I want to convert a sequence of png images to a HEVC video with alpha, I would like to use ffmpeg to do this work and find the following command(images name are p01.png, p02.png...):
ffmpeg -framerate 10 -i p%02d.png -c:v hevc_videotoolbox -require_sw 1 -allow_sw 1 -alpha_quality 0.5 -vtag hvc1 hevc.mov
the print is here:
ffmpeg version 5.1.2 Copyright (c) 2000-2022 the FFmpeg developers
built with Apple clang version 14.0.0 (clang-1400.0.29.202)
configuration: --prefix=/opt/homebrew/Cellar/ffmpeg/5.1.2_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 --enable-neon
libavutil 57. 28.100 / 57. 28.100
libavcodec 59. 37.100 / 59. 37.100
libavformat 59. 27.100 / 59. 27.100
libavdevice 59. 7.100 / 59. 7.100
libavfilter 8. 44.100 / 8. 44.100
libswscale 6. 7.100 / 6. 7.100
libswresample 4. 7.100 / 4. 7.100
libpostproc 56. 6.100 / 56. 6.100
Input #0, image2, from 'p%02d.png':
Duration: 00:00:09.60, start: 0.000000, bitrate: N/A
Stream #0:0: Video: png, rgba(pc), 375x812 [SAR 3779:3779 DAR 375:812], 10 fps, 10 tbr, 10 tbn
Stream mapping:
Stream #0:0 -> #0:0 (png (native) -> hevc (hevc_videotoolbox))
Press [q] to stop, [?] for help
[1] 16348 trace trap ffmpeg -framerate 10 -i p%02d.png -c:v hevc_videotoolbox -require_sw 1 1 0.
It seems like there is no error and the video has been generated but the size of video is always 0kb, I try to change the parameter for command but nothing changed, so is there something working with the command? or Is there is a simple way to create the HEVC video using png image? Thanks
My Environment: Apple silicon(MacBook with M1 Pro clip) Mac OS 13.0 ffmpeg: 5.1.2
