Greetings, I am looking for a way to specify output codec timebase (tbc, or codec_time_base as reported by ffprobe -show_streams). Searching for a solution and asking in #ffmpeg have not been entirely fruitful. The documentation suggests that -time_base should be an option:
| The list of supported options follow: | [...] | time_base rational number | Set codec time base. | It is the fundamental unit of time (in seconds) in terms of which frame timestamps are represented. For fixed-fps content, timebase should be 1 / frame_rate and timestamp increments should be identically 1. As per https://www.ffmpeg.org/ffmpeg-codecs.html#Codec-Options However, recent-ish repo (2.6.3) and compiled (N-73111-ge22edbf) version of ffmpeg complain: | Unrecognized option 'time_base'. Is there a way of achieving this in current versions? Thanks in advance, Rob -- Extra info: The lack of references suggests that setting output timebase is not a usual or recommended thing to do in most cases. However, I am trying to produce video with the exact same parameters so that they can be joined together using the concat demuxer. ("If you have media files with exactly the same codec and codec parameters you can concatenate them...") There is more detail available in a question I asked on SuperUser (http://superuser.com/questions/931969/creating-videos-for-ffmpegs-concat-demuxer-to-avoid-a-large-re-encode - I suspect that it is too niche to attract an answer there however); but I will summarise briefly to save clicking through. I have a long file that I wish to extract useful parts from, which can be done by cutting and rejoining with no problems. However, for aesthetics I would like to include short transitions between these parts. This would normally incur a long re-encode of the entire set of clips which I would like to avoid to save time and transcoding something already in a lossy format. The parts are split further at the ends, and these small subclips used to generate the transitions- no problems there either. I am trying to glue all this back together and getting artifacts, because of what I presume are mismatches in codec parameters. It's not an entirely typical use case, and may be a wild goose chase but I figured it was worth a shot to make things a bit more efficient. -- Console output for unrecognised option, time_base using example generated output: $ ./ffmpeg -y -f lavfi -i color=red -frames:v 200 -r 62.5 -time_base 60.0 test.mp4 ffmpeg version N-73111-ge22edbf Copyright (c) 2000-2015 the FFmpeg developers built with gcc 4.9.2 (Debian 4.9.2-10) configuration: --pkg-config-flags=--static --enable-gpl --enable-libass --enable-libfreetype --enable-libmp3lame --enable-libtheora --enable-libvorbis --enable-libx264 --enable-nonfree libavutil 54. 27.100 / 54. 27.100 libavcodec 56. 44.100 / 56. 44.100 libavformat 56. 38.100 / 56. 38.100 libavdevice 56. 4.100 / 56. 4.100 libavfilter 5. 17.100 / 5. 17.100 libswscale 3. 1.101 / 3. 1.101 libswresample 1. 2.100 / 1. 2.100 libpostproc 53. 3.100 / 53. 3.100 Unrecognized option 'time_base'. Error splitting the argument list: Option not found _______________________________________________ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-user
