[Cin] DV to DVD rendering - questions and issues

Phyllis Smith phylsmith2017 at gmail.com
Tue May 30 02:26:00 CEST 2023 

Andrew, changed to -I 2 and -z b in filempeg.C but ends up with "Error
rendering data." and SIGPIPEs as shown far below.  I was looking for an
easy out but there appears to be none, so going back to testing ffmpeg 6.0,
although that is what I have been using so really still testing by default !

I have not found any definitive source saying that DVDs do not handle
Bottom Field First.

Cinelerra Infinity - built: May 27 2023 18:56:09
git://git.cinelerra-gg.org/goodguy/cinelerra.git
(c) 2006-2019 Heroine Virtual Ltd. by Adam Williams
2007-2020 mods for Cinelerra-GG by W.P.Morrow aka goodguy
Cinelerra is free software, covered by the GNU General Public License,
and you are welcome to change it and/or distribute copies of it under
certain conditions. There is absolutely no warranty for Cinelerra.

FileMPEG::open_file: Running /tmp/cinelerra-5.1/bin//mpeg2enc -v 0  -b 8000
-q 1 -a 2 -F 4 -H -I 2 -M 8 -z b -f 8 -g 15 -G 15 -R 0 -o
'/tmp/dvd_20230529-182026/dvd.m2v'
signal_entry_recoverable: got SIGPIPE my pid=21664
signal_entry_recoverable: got SIGPIPE my pid=21664
signal_entry_recoverable: got SIGPIPE my pid=21664
signal_entry_recoverable: got SIGPIPE my pid=21664
signal_entry_recoverable: got SIGPIPE my pid=21664
signal_entry_recoverable: got SIGPIPE my pid=21664
signal_entry_recoverable: got SIGPIPE my pid=21664
signal_entry_recoverable: got SIGPIPE my pid=21664
signal_entry_recoverable: got SIGPIPE my pid=21664
signal_entry_recoverable: got SIGPIPE my pid=21664
Render::render_single: Session finished.

On Mon, May 29, 2023 at 3:46 PM Andrew Randrianasulu <
randrianasulu at gmail.com> wrote:

