[FFmpeg-user] ffmpeg output list question

Mark Filipak markfilipak.windows+ffmpeg at gmail.com
Mon Dec 16 10:03:14 EET 2019

On 12/15/2019 06:58 PM, Carl Eugen Hoyos wrote:
> Am So., 15. Dez. 2019 um 22:20 Uhr schrieb Mark Filipak
> <markfilipak.windows+ffmpeg at gmail.com>:
>> On 12/15/2019 02:38 PM, Carl Eugen Hoyos wrote:
>>> Am So., 15. Dez. 2019 um 16:50 Uhr schrieb Mark Filipak
>>> FFmpeg (and digital transcoders in general) doesn't know about fields,
>>> it can only work with frames. (This is also related to the specifications
>>> of sane video codecs.)
>> If ffmpeg doesn't know about fields, how can it decode interlaced content?
> The mentioned specifications require that conforming decoders output
> frames...

Carl, that's the most important information I've received to date. It 
changes most of all my research -- mostly, it simplifies things. Thank 
you very, very much.

I knew that ffmpeg encoders output solely frames, but I assumed that, 
when an interlaced container was encountered, ffmpeg decoders (hence 
HandBrake) worked with fields.

Due to the German in your messages, I assume you're in Europe. My 
research needs some PAL VOB samples of the following:

- Vintage "PAL" Cinematic Source -- Purely 24 FPS content (no VBR) in an 
25 FPS container (that plays at 25 Hz with 4% speedup).
- "PAL" Cinematic Source -- 25 FPS source (25th frame repeat) in a 25 
FPS container (I currently have only 1 modern "PAL" movie sample).
- PAL TV Source -- 25 FPS sequential fields (from PAL TV).
- Mixed PAL Source -- PAL TV show with embedded movie clips (e.g., some 
"Making of" documentaries).
- Vintage Mixed PAL Source -- Vintage PAL TV show (4% speedup) with 
embedded movie clips (e.g., some "Making of" documentaries).

Do you know how/where I can obtain samples of the 5 source videos above?

=== Details ===
I've found, when VBR sources contain mixed sequential/progressive 
content (example: Mixed NTSC TV with embedded 24 FPS clips), that line 
doubling at 60 FPS (instead of decombing) produces a better transcode. I 
assume that the same would be true for PAL at 50 FPS, but I don't have 
any samples to confirm it.

Currently, getting the best HandBrake transcode is a matter of 
trial-&-error. I'm trying to use the reports returned by
ffmpeg -ss 30.0 -i %1 -filter:v idet -frames:v 900 -an -f rawvideo -y NUL
to change that.

As I wrote in my initial post, so far I've been wildly successful. My 
approach may be unique. It could revolutionize HandBrake -- it could 
turn HandBrake into a truly 'one-click' transcoder. But I need some 
sample PAL VOBs to proceed.

Best Regards, and Thanks Again! Happy Holidays!

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