ffmpeg ignores -hls_time if -hls_init_time is set

[brunoais]

Summary of the bug:
If you try to remux an mp4 file and you provide both -hls_time and -hls_init_time with different values, apparently -hls_time is ignored.

How to reproduce:

% ffmpeg -i "video.mp4"  -f hls -start_number 0 -hls_list_size 0 -hls_playlist 1 -hls_init_time 10 -hls_time 60 -strftime 1  -hls_flags second_level_segment_index -hls_segment_filename '%%03d.ts' -c copy -copyts -hls_playlist_type vod out.m3u8

ffmpeg version 5.1.1-static https://johnvansickle.com/ffmpeg/  Copyright (c) 2000-2022 the FFmpeg developers
  built with gcc 8 (Debian 8.3.0-6)
  configuration: --enable-gpl --enable-version3 --enable-static --disable-debug --disable-ffplay --disable-indev=sndio --disable-outdev=sndio --cc=gcc --enable-fontconfig --enable-frei0r --enable-gnutls --enable-gmp --enable-libgme --enable-gray --enable-libaom --enable-libfribidi --enable-libass --enable-libvmaf --enable-libfreetype --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-librubberband --enable-libsoxr --enable-libspeex --enable-libsrt --enable-libvorbis --enable-libopus --enable-libtheora --enable-libvidstab --enable-libvo-amrwbenc --enable-libvpx --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxml2 --enable-libdav1d --enable-libxvid --enable-libzvbi --enable-libzimg

With my ~2:11:10 file:

If I use -hls_init_time 60 and -hls_time 60, it produces up to Opening '153.ts' for writing
If I use -hls_init_time 10 and -hls_time 60, it produces up to Opening '981.ts' for writing

I'd expect the first one to produce 153 files and the 2nd to produce 154 or 155 files.

[Steven Liu]

hls_init_time should be used in -hls_list_size > 0

​https://patchwork.ffmpeg.org/project/ffmpeg/patch/20221209043736.29531-1-lq@chinaffmpeg.org/

Try this patch please.

[brunoais]

Replying to Steven Liu:

hls_init_time should be used in -hls_list_size > 0

​https://patchwork.ffmpeg.org/project/ffmpeg/patch/20221209043736.29531-1-lq@chinaffmpeg.org/

Try this patch please.

Thank you very much for such fast reply!

If I don't change any options, with this, hls_init_time is being ignored.

Should documentation be changed to clarify for non-native english speakers? If so I just don't use this option and take the performance optimization loss.

OR

Would it be feasible to change ffmpeg to support this option when -hls_list_size is 0?

[Steven Liu]

Replying to brunoais:

Replying to Steven Liu:

hls_init_time should be used in -hls_list_size > 0

​https://patchwork.ffmpeg.org/project/ffmpeg/patch/20221209043736.29531-1-lq@chinaffmpeg.org/

Try this patch please.

Thank you very much for such fast reply!

If I don't change any options, with this, hls_init_time is being ignored.

Should documentation be changed to clarify for non-native english speakers? If so I just don't use this option and take the performance optimization loss.

OR

Would it be feasible to change ffmpeg to support this option when -hls_list_size is 0?

The above patch is used for fix the problem.

[brunoais]

Replying to Steven Liu:

The above patch is used for fix the problem.

Your answer is ambiguous to me. So I need clarification.

Do you mean:

1. The above patch is to provide support for a different length for the first file using hls_init_time, even when running with -hls_list_size 0 and -hls_playlist_type vod?
2. Don't let hls_init_time override hls_time?

It achieved the 2nd one, not the first one.