Hi everyone, I need help figure out a way to get accurate time stamps on my closed captioning files using zvbi-atsc-cc. I have Hauppauge HVR-1850 cards working in digital mode. I need separate recordings of the video/audio file (mpeg2) and the closed captioning (plain text). I can capture a plain mpeg stream by issuing this in one console: * azap -r KOCE-HD And this in a second console: * cat /dev/dvb/adapter0/dvr0 > test-cat3.mpeg I tested this file and it plays fine. To generate the closed captioning, I feed this file into zvbi-atsc-cc: * zvbi-atsc-cc --atsc -c KCAL-HD -T < test-cat3.mpeg "KCAL-HD" being the the channel in my channels.conf that I captured from. The problem: I need accurate time stamps. Normally, I add the time stamps during capture, so they match reality. If I get the closed captioning from a file, the information is still in the file (I just need to set the start time), but how do I get that information out? Our system relies on the time stamps in the closed captioning to cue the video, so they need to be accurate. One-second accuracy is adequate, so if I can get the STT information from the PSIP info, that would be good enough. I'm using an off-air signal, so these are ATSC 8VSB channels: LA18.8:497000000:8VSB:161:164:8 KBEH-DT:533000000:8VSB:49:52:1 KCET-HD:557000000:8VSB:49:52:1 A typical closed captioning file should end up looking like this: 2010-05-02_1100_CNN_Amanpour_2010-05-02_11:00:02 % Communication Studies Archive, UCLA % 87e70c70-5614-11df-b2f7-00e0815fe826 % Video length 0:59:54.024 % Christiane Amanpour 2010-05-02_1100_CNN_Amanpour_2010-05-02_11:00:12 2010-05-02_1100_CNN_Amanpour_2010-05-02_11:00:22 A HIGH STAKES INVESTIGATION IS STARTED AFTER A CAR BOMB IS 2010-05-02_1100_CNN_Amanpour_2010-05-02_11:00:32 FOUND IN NEW YORK'S TIMES SQUARE. WHO WANTED TO ATTACK THE CROSSROADS OF THE WORLD AND WHY. PRESIDENT OBAMA HEADS TO THE GULF COAST FOR A FIRSTHAND LOOK 2010-05-02_1100_CNN_Amanpour_2010-05-02_11:00:42 AT DESPERATE EFFORTS TO MAINTAIN AN OIL SPILL. -- in other words, a time stamp every ten seconds, which is then used by our search engine to link to the video. The header (%) is added afterward. Ideally for us, then, I would get the STT stamp at ten-second intervals inserted into the closed captioning file. Are there command-line Linux tools for reading PSIP? (There are also other possible uses of PSIP. xds information is too unreliable and inconsistent for us to use, but if PSIP is reliable, I'd like to use it to verify that I'm getting the recording I intended to get (channel and program name). I could potentially use this information to crop the video to the exact program -- but it would have to be reliable enough to be automated, I don't have staff to do anything manual with individual recordings.) Alternatively, Devin Heitmueller tells us that there is also the PTS (presentation timestamp), which should be pretty easy to modify zlib-atsc-cc to show. Since the PTS can be used to synchronize the video to the CC info is it possible to make a small modification to zvbi-atsc-cc to log the CC info with the PTS, and then write a really simple utility to seek to a given PTS and play the video? Could someone help me out with accurate timestamps in relation to PSIP info and PTS? Warm wishes, Santino -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
