[FFmpeg-devel] {WIP} {HELP} Dvb Subtitles and Hard Subtitles
JULIAN GARDNER
joolzg at btinternet.com
Sat Jun 11 13:46:09 CEST 2011
----- Original Message -----
> From: JULIAN GARDNER <joolzg at btinternet.com>
> To: FFmpeg development discussions and patches <ffmpeg-devel at ffmpeg.org>
> Cc:
> Sent: Wednesday, 8 June 2011, 8:29
> Subject: Re: [FFmpeg-devel] {WIP} {HELP} Dvb Subtitles and Hard Subtitles
>
>
>
>
>> ________________________________
>> From: Michael Niedermayer <michaelni at gmx.at>
>> To: FFmpeg development discussions and patches
> <ffmpeg-devel at ffmpeg.org>
>> Sent: Wednesday, 8 June 2011, 5:15
>> Subject: Re: [FFmpeg-devel] {WIP} {HELP} Dvb Subtitles and Hard Subtitles
>>
>> On Tue, Jun 07, 2011 at 11:56:44PM +0100, JULIAN GARDNER wrote:
>>>
>>>
>>>
>>> >________________________________
>>> >From: JULIAN GARDNER <joolzg at btinternet.com>
>>> >To: FFmpeg development discussions and patches
> <ffmpeg-devel at ffmpeg.org>
>>> >Sent: Tuesday, 7 June 2011, 14:00
>>> >Subject: Re: [FFmpeg-devel] {WIP} {HELP} Dvb Subtitles and Hard
> Subtitles
>>> >
>>> >
>>> >
>>> >
>>> >
>>> >----- Original Message -----
>>> >> From: Michael Niedermayer <michaelni at gmx.at>
>>> >> To: FFmpeg development discussions and patches
> <ffmpeg-devel at ffmpeg.org>
>>> >> Cc:
>>> >> Sent: Monday, 6 June 2011, 13:34
>>> >> Subject: Re: [FFmpeg-devel] {WIP} {HELP} Dvb Subtitles and
> Hard Subtitles
>>> >>
>>> >> On Mon, Jun 06, 2011 at 11:15:32AM +0100, JULIAN GARDNER
> wrote:
>>> >>>
>>> >>>
>>> >>>
>>> >>> >________________________________
>>> >>> >From: JULIAN GARDNER <joolzg at btinternet.com>
>>> >>> >To: FFmpeg development discussions and patches
>>> >> <ffmpeg-devel at ffmpeg.org>
>>> >>> >Sent: Sunday, 5 June 2011, 14:58
>>> >>> >Subject: [FFmpeg-devel] {WIP} {HELP} Dvb Subtitles
> and Hard Subtitles
>>> >>> >
>>> >>> >Ok needing a bit of help here, ive added my current
> diff in the hope of
>>> >> some help from a more knowledgable ffmpeg developer.
>>> >>> >
>>> >>> >My problem is that i need to get the main output loop
> to eventually
>>> >> call the do_subtitle_out for every frame of video that is
> produced.
>>> >>> >
>>> >>> >I have attempted to change the code where the
> subtitle is decoded, only
>>> >> once in the case of dvbsubs, and to output it multiple times,
> but the output bit
>>> >> is still only called once.
>>> >>> >
>>> >>> >Can anybody help me in getting the loop to make the
> multiple calls to
>>> >> output the subtitles, im trying not to have to write this as a
> filter, but to
>>> >> have the subs placed on the output video plane BEFORE resizing
> and ENCODING?
>>> >>> >
>>> >>> >If you think im going about it the wrong way then let
> me know, and if
>>> >> the only way is to produce a filter i will spend my time on
> that instead.
>>> >>> >
>>> >>> >So just for clarity i need to get the subs to be
> copied to the video
>>> >> before any resize or encoding is performed, if this works it
> should be possible
>>> >> to take any subs and have them placed on the video.
>>> >>> >
>>> >>> >also one more problem is that the TS si still has the
> entry for
>>> >> "dvb subs" in its pmt, this will need removing, as i
> cant see the
>>> >> point of having hard subs and soft subs whch are the same.
>>> >>> >
>>> >>> >joolz
>>> >>> >
>>> >>> >_______________________________________________
>>> >>> >ffmpeg-devel mailing list
>>> >>> >ffmpeg-devel at ffmpeg.org
>>> >>> >http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
>>> >>> >
>>> >>> >
>>> >>> >
>>> >>>
>>> >>> Ok boys i have the "hards subs" kind of
> working, but i need some
>>> >> help in dumping the subtitles onto the screen in the correct
> format.
>>> >>>
>>> >>> I have modified ffmpeg.c and in the routine
>>> >> "pre_process_video_frame" i aim to do the dump of
> the subs, im just
>>> >> testing but if i do a memset on the memory pointed at by
>>> >> picture->data[0]+x+y*picture->linesize[0] i get my boxes
> in the correct
>>> >> place.
