October 2021 - Cin - Cinelerra-GG Mailing Lists

Re: [Cin] offtopic: Digitize and record Audio via Line-In Jack or via USB adapter?
by mat 04 Oct '21

04 Oct '21

Your MSI Z170-A PRO motherboard has according to specs a Realtec AL892 audio chip. The input converters should have 90 dB S/N (signal-to- noise) ratio (A-weighted), but of course the motherboard might make it a little worse. However, from you record player of tape you will be very lucky to get better than 65 dB S/N. So if an A-D converter has a S/N of 70 dB or better, it is more than good enough for this. Regarding your PC input channels, on current desktop motherboards I usually see three 3.5 mm mini-jacks. Their recording quality for line- in is close to 90 dB S/N or even above 100 on the better ones. In pavucontrol (audio mixer), first check the configuration tab, to see if the Built-in Audio is set up correctly. "Analog stereo duplex" is probably right. Then, on the "Input devices" tab, at the bottom set it to show "Hardware Input Devices", then check that the Port is set to the correct port. For me, "Line In" shows correctly if something is plugged in or not. Make also sure the gain is set to 100%. That said, I sometimes have problems recording LineIn with Audacity, even though all seems OK. have not yet determined what the cause is. External USB sound cards can be quite good, if you stay away from the very cheap ones that are mic/phone only. I have a Behringer UCA-202 which is good enough for this, but there are much better ones (at a price), look at music-oriented webshops. I presume to have an RIAA pre- amp for you record player, these are usually set up for less output that typical PC or usb-audio input, which expect 1 Volt. Drivers are not needed, and disregard any reviews that don't show measurements. MatN

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Crash when using OpenEXR image sequence
by Andrea paz 02 Oct '21

02 Oct '21

>From this forum post: https://www.cinelerra-gg.org/forum/everything-else/youtubes-video-edit-with… I was inspired to try a workflow with a sequence of images. I took a 32 sec video (in AV1) and rendered it as an OpenEXR image sequence. The 32 sec video was rendered in 5 seconds resulting in 881 images and a TOC file (test-exr.exrs). I created a new project in CinGG and imported the files + TOC but every time I have a crash in the middle of the images (about 480 images). >From the terminal you can see that all 881 images are indexed, but then in a second step, it crashes towards the 480th image. The error is as follows: FFMPEG::open_decoder: some stream have bad times: /home/paz/test-exr/test-exr000001.exr I attach the terminal lines file and also test-exr.exrs. I used both "Replace current project and concatenate tracks" and "Create new resources only". In the first case the images are loaded in the timeline but the crash happens anyway. I used both AppImage and Build. Can you identify/reproduce/resolve the problem? NOTE: In the terminal output I removed many repetitive lines. The file "test-exr.exrs" is the TOC file. I have the same crash both trying to import it into CinGG along with the images and excluding this file. NOTE 2: same crash with PNG sequence!

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Re: [Cin] even more OT: time-base correctors
by Terje J. Hanssen 01 Oct '21

01 Oct '21

Den 28.09.2021 18:36, skrev Andrew Randrianasulu via Cin: > I read elsewhere [0] you might want such device for bad quality vhs > tapes - > yet they tend to expensive, either in terms of money or skills. > > Still, it was pleasure to find some schematic I thought completely lost to > sands of time: > > https://web.archive.org/web/20181219122351/http://marcusgun.awardspace.com/ > newvidproc.html > > https://web.archive.org/web/20051101234823/http://www.astro.uu.se/~marcus/p… > > [0] > https://forum.videohelp.com/threads/402960-VHS-recording-advices-would-be-a… > > reviews on Amazon tend to be mixed - complex and costly devices do not > works for some, yet work for others (due to condition of device itself?) > > "Short Overview: A time-base corrector is essentially a device that > reconstructs a composite video signal scan line by scan line. Composite > video signals (both NTSC and PAL) interlace two fields of lines to > construct a single frame. With NTSC, you are viewing (approximately) 60 > fields per second, while PAL uses 50 fields per second. Each line has a > pulse/signal that tells the display device to start the next line. If the > timing is off even slightly for a single field or for a set of scan lines, > the individual scan lines don't align with each other and you get a jagged > effect. A time base corrector tries to correct the timing for the > individual scan lines to improve the picture. This process never works > perfectly, but you can definitely see an improvement on most video > material. > > A full-frame TBC actually stores the lines to build up a single frame and > then sends them to the video display or monitor. This is preferable to a > unit that just tries to adjust each line as it is processed. An advantage > to the full-frame units is that they normally eliminate the copy > protection > signals that are often placed in the unseen scan lines between fields and > frames. They do this because they insert their own synch signals, > discarding the "corrupted" ones that Macrovision and other copy protection > schemes have deliberately inserted. (Yes, I know this is a simplified > description of a complex process.) > > The 8710 is one of a series of TBC units that are reasonably priced and do > a pretty good job of correction. The improvement is most noticeable when > you have vertical lines in the picture (telephone poles, lettering, etc.) > The other features on this unit (saturation control, color correction, and > so forth) are secondary. It is a full-frame unit and it builds each frame > using two fields. This allows better alignment of the scan lines and a > better picture." I want to confirm from my own experience the importance of using a good TBC at the End of the analog workflow from tape source playback, just in front of A/D converting and recording. Especial early generation Hi8 recordings, in the first nineties with Sony CCD-TR805 & TR808 camcorders, got unacceptable images with jitter, flagging and even dropouts. If this was due to unstable tape operation with slippery Hi8 Pro tapes, I don't know. The footages became fine and stable with upgrade/replacement to Sony TR-2000 camcorder, still functional as Hi8 VCR player). * A simple Line based TBC for normal playback were built-in in good, reference VCR decks, like my Panasonic FS-200EC S-VHS VCR and Sony EV-S880E Hi8 VCR. * A full frame or Dual Field TBC was built-in in my Videonics MX-1 digital videomixer, which resulted in wonderful clear and steady analog video images. As Videonics also published a Digital Video Primer that explained the Time Base problems in an easy and useful way, I have scanned and attached these 4 pages to this post. And for further references and reading this old stuff, follow some related urls which are still active: What is a TBC? Time Base Correction for Videotapes www.digitalfaq.com/forum/video-restore/2251-tbc-time-base.html What is a TBC* and why would I need one? https://www.questronix.com.au/tbc.htm Videomaker https://www.videomaker.com/article/f3/641-a-tbc-tale https://www.videomaker.com/article/1210-edit-suite-tbc-trivia Videonics MX-1 videomixer https://www.southernadvantage.com/products/videonics-mx-1-4-input-synchroni… https://www.amazon.com/Videonics-MX-1-Video-Mixer-MX1/dp/B000ZS88N8 Terje J. H

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