Suggestions For CC Handling

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eddyg
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Re: Suggestions For CC Handling

Post by eddyg »

Was there a sync issue between the audio/video or the captions and the audio/video?

It is possible that I've stuffed up the timestamps - I haven't actually watched a movie from start to finish with captions, I don't have many NTSC titles and didn't really feel like rewatching any of them. I did fast forward etc though - and it all appeared to be OK.

Please do keep me abreast of your findings. I may have to encode an entire movie with Captions and then sit down and watch it.

Cheers, Ed.
kneeslasher
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Re: Suggestions For CC Handling

Post by kneeslasher »

I personally prefer the subs to appear *very slightly* later, but that probably isn't a reflection on the implementation. The syncing of subs to a/v therefore isn't a problem. Indeed I've gone back to the source DVD and checked where the subs appear there: HB has done a good job of following the source exactly.

It was actually the audio to the video I was mentioning, but it's a trifle off-topic in a subs thread. And again, I went and checked the source DVD and it seems the very slight a/v mismatch (< 100 ms) is actually on the source too, so there is no error in the way that HB has done its duty.

All in all, it's shaping up well. By all means, watch a movie through to the end in order to give the new functionality a thorough test.


A general point leading on from the a/v issue (unrelated to subs): Are there DVDs which consistently exhibit a/v mismatches? What is advised in such circumstances? My specific example doesn't count since the mismatch is far too small to matter, but it must be annoying if the sync is out by, say, 500 ms.
kneeslasher
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Re: Suggestions For CC Handling

Post by kneeslasher »

Um. What on Earth is going on with the capitalisation consistency? The last encode I did had all caps, just like I wanted. I've just finished a four hour encode of a film to find that, without my setting anything differently, HB has started making corrections to the text track, it's not all caps! Is there a secret setting I've neglected?
eddyg
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Re: Suggestions For CC Handling

Post by eddyg »

kneeslasher wrote:Um. What on Earth is going on with the capitalisation consistency? The last encode I did had all caps, just like I wanted. I've just finished a four hour encode of a film to find that, without my setting anything differently, HB has started making corrections to the text track, it's not all caps! Is there a secret setting I've neglected?
Nope - there are now no settings - HB shouldn't be touching the case of the subs. Check for human error..

Cheers, Ed.
WhosAsking
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Re: Suggestions For CC Handling

Post by WhosAsking »

I do not wish to be a bother, but perhaps I am not so clear on what the thinking is around here.

Seeing as how QuickTime and video iPods support Closed Captions as Closed Captions (and feature options for such), is there anything preventing the encoding of Closed Captions as Closed Captions? I am interested in this feature because true Closed Captioning contains not just text but screen position information as well, such that captions may appear at the top or the bottom of the screen as appropriate, and the current soft subtitle approach does not preserve this positioning. Is it due to the format by which the captions are extracted from the original source or a lack of means to translate the captions into the CEA-608 format supported by QuickTime?
kneeslasher
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Re: Suggestions For CC Handling

Post by kneeslasher »

OK it was all my fault. I now have three HB apps sitting on my system, 0.93, the experimental binary release and an svn build. I just happened to run the wrong binary. With the svn build, no problems with the caps. It's all perfect... it was just me being silly.
kneeslasher
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Re: Suggestions For CC Handling

Post by kneeslasher »

New problem. I tested the final m4v with soft subs in QuickTime. Works perfectly. Ditto for iTunes and iPhone. But not in Front Row! Just a pure black screen with audio running in the background! The weird thing is, when the movie (Watership Down, Region 1, 720x400, soft subs) is selected in the Front Row menu, the preview picture comes up perfectly. The preview picture even has the right subs superimposed. Just no video or subs when the video is played in Front Row.

Normally I haven't used Front Row much myself, but I thought it would be worth giving it a try to stress test the new subs implementation. Is no video a common problem? Have I used the wrong resolution or some such?
eddyg
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Re: Suggestions For CC Handling

Post by eddyg »

WhosAsking wrote:I do not wish to be a bother, but perhaps I am not so clear on what the thinking is around here.

