[FFmpeg-user] framecrc

Mark Filipak markfilipak.imdb at gmail.com
Mon Nov 13 12:33:27 EET 2023

On 11/13/23 04:04, Paul B Mahol wrote:
> On Mon, Nov 13, 2023 at 4:33 AM <markfilipak.imdb at gmail.com wrote:
>> Why are the target PTSs out of order?
>> Why are there no 0 or 1001 DTSs?
> DTS is different from PTS.

Indeed: Decoder versus Presentation.
'-bsf:v setts' is before decoding, so there's both PTS & DTS, right?
'-vf setpts' is after decoding, so there's no '-vf setdts', right? And '-vf setpts' applies to the 
pictures going to the encoder, right?
Is PTS > DTS? Or is PTS <= DTS? I've seen it both ways in professional DVDs.
What do you say, Paul?

> And you should probably reorder DTS by keeping original order - just do
> offset and not by using packet number.

Then, of what use is '-bsf:v setts=pts=xxxx:dts=xxxx'? Why do they exist?

I designed video hardware/chips at Atari in the early 1980s, so I know every detail of PAL & NTSC 
and I designed state machine sequencers to generate the signals -- pretty easy, actually. The 
engineers before me screwed the signals up and got Atari a bad name for a while.

Maybe I don't understand how 'bit stream filter' got its name. Everything is a bit stream, so I 
don't really know to what 'stream' 'bsf' refers to. I've assumed that 'bsf' refers to the packet 
stream prior to decoding. Is that right, Paul?

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