>>> >>>
>>> >>> What i need to do now is translate the subtitles pixel
> and clut map into
>>> >> the correct format and add this to the plane, now the good
> point of this is that
>>> >> scaling the video works after this.
>>> >>>
>>> >>> Any help please.
>>> >>
>>> >> for format convert see swscale (maybe libavfilter/vf_scale.c
> is a
>>> >> useable example on its useage)
>>> >>
>>> >> for blend/overlay of stuff see vf_overlay.c
>>> >>
>>> >>
>>> >> [...]
>>> >>
>>> >> --
>>> >> Michael GnuPG fingerprint:
> 9FF2128B147EF6730BADF133611EC787040B0FAB
>>> >>
>>> >> The real ebay dictionary, page 2
>>> >> "100% positive feedback" - "All either got
> their money back or
>>> >> didnt complain"
>>> >> "Best seller ever, very honest" - "Seller
> refunded buyer after
>>> >> failed scam"
>>> >>
>>> >> _______________________________________________
>>> >> ffmpeg-devel mailing list
>>> >> ffmpeg-devel at ffmpeg.org
>>> >> http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
>>> >>
>>> >
>>> >OK "Hard Subtitles" working now, test phase to continue
> but i have a few queries regarding what should be done with certain cases
>>> >
>>> >1. dvd-subtitle-problem.vob
>>> > This file has a video size of 352x288 but the dvbsubs are being
> displayed out of this range so my options are
>>> > a) Dont render out of visible screen area (current system)
>>> > b) Swscale the video to fix the subtitle expected screen size,
> draw subs, recscale back to original size (lots of cpu)
>>> > c) Rescale the subtitles themselves and also the position and
> then draw on screen (need a new rescaler)
>>> >
>>> >2. As i see it .SRT and .SUB decode the subs but dont render them,
> what would be good would be for all the subtitle engines to render to a bitmap
> buffer, with clut and regions. If this is the case then we could do things like
> Hard Subs, Ass->Dvb, Srt-Dvb etc Is this a feasable way forward?
>>> >
>>> >3. Xsub seems to work now except for the demo i have being a
> 720x408 screen and the subtitles are positioned at 174,464, so back to 1
>>> >
>>> >I need to do more testing but the problem streams i started with
> all work well and the subtitles appear where and in the correct colours as they
> should.
>>> >
>>> >I have some encoded files i will put up on my ftp if anyone want to
> see some examples or the hard subs
>>> >
>>> >
>>> >joolz
>>> >_______________________________________________
>>> >ffmpeg-devel mailing list
>>> >ffmpeg-devel at ffmpeg.org
>>> >http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
>>>
>>>
>>> OK boys i have another small problem, which im having trouble finding
> the cause of?
>>>
>>>
>>
>>> When i put "hard subtitles" on the screen i get nice
> subtitles, but i also get atrifacts around the subtitles which move around the
> subtitle.
>>
>> sounds like you write into the reference frames.
>> theres no alternative than making a copy
>>
>> [...]
>> --
>> Michael GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB
>>
>> While the State exists there can be no freedom; when there is freedom there
>> will be no State. -- Vladimir Lenin
>>
>> _______________________________________________
>> ffmpeg-devel mailing list
>> ffmpeg-devel at ffmpeg.org
>> http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
>
>
> Thanks for that, will modify the code and test again.
>
> Now another question. This test is being done on LIVE streams.
>
> Iissue the ffmpeg line without the "-scodec" line everything works as
> it should.
>
> Issue with the "-scodec dvbsub" AND THERE ARE dvbsubs in the stream
> again we work, not perfectly.
>
> Issue with the "-scodec dvbsub" AND THERE ARE NO SUBS BEING
> TRANSMITTED, but the si contains the correct si saying they are there we get a
> problem.
>
> What seems to be happening is that the new encoded data is being buffered and is
> waiting for the dvbsub title stream to pass data into the stream, what i see is
> the status line does not change so we get "time=00:00:00.00
> bitrate=0.0kbits/s" and after a while ffmpeg just drops out without an
> error
>
> joolz
> _______________________________________________
> ffmpeg-devel mailing list
> ffmpeg-devel at ffmpeg.org
> http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
>
Anybody out there able to help, i have 7 patches which fix most of the DVB Subtitles problems but i can finish my test as i need to be able to get the problem with the bitrate/time not moving when we have dvbsubs marked as being in the stream but there is no data.
biggest problem happens on live tv when they goto a program without subtitles, ffmpeg just drops back to cli
also anybody interested in changing the current subtitle .sub and i think .srt to produce a bitmap ON DECODE?
we would then be able to do dvbsub/xsub/sub/srt -> dvbsub/hard subtitles
I have also fixed and added 8bit mode, tested by making xsub say it had 8 bit data, worked really well.
Also a LOGO adder would now be real easy to add in, anybody think this is a good idea
joolz
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