Very slow yuv file writer
-c:v libopenh264 -i solo.mp4 -map 0:v -an -pix_fmt yuv420p -y solo.yuv
ffmpeg is built on
https://github.com/xiaotiansf/FFmpeg
./configure --toolchain=msvc --enable-asm --enable-x86asm --arch=x86_64 --disable-shared --enable-static --enable-gpl --enable-libopenh264 --enable-libx264
libopenh264 is built on
https://github.com/xiaotiansf/openh264-1/tree/thread_support2
The problems observed using profile tool http://www.codersnotes.com/sleepy/
- Writing output YUV (file_write in libavformat/file.c) uses about 95% overal time which makes overall progress exceptional slow.
- ffmpeg Benchmark log shows that the overall speeds becomes slower and slower from start to end.
- By commenting out file_write in libavformat/file.c, it takes no time to finish the entire process.
Change History
(7)
Analyzed by developer: |
unset
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Keywords: |
Slow added; slow removed
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Reproduced by developer: |
unset
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Resolution: |
→ invalid
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Status: |
new → closed
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Resolution: |
invalid
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Status: |
closed → reopened
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Resolution: |
→ invalid
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Status: |
reopened → closed
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Keywords: |
Slow YUV writer removed
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Priority: |
important → normal
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Component: |
ffmpeg → undetermined
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Can use any mp4 file to reproduce the issue.