CC extract

[vidblue]

I have an ISO which was created from a NTSC DVD recorded from a NTSC VHS. I don't have the VHS. Vidcoder does show that is has CC608 in it but after encoding I don't see the CC. The mediainfo shows the format as ASS. I'm not sure if CC exists in it or not.. maybe were not included in the recording, I just don't know. I wonder if there is another way/tool to confirm if the CC really exists or not?

Thanks

[usually_quiet]

EIA 608 CCs are stored in the video's MPEG user data. Because of this, CCs are not preserved when video is re-encoded. Some editing software also strips them, even in sections where the video is not re-encoded.

[Hurda]

CCExtractor

[ndjamena]

Ass? Let's see, MP4 doesn't take ASS, in fact as far as I'm aware only MKV can mux ASS internally... so if we assume you created an MKV, MKV DOESN'T take 608 captions, so in order to keep them VidCoder would have to convert them to something else. ASS has positions where SRT doesn't so that makes sense...

MKV

Am I right?

[usually_quiet]

Ass? Let's see, MP4 doesn't take ASS, in fact as far as I'm aware only MKV can mux ASS internally... so if we assume you created an MKV, MKV DOESN'T take 608 captions, so in order to keep them VidCoder would have to convert them to something else. ASS has positions where SRT doesn't so that makes sense...

MKV

Am I right?

MKV and MP4 both support NTSC EIA-608 closed captions. Because NTSC EIA-608 closed captions are stored in the video's MPEG user data, the container file format doesn't matter.

[ndjamena]

MKV doesn't support tracks within tracks, any MKV compliant remuxer would remove the captions from the video before muxing it into an mkv.

Have you ever actually seen an mkv with captions in it? Really I'd be interested to know what created it. MKV has NO official support of 608 captions at all, that's a sore point for some people.

MP4 tends to store its captions in it's own track, since MPC-HC can't read them that way and VLC only recently gained that ability it's doubtful many non-apple re-encoders would bother storing them that way, add to that the fact that they tend to alter the frame rate making storing them in the video impossible and you're left with very little chance of retaining the captions in their input format.

[vidblue]

Yes the encode was mkv. I just tried CCExtractor, though I never used it before so not sure about the right option I must use. It tried some formats and it did create a file for "dvdraw". Does it mean the source has CC?

When I play the VOB file ( ISO extract ), VLC shows Closed Caption 1-4 in the subtitle menu. But no matter what option I select, it won't show any CC. The mediainfo doesn't show any info about CC though.



Thanks

[usually_quiet]

MKV doesn't support tracks within tracks, any MKV compliant remuxer would remove the captions from the video before muxing it into an mkv.

Have you ever actually seen an mkv with captions in it? Really I'd be interested to know what created it. MKV has NO official support of 608 captions at all, that's a sore point for some people.

The fact that the MKV header is missing some information doesn't mean that there are no closed captions present. I just used VideoReDo TV Suite to create an MKV (MPEG-2 video and AC3 audio) from a DVD containing a TV broadcast which included closed captions. MediaInfo didn't reveal that there are EIA-608 captions present but they were still there. All I had to do was use CCExtractor GUI on the MKV file to retrieve them. On the other hand, when I tried MakeMKV on the same DVD, it stripped the closed captions.

MP4 tends to store its captions in it's own track, since MPC-HC can't read them that way and VLC only recently gained that ability it's doubtful many non-apple re-encoders would bother storing them that way, add to that the fact that they tend to alter the frame rate making storing them in the video impossible and you're left with very little chance of retaining the captions in their input format.

I download video from OTA broadcast networks here in the USA sometimes to catch up on a missed episode. Some MP4s have EIA 608 and even EIA 708 closed captions and some don't. The timing doesn't seem to be wrong when I watch them.

General
Complete name                            : K:\Grimm\El Cuegle.mp4
Format                                   : MPEG-4
Format profile                           : Base Media
Codec ID                                 : isom
File size                                : 560 MiB
Duration                                 : 43mn 16s
Overall bit rate                         : 1 808 Kbps
Movie name                               : GRIMM
Law rating                               : TV-14 (V)
Writing application                      : Lavf57.66.101

Video
ID                                       : 1
Format                                   : AVC
Format/Info                              : Advanced Video Codec
Format profile                           : High@L3.1
Format settings, CABAC                   : Yes
Format settings, ReFrames                : 1 frame
Format settings, GOP                     : M=1, N=48
Codec ID                                 : avc1
Codec ID/Info                            : Advanced Video Coding
Duration                                 : 43mn 16s
Bit rate                                 : 1 696 Kbps
Width                                    : 1 280 pixels
Height                                   : 720 pixels
Display aspect ratio                     : 16:9
Frame rate mode                          : Variable
Frame rate                               : 23.976 fps
Minimum frame rate                       : 23.810 fps
Maximum frame rate                       : 24.390 fps
Color space                              : YUV
Chroma subsampling                       : 4:2:0
Bit depth                                : 8 bits
Scan type                                : Progressive
Bits/(Pixel*Frame)                       : 0.077
Stream size                              : 528 MiB (94%)
Writing library                          : x264 core 120
Encoding settings                        : cabac=1 / ref=1 / deblock=1:0:0 / analyse=0x3:0x113 / me=hex / subme=6 / psy=1 / psy_rd=1.00:0.00 / mixed_ref=0 / me_range=16 / chroma_me=0 / trellis=1 / 8x8dct=1 / cqm=0 / deadzone=21,11 / fast_pskip=1 / chroma_qp_offset=-2 / threads=8 / sliced_threads=0 / nr=0 / decimate=1 / interlaced=0 / bluray_compat=0 / constrained_intra=0 / bframes=0 / weightp=2 / keyint=48 / keyint_min=25 / scenecut=0 / intra_refresh=0 / rc=abr / mbtree=0 / bitrate=1696 / ratetol=1.0 / qcomp=0.60 / qpmin=10 / qpmax=51 / qpstep=4 / ip_ratio=1.40 / aq=1:1.00

