> On May 8, 2016, at 1:40 AM, Francois Visagie <francois.visa...@gmail.com> > wrote: > >> -----Original Message----- >> From: ffmpeg-user [mailto:ffmpeg-user-boun...@ffmpeg.org] On Behalf Of >> Martynas Brijunas >> Sent: 07 May 2016 01:29 >> To: ffmpeg-user@ffmpeg.org >> Subject: [FFmpeg-user] Encoding DV tapes with "datecode" preserved for >> each frame >> >> Hi, >> >> I have a collection of AVI files which were created from DV tapes. Each frame >> in these AVI files has a "datecode" field which can be seen with a tool like >> "dvdate". I would like to move my collection from the very bulky AVI files >> (16GB per tape) to a very manageable MP4. My question is: can the >> "datecode" field be preserved when transcoding from dvvideo (native) to >> h264 (libx264)? I am attaching a screenshot of how this "datecode" looks like >> on one of my files. > > Not saying it isn't possible, but I never managed to do this. It could be > that datecode is proprietary DV codec metadata not understood by ffmpeg (at > least with the versions I tried).
Here's a sample with recording data and time in the VAUX of the DV encoding: https://archive.org/download/DvAnalyzerSampleDvAudioErrors/dvanalyzer_sample_EVIA_IU.mov <https://archive.org/download/DvAnalyzerSampleDvAudioErrors/dvanalyzer_sample_EVIA_IU.mov>. The VAUX structure is defined in http://web.archive.org/web/20060927044735/http://www.smpte.org/smpte_store/standards/pdf/s314m.pdf <http://web.archive.org/web/20060927044735/http://www.smpte.org/smpte_store/standards/pdf/s314m.pdf> but this spec doesn't seem to identify or explain the vaux packs for recording date and recording time. In the same the first recording date vaux pack is at 129,482 bytes and the first recording time vaux pack is at 129,487 bytes (or 458 and 463 bytes from the start of the dv encoding). There's a rough guide to parsing these to packs at https://groups.google.com/d/msg/microsoft.public.win32.programmer.directx.video/3kMuSYZ-KFw/CKfl0xeZ8FUJ <https://groups.google.com/d/msg/microsoft.public.win32.programmer.directx.video/3kMuSYZ-KFw/CKfl0xeZ8FUJ>, copying the most relevant part here: BYTE magic_62; BYTE magic_FF_5; BYTE day:5; //max = 0x31 BYTE msb_day:3; BYTE month:5; //max = 0x12 BYTE msb_month:3; BYTE year; //max = 0x99 BYTE magic_63; BYTE magic_FF_6; BYTE second:6; //max = 0x59 BYTE msb_second:2; BYTE minute:6; //max = 0x59 BYTE msb_minute:2; BYTE hour:6; //max = 0x23 BYTE msb_hour:2; For the sample the recording date time should be 2004-07-09 13:53:52. Hope this helps. > Failing that, you have a couple of alternatives. To help ffmpeg access > datecodes, extract them to subtitle text file format with dvdate or similar > beforehand, and then try mux them in (converting format if necessary) with > ffmpeg during encoding. The other alternative follows from this - extract > datecode to subtitle files for your player to render during playback. The > latter is what I usually do. > >> >> Thank you in advance. > > _______________________________________________ > ffmpeg-user mailing list > ffmpeg-user@ffmpeg.org > http://ffmpeg.org/mailman/listinfo/ffmpeg-user > > To unsubscribe, visit link above, or email > ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe". _______________________________________________ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".
