FFmpegSource

[wonkey_monkey]

I've run into a problem with FFmpegSource, and I'm not sure if it isn't just something which is already understood to happen and just doesn't affect most users.

https://filebin.net/ycobtv5flicijv2e/trim.ts?t=9ldisa80

I can open this file with VirtualDub via Avisynth and ffmpegsource2 and I can step forward through it frame-by-frame without problems. The trouble starts when I try to step through it backwards - once they fall out of whatever caches they might be in (e.g. by advancing past frame 50), frames 24 and 25 become duplicates of frame 26. This is a problem because the filters I want to call on this clip do a lot of random access and the end result suffers from these duplicates even when stepped through forwards.

seekmode = 0 fixes it, but is impractical since the source file has 180000 frames and it takes several minutes to seek into the middle of the file.

Is there any other way to avoid this, or is there another source filter (edit: an x64 one, since my project is ravenous for RAM) for h.264/.ts that won't exhibit this behaviour? (apart from DGIndexNV, which I know would work fine but my new laptop isn't compatible with it).

[poisondeathray]

@w_m , lsmash works ok , HolyWu branch

https://github.com/HolyWu/L-SMASH-Works/releases

[wonkey_monkey]

Thanks, I'll give it a try.

ffmpegsource also seems to have a habit of silently killing VirtualDub at random. Hopefully LSmash won't do that either.

[wonkey_monkey]

Originally Posted by poisondeathray

@w_m , lsmash works ok , HolyWu branch

https://github.com/HolyWu/L-SMASH-Works/releases

It (LWLibavVideoSource) doesn't cause frames 24 and 25 to become duplicates of 26... but it does cause frame 55 to become a duplicate of frame 56

You can also exhibit this behaviour by adding the "reverse" filter and stepping through forwards.

[manolito]

For me seeking in transport stream has always been problematic, even when using an indexing source filter. I made it a habit to repack transport streams into an MKV container before I do anything else to them.

Tested your sample, and after using MKVToolNix to repack the file all my source filters (even DSS2Mod) behaved nicely.

[poisondeathray]

Originally Posted by wonkey_monkey

It (LWLibavVideoSource) doesn't cause frames 24 and 25 to become duplicates of 26... but it does cause frame 55 to become a duplicate of frame 56

You can also exhibit this behaviour by adding the "reverse" filter and stepping through forwards.

threads=1 looks ok, but slower

Does that computer not have nvidia card ? Interesting that gpu decoding with decoder="h264_cuvid" works (or prefer_hw=1) , but intel QS does not on that clip (prefer_hw=2)

Originally Posted by manolito

Tested your sample, and after using MKVToolNix to repack the file all my source filters (even DSS2Mod) behaved nicely.

This did not work for me using ffms2 or lsmash x64 (same problem); and dss2 x64 drops the last frame

[stax76]

In my experience it's better to use ffmpeg to remux ts to mkv, that is the default handling in staxrip, mkvmerge is fine for playback but not so for editing, causes sync issues.

[wonkey_monkey]

Well this is a minefield...

Results of remuxing to MKV (with ffmpeg):

LWLibavVideoSource: still skips frame 55
LSmashVideoSource: doesn't open this container
FFMpegSource2: seems to work okay so far

Results of remuxing to MP4 (with ffmpeg):

LWLibavVideoSource: still skips frame 55
LSmashVideoSource: First two frames get repeated, a couple of later frames get skipped. Definite no-go.
FFMpegSource2: Freezes on the first few frames, skips a couple of later frames (despite claiming to be frame accurate on Avisynth wiki)

--------------------------------------------------------------------------------------------------------

Is this all as expected?

[qyot27]

It may be the method you're using to rip the Blu-ray. If I have to, I make a full-disc decrypted backup with MakeMKV (arguably you could maybe do a more restricted rip using BlurayTestAndDecrypt and libaacs/KEYDB.cfg, but you'd lose the disc structure), and then use mkvmerge to remux the main title to MKV by giving it the index.bdmv to parse. No demuxing to elementary streams and then remuxing them into other containers, if that's where the .ts sample came from.

I say this because there was a point, not sure how long ago exactly or if it's been fixed since, that MakeMKV's Matroska output acted strangely when given to source filters (or maybe it was eac3to? Like I said, it was a while ago). The simplest way to sidestep the problem is not to let MakeMKV make an MKV of whatever you're ripping.

[Atak_Snajpera]

Originally Posted by wonkey_monkey

Well this is a minefield...

Results of remuxing to MKV (with ffmpeg):

LWLibavVideoSource: still skips frame 55
LSmashVideoSource: doesn't open this container
FFMpegSource2: seems to work okay so far

Results of remuxing to MP4 (with ffmpeg):

LWLibavVideoSource: still skips frame 55
LSmashVideoSource: First two frames get repeated, a couple of later frames get skipped. Definite no-go.
FFMpegSource2: Freezes on the first few frames, skips a couple of later frames (despite claiming to be frame accurate on Avisynth wiki)

--------------------------------------------------------------------------------------------------------

Is this all as expected?

I can confirm. Remuxing to mkv with mkvtoolnix solves nothing

[wonkey_monkey]

I'd forgotten about Seek Tester! Definitely going to put that to some good use.

Does it seek forward and store a hash per frame, or something, and then seek randomly and test the hashes to see which frames are returned?

[kedautinh12]

Any update FFmpegSource with FFmpeg 4.3.1??

[StvG]

ffms2:
- ffmpeg n4.4@1c7e55dd50;
- zlib 1.2.11;
- dav1d 0.7.1.

[kedautinh12]

Originally Posted by StvG

ffms2:
- ffmpeg n4.4@1c7e55dd50;
- zlib 1.2.11;
- dav1d 0.7.1.

Thanks

[Myrsloik]

FFMS 2.40-RC1

Test it. Don't bitch about missing libraries (apart from zlib but I think I got that one included).

[kedautinh12]

Originally Posted by Myrsloik

FFMS 2.40-RC1

Test it. Don't bitch about missing libraries (apart from zlib but I think I got that one included).

Thanks

[ChaosKing]

My results:

[Myrsloik]

Originally Posted by ChaosKing

My results:

What's different in the stvg builds? From what I can tell the results should be more similar.

[StvG]

This is the patch for my builds.

[StainlessS]

Impressive update, thanks.