[Cin] Anamorphic 16:9 SD-DV(D) widescreen to AV1.webm

Terje J. Hanssen terjejhanssen at gmail.com
Mon Jan 15 01:24:08 CET 2024 


Den 14.01.2024 23:03, skrev Andrew Randrianasulu:
> On Mon, Jan 15, 2024 at 1:10 AM Terje J. Hanssen
> <terjejhanssen at gmail.com>  wrote:
>>
>>
>> Den 14.01.2024 21:42, skrev Andrew Randrianasulu:
>>> On Sun, Jan 14, 2024 at 11:14 PM Terje J. Hanssen
>>> <terjejhanssen at gmail.com>  wrote:
>>>>
>>>> Den 14.01.2024 18:41, skrev Andrew Randrianasulu:
>>>>
>>>>
>>>>
>>>> вс, 14 янв. 2024 г., 19:51 Terje J. Hanssen<terjejhanssen at gmail.com>:
>>>>>
>>>>> Den 14.01.2024 17:43, skrev Terje J. Hanssen:
>>>>>
>>>>>
>>>>>
>>>>> Den 13.01.2024 18:48, skrev Andrew Randrianasulu:
>>>>>
>>>>>
>>>>>
>>>>> сб, 13 янв. 2024 г., 07:47 Andrew Randrianasulu<randrianasulu at gmail.com>:
>>>>>>
>>>>>> сб, 13 янв. 2024 г., 03:26 Terje J. Hanssen via Cin<cin at lists.cinelerra-gg.org>:
>>>>>>>
>>>>>>> Den 11.01.2024 23:43, skrev Terje J. Hanssen:
>>>>>>>
>>>>>>> .......
>>>>>>>
>>>>>>>
>>>>>>> 4 a) Cin-GG
>>>>>>> Loaded a PAL 1080i/50 HDV clip
>>>>>>> Set Format Preset: PAL 576i (16:9) - DV(D)
>>>>>>> File Render File Format: FFmepg - avi   (NB! because plain Raw DV still causes DAR 4:3)
>>>>>>>                        Audio: Preset: avi_pcm_s16.avi
>>>>>>>                        Video: Compression: dv_pal.avi
>>>>>>>
>>>>>>>
>>>>>>> For me it looks like the Set Format Preset: PAL 576i (16:9) - DV(D and/or the File Format: FFmpeg make up the correct DAR 16:9 here, right?
>>>>>>>
>>>>>>> Because by Selecting the Format: Raw DV cause rendering to DAR 4:3 as shown below !
>>>>>>> This makes me wonder if it is only the FFmepg File formats that currently is fixed by patches?
>>>>>>> May also other non-FFmpeg formats be affected by anamorphic aspect ratios ?
>>>>>> This is possible! I basically never used non-ffmpeg video encoders! I think we have 3 of them - raw dv, mpeg video and theora video.
>>>>>>
>>>>>> I'll check each of them.
>>>>>
>>>>> OOPS!
>>>>> As already mentioned, CinGG's FFmpeg-avi was saved/displayed 16:9 and the Raw DV was saved/displayed 4:3.
>>>>> BUT, in addition I discovered now that in both cases the images have been cropped around, that is cut off at both sides, top and bottom.
>>>> I wonder how much was cropped?
>>>>
>>>> May be I misread you but you loaded HDV 1440*1080 clip and then rendered it into ffmpeg DV at 576i WITHOUT any scaling on top?
>>>>
>>>>
>>>> Yes, I loaded the anamorphic 16:9 HDV 1440x1080 clip and then rendered it using Set Format Preset PAL 576i (16:9)-DV(D) - without any scaling on top.
>>> I think only DVD/BD render adds scaling automatically on size mismatch ...
>>>
>>> so, for proper downscaling you need to apply it manually.
>>>
>> Learning by failing :)
>> DVD Render Format autoscales the input HDV format to fit the selected
>> 16x9 DVD output format.
>> When input format and output rendering formats are identical, it seems
>> that nothing needs to be set/edited manually in Set Format.
>>
>> Then the unavoidable request/suggestion:
>> Could correspondingly different I/O format via selected Presets also
>> bake in Autoscale as default (beside color space mentioned before) ?
> I think no, it was intended to give users control over what  kind of
> filters they  want to apply.

Yeah, if the Preset's default setting cannot be user overrided?

Fx. the DVD Render window has a Scale dropdown menu, where "Scaled" is 
default.
The other options are None and Cropped (various).
As an additional test I rendered with None, and then got similar 16:9 
output displayed as ffmpeg-avi.
(The Raw DV differed with 4_3 display)

> Even with ffmpeg you still manually add scale filter ...
>
> More interesting question if we should leave 1440x1080 BD render as is
> or force it to be 16/9 in other words FullHD 1920x1080 visually ?
>
> Some web posts indicated bluray is always 16:9 but libbluray sources
> contradict that.