>
>
> пн, 29 мая 2023 г., 23:47 Phyllis Smith <phylsmith2017 at gmail.com>:
>
>> More feedback to add to Andrew's reply.
>>
>> 2. Deinterlacing:
>>>
>>
>>>> The input PAL DV source file is Interlaced, Bottom Field First
>>>>
>>>> ffprobe:
>>>>   Stream #0:0: Video: dvvideo, none, 25000 kb/s, SAR 16:15 DAR 0:0, 25
>>>> fps, 25 tbr, 25 tbn
>>>>   Stream #0:1: Audio: pcm_s16le, 48000 Hz, stereo, s16, 1536 kb/s
>>>> Unsupported codec with id 24 for input stream 0
>>>>
>>>> mediainfo:
>>>> Width                                    : 720 pixels
>>>> Height                                   : 576 pixels
>>>> Color space                              : YUV
>>>> Scan type                                : Interlaced
>>>> Scan order                               : Bottom Field First
>>>>
>>>>
>>>> Why does deinterlacing with dvd default rendering (mpeg2enc) still come
>>>> out as Interlaced, but Top Field first?
>>>>
>>>
>>>
>>> May be bug in mpeg2 output? Does it look interlaced, or it just flag set
>>> wrongly?
>>>
>>> It does seem that it really is Top Field First all of the time when
>> doing a DVD render despite whether or not the input is Top or Bottom
>> first.  I temporarily modified filempeg.C for the "mpegenc" line to change
>> the -I parameter from 1 to 2 as in:
>>    Running /tmp/cinelerra-5.1/bin//mpeg2enc -v 0  -b 8000 -q 1 -a 2 -F 4
>> -H *-I 1* -M 8 -z t -f 8 -g 15 -G 15 -R 0 -o
>> '/tmp/dvd_20230529-140337/dvd.m2v'
>>
>
>
> try also to change " -z b" as recommended by manual
>
> *-z|--playback-field-order* b|t
>
> This flag overrides the field-order specified in the interlacing tag of
> the input stream header. (If you need this option, it indicates a problem
> in the capturing/encoding process where the temporal order of the two
> fields in each frame has been mislabeled. The effect of this is weird
> "juddering" when playing back the stream on a TV. Check the mjpeg-howto for
> more information about interlacing problems.)
>
>
> ===
>
>
> Also interesting settings are
>
>
> *-c|--closed-GOPs*
>
> Setting this flag causes the encoder to generate only "closed" GOPs
> (Groups of Pictures) that can be decoded without reference to their
> predecessor. This is useful for streams that are supposed to be used in
> multi-angle DVD's and applications where more easily edittable MPEG is
> required.
>
> *-P|--force-b-b-p*
>
> This flag forces the GOP size selection to choose sizes that ensure 2 B
> frames appear between adjacent I/P frames. Several common MPEG-1 decoders
> can't handle streams where less than 2 B-frames appear between I/P frames.
>
>
> but be sure you modify correct profiles ...
>
>
> Also, not sure if consumer DV especially can be bottom field first? Still,
> getting this setting from session parameters probably important , will look
> more into code ...
>
>
>
>
>> but that leads to a SIGPIPE and/or hangs in Cinelerra and when I run
>> manually.  I am not even sure that "-I 2" really preserves Bottom Field
>> First as I can not tell from the documentation (Andrew?).  Documentation on
>> mpeg2enc is at:
>>    https://linux.die.net/man/1/mpeg2enc
>> specifically:
>>
>>> *-I|--interlace-mode* 0|1|2
>>>
>>> Set the sequence picture structure and block encoding type for MPEG-2
>>> streams. By default, this value is inferred from the interlacing tag of the
>>> input stream. Setting 0 encodes frame-by-frame with support for interlaced
>>> video turned off, and specifies that progressive chroma subsampling has
>>> been used. Setting 1 encodes frame-by-frame with interlace-adapted motion
>>> compensation and block encoding, and specifies that interlaced chroma
>>> subsampling has been used. Setting *2* encodes interlaced material
>>> field-by-field, which will produce more accurate results for highly
>>> textured interlaced material with lots of motion, at the expense of
>>> generally less efficiency.
>>>
>>
>>
>>>
>>> But the result is visually better than without deinterlacing, which is
>>> awful jagged at camera movements zoom/pan, at least on my 2560x1440 res
>>> monitor using VLC.
>>>
>> I do not understand the above sentence.  Which result is better? with
>> deinterlacing or without deinterlacing? So Progressive is better? which
>> makes more sense to me in this day and age.  As far as I read on the
>> internet, DVDs can be either Progressive or Interlaced.
>>
>>> 3. Dvd Interlaced Chroma
>>>>
>>>> With reference to the CinGG manual
>>>>
>>>> https://cinelerra-gg.org/download/CinelerraGG_Manual/Dvd_Interlaced_Chroma.html
>>>>
>>>> *Now you can use the YUV420P DVD Interlace Mode when rendering DV
>>>> directly to mpeg2 through a yuv4mpeg stream and when using video effects on
>>>> HDV video.*
>>>> *With this option enabled, improved chroma results will be obtained
>>>> from your DV or HDV source. Editing DV or HDV and rendering it back to the
>>>> same format does not require any special handling. In order to perform
>>>> colorspace conversions correctly in CINELERRA-GG and avoid Chroma errors
>>>> for interlaced 4:2:0 video, check the box as follows:*
>>>>
>>>> Settings → Performance → YUV420P DVD Interlace Mode
>>>>
>>>>
>>>> I can't find this option and is it relevant for DVD rendering?
>>>>
>>>
>>>
>>>
>>> Its in Interface section ..
>>>
>>> I can attach screenshot separately.
>>>
>>>
>>> Thx, I found it. Then there is a need to correct this in the manual.
>>>
>> Fixed this and checked into GIT for the manual (which will only be
>> updated with the next release).
>>
>>
>>> Wonder if there is a reason why YUV420P DVD Interlace Mode is not set as
>>> default?
>>>
>> It is used in "filempeg.C" and it is safer to not assume that it is
>> needed.  Read simple example/explanation at:
>>      https://renomath.org/ejolson/video/dv/chroma.html
>>
>
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