From 7ed4d77a97bc17d96967f7f2bfa41842226d0c1c Mon Sep 17 00:00:00 2001 From: wm4 Date: Sun, 2 Jun 2019 02:24:43 +0200 Subject: manpage: some more backward playback edits --- DOCS/man/options.rst | 34 ++++++++++++++++++++++------------ 1 file changed, 22 insertions(+), 12 deletions(-) (limited to 'DOCS/man/options.rst') diff --git a/DOCS/man/options.rst b/DOCS/man/options.rst index 754c2476f8..944b50c1d1 100644 --- a/DOCS/man/options.rst +++ b/DOCS/man/options.rst @@ -496,8 +496,8 @@ Playback Control Tuning: - - Remove all ``--vf``/``--af`` filters you have set. Disable deinterlacing. - Disable idiotic nonsense like SPDIF passthrough. + - Remove all ``--vf``/``--af`` filters you have set. Disable hardware + decoding. Disable idiotic nonsense like SPDIF passthrough. - Increasing ``--video-reversal-buffer`` might help if reversal queue overflow is reported, which may happen in high bitrate video, or video @@ -505,17 +505,20 @@ Playback Control increase ``--hwdec-extra-frames`` instead (until you get playback without logged errors). - - The demuxer cache is essential for backward demuxing. If it's too small, - a queue overflow will be logged, and backward playback cannot continue, - or it performs too many low level seeks. If it's too large, implementation - tradeoffs may cause general performance issues. Use ``--demuxer-max-bytes`` - to potentially increase the amount of packets the demuxer layer can queue - for reverse demuxing (basically it's the ``--video-reversal-buffer`` - equivalent for the demuxer layer). + - The demuxer cache is essential for backward demuxing. Make sure to set + ``--demuxer-seekable-cache`` (or just use ``--cache``). The cache size + might matter. If it's too small, a queue overflow will be logged, and + backward playback cannot continue, or it performs too many low level + seeks. If it's too large, implementation tradeoffs may cause general + performance issues. Use ``--demuxer-max-bytes`` to potentially increase + the amount of packets the demuxer layer can queue for reverse demuxing + (basically it's the ``--video-reversal-buffer`` equivalent for the + demuxer layer). - ``--demuxer-backward-playback-step`` also factors into how many seeks may be performed, and whether backward demuxing could break due to queue - overflow. + overflow. If it's set too high, the backstep operation needs to search + through more packets all the time, even if the cache is large enough. - Setting ``--demuxer-cache-wait`` may be useful to cache the entire file into the demuxer cache. Set ``--demuxer-max-bytes`` to a large size to @@ -524,7 +527,7 @@ Playback Control cache. - If audio artifacts are audible, even though the AO does not underrun, - increasing ``--audio-reversal-buffer`` might help in some cases. + increasing ``--audio-backward-overlap`` might help in some cases. ``--video-reversal-buffer=``, ``--audio-reversal-buffer=`` For backward decoding. Backward decoding decodes forward in steps, and then @@ -533,8 +536,13 @@ Playback Control unbounded resource usage; during normal backward playback, it's not supposed to hit the limit, and if it does, it will drop frames and complain about it. + Use this option if you get reversal queue overflow errors during backward + playback. Increase the size until the warning disappears. Usually, the video + buffer will overflow first, especially if it's high resolution video. + This does not work correctly if video hardware decoding is used. The video - frame size will not include the referenced GPU and driver memory. + frame size will not include the referenced GPU and driver memory. Some + hardware decoders may also be limited by ``--hwdec-extra-frames``. How large the queue size needs to be depends entirely on the way the media was encoded. Audio typically requires a very small buffer, while video can @@ -591,6 +599,8 @@ Playback Control Setting this to a very low value or 0 may make the player think seeking is broken, or may make it perform multiple seeks. + Setting this to a high value may lead to quadratic runtime behavior. + Program Behavior ---------------- -- cgit v1.2.3