IMO keep it with SAR (PAR) and DAR.
According to Wikipedia the supported BD-Video formats includes

  * HD Resolution 1440 × 1080 25i [c]   with Display Aspect Ratio 16:9 [d]
  * [c] MPEG-2 at 1440 × 1080 was previously not included in a draft
    version of the specification from March 2005
  * [d] These resolutions are stored anamorphically
    <https://en.wikipedia.org/wiki/Anamorphic_format>, i.e. they are
    stretched to the display aspect ratio by the player or display.

https://en.wikipedia.org/wiki/Blu-ray#Video

In addition, as in previouus and current discussions:

Distribution:

  * For consumer use, HDV-sourced video can be delivered on a Blu-ray
    Disc without re-encoding, can be converted to AVCHD and delivered on
    an AVCHD disc, or can be downconverted to DVD-Video.

https://en.wikipedia.org/wiki/HDV#Distributing

>
>> (refer to the: -vf scale=720:576,setsar=64/45,setdar=16/9 in the ffmpeg
>> line below)
>>
>>>> According to my understanding this should down-convert the full source image to DVD 16:9 anamorphic format, which at playback should display upscaled 16:9 screen.
>>>> That is, just as in my first post
>>>> 4 b) FFmpeg transcode HDV to DV-wide
>>>> ffmpeg -hide_banner -i hdv07_05.m2t -vf scale=720:576,setsar=64/45,setdar=16/9 -c:v dvvideo -c:a pcm_s16le dv07_05_wide.dv
>>>>
>>>> Gnome File properties and VLC Tools Codec info just say1440x1080 resolution for the HDV source and 720x576 for the CinGG rendered avi and dv output.
>>>> I don't know if it possible to find out exactly, but
>>>>
>>>> Visually I espect and will estimate that the "middle part" 720x576 px symmetrical around the center of the source image is kept. That is cropped away
>>>>
>>>> horizontally at each side: (1440-720)/2 = 360 px
>>>> vertically top and bottom: (1080-576)/2 = 252 px
>>>>
>>>>
>>>>
>>>>> That is, the 16:9 avi is displayed with correct geometry, while the 4:3 Raw DV is displayed stretched vertically.
>>>>> The latter get correct geometry if forced aspect 16:9 during VLC playback..
>>>>>
>>>>> Actually, only my ffmpeg manual encoded DV-wide has got correct DAR 16:9 and also correct geometry.
>>>>>
>>>>> And kept the full image (un-cropped).
>>>>>
>>>>>
>>>>> A visual tip is that this is easiest to discover and compare side by side using large file thumbnails with (Gnome) Filemanager.
>>>>>
>>>>>
>>>>> in cinelerra/fileogg.C I found this comment:
>>>>> =====
>>>>>
>>>>> if( asset->aspect_ratio > 0 ) {
>>>>>                   // Cinelerra uses frame aspect ratio, theora uses pixel aspect ratio
>>>>>     float pixel_aspect = asset->aspect_ratio / asset->width * asset->height;
>>>>>
>>>>>    aratio_num = pixel_aspect * 1000000;
>>>>>     aratio_den = 1000000;                                                                      }
>>>>>           else {
>>>>>    aratio_num = 1000000;
>>>>>
>>>>>    aratio_den = 1000000;                                                                      }
>>>>> =====
>>>>>
>>>>> strangely enough filedv seems to contain code to set is16x9 encoder flag ... not sure why it fails ....
>>>>>
>>>>> mpeg video also should honor aspect ratio, but not tested yet.
>>>>>
>>>>>
>>>>>
>>>>>>> mediainfo dv07_05_wide_cingg.dv | grep Display
>>>>>>>     Display aspect ratio                     : 4:3
>>>>>>>
>>>>>>> ffprobe -hide_banner dv07_05_wide_cingg.dv
>>>>>>> Input #0, dv, from 'dv07_05_wide_cingg.dv':
>>>>>>>     Duration: 00:06:58.08, start: 0.000000, bitrate: 28800 kb/s
>>>>>>>     Stream #0:0: Video: dvvideo, yuv420p, 720x576 [SAR 16:15 DAR 4:3], 25000 kb/s, 25 fps, 25 tbr, 25 tbn, 25 tbc
>>>>>>>     Stream #0:1: Audio: pcm_s16le, 48000 Hz, stereo, s16, 1536 kb/s
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> --
>>>>>>> Cin mailing list
>>>>>>> Cin at lists.cinelerra-gg.org
>>>>>>> https://lists.cinelerra-gg.org/mailman/listinfo/cin
>>>>>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.cinelerra-gg.org/pipermail/cin/attachments/20240115/c94ebc75/attachment-0001.htm>

More information about the Cin mailing list