Seeing as how QuickTime and video iPods support

Closed Captions as Closed Captions (and feature options for such), is there anything preventing the encoding of Closed Captions as Closed Captions? I am interested in this feature because true Closed Captioning contains not just text but screen position information as well, such that captions may appear at the top or the bottom of the screen as appropriate, and the current soft subtitle approach does not preserve this positioning. Is it due to the format by which the captions are extracted from the original source or a lack of means to translate the captions into the CEA-608 format supported by QuickTime?
It was done the current way because I don't know how to write the 608 format into an mp4.

But also since it fits in with other subtitles as far as a workflow is concerned.

When I find out how to write the 608 into mp4 I'll consider having a pass-through option for the captions.

Some people like the cc's presented as subs, so we'd still leave in an option for them to be translated into subtitles.

Cheers Ed
WhosAsking
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Re: Suggestions For CC Handling

Post by WhosAsking »

eddyg wrote:
WhosAsking wrote:I do not wish to be a bother, but perhaps I am not so clear on what the thinking is around here.

Seeing as how QuickTime and video iPods support

Closed Captions as Closed Captions (and feature options for such), is there anything preventing the encoding of Closed Captions as Closed Captions? I am interested in this feature because true Closed Captioning contains not just text but screen position information as well, such that captions may appear at the top or the bottom of the screen as appropriate, and the current soft subtitle approach does not preserve this positioning. Is it due to the format by which the captions are extracted from the original source or a lack of means to translate the captions into the CEA-608 format supported by QuickTime?
It was done the current way because I don't know how to write the 608 format into an mp4.

But also since it fits in with other subtitles as far as a workflow is concerned.

When I find out how to write the 608 into mp4 I'll consider having a pass-through option for the captions.

Some people like the cc's presented as subs, so we'd still leave in an option for them to be translated into subtitles.

Cheers Ed
I see the situation now, and I'll leave it at that. If I learn more about this that can help you, I'll let you know. I'll work on my own issue, which is to find a way to get the caption data itself imported into QuickTime without having to resort to that (Mac-only) import filter.
kneeslasher
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Re: Suggestions For CC Handling

Post by kneeslasher »

Hang on. Video (5G and up?) iPods you say? What happens if you play an m4v with CCs on a video iPod with CCs turned on? Does it (the iPod) shows them (the captions)? If so, then one can see how this option may be considered superior in some respects to soft subs since soft subs simply aren't supported on the video iPods... interesting.
WhosAsking
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Re: Suggestions For CC Handling

Post by WhosAsking »

kneeslasher wrote:Hang on. Video (5G and up?) iPods you say? What happens if you play an m4v with CCs on a video iPod with CCs turned on? Does it (the iPod) shows them (the captions)? If so, then one can see how this option may be considered superior in some respects to soft subs since soft subs simply aren't supported on the video iPods... interesting.
Allow me to correct myself. Classics and up support CC, and yes, they are shown as they would on a TV (only with thinner rounded borders, but that's irrelevant). Don't know how it would work hooked to a TV (does it show on its own or use the TV's CC system?). The point is that it works. I did it myself with a TV episode on my 160GB Classic. Thing was, I used a MOV file (QuickTime supported c608 CC's since 7.2). How they would be in the M4V format is not yet clear.
kneeslasher
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Re: Suggestions For CC Handling

Post by kneeslasher »

Even iPod Classics and up represents an area where soft subs were otherwise thought impossible. So pass through for CCs (DVD) to CCs (encoded file) would definitely add functionality!
WhosAsking
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Re: Suggestions For CC Handling

Post by WhosAsking »

eddyg wrote:
WhosAsking wrote:I do not wish to be a bother, but perhaps I am not so clear on what the thinking is around here.

Seeing as how QuickTime and video iPods support

Closed Captions as Closed Captions (and feature options for such), is there anything preventing the encoding of Closed Captions as Closed Captions? I am interested in this feature because true Closed Captioning contains not just text but screen position information as well, such that captions may appear at the top or the bottom of the screen as appropriate, and the current soft subtitle approach does not preserve this positioning. Is it due to the format by which the captions are extracted from the original source or a lack of means to translate the captions into the CEA-608 format supported by QuickTime?
It was done the current way because I don't know how to write the 608 format into an mp4.

But also since it fits in with other subtitles as far as a workflow is concerned.

When I find out how to write the 608 into mp4 I'll consider having a pass-through option for the captions.

Some people like the cc's presented as subs, so we'd still leave in an option for them to be translated into subtitles.

