how do i open ffdshow (h264/avc) encoded videos inside avisynth ?

[vhelp]

is there any way to open these ffdshow (h264/avc) encoded videos ? i'm quite sure i captured with that codec dispite the message below from avisynth->virtualdub.

AVIsource(video) = "couldn't locate a decompressor fourcc MJPG" error.

when i open the video file directly inside virtualdub, the Info screen report it as MJPG.

when i open through..

LoadPlugin( "C:\PLUGINS\LSMASHSource.dll" )
LWLibavVideoSource(v, cache=true , seek_mode=0 )

or

LoadPlugin( "C:\PLUGINS\avss.dll")
dss2(video)

..the video takes forever to arrive at a random position in the timeline. i had to ctrl+del on virtualdub when i went to position 10,000 on the timeline.

[hello_hello]

Is MJPG enabled in ffdshow's vfw configuration? It seems to be disabled by default. Enabling it should allow VirtualDub to open the file directly. Or hopefully via AVISource. Is the file type AVI?

I don't quite understand the reference to h264/avc encoded video if the fourcc is MJPG. ffdshow doesn't have a h264 encoder. At least not these days.

[vhelp]

if you scroll up to the top, you should see h.264/avc as the first. i manually disabled *all* the remaining codecs in that list. since there is no "property" page to make any final adjustments to any of the codecs, i assumed that when in capture mode, all codecs are "I" frame or as lossless as they are set to in ffdshow.

after i finish a capture, i can open the avi directly in vdub but as i said the info screen reports it as MJPG, which is confusing me. and avisynth won't open it in avisource() either. i assume that h.264/avc is included as an encoder like all the codecs in the list, as they are listed like in your post.

[vhelp]

not sure if anyone has reported this but it seems that the latest version of ffdshow is borked, since all the codecs are saving to MJPG. i tried many of them and they save to mjpg and same filesize.

the version i have installed since last week or so is rev4515, may 20 2013 02:52:42

[vhelp]

just found and d/l'ed rev4527 and will give that a try, soon as i uninstall rev4515.

[jagabo]

if you scroll up to the top, you should see h.264/avc as the first.

Your video is MJPG not AVC.

AVIsource(video) = "couldn't locate a decompressor fourcc MJPG" error.

not sure if anyone has reported this but it seems that the latest version of ffdshow is borked, since all the codecs are saving to MJPG.

That list is decoders, not encoders. Go to the Encoder tab and you'll see that all the encoders except a few have been removed. You need to revert to an version from a few years ago to get the other encoders. There's a post around here somewhere that points out the last ffdshow that includes the other decoders.

[vhelp]

i just had another look and it seems i made a mistake misreading the tabs. the defalt codec is mjpeg at quality 85, but all the while i was looking at the decoder tab while chooseing h.264/avc as the enocder.

sorry for the confusion.

however, after testing what was actually mjpeg, that 85 quality setting was actually quote good, comparing it visually for any pixelation vs lossless UT or Huffy, i could find no major difference in everyday (tipicle) captures.

edit: but the deal-breaker with mjpeg is that it can't be opened in avisynth unless you use either l-smash or haali plugin and expect long delays or lockups as stated in post #1. not practicle.

[jagabo]

Here's a post that discusses the loss of ffdshow's encoders and lists some older versions:
https://forum.videohelp.com/threads/356824-ffdshow-virtualdub-problem

after testing what was actually mjpeg, that 85 quality setting was actually quote good, comparing it visually for any pixelation vs lossless UT or Huffy, i could find no major difference in everyday (tipicle) captures.

Look for DCT ringing artifacts at sharp edges. You'll also see some block on smooth gradients. These won't be visible with VHS caps because of all the noise.

[vhelp]

i didn't notice any DCT ringing artifacts in my Tron dvd capture tests with Ut vs MJPEG.

what i looked for was anything that looked similar or close to pixelation. these days, what i'm concirned about is that, not things you have you have analize close up pixel for pixel, although i did a few of those type of tests as well. i will run a few more later just to be certain since you brought it up and now i'm curious.

[vhelp]

ok, so i mainly been using my hdpvr for capturing content from my directv. even in that there is plenty of dct ringing like when i select the info button on the remote to view the tv listing. in fact, i use that as the intro guage for most of my capture, just to be sure of what i was using as the codec, plus what was on at the time. i guess i can use that in my next tests.

[jagabo]

Here's a sample from VirtualDub's built in RGB cube test video:

Original RGB24:


ffdshow MJPG 85:


You can see DCT ringing artifacts, posterization/block artifacts, YV12 chroma subsampling blurring. The colors are a little different because MJPG uses a PC.601 matrix to convert RGB to YV12, but I had ffdshow set to output YUY2 and VirtualDub used a rec.601 matrix to convert to RGB for export.

And yes, since most delivery formats use YV12 and MPEG family compression, they're full of such artifacts already.

[vhelp]

all true.

[hello_hello]

If you can't open the AVI easily, maybe try remuxing it as an MKV and opening it with L-Smash. If that doesn't work, try ffmsindex instead.

What does "seek_mode=0" do for L-Smash? I don't know a lot about it.

If you don't want to lose the captures you already have and can't replace them, if nothing else works you could convert them to a lossless format (ie huffyuv using ffdshow) and edit/re-encode the lossless version.

[Selur]

                + seek_mode (default : 0)
                    How to process when any error occurs during decoding a video frame.
                        - 0 : Normal
                            This mode retries sequential decoding from the next closest RAP up to 3 cycles when any decoding error occurs.
                            If all 3 trial failed, retry sequential decoding from the last RAP by ignoring trivial errors.
                            Still error occurs, then return the last returned frame.
                        - 1 : Unsafe
                            This mode retries sequential decoding from the next closest RAP up to 3 cycles when any fatal decoding error occurs.
                            If all 3 trial failed, then return the last returned frame.
                        - 2 : Aggressive
                            This mode returns the last returned frame when any fatal decoding error occurs.

source: the README which comes with the files,...
0 is the default

[hello_hello]

Ah..... The old "look at the readme file" trick.

[Selur]

oldie, but goody

[vhelp]

You can see DCT ringing artifacts, posterization/block artifacts, YV12 chroma subsampling blurring. The colors are a little different because MJPG uses a PC.601 matrix to convert RGB to YV12, but I had ffdshow set to output YUY2 and VirtualDub used a rec.601 matrix to convert to RGB for export.

i'm back to do some more testing. can you post the steps to produce those images in virtualdub ? i thought it was "test video capture" but that didn't work.

[jagabo]

Tools -> Create Test Video -> RGB Color Cube. I then cropped the frame down to just the cube in the center and resized 2x with the nearest neighbor filter (to keep the sharp edges).

[vhelp]

after some testing with latest rev4527 i learened its mjpeg version is horible. i also been downloading a bunch of other mjpeg codecs (for capturing) and so far i didn't like any of them. i much prefer { rev4515, may 20 2013 02:52:42 } and will be bumping back down to that version. i believe that capturing aspects might be different than the timeline conversion, iow, virtualdub[ffdshow.mjpg] -> video.avi file. i was sure it was lossless but can't fully test this in the same way i could test that color cube and i just don't have the bother to put together a dvd version.

[pandy]

Any reason why you not using ffms2?