As a Christmas gift and before mpeg2 becomes completely obsolete with the arrival of H264 streams here is a version of the IVTC mod for DSCALER 5 that has been sleeping on my hard drive for almost one year.
He are are the changes
- Cleaned up code, removed the experimental 720p which was useless
- Attempt to Autoresync audio / video for badly damaged MPEG2 streams, this may help in some case when audio and video becomes out of sync
- Deinterlacing type is now ignored and forced to weave when IVTC is in progress. Configuration will be simpler and mixed stream video / film may be better
- Support for ATSC Closed Captioning. Dscaler 5 supported already closed captioning for NTSC DVD. There was some code for ATSC streams. However it was broken because it didn't take into account the order of the frames in the video buffer.
Here is a quickrecap for those who are not completely familiar with Closed Captioning (CC). CC contains texts that can be displayed when watching a video or a movie. Usually these texts correspond to subtitles. Contrary to recent DVDs and DVB streams Closed Captioning is not contained in a separate stream of the Mpeg2 file, it is stored in "user data" information of the video stream (in ATSC streams two characters that are to be displayed are associated to each frame of the video).
Dscaler 5 supported already CC for old NTSC DVDs. In this particular case, the CC information for several frames is stored in each GOP "user data". However When CC information is associated to each frame like in an ATSC streams, the question of reordering the CC information arises especially because of B frames, the frames are not displayed in the order they are processed. This were Dscaler was broken.
Since the CC in stored in "user data" of video streams, the CC information resists to quite a lot of processing such as video editing, it is why it is quite interesting to discover how many streams available around offers Closed Captioning.
How to use CC with Dscaler 5
Unless you use a DVD player such as Zoom Player, you won't be able to view the closed captioning without doing some specific setup. Indeed, for ordinary ATSC stream files you need specific Directshow graphs. Indeed, Dscaler is capable to output CC information. However, to be displayed they need a specific filter which will turn cc info into characters to display. This filter is named "Line 21 decoder" its name refer to the 21th line which is used in NTSC analog signal to store CC information. Note that that there are two versions of the filter whether your video renderer is overlay or VMR9.
You will find attached the file graph.jpg which gives a general idea on how to connect Dscaler to display the Closed captioning.
In case you use Zoomplayer, here are the ready to use configuration which assumes you use Reclock as the Audio renderer. In order to make it work you must copy either of these file in the "ZoomPlayer\\MediaGraph" directory and rename then to "ts.mediagraph". Then in the "Filter" menu of Zoomplayer 4.51, you need to uncheck the option "Enable customized playback" and select the option "auto by extension" in the "management" Tab.
- "VMR ts.mediagraph": use VRM9 as video renderer
- "overlay ts.mediagraph": use overlay as video renderer
I kind of forget where I put the modified source code, so it will come later.
Dscaler5.IVTC.251206.zip 152.6962890625k . file