When editing or replaying material from multiple devices, it is usually necessary to maintain a direct time relationship between the devices. This explanation was written by Alistair Jackson of EditHouse as supporting material for use in his training courses. It is just like shooting 24p film.Timecode Explained - EditHouse Television Production Articles Legacy analog film conversion: 23.976p would run 0.001 % fast on a 24 fps projectorĪn added business bonus is shooting digital 23.976p doesn't upset existing unionized craft relationships or require extensive retraining. The finished master could be converted to all the current and lagacy world formats as follows.Ģ3.976 to 480i/1080i 29.97 fps using pulldown (aka "telecine")Ģ3.976 to 480p/720p/1080p 59.94 fps using a 3:2 frame repeatsĢ3.976 to 576i/1080i 25 fps by frame interpolation (speedup)Ģ3.976 to 576p/720p/1080p 50 fps by frame interpolation (speedup) You would transfer legacy film at slightly slow 24000/1001 ~=23.976 and you would use 23.976 for all electronic production and editing. So if you are going to shoot "24p" for worldwide film and television distribution, how would you define a digital master frame rate? You would choose the frame rate that directly converts as much as possible. You may want to argue techincal or artistic reasons to do otherwise but those arguements didn't fly in the HDTV or Digital Cinema standardization process. 24p was originally chosen is still used for business reasons. ![]() Whatever artistic defense you have heard for 24p, it is all rationalization. ![]() So we are left with 24p as the legacy base to build a world distribution empire. In other words 25 fps is regionally isolated and can't be easily converted into anything else. ![]() There is no direct conversion possible between 25fps to 29.97fps or 25fps to 24 fps. This determines the following versions of NTSC derived HD formats used today.Ģ3.976 fps (29.97*24/30) for progressive film rateįor historical reasons, the PAL/SECAM regions use a 25 fps base for interlace and 50 fps for progressive. HDTV standards have consolidated world TV resolution standards to 1920x10x720 leaving only frame rate differences between the formerly NTSC and PAL/SECAM regions.Īs Jagabo explains NTSC television uses 30/1001=29.97 as a frame rate base. In the analog days, NTSC and PAL transfers from film required a completely separate transfer and edit because of resolution and frame rate differences. The business goal is to shoot and edit in a single format that can be directly converted to all the common world film and TV formats and be compatible with legacy format archives.įor historical technical reasons the world has a common 24 fps film format and different regional television formats. Without sinking into too much detail unless you want to, I'll give the business reason. If I use soundforge, do I increase the audio by 104%?Īnd why they wanted to slow down to 23.976 instead of 24? I myself have no idea if it will works, thus seeking help. But I have to tally to see if it match up. All I want is audio.įor video, I am using the original one. I thought by matching up the NTSC audio and video, I can convert it to PAL using TMGenc 4 xpress. The reason why I want to get the video in NTSC is to get the audio match up for confirming. Now, what am I suppose to do is to get the audio match with the video. Which I am sure that the audio is tally with NTSC. 1, the audio from the feature in digi beta.Īs the fact, I tally against the commentary audio to video, my audio is longer than the feature. There are 2 audio involved in this scenario. It is already in PAL.Īs I have to send the feature in mpeg1 to my client for Chinese subtitling, I had it captured using optibase. Perhaps let me explain in details.įirst, my job is to capture the feature from digi beta tape. Initially, this audio is given separately with the video tho. In what way, can I really match the audio perfectly along with the video? It is slightly drift as I notice the percentage is 104.+%. Now I am using Time Shift in Protools, I set the end timecode to match up with the video. The 2nd audio, which is the commentary, is matched with NTSC video. ![]() The first audio, which is 5.1, is 100% match with PAL video. Thanks Alex, now I get your meaning tho.įor instance, right now, I have the digi beta tape (PAL) been captured to my PC using Blackmagic.Īs such, I have 2 set of audio to match with the video too. This conversion method makes PAL 4% shorter. To keep frames unmodified at conversion to PAL, first 23.976 is restored, then it is sped-up to 25. Talking about 4% difference in length, people mean conversion between PAL/NTSC for film source which is 24fps (modified to 23.976 with pulldown to 29.97 for NTSC).
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