Re: [CinCVS] render twice causes quality loss?
flavio wrote: > But I always thought also that DV was supposed to be lossless compression... > Now that you mention it I had some real problems rendering a red-saturated > thing last yeah using DV. DV has always been a lossy compressor but being 5:1 it has much higher perceived visual quality than, say, DVD MPEG2 which comes in at around 20:1 or higher (depending on the quality/bitrate settings etc). Yes, red can be problematic for DV and I've seen similar things myself. However that's not all that unusual - red has always been problematic for video systems since the dawn of the colour era. This is one of the reasons early colour studio cameras (in particular) only ever used black and white monitors/viewfinders - red bloomed too much making focus pulling almost impossible in scenes dominated by shades of red. Regards jonathan ___ Cinelerra mailing list Cinelerra@skolelinux.no https://init.linpro.no/mailman/skolelinux.no/listinfo/cinelerra
Re: [CinCVS] render twice causes quality loss?
I splited my project into smaller projects to make it easy to handle with a > > complex edit.. > > > A workaround that would prevent this from happening would be - after > finishing all your edits - opening two cinelerras on diferent desktops. One > with one of your projects (say, project#1) on it and one with the same > number of audio/video tracks as the first one and the same settings as the > whole project (say, stereo NTSC at 4:3, 29.97). > > Toggle all the tracks of project#1 so that you can copy every one of them > and select all the information there (press 'a'). Paste them on the second > cinelerra that's open. Do the same thing for projects#2, #3, etc, in order > and you'll have a final project with all the edit inside, ready to do one > single render, instead of many. Thats what I did... I spent the night doing... Im awake since yesterday working on this video and Im happy with the result.. although I would prefer to have not only different projects for each section of the video.. but also another one to apply the Titles.. I feel very vurenable with a huge single project > > > Also: if the video is being shown at the compositor while render is in > progress (usually at about the same speed or lower than what the original's > was supposed to be), cinelerra is indeed processing something on the video - > this may be something as simple as a opacity level being at 99% instead of > 100%, or a lost keyframe somewhere that may be affecting those parts of the > video being shown. > > But I always thought also that DV was supposed to be lossless > compression... Now that you mention it I had some real problems rendering a > red-saturated thing last yeah using DV. I had this problem too.. even sent an email to this list... changed to a less satured color did it... cheers Leo,, -- leogermani.pirex.com.br leogermani.estudiolivre.org
Re: [CinCVS] render twice causes quality loss?
> > I splited my project into smaller projects to make it easy to handle with > a complex edit.. A workaround that would prevent this from happening would be - after finishing all your edits - opening two cinelerras on diferent desktops. One with one of your projects (say, project#1) on it and one with the same number of audio/video tracks as the first one and the same settings as the whole project (say, stereo NTSC at 4:3, 29.97). Toggle all the tracks of project#1 so that you can copy every one of them and select all the information there (press 'a'). Paste them on the second cinelerra that's open. Do the same thing for projects#2, #3, etc, in order and you'll have a final project with all the edit inside, ready to do one single render, instead of many. Also: if the video is being shown at the compositor while render is in progress (usually at about the same speed or lower than what the original's was supposed to be), cinelerra is indeed processing something on the video - this may be something as simple as a opacity level being at 99% instead of 100%, or a lost keyframe somewhere that may be affecting those parts of the video being shown. But I always thought also that DV was supposed to be lossless compression... Now that you mention it I had some real problems rendering a red-saturated thing last yeah using DV.
Re: [CinCVS] render twice causes quality loss?
Im using the package made for ubuntu studio 7.04.. But I think I saw this behavior (compositor black when footage is the same as output) in this same installation On Wed, Feb 20, 2008 at 9:48 AM, Bhikkhu Mettavihari <[EMAIL PROTECTED]> wrote: > On Feb 20, 2008 6:59 PM, Leo germani <[EMAIL PROTECTED]> wrote: > > > > > > > > Note that we're talking about sections of footage which have to be > > > re-encoded. In terms of Cinelerra such re-encoding has to be done if > the > > > input frame is modified in any way by Cinelerra - through the > application > > of > > > transitions, blends, amplitude changes, overlays, effects etc. If you > > have > > > uneffected sections of footage and their quality is dropping then > perhaps > > > Cinelerra is forcing a re-encoding across all frames for some reason. > > While > > > fixing this won't help the quality of effected frames it will improve > the > > > quality of frames which are not being changed. > > > > > > > > > > yes... thats the point.. There are no effects or anythings... > > I remember that the compositor window would stay black while render > files > > like this, and would display the videos that have to be encoded (such as > > transitions)... > > > > But now it play all the video on the compositor window while > rendering... is > > this an option?? > > > That is interesting. > My one is staying all black when there is no change. > > What version of Cinelerra are you using ? > I am using a rather older version. > > regards > Mettavihari > > > -- > Streaming video from http://dharmavahini.tv > > ___ > Cinelerra mailing list > Cinelerra@skolelinux.no > https://init.linpro.no/mailman/skolelinux.no/listinfo/cinelerra > -- leogermani.pirex.com.br leogermani.estudiolivre.org
Re: [CinCVS] render twice causes quality loss?
