[Cin] Fwd: [FFmpeg-devel] qsvenc.c & AV_CODEC_FLAG_INTERLACED_DCT

[Terje J. Hanssen]

Den 25.11.2024 19:44, skrev Andrew Randrianasulu:
> On Mon, Nov 25, 2024 at 6:27 PM Terje J. Hanssen
> <terjejhanssen at gmail.com> wrote:
>>
>> Den 25.11.2024 11:20, skrev Mat:
>>> On Sun, 24 Nov 2024 23:11:07 +0100
>>> "Terje J. Hanssen via Cin" <cin at lists.cinelerra-gg.org> wrote:
>>>
>>>> Den 24.11.2024 22:22, skrev Andrew Randrianasulu:
>>>>> вс, 24 нояб. 2024 г., 19:45 Terje J. Hanssen
>>>>> <terjejhanssen at gmail.com>:
>>> <snip>
>>>>>       I can't notice differences at playback with VLC and FFplay
>>>>> (other than 16:9 vs 4:3 format as usual). And both visually with
>>>>> good qualities in my eyes.
>>>>>
>>>>>       Cingg Set Format Interlace Mode: Not interlaced
>>>>>       did the trick and both hdv and hd could be rendered
>>>>>       FFprobe reported it is pgogressiv, while native FFmpeg
>>>>> transcoding still say interlaced.
>>>>>
>>>>>
>>>>>
>>>>> But do files rendered by cingg set to progressive and ffmpeg from
>>>>> same tff source differ visually?
>>>> No. It is easy to see during VLC  playback that neither av1_qsv from
>>>> Cin/ffmpeg is progressive, but rather interlaced:
>>>> Pause during horizontal movements (camcorder panning) shows
>>>> interlaced vertical edges. Then shortcut "D" on this still image
>>>> swithch it to deinterlaced and smoother edges. This is on a computer
>>>> LCD monitor.
>>> I've have that problem as well, converting old VHS videos in PAL format
>>> to MP4 format. My solution is to use ffmpeg before editing in CinGG,
>>> using a de-interlace filter, as follows:
>>>
>>> ffmpeg -i inputvideo -vf bwdif outputvideo.mp4
>>>
>>> Using mp4 as output format also reduces the original mpeg file to half
>>> the size. Instead of the -vf bwdif you can use the -vf yadif
>>> filter, but bwdif gave slightly better results for my videos.
>>>
>>> MatN
>> For end-user formats like AV1 and HEVC etc. I don't think interlaced
>> video is an issue as mediaplayers handle it simply.
>> What I don't understand is why my system ffmpeg 7.1 is capable to
>> transcode tff interlaced input video to av1_qsv, while Cingg's internal
>> ffmpeg 7.0 error out due to unsupported pixel structure. May something
>> have changed here between ffmpeg 7.0 and 7.1?
>
> ffmpeg by default does not add +ildct flag, we do (if input is interlaced)

Something similar for NVENC?
https://stackoverflow.com/questions/57103688/ffmpeg-nvenc-encoding-with-flagsv-ildct-shows-no-nvenc-capable-devices-found
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