix=/usr/local/Cellar/ffmpeg/5.0.1_1 --enable-shared --enable-pthreads --enable-version3 --cc=clang --host-cflags= --host-ldflags= --enable-ffplay --enable-gnutls --enable-gpl --enable-libaom --enable-libbluray --enable-libdav1d --enable-libmp3lame --enable-libopus --enable-librav1e --enable-librist --enable-librubberband --enable-libsnappy --enable-libsrt --enable-libtesseract --enable-libtheora --enable-libvidstab --enable-libvmaf --enable-libvorbis --enable-libvpx --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxml2 --enable-libxvid --enable-lzma --enable-libfontconfig --enable-libfreetype --enable-frei0r --enable-libass --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-libspeex --enable-libsoxr --enable-libzmq --enable-libzimg --disable-libjack --disable-indev=jack --enable-videotoolbox
libavutil 57. 17.100 / 57. 17.100
libavcodec 59. 18.100 / 59. 18.100
libavformat 59. 16.100 / 59. 16.100
libavdevice 59. 4.100 / 59. 4.100
libavfilter 8. 24.100 / 8. 24.100
libswscale 6. 4.100 / 6. 4.100
libswresample 4. 3.100 / 4. 3.100
libpostproc 56. 3.100 / 56. 3.100



Thanks so much for pointing me in the right direction.


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Error while opening encoder for output stream ffmpeg from php
21 juin 2022, par Ali Akbar AziziI try to run this command in
php
withexec


'ffmpeg' '-y' '-i' '/home/api/test.mp4' '-async' '1' '-metadata:s:v:0' 'start_time=0' '-vcodec' 'libx264' '-acodec' 'aac' '-b:v' '1000k' '-refs' '6' '-coder' '1' '-sc_threshold' '40' '-flags' '+loop' '-me_range' '16' '-subq' '7' '-i_qfactor' '0.71' '-qcomp' '0.6' '-qdiff' '4' '-trellis' '1' '-b:a' '128k' '-pass' '1' '-passlogfile' '/home/api/tmp/unb2a/pass-62aeeac90d83c' '/home/api/Pre_zygJYg1.mp4' 2>&1


and my output is


ffmpeg version 4.2.7-0ubuntu0.1 Copyright (c) 2000-2022 the FFmpeg developers
 built with gcc 9 (Ubuntu 9.4.0-1ubuntu1~20.04.1)
 configuration: --prefix=/usr --extra-version=0ubuntu0.1 --toolchain=hardened --libdir=/usr/lib/x86_64-linux-gnu --incdir=/usr/include/x86_64-linux-gnu --arch=amd64 --enable-gpl --disable-stripping --enable-avresample --disable-filter=resample --enable-avisynth --enable-gnutls --enable-ladspa --enable-libaom --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libcdio --enable-libcodec2 --enable-libflite --enable-libfontconfig --enable-libfreetype --enable-libfribidi --enable-libgme --enable-libgsm --enable-libjack --enable-libmp3lame --enable-libmysofa --enable-libopenjpeg --enable-libopenmpt --enable-libopus --enable-libpulse --enable-librsvg --enable-librubberband --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libssh --enable-libtheora --enable-libtwolame --enable-libvidstab --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx265 --enable-libxml2 --enable-libxvid --enable-libzmq --enable-libzvbi --enable-lv2 --enable-omx --enable-openal --enable-opencl --enable-opengl --enable-sdl2 --enable-libdc1394 --enable-libdrm --enable-libiec61883 --enable-nvenc --enable-chromaprint --enable-frei0r --enable-libx264 --enable-shared
 libavutil 56. 31.100 / 56. 31.100
 libavcodec 58. 54.100 / 58. 54.100
 libavformat 58. 29.100 / 58. 29.100
 libavdevice 58. 8.100 / 58. 8.100
 libavfilter 7. 57.100 / 7. 57.100
 libavresample 4. 0. 0 / 4. 0. 0
 libswscale 5. 5.100 / 5. 5.100
 libswresample 3. 5.100 / 3. 5.100
 libpostproc 55. 5.100 / 55. 5.100
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '/home/api/test.mp4':
 Metadata:
 major_brand : mp42
 minor_version : 512
 compatible_brands: mp42iso2avc1mp41
 creation_time : 2022-06-18T07:02:26.000000Z
 encoder : HandBrake 1.4.2 2021100300
 Duration: 00:00:59.14, start: 0.000000, bitrate: 2694 kb/s
 Stream #0:0(und): Video: h264 (Main) (avc1 / 0x31637661), yuv420p(tv, bt709), 1080x1080 [SAR 1:1 DAR 1:1], 2524 kb/s, 30 fps, 30 tbr, 90k tbn, 180k tbc (default)
 Metadata:
 creation_time : 2022-06-18T07:02:26.000000Z
 handler_name : VideoHandler
 Stream #0:1(eng): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 161 kb/s (default)
 Metadata:
 creation_time : 2022-06-18T07:02:26.000000Z
 handler_name : Stereo
Stream mapping:
 Stream #0:0 -> #0:0 (h264 (native) -> h264 (libx264))
 Stream #0:1 -> #0:1 (aac (native) -> aac (native))
Press [q] to stop, [?] for help
-async is forwarded to lavfi similarly to -af aresample=async=1:min_hard_comp=0.100000:first_pts=0.
[libx264 @ 0x5640d624b2c0] using SAR=1/1
[libx264 @ 0x5640d624b2c0] using cpu capabilities: MMX2 SSE2Fast SSSE3 SSE4.2 AVX FMA3 BMI2 AVX2
Error initializing output stream 0:0 -- Error while opening encoder for output stream #0:0 - maybe incorrect parameters such as bit_rate, rate, width or height
[aac @ 0x5640d62b9580] Qavg: 6009.205
[aac @ 0x5640d62b9580] 2 frames left in the queue on closing
Conversion failed!



When I run this command in the terminal it works, But its not working when I'm using
exec


UPDATED
This issue happened when I changed my webserver from apache to openlitespeed