On Feb 20, 2008 6:59 PM, Leo germani <[EMAIL PROTECTED]> wrote: > > > > > Note that we're talking about sections of footage which have to be > > re-encoded. In terms of Cinelerra such re-encoding has to be done if the > > input frame is modified in any way by Cinelerra - through the application > of > > transitions, blends, amplitude changes, overlays, effects etc. If you > have > > uneffected sections of footage and their quality is dropping then perhaps > > Cinelerra is forcing a re-encoding across all frames for some reason. > While > > fixing this won't help the quality of effected frames it will improve the > > quality of frames which are not being changed. > > > > > > yes... thats the point.. There are no effects or anythings... > I remember that the compositor window would stay black while render files > like this, and would display the videos that have to be encoded (such as > transitions)... > > But now it play all the video on the compositor window while rendering... is > this an option?? That is interesting. My one is staying all black when there is no change. What version of Cinelerra are you using ? I am using a rather older version. regards Mettavihari -- Streaming video from http://dharmavahini.tv ___ Cinelerra mailing list Cinelerra@skolelinux.no https://init.linpro.no/mailman/skolelinux.no/listinfo/cinelerra
Re: [CinCVS] render twice causes quality loss?
> > > Note that we're talking about sections of footage which have to be > re-encoded. In terms of Cinelerra such re-encoding has to be done if the > input frame is modified in any way by Cinelerra - through the application > of > transitions, blends, amplitude changes, overlays, effects etc. If you > have > uneffected sections of footage and their quality is dropping then perhaps > Cinelerra is forcing a re-encoding across all frames for some reason. > While > fixing this won't help the quality of effected frames it will improve the > quality of frames which are not being changed. > > yes... thats the point.. There are no effects or anythings... I remember that the compositor window would stay black while render files like this, and would display the videos that have to be encoded (such as transitions)... But now it play all the video on the compositor window while rendering... is this an option?? Leo,,
Re: [CinCVS] render twice causes quality loss?
Hi Leo > I splited my project into smaller projects to make it easy to handle with a > complex edit.. > > after I render each project, I join them together into another program, and > then render it again with exactly the same settings as used before > (quicktime DV)... but I see that this is resulting in an image with less > quality (kind of a squared image...) > > If the source is quicktime DV and Im rendering to quicktime DV this shouldnt > happen, right? DV is a lossy compressor, it's just not as lossy as others. Therefore while one would expect some generational loss in sections which have been re-encoded the effect isn't likely to be significant UNLESS the encoding was not optimal. Unfortunately most opensource DV codecs have limitations in their encoder. I did a number of tests about 3 years ago and discovered that both the libdv and ffmpeg DV encoders of the day introduced significant artifacts. Since that time my workflow has changed and this is no longer relevant for me so I don't know the current situation. I do know that libdv's encoder has received very little attention in the years since my tests so I would expect that it still suffers from the problem today. From what I've heard on this list and elsewhere the ffmpeg DV encoder has improved in this time but I don't know to what extent and I have not done any tests myself to quantify this. So it all comes down to which DV codec you're using to make do your intermediate renders. If it's libdv then I would expect there to be noticeable artifacts after the first encode and these will only get worse after the second one. If instead you utilise ffmpeg then maybe things are better. You mentioned using quicktime DV which means you're probably using libquicktime. AFAIK this uses libdv as its DV codec (at least by default) so this may be the root of your problem. Note that we're talking about sections of footage which have to be re-encoded. In terms of Cinelerra such re-encoding has to be done if the input frame is modified in any way by Cinelerra - through the application of transitions, blends, amplitude changes, overlays, effects etc. If you have uneffected sections of footage and their quality is dropping then perhaps Cinelerra is forcing a re-encoding across all frames for some reason. While fixing this won't help the quality of effected frames it will improve the quality of frames which are not being changed. Regards jonathan ___ Cinelerra mailing list Cinelerra@skolelinux.no https://init.linpro.no/mailman/skolelinux.no/listinfo/cinelerra
[CinCVS] render twice causes quality loss?
hi there, I splited my project into smaller projects to make it easy to handle with a complex edit.. after I render each project, I join them together into another program, and then render it again with exactly the same settings as used before (quicktime DV)... but I see that this is resulting in an image with less quality (kind of a squared image...) If the source is quicktime DV and Im rendering to quicktime DV this shouldnt happen, right? Leo,, -- leogermani.pirex.com.br leogermani.estudiolivre.org
