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Codec stands for 'coder-decoder', it is a method of compressing video in order to strike a balance between file size and quality. Different codecs have different data rates, aspect ratios, and methods of closed captioning in order to achieve this balance. Some examples of codecs are DV, MPEG-2, WMV, H.264, Uncompressed, and ProRes. To watch a video, your computer needs the specific codec that video uses, otherwise it will not play. Not all codecs are available for all operating systems, and they may not be free to use.
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Drop-frame timecode refers to a method of counting timecode in 29.97 fps video. It does not refer to actual frames of video being dropped that would affect video quality. Since 29.97 fps is not exactly 30 fps, when counting in drop-frame certain numbers in the timecode counter are skipped in order to ensure that the timecode will reflect the real-time length of the program.The counterpart of drop-frame is non-drop which does not skip numbers when counting timecode.
Thank you for your continued support of Pegasys products. Sale of TMPGEnc Video Mastering Works 6 has ended because the successor product, TMPGEnc Video Mastering Works 7, is now available. For more details about TMPGEnc Video Mastering Works 7, please visit the product page.
To prevent drift, it is important to timestamp in the correct mode (or convert your captions' timecode using CPC software) when closed captioning a 29.97 fps program. The term 'encoder' typically refers to a hardware encoder, but can refer to software encoders as well. A hardware encoder is usually a rack-mounted device that accepts a video signal, marries it to closed captions, and then outputs a new closed captioned video signal, usually resulting in generation loss.A software encoder, such as MacCaption, can add captions to video without a hardware encoder.
You can simply encode captions to video files already present on your computer, or to file formats that will add captions as you output from your NLE with no generation loss. Live captioning is captioning process used for live webcasts or broadcasts to add captions to video on the fly. It requires several important tools.
The first is a source of transcription such as a stenographer or speech recognition software.Please note, getting speech recognition software to usable levels of accuracy still requires an individual to operate it. That second item required for live captioning is a hardware encoder which will accept the video signal and the closed caption data and combine them for output. Last, you may need captioning software to tie these two things together (especially if you're using speech recognition software). Non-Drop timecode refers to a method of counting timecode in 29.97 fps video.
It does not refer to actual frames of video being dropped that would affect video quality. Since 29.97 fps is not exactly 30 fps, when counting in non-drop, the timecode will get progressively further and further behind 'real time.' For instance, after 2000 frames a drop-frame counter will display 00:01:06:22, while a non-drop counter will display 00:01:06:20, but the content and real-time length of the video will be the same. The drop-frame counter is slightly ahead because it's goes straight from 00:00:59:29 to 00:01:00:02. To prevent drift, it is important to timestamp in the correct timecode mode (or convert your captions' timecode using CPC software) when closed captioning a 29.97 fps program.
OP-47 (Operational Practice number 47) is a solution for inserting a Teletext ancillary data channel into HD media. OP-47 was originally developed by Australian broadcasters and is now widely used. The data can be stored in the SMPTE 436M track of an MXF wrapper. OP-47 Teletext stores data in selectable pages within magazines (1-8).
These can be selected by viewers using menu controls on their TV monitor. Typically, the subtitle data can be stored in magazine 8 page 01, or Teletext 801. Other samples may have Teletext 888, which is magazine 8 page 88.
This is according to the SMPTE-RDD8 specification.Teletext supports Latin, Hebrew, Arabic, Greek, and Cyrillic alphabet. However, it does not support Asian unicode characters such as Chinese and Japanese. CaptionMaker can only insert Latin alphabet Characters into OP-47.
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I'm using FCP 7.0.3 and am using it to edit short video and audio clips to use in a Keynote presentation. I am following instructions to the letter on how to export sequences to Quicktime.mov format and am ALWAYS selecting the box 'Make movie self-contained' so that all the relevant info will be included to enable this to be played on any computer. However, this is not what's happening - only the audio is playing. It won't even play on any of the other iMacs in the office. It would appear it is exporting the sequences as reference files even though I am selecting 'make movie self-contained' box. Getting desperate, very frustrated and would be grateful for some help here as I have to make this presentation in 2 days. Hi Julie,Your workflow and your settings seem to be correct.Have you tried trashing your FCP preferences?
This might solve your problem.If that does not help, try this: export your sequence Using QuickTime Conversion instead of 'As a QuickTime Movie'. Use current settings as your export format.
The main difference between the two approaches is that when you export using QT conversion every single frame of your video is re-encoded. This will introduce a very slight generation loss (which you won't even notice in one generation), but it will solve any codec or QT related issues.Best wishes,Ronny. Hi RonnyYou're right - using just the Quick Time Conversion allows the other computers to play the clips but the compression seems to have elongated/stretched the sequence - i.e.
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My subjects are suddenly tall and thin rather than a proper shape. In custom settings I've also tried to export by changing the Quicktime Video Compressor settings to H.264 and changing everything else to represent the HDV format 1440x1080i etc. This also works and the clips can be played on the other computers but produces a much reduced file size (i.e. 12.5MB compared to original file 71.6MB), and also creates a sort of flash just before the cross-fade transitions. From this it would seem that the other 3 Apple iMacs (relatively new and running Snow Leopard) aren't reading the clips when the Quicktime Video settings are 'HDV 1080i50).Not too sure about trashing all the FCP settings as I don't understand it all well enough to put them back if needed.Anything else I can try?Thanks for your help so far.Julie. Hi KenThanks - hope you don't think I'm being a nuisance.I'm not selecting/choosing to use the MPEG-2 Video Codec. When I looked at the.mov info file on the original one that I exported (using Export as Quicktime movie, then opting for Current settings, include Audio and Video, Make movie self-contained) this was one of the Codecs listed.The very first sequence I ever put together for a friend for a fund raiser (in May 2012) worked fine and still does on the other computers.
Now when I look at the info on that clip sequence it still has the MPEG-2 Video and Timecode Codecs but it's missing the Linear PCM. I don't know why the Codecs would have changed and the clips I'm using now were all recorded at the same time and using the same video recorder. Does this info help you to help me???CheersJulie. Hey KenYou did give me an idea to try and believe it or not it has worked - thought I'd share in case anyone else runs into this problem.Rather than downloading MPEG Streamclip, as a long-shot/gamble, I decided to use the additional info you gave me and in FCP exported as a Quicktime movie, left everything as per my previous settings ( i.e. Includechanged the Settings to Custom and selected Apple ProRes 422 1440x1080 50i and see what happened. This changed the MPEG-2 Codec to apco. I don't understand all the ins and outs of this enough but the sequence looks OK and plays on the other Macs and in Keynote so I'm going to run with this.Many, many thanks for your help and suggestions - very much appreciated.Cheers.Julie.Cheers.
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January 2023
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