Audio
ID                                       : 2
Format                                   : AAC
Format/Info                              : Advanced Audio Codec
Format profile                           : LC
Codec ID                                 : 40
Duration                                 : 43mn 16s
Bit rate mode                            : Constant
Bit rate                                 : 96.0 Kbps
Channel(s)                               : 2 channels
Channel positions                        : Front: L R
Sampling rate                            : 44.1 KHz
Compression mode                         : Lossy
Stream size                              : 29.7 MiB (5%)

Text #1
ID                                       : 1-CC1
Format                                   : EIA-608
Muxing mode                              : SCTE 128 / DTVCC Transport
Muxing mode, more info                   : Muxed in Video #1
Duration                                 : 43mn 16s
Bit rate mode                            : Constant
Stream size                              : 0.00 Byte (0%)
Encoded stream size                      : 0.00 Byte (0%)

Text #2
ID                                       : 1-CC4
Format                                   : EIA-608
Muxing mode                              : SCTE 128 / DTVCC Transport
Muxing mode, more info                   : Muxed in Video #1
Duration                                 : 43mn 16s
Bit rate mode                            : Constant
Stream size                              : 0.00 Byte (0%)
Encoded stream size                      : 0.00 Byte (0%)

Text #3
ID                                       : 1-1
Format                                   : EIA-708
Muxing mode                              : SCTE 128 / DTVCC Transport
Muxing mode, more info                   : Muxed in Video #1
Duration                                 : 43mn 16s
Bit rate mode                            : Constant
Stream size                              : 0.00 Byte (0%)
Encoded stream size                      : 0.00 Byte (0%)

Text #4
ID                                       : 1-3
Format                                   : EIA-708
Muxing mode                              : SCTE 128 / DTVCC Transport
Muxing mode, more info                   : Muxed in Video #1
Duration                                 : 43mn 16s
Bit rate mode                            : Constant
Stream size                              : 0.00 Byte (0%)
Encoded stream size                      : 0.00 Byte (0%)

Text #5
ID                                       : 1-4
Format                                   : EIA-708
Muxing mode                              : SCTE 128 / DTVCC Transport
Muxing mode, more info                   : Muxed in Video #1
Duration                                 : 43mn 16s
Bit rate mode                            : Constant
Stream size                              : 0.00 Byte (0%)
Encoded stream size                      : 0.00 Byte (0%)

[Edit]VideoReDo TV Suite 5 mentions using libraries from FFmpeg in "Help" under "About VideoReDo", although I'm not certain, I'm guessing MKV multiplexing could be provided via these libraries. Is FFmpeg's MKV muxer non-compliant?

[ndjamena]

If nothing plays them they're kind of useless, that's what standards are for and currently there is no official method of storing 608 captions in an MKV. Theoretically you can put pretty much anything in either an MP4, an MKV, or even the user data in the MPEG2 stream, but just because you can doesn't mean anything.

You're trivialising a sore spot for some people. If you know of official standards for having 608 captions in mkvs then I'd love to go around to all the players and muxers bug trackers to spread the word, I've already managed to get VLC playing Final Cut Pro mp4 captions, but just saying they're in there is meaningless.

[usually_quiet]

but just saying they're in there is meaningless.

...except apparently to the OP in this thread. He wants to know if CCs are present in his MKV.

I just demonstrated that it is possible that a video in a MKV might have CCs. Assuming the DVD video was not re-encoded and they were not simply stripped for some other reason, CCExtractor GUI will normally retrieve them

[Edit]

You're trivialising a sore spot for some people. If you know of official standards for having 608 captions in mkvs then I'd love to go around to all the players and muxers bug trackers to spread the word, I've already managed to get VLC playing Final Cut Pro mp4 captions

CCs can be there and officially supported and still not play. Some software players don't play closed captions at all and some will only play CCs for DVD video or ts files.

I use CCs fairly often, and find the poor support for them to be disappointing, so I'm not trivializing the situation. I'm addressing the question at hand.

[Edit 2] Just for fun, I tried playing the MKV with intact closed captions using VLC. VLC displayed them.

[vidblue]

So how do I confirm the existence or extract CC using CCExtractor with right selection off the ISO? The activity log of CCExtractor shows this -

File seems to be an elementary stream, enabling ES mode
Found PACK header in ES data.  Probably wrong stream mode!

Skip forward to the next Sequence or GOP start.

Thanks

[usually_quiet]

Yes the encode was mkv. I just tried CCExtractor, though I never used it before so not sure about the right option I must use.

I think I used the default settings on the MKV file.

It tried some formats and it did create a file for "dvdraw". Does it mean the source has CC?

CCExtractor GUI produces an empty file if there are no closed captions present.

When I play the VOB file ( ISO extract ), VLC shows Closed Caption 1-4 in the subtitle menu. But no matter what option I select, it won't show any CC. The mediainfo doesn't show any info about CC though.

I think I have seen that once or twice. CCs are flagged but the fields are empty.

So how do I confirm the existence or extract CC using CCExtractor with right selection off the ISO? The activity log of CCExtractor shows this -

File seems to be an elementary stream, enabling ES mode
Found PACK header in ES data.  Probably wrong stream mode!

Skip forward to the next Sequence or GOP start.

Thanks

I haven't seen that error message before. I don't know what it means.