On Wed, Dec 2, 2020 at 9:26 AM Mathieu Malaterre <[email protected]> wrote: > > Hi there, > > I am trying to find the documentation for a specific metadata tag: > 'date'. According to the following page: > > * https://wiki.multimedia.cx/index.php/FFmpeg_Metadata
Here is a small reproducer. Let's consider the following reference: * https://www.matroska.org/technical/tagging.html#temporal-information In particular the line: "DATE_RECORDED UTF-8 The time that the recording began. This is akin to the TDRC tag in ID3." Steps: $ wget http://samples.mplayerhq.hu/A-codecs/lossless/luckynight.flac $ ffmpeg -i luckynight.flac test1.mp3 $ ffmpeg -i test1.mp3 test2.mkv Gives: $ exiftool -v3 -l test1.mp3| grep -1 TDRC | RecordingTime = 1995 | - Tag 'TDRC' (6 bytes): | 0101: 03 31 39 39 35 00 [.1995.] While: $ exiftool -v3 -l test2.mkv| grep -3 1995 | | | | TagName = DATE | | | | - Tag 0x05a3 (4 bytes): | | | | 1292: 44 41 54 45 [DATE] | | | | TagString = 1995 | | | | - Tag 0x0487 (4 bytes): | | | | 1299: 31 39 39 35 [1995] | | | + [SimpleTag directory, 21 bytes] | | | | TagName = GENRE | | | | - Tag 0x05a3 (5 bytes): So in summary ID3:TDRC is being copied to Matroska:SimpleTag:DATE, however the specification seems to indicate that in this case 'DATE_RECORDED' should be prefered. > ffmpeg has a built-in mechanism for tag: 'title'. I also see that my > ffmpeg version has the same property for tag 'date' but only for a > round trip mp4 ⇔ avi. This property does not work with an mkv > container. > > Is this pure luck that tag 'date' is transferred from avi to mp4 & mp4 > to avi ? Should it work the same way for mkv container ? > > Thanks for clarification, > > For reference: > > ./ffmpeg -version > ffmpeg version N-100064-g3c92268 Copyright (c) 2000-2020 the FFmpeg developers > built with gcc 8 (Debian 8.3.0-6) > configuration: --prefix=/home/mathieu/ffmpeg_build > --pkg-config-flags=--static > --extra-cflags=-I/home/mathieu/ffmpeg_build/include > --extra-ldflags=-L/home/mathieu/ffmpeg_build/lib > --extra-libs='-lpthread -lm' --bindir=/home/mathieu/bin --enable-gpl > --enable-gnutls --disable-libaom --enable-libass --enable-libfdk-aac > --enable-libfreetype --enable-libmp3lame --enable-libopus > --disable-libsvtav1 --enable-libvorbis --enable-libvpx > --enable-libx264 --enable-libx265 --enable-nonfree > libavutil 56. 61.100 / 56. 61.100 > libavcodec 58.113.100 / 58.113.100 > libavformat 58. 64.100 / 58. 64.100 > libavdevice 58. 11.103 / 58. 11.103 > libavfilter 7. 91.100 / 7. 91.100 > libswscale 5. 8.100 / 5. 8.100 > libswresample 3. 8.100 / 3. 8.100 > libpostproc 55. 8.100 / 55. 8.100 The above steps where run using: $ ffmpeg -version ffmpeg version N-100132-g53b4550bdd Copyright (c) 2000-2020 the FFmpeg developers built with gcc 8 (Debian 8.3.0-6) configuration: --prefix=/home/mathieu/ffmpeg_build --pkg-config-flags=--static --extra-cflags=-I/home/mathieu/ffmpeg_build/include --extra-ldflags=-L/home/mathieu/ffmpeg_build/lib --extra-libs='-lpthread -lm' --bindir=/home/mathieu/bin --enable-gpl --enable-gnutls --enable-libaom --enable-libass --enable-libfdk-aac --enable-libfreetype --enable-libmp3lame --enable-libopus --disable-libsvtav1 --enable-libvorbis --enable-libvpx --enable-libx264 --enable-libx265 --enable-nonfree libavutil 56. 61.100 / 56. 61.100 libavcodec 58.114.100 / 58.114.100 libavformat 58. 64.100 / 58. 64.100 libavdevice 58. 11.103 / 58. 11.103 libavfilter 7. 91.100 / 7. 91.100 libswscale 5. 8.100 / 5. 8.100 libswresample 3. 8.100 / 3. 8.100 libpostproc 55. 8.100 / 55. 8.100 -- Mathieu _______________________________________________ ffmpeg-user mailing list [email protected] https://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email [email protected] with subject "unsubscribe".
