Closed captions 608 to 708 VANC

[Ray4x4x4]

Is it possible to find a way to preserve or convert the EIA-608 Closed Caption data into CEA-708 (10 bit VANC) when transcoding files?
Here is the source file info. Scrolling down to the bottom, you see the existing EIA-608 data location.


Complete name : \\10.0.0.202\dubs\AM9196SPPZ24.mpg
Format : MPEG-PS
File size : 1.30 GiB
Duration : 28 min 30 s
Overall bit rate mode : Constant
Overall bit rate : 6 512 kb/s
Frame rate : 29.970 FPS

Video
ID : 224 (0xE0)
Format : MPEG Video
Format version : Version 2
Format profile : Main@Main
Format settings : BVOP
Format settings, BVOP : Yes
Format settings, Matrix : Default
Format settings, GOP : M=3, N=12
Format settings, picture structure : Frame
Duration : 28 min 29 s
Bit rate mode : Constant
Bit rate : 6 127 kb/s
Maximum bit rate : 6 000 kb/s
Width : 720 pixels
Height : 480 pixels
Display aspect ratio : 4:3
Frame rate : 29.970 (30000/1001) FPS
Standard : NTSC
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 8 bits
Scan type : Interlaced
Scan order : Bottom Field First
Compression mode : Lossy
Bits/(Pixel*Frame) : 0.591
Time code of first frame : 00:00:10;00
Time code source : Group of pictures header
GOP, Open/Closed : Closed
Stream size : 1.22 GiB (94%)

Audio
ID : 192 (0xC0)
Format : MPEG Audio
Format version : Version 1
Format profile : Layer 2
Duration : 28 min 30 s
Bit rate mode : Constant
Bit rate : 256 kb/s
Channel(s) : 2 channels
Sampling rate : 48.0 kHz
Frame rate : 41.667 FPS (1152 SPF)
Compression mode : Lossy
Stream size : 52.2 MiB (4%)

Text
ID : 224 (0xE0)-CC1
Format : EIA-608
Muxing mode : A/53 / DTVCC Transport
Muxing mode, more info : Muxed in Video #1
Duration : 28 min 29 s
Duration of the visible content : 28 min 28 s
Start time (commands) : 604 ms
Start time : 638 ms
End time : 28 min 29 s
Bit rate mode : Constant
Stream size : 0.00 Byte (0%)
Count of frames before first event : 44
Type of the first event : RollUp

[emcodem]

Hi Ray,
transporting teletext data is a very very dark ancient art.
Answer is: cannot be answered without knowing your output format but for start i can tell you that for mxf you have to buy something, no open source that i know can put 608/708 into mxf.

[FranceBB]

yeah... emcodem is right, unfortunately with open source tools the only thing we can do is preserve a subtitles track, like if you wanted to remux it in the end file but without changing container nor Teletext page. Unfortunately there's no way to convert it or indeed change the page.
I know 'cause I still mux .stl subtitles into mxf as OP-47 (i.e carried via a 436M track) with the Italian being in page 777 and the original language being in page 778. Unfortunately no open source implementation was able to do that.

Oh and by the way, that would only work with a command line execution node that uses ffmpeg because any internal encoder has -map_metadata -1 which would nuke the TTX (which is the right thing to do in 99.9% of the use cases). Also keep in mind that open source tools also can't change the timecode of embedded subtitles, which means that if you had a source at let's say 01:00:00:00 and you changed the timecode to 10:00:00:00 then the subtitles would no longer be displayed. Last but not least, subtitles are also frame rate dependant, so if you convert the video frame rate and just remux them they would go out of sync.


TL;DR it's a mess and unfortunately it's such a tiny market that nobody ever made an open source implementation.

[luzimarsorgi]

HI, TKS FOR YOUR HELP.
Here is the configuration file that i need to keep when file pass true FFastrans.
Format: .MXF
Format profile: OP-1a
VIDEO
Format: MPEG Video: XDCAM HD422
Bit rate: 50.0 Mb/s
Width: 1 920 pixels
Height: 1 080 pixels
Display aspect: 16:9
Frame rate: 29.970
Scan type: Interlaced
Audio #1
Format: PCM
Sampling rate: 48.0 kHz
Frame rate: 29.970 FPS
Bit depth: 24 bits
Audio #2 (AUDIO DESCRICAO)
Format: PCM
Sampling rate: 48.0 kHz
Frame rate: 29.970 FPS
Bit depth: 24bits
CLOSED CAPTION
Text
ID: 1024-CC1
Format: EIA-608
Caption Service Name: CC1

[emcodem]

hi @luzimarsorgi
unfortunately we do not know any opensource tools that are able to deal with EIA-608 in MXF container. I looked into it myself but it is just too much work to add this to BMX or ffmpeg just for fun.