Cheers Ed
Allow me to re-open the discussion with a few things I've learned, to see if they can be of assistance in helping you incorporate Closed-Caption Passthrough.

As far as I know, the two key elements in the closed captions are a track media and a timing track. The track media (with a "clcp" handler tag) contains the actual closed-caption raw data (encoded as individual "c608" atoms for each event, in line with the Scenarist events). The timing track then triggers these events for their appropriate durations.

I've tried doing this myself, but I lack enough knowledge of QuickTime and MP4 to pull this off, but perhaps this information may be of assistance to you. If you wish, I could send you some sample MOVs that contain just captions so you can better decipher how they're structured. Since the MP4 is more or less based on QuickTime, perhaps all that's needed to put captions into an .mp4/.m4v file is to follow the QuickTime .mov method.
gambitz
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Re: Suggestions For CC Handling

Post by gambitz »

1. It is in my great interest to have HB do a pass-through for CC to preserve 608 encoding.

2. It is also in my great interest to encode CC into Subtitiles as well for HD videos and movies becasue HDMI does not pass through 608 so, we need to have CC converted to bitmap so it can be passed through via HDMI.

HB does the #2 perfectly, however, it loses the positioning of the texts. All texts appear in the bottom middle.

I need to have it keep the CC positioning but now in subtitles with positioning. Deaf and hard of hearing users struggle to detect who is speaking when all texts are in the middle. For example please refer to this picture. From this, we know who is speaking what. and since on the right, the text is slightly higher, it shows that the man in the back spoke "Really?"
Image
(Movie: An Unfinished Life)

HB does this well with SDH subtitles (in vobsub format) but my streamer and blu-ray player doesnt support vobsub grrr. So is there a way to preserve the positioning when ripping to srt format?

This is considered ponies for you, but a big deal to me.
Thanks for your hard work, developers.
Last edited by gambitz on Mon Feb 28, 2011 7:15 pm, edited 1 time in total.
eddyg
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Re: Suggestions For CC Handling

Post by eddyg »

AFAIK subtitles don't allow positioning. However you do have rows, so in theory you could map the position to which row of the three (two?) available to display it on.

As far as the internals of HB are concerned if we did this I'd embed the smarts for the positioning within the 608 decoder so that it outputted the subs as they should be played, rather than add positioning to the protocol.

Cheers, Ed.
gambitz
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Re: Suggestions For CC Handling

Post by gambitz »

Thks for replying.

1.
AFAIK subtitles don't allow positioning.
Vobsubs does have positioning info. Example movie: "Faster". Has SDH with positioning and black bar as subtitle background. I test the ripping to mp4 and mkv. It preserves the vobsub positioning (tested with VLC) but too bad both my streamers doesnt support vobsub or idx/subs. So I have been looking everywhere to find a program that can convert vobsubs to srt but with same bitmap info (positioning). All programs will put text in the middle.

What I learned so far is that vobsub is a bitmap while all other subtitle formats is text based.

(Of course I will try to get my streamer's firmware updated to support vobsubs)

2. CC wise, I will test if "hard-burn" the CC will keep the positioning.

3. Could you consider converting CC into vobsubs? So VLC player will play it with positioning instead of in the middle?

Thanks again! I gotta say, I'm impressed with Handbrake's progress. I know its a long one, but very positive so far.
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Rodeo
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Re: Suggestions For CC Handling

Post by Rodeo »

gambitz wrote:Thks for replying.

1.
AFAIK subtitles don't allow positioning.
Vobsubs does have positioning info.
I suspect he meant TX3G subtitles.
gambitz wrote:2. CC wise, I will test if "hard-burn" the CC will keep the positioning.
Not supported. HandBrake doesn't have a text subtitle renderer (well, it does have libass but it only works for ASS/SSA).

I don't believe the CC decoder preserves the positioning anyway; moreover, I don't think HB's internal data structures have any way to store positioning for text subs.
gambitz wrote:3. Could you consider converting CC into vobsubs? So VLC player will play it with positioning instead of in the middle?
No subtitle renderer -> no burn-in and no conversion to bitmap formats possible.

Long story short: this isn't a trivial feature to add.
kneeslasher
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Re: Suggestions For CC Handling

Post by kneeslasher »

Great to hear the discussion on this is ongoing. CCs passed through to iPod Classic and up compatible CCs would be great: the final step